Sound Absorption Properties of Natural Fibre Reinforced Polypropylene Needle-Punched Nonwoven Fabrics Used in Automotive Interior

Zeliha ÇAVUŞ; *Mustafa Sabri ÖZEN; Aysun GENÇTÜRK;

Serdar EVİRGEN; *Mehmet AKALIN

SİTEKS, Sismanlar Textile Company, Saray, TEKIRDAG

*Marmara University, Technology Faculty, Textile Engineering Department, Kadıköy, İSTANBUL

Abstract

In this study, the properties of sound absorption of needle punched nonwoven fabrics produced at three different fabric weight such as 1300g/m2, 1600g/m2 and 2200g/m2 by blending of polypropylene fibres with flax and hemp fibres separately in the ratio of 50/50% were investigated. The sound absorption properties of produced nonwoven fabrics were measured in the frequency range of 100-5000Hz, and the results were given in the unit of the sound absorption coefficient. The effect of fabric weight in grams per square meter on the sound absorption properties of needle punched nonwoven made from hemp and polypropylene fibres in blending ratio of 50/50% were shown graphically.

The production work was carried out at large scale industrial machines instead of small scale laboratory type machines for more consistent results. These fibres were firstly blended and then carded, laid up and finally, needle punched. The fibre webs were formed at the carding machine and laid up at cross lapper machine according to the required web weight per square meter. Finally, the carded and folded webs (batt) were bonded at needle punching machines, and the needle punched nonwoven fabric production was finished.

The sound absorption coefficients of needle punched nonwoven fabrics were measured by impedance tube method according to ASTM 1050-98 standard in the frequency range of 100-5000Hz.

It was found that the nonwoven fabric produced from PP/Flax fibres had higher sound absorption coefficient values compared to the nonwoven fabrics made from PP/Hemp fibres at 1600g/m2 and 2200g/m2 fabric weight in the medium and high-frequency range. It was seen that the trends of graphs showing the sound absorption coefficient against the frequency of the PP/Flax and PP/Hemp nonwoven fabrics with 1300g/m2 fabric weight are very similar and their values of sound absorption coefficient are close to each other.

It was observed that the values of the sound absorption coefficient of the needle-punched nonwoven fabrics produced at three different fabric weight such as 1300g/m2, 1600g/m2, 2200g/m2 from hemp and polypropylene fibres in the blending ratio of 50/50% increased with the increase of fabric weight in grams per square meter. It was found that there is a positive correlation between fabric weight and sound absorption coefficient.

Keywords: Natural Fibre, Nonwoven, Sound Absorption Coefficient, Needle Punching Technology

I. Introduction

Noise, which is defined as unwanted or excessive sound, is considered a pollution type like water or air pollution and causes negative impacts on human health. Long term exposure to noises generated in the environment and workplaces can cause many health problems ranging from stress, loss of hearing, tiredness, poor concentration, sleep disturbance, productivity losses, communication difficulties, fatigue, lack of sleep, to more serious issues such as cardiovascular disease, cognitive impairment, tinnitus, annoyance and inner ear damage.

In 1971, the World Health Organization (WHO) stated that noise should be accepted as a major environmental threat to human health. It is necessary to protect human health from exposure to environmental noises originating from transportation (road traffic, railway, aircraft, etc.) and leisure noise (nightclubs, concerts, live sporting events, loud music etc.) in addition to noises originating from machines used in workplaces. Many material and methods have been developing to provide acoustic comfort in indoor spaces such as automobile, building, aeroplane and cinema. [1] Compared to commonly used synthetic fibrous material, the materials developed from natural fibres represent eco-friendly solutions in various technical textile applications such as automotive, building, industrial. [2] The nonwoven products produced from natural fibres can be used in building as an alternative to insulation materials such as glass wool, rock wool or mineral wool. [3]

Especially, reducing unwanted noise coming from the engine, tires and traffic on the road in passenger compartments of vehicles is very important for automobile manufacturers. The most preferred fibre-based sound absorbers for noise control applications are nonwoven fabrics. The sound-absorbing nonwoven materials attached to various components such as floor carpet, headliners, trunk&luggage side, parcel shelf, door panels, trunk&luggage floor, protector wheelhouse, accessories mat, dash engine room insulator and pad&spacer tray are used in car interiors. The nonwoven fabrics used in car interiors have superior properties comparing to textile fabrics, including cost-effective, easy moulding, recyclability and attractive cost/performance ratio. In addition to that, the nonwoven fabrics can be designed with specifically targeted properties as thickness, mass and voluminous. Their porous structure and high surface areas make nonwoven fabrics attractive for being used in technical textile applications where sound absorption is desired. [4], [5]

The nonwoven fabrics have a porous structure inherently with interconnected cavities, allowing the sound waves to enter through them. When porous material is exposed to incident sound waves, the air molecules in the material are forced to vibrate and, in doing so, lose some of their original energy. This is because a part of the energy of the air molecules is converted into heat due to thermal and viscous losses at the walls of the interior pores and tunnels within the material. [3], [5]

Figure1-Nonwoven Fabric Applications in Automotive Interior-Otomotiv İç Mekanlarında Dokunmamış Kumaş Uygulamaları

Fibrous materials have been widely used in noise reduction due to porous structures. [6] Today, the existing sound-absorbing nonwoven materials are mostly produced from synthetic materials such as recycled polyester, virgin polyester and polypropylene, which are not biodegradable and eco-friendly. [7] As environmental protection, biodegradability and sustainability are very important issues, the usage of natural fibres such as flax, hemp, kenaf, jute and kapok for automotive textiles applications has been increasing as an alternative material to the synthetic fibres. Natural fibres are considered effective raw materials for producing noise reduction materials.

As the fabric weight in grams per square meter and thickness are important parameters, carding/needle punching or air-laid/ thermal bonding technologies as web forming and web bonding methods are preferred for the production of nonwoven fabrics with sound absorption property.

In previous scientific studies, many researchers have investigated the effect of fibre and fabric properties in addition to fibre type on the sound absorption properties of nonwoven fabrics. The results showed that the use of finer fibres, low fabric density, higher thickness and fabric weight in grams per square meter has a positive effect on the sound absorption of nonwoven materials. Gomez and his colleagues said that the sound absorption performance could be improved by increasing the thickness of the fabric or sample and by having a small fibre diameter. [8] Guzdemir et al. expressed that the jute, flax, hemp, kenaf fibres could be used instead of synthetic fibres such as polyester and polypropylene in construction and automotive application. These natural fibres are generally blended with staple polylactic acid (PLA) fibres. The polylactic fibres (PLA) have significant potential as a biodegradability polymer, but its high cost and slow biodegradability restrict its use. [9] Zhang et al. studied sound and vibration damping property of biocomposites produced from bamboo, cotton, flax and PLA fibres by using carding and needle punching machines. The best acoustic performance was exhibited by bamboo/cotton/PLA composite. [10] Pasayev et al. the sound-absorbing properties of nonwoven webs produced from chicken feather fibres were investigated. In this study, it was stated that nonwoven webs could be used as a sound-absorbing material. [1] Bhat et al. researched that effect of microfiber layers on acoustical absorptive properties of nonwoven fabrics. It was found that polypropylene microfiber melt-blown nonwoven fabric displayed good sound absorption behaviour. [11] Islam et al. indicated that there is a direct correlation between loss of sound transmission with an increase in thickness and fabric weight, decrease in air permeability. [12] Muthukumar et al. studied sound and thermal insulation properties of needle punched nonwoven fabrics produced from flax/low melting polyester. The low melting bonding polyester fibres were used at three different blending ratios such as 10%, 20% and 30%. It was found that developed nonwoven fabrics had better sound insulation values at medium and high frequency, and there was no significant change in sound insulation value with increase in the ratio of low melting bonding polyester fibre. It is considered that the presence of central canal-like free space in the flax fibre, which is referred to as lumen can contribute to sound absorption. [3]

Figure2-Some of the Vegetable Fibres-Bitkisel Lif Örnekleri

Thilagavathi et al. compared sound and thermal insulation properties of the needle-punched nonwoven fabrics made from 100% pineapple fibre (PALF) and blend of pineapple/low melting bonding polyester fibre. It was found that nonwoven fabrics produced from the blending of pineapple fibres and low melting bonding PET fibre had better sound insulation properties. [13] Campeau et al. verified the hypothesis that hollowness of the fibre has only small effects on the acoustics of the material in his study. [14] Tang et al. found that the tailored cross-sections of synthetic fibres such as circle, hollow and triangle are beneficial to improve the acoustic properties of the material in his review study. [6] Ganesan and Karthik investigated the effects of blend ratio of cotton fibre with kapok and milkweed fibres, fabric weight and bulk density on acoustic properties of nonwoven fabric. It was found that there is a positive correlation between fabric weight in grams per square meter and sound reduction and negative correlation between bulk density and sound reduction. It should remember that the porosity of nonwoven fabric is a very significant parameter on sound reduction. [7] Liu et al. investigated the sound-absorbing properties of nonwoven composites made from kapok fibre with polypropylene fibre and hollow polyester fibre in the low-frequency region of 100-500Hz. It was found that kapok fibre had a superior acoustical property at low frequency. [15]

In this study, the sound absorption properties of needle punched nonwoven fabrics produced at three different fabric weight such as 1300g/m2, 1600g/m2 and 2200g/m2 from Polypropylene/Flax and Polypropylene/Hemp fibres in blending ratio of 50/50% were investigated in the frequency range of 100Hz to 5000Hz. Moreover, the influence of fabric weight on sound absorption properties of needle punched nonwoven fabrics produced at three different fabric weight such as 1300g/m2, 1600g/m2 and 2200g/m2 from PP/Hemp fibres in the blending ratio of 50/50% were studied.

Figure3-Natural Fibre Reinforced Nonwoven Composites-Doğal Elyaf Takviyeli Dokunmamış Kumaş Esaslı Kompozit Ürünler

II. Materials and Method

II.1. Materials

Hemp and flax fibres were procured from local fibre producer in Romania. As the fine flax fibres used at yarn production in the textile industry are not cost-effective for the nonwoven industry, the coarse flax fibres were preferred in the production of nonwoven fabrics. The flax and hemp fibres were not treated with alkali solution before further processing.

The polypropylene fibre with 6.7dtex fineness and 75mm staple length was used in the study. The mechanical properties of fibres were tested according to “TSE EN ISO 5079 Textiles-Fibres-Determination of Breaking Force and Elongation at Break of Individual Fibres” standard. The mechanical properties and fineness values of the fibres used in the experimental study were given at Table1.

Table1-Mechanical Properties and Fineness Values of Fibres, Liflerin Mekanik Özellikleri ve İncelik Değerleri

  Tenacity

Mukavemet

(cN/tex)

Elongation

Uzama

(%)

   Fibre Fineness

Lif İnceliği

(tex)

Polypropylene (Polipropilen) 27,42 198,58              0,670
Flax (Keten) 45,72 4,5154 4,488
Hemp (Kenevir) 53,82 6,2860 6,941

II.2. Web Formation

The staple polypropylene fibres were blended with flax and hemp fibres in the ratio of 50/50% separately. The production study was carried out at industrial type needle punching line consisting of carding, cross lapper, pre-needling and needle punching machines instead of laboratory-type machines.

II.3. Web Bonding-Production of Needle Punched Nonwoven Fabrics

The webs were formed at the carding machine and overlapped at cross lapping machine according to required web weight. The carded webs in which the fibres are laid parallel to each other were pre-needled at punch density of 5punch/cm2. The pre-needled nonwoven fabrics were mechanically bonded by using two needle punching machines. The needle punched nonwoven fabrics were produced with punch densities of 50punch/cm2 and 45 punch/cm2 at needle punching machines respectively. The depth of needle penetration was determined to 10mm for all needle punching process.

Test Results

The values of the sound absorption coefficient of needle punched nonwoven fabrics were measured by using BSWA TECH impedance tube system and method according to ASTM 1050-98 standard in the frequency range of 100-5000Hz. The nonwoven fabrics were cut into 100mm and 30mm diameters for measurements in low, medium and high-frequency ranges.

Figure4-The Values of Sound Absorption Coefficient of PP/Hemp Nonwoven Fabric-PP/Kenevir Esaslı Dokunmamış Kumaşların Ses Yutum Katsayısı Değerleri

Figure4 shows the influence of fabric weight on the sound absorption properties of needle punched nonwoven fabrics produced at three different fabric weight such as 1300g/m2, 1600g/m2, 2200g/m2 from hemp and staple polypropylene fibres in the blending ratio of 50/50%. The sound absorption results were given in the unit of the sound absorption coefficient. The values of the sound absorption coefficient of needle punched nonwoven fabrics were measured in the frequency range of 100Hz to 5000Hz. It was seen that all needle punched nonwoven fabrics had lower sound absorption coefficient values in the low-frequency range.

As the nonwoven fabric weight in grams per square meter increased, it was observed that the values of the sound absorption coefficient of all nonwoven fabrics increased starting from 500Hz. This result can be explained with due to the higher number of fibres in nonwoven fabric structure and larger fibre surface area, thus longer tortuous path for sound waves to travel in nonwoven fabric structure. The damping of sound waves depends on the tortuous paths of fibres in the nonwoven fabric. [16]

It was remarkable that all of the PP/Hemp needle-punched nonwoven fabrics have exhibited poor sound absorption performance in the low-frequency range of 100-500Hz. It is suggested that the addition of viscous interlayer material with sound-proofing property could be used to increase the damping effect. [4] Sound absorption at low frequencies can be improved either by increasing the thickness of the sound absorbers and providing an air gap between the sound absorber and solid backing. [16], [17]

Figure5-Sound Absorption and Insulation Mechanisms-Ses Yutum ve Yalıtım Mekanizmaları

Figure6-The Values of Sound Absorption Coefficient of PP/Hemp and PP/Flax Nonwoven Fabric at 1300g/m2 Fabric Weight-1300g/m2 PP/Kenevir ve PP/Keten Esaslı Dokunmamış Kumaşların Ses Yutum Katsayısı Değerleri

In the Figure6, the values of the sound absorption coefficient of needle punched nonwoven fabrics produced at 1300g/m2 fabric weight from PP/Flax and PP/Hemp fibres in the blending ratio of 50/50% were compared in the frequency range of 100-5000Hz. It was seen that the values of the sound absorption coefficient of both of the needle-punched nonwoven fabrics increased continuously in the frequency range of 500Hz to 5000Hz. It was observed that the trends of the sound absorption coefficient graphs of both PP/Flax and PP/Hemp nonwoven fabrics were similar to each other. Both of the needle-punched nonwoven fabrics exhibited poor sound absorption performance in the low-frequency range of 100Hz to 500Hz. This result can be explained by the fact that the wavelength of the sound wave is longer and the propagation path of the sound wave is the shorter at low frequency.

Figure7-The Values of Sound Absorption Coefficient of PP/Hemp and PP/Flax Nonwoven Fabric at 1600g/m2 Fabric Weight-1600g/m2 PP/Kenevir ve PP/Keten Esaslı Dokunmamış Kumaşların Ses Yutum Katsayısı Değerleri

In the Figure7, the values of the sound absorption coefficient of needle punched nonwoven fabrics produced at 1600g/m2 fabric weight from PP/Flax and PP/Hemp fibres in the blending ratio of 50/50% were compared in the frequency range of 100-5000Hz. It was seen that the values of the sound absorption coefficient of both of the needle punched nonwoven fabrics increased continuously in the frequency range of 400 to 5000Hz. It was observed that PP/Flax nonwoven fabric had higher sound absorption coefficient values compared to PP/Hemp nonwoven fabric in the frequencies between 1250 and 4000Hz. It was seen that the sound absorption coefficient values of PP/Flax and PP/Hemp nonwoven fabrics were almost the same in the frequencies between 100Hz and 1000Hz.

Figure8-The Values of Sound Absorption Coefficient of PP/Hemp and PP/Flax Nonwoven Fabric at 2200g/m2 Fabric Weight-2200g/m2 PP/Kenevir ve PP/Keten Esaslı Dokunmamış Kumaşların Ses Yutum Katsayısı Değerleri

In the Figure8, the values of the sound absorption coefficient of needle punched nonwoven fabrics produced at 2200g/m2 fabric weight from PP/Flax and PP/Hemp fibres in the blending ratio of 50/50% were compared in the frequency range of 100Hz to 5000Hz. It was seen that the values of the sound absorption coefficient of both of the needle punched fabrics nonwoven increased continuously in the frequencies between 315Hz and 5000Hz. It was observed that PP/Flax nonwoven fabric had higher sound absorption coefficient values compared to PP/Hemp nonwoven fabric in the frequencies between 315 and 2500Hz. This result may be due to the fact that the flax fibres are finer than hemp fibres. As the flax fibres are finer than hemp fibres, the nonwoven fabric produced from flax fibres has a higher number of fibres. This leads to an increase in surface area of fibre in nonwoven fabric and higher sound absorbency. It was seen that PP/Flax and PP/Hemp needle punched nonwoven fabrics had low sound absorption coefficient values in the low-frequency range. This result can be explained by the fact that the wavelength of the sound wave is longer and the propagation path of the sound wave is the shorter at low frequency. As a result, dissipation of sound energy at lower frequencies is less and more dissipation in higher frequencies. Developed nonwoven fabrics can be used as effective sound absorptive materials for medium and high-frequency sound absorption applications. The nonwoven fabrics with higher sound absorption properties in the low-frequency range should be developed in the future.

III. Conclusion

In this study, the values of the sound absorption coefficient of needle punched nonwoven fabrics produced at three different fabric weight such as 1300g/m2, 1600g/m2 and 2200g/m2 from PP/Flax and PP/Hemp fibres in blending ratio of 50/50% were compared in the frequency range of 100Hz to 5000Hz. Moreover, the influence of fabric weight on sound absorption property of needle punched nonwoven fabric produced hemp and polypropylene fibres in the blending ratio of 50/50% was investigated. The nonwoven fabrics were produced by using industrial type the carding, cross lapping and needle punching machines.

It was observed that the PP/Flax needle-punched nonwoven fabrics had higher sound absorption coefficient values compared to PP/Hemp nonwoven fabric at 1600g/m2 and 2200g/m2 fabric weight in the medium and high-frequency range. This result could be due to the finer and more porosity structure of flax fibres compared to hemp fibres.

It was seen that the values of the sound absorption coefficient of needle punched nonwoven fabrics produced from hemp and polypropylene fibres increased with the increase of fabric weight in grams per square meter. As the weight of nonwoven fabric in grams per square meter increased, it was seen that the values of the sound absorption coefficient of needle punched nonwoven fabrics increased significantly due to the increasing number of fibres and fibre surface area in the nonwoven fabric structure. It should be emphasized once again that the nonwoven fabrics produced from finer fibres are ideal materials for sound absorption applications due to the fact that they have a higher total surface area.

References

1- Pasayev,N.; Kocatepe,S.; Maras,N.: (2018) “Investigation of Sound Absorption Properties of Nonwoven Webs Produced from Chicken Feather Fibers”, Journal of Industrial Textiles, Vol.48, Issue:10, pp.1616-1635

2- L.,Jiangbo; Z,Shangyong; T,Xiaoning : (2020) “Sound Absorption of Hemp Fibers Based Nonwoven Fabrics and Composites, Journal of Natural Fibres.

3- Muthukumar,N.; Thilagavathi,G.; Neelakrishnan,S.; Poovaragan,P.T.: “Sound and Thermal Insulation Properties of Flax/Low Melt PET Needle Punched Nonwovens”, Journal of Natural Fibres, 2019, Vol.16, No.2, pp.245-252.

4-Prahsarn,C.; Klinsukhon,W.; Suwannnamek,N.; Wannid,P.; Padee,S.: (2020) “Sound Absorption Performance of Needle Punched Nonwovens and Their Composites with Perforated Rubber”, SN Applied Sciences, 2020

5-Palak,H.; Karaguzel Kayaoglu,B.: (2020) “Analysis of the Effect of Fiber Cross Section and Different Bonding Methods on Sound Absorption Performance of PET Fiber Based Nonwovens Using Taguchi Method”, The Journal of the Textile Institute, 2020, Vol.111, No.4, pp.575-585.

6-Tang,X.; Yan,X.: (2017) “Acoustic Energy Absorption Properties of Fibrous Materials: A Review”, Composites Part A-Applied Science and Manufacturing, Vol.101, pp.360-380

7-Ganesan,P.; Karthik,T.: (2016) “Development of Acoustic Nonwoven Materials from Kapok and Milkweed Fibres”, Journal of   Textile Institute, Vol.107, Issue:4, Apr, pp.477-482

8-Gomez,T.S.; Navacerrada,M.A.; Diaz,C.: (2020) “Fique Fibres as a Sustainable Material for Thermoacoustic Conditioning”, Applied Acoustics, Vol.164, No.UNSP 107240.

9-Guzdemir,O.; Bermudez,V.; Kanhere,S.: “Melt-Spun Poly(lactic acid) Fibers Modified with Soy Fillers: Toward Environment-Friendly Disposable Nonwovens”, Polymer Engineering and Science, Vol.60, Issue:6, pp.1158-1168, Jun2020.

10-Zhang,J.; Khatibi,A.A.; Castanet,E.: “Effect of Natural Fibre Reinforcement on the Sound and Vibration Damping Properties of Bio-Composites Compression Moulded by Nonwovens Mats”, Composites Communications, Vol.13, pp.12-17, Jun2019.

11-Bhat,G.; El Messiry,M.: “Effect of Microfiber Layers on Acoustical Absorptive Properties of Nonwoven Fabrics”, Journal of Industrial Textiles, Vol.50, Issue:3, pp.312-332

12-Islam,S.; El Messiry,M.; Sikdar,P.P.; Seylar,J.; Bhat,G.: (2020) “Microstructure and Performance Characteristics of Acoustic Insulation Materials from Post-Consumer Recycled Denim Fabrics”, Journal of Industrial Textiles, DOI:10.1177/1528083720940746

13-Thilagavathi,G.; Muthukumar,N.; Krishnanan,S.N.; Senthilram,T.: (2019) “Development and Characterization of Pineapple Fibre Nonwovens fro Thermal and Sound Insulation Applications”, Journal of Natural Fibers, Vol.17, Isuue:10, pp.1391-1400.

14-Campeau,S.; Panneton,R.; Elkoun,S.: “Experimental Validation of an Acoustical Micro-Macro Model for Random Hollow Fibre Structures”, Acta Acustica United with Acustica, Vol.105, Issue1, Special Issue:SI, Jan-Feb 2019, pp.240-247

15-Liu,X.; Li,L.; Yan,X.: “Sound-Absorbing Properties of Kapok Fiber Nonwoven Composite at low Frequency”, 3rd International Conference o Textile Engineering and Materials, Aug 24-25, Dalian, Peoples R China, 2013.

16-Ramamoorthy,M.; Rengasamy,R.S.: “Study on the Effects of Denier and Shapes of Polyester Fibres on Acoustic Performance of Needle Punched Nonwovens with Air-Gap” The Journal of The Textile Institute, 2019, Vol.110, No.5, pp.715-723

17-Shoshani,Y.;Yakubov,Y.: “A Model for Calculating the Noise Absorption Capacity of Nonwoven Fibre Webs, Textile Research Journal, Vol.69(7), pp.519-526.

Elastic Nonwovens and Application Areas

Deniz Duran1, Hatice Aktekeli2

1Ege University – Faculty of Engineering – Textile Engineering Department.35100 Bornova, İzmir/TÜRKİYE

2Ege University – Faculty of Engineering – Textile Engineering Department., 35100 Bornova, İzmir/TÜRKİYE

deniz.duran@ege.edu.tr

 

Elastic Nonwovens and Application Areas

Abstract

Nonwoven surfaces have become one of the fastest-growing textile branches in recent years, which significantly stems from the practical use of disposable products, and awareness on its importance in terms of hygiene. It is desired that nonwoven surfaces used in some areas should have high flexibility in terms of comfort and ease of use and maintain this flexibility. For this reason, there is a day-by-day increasing interest in flexible nonwoven surfaces. In this study, the definition of flexible nonwoven surfaces, methods for obtaining flexible nonwoven surfaces and their application areas are specified.

Key Words:Nonwoven surface; Flexible nonwoven surface; Elastic nonwovens; Thermoplastic elastomer.

  1. INTRODUCTION

In the globalizing world, it has become a necessity to manufacture innovative products for the development of our industry and economy. Cost and speed are two of the most important factors in the production phase. In this area, nonwoven surfaces allow us to find fast, easy, effective and economical solutions to problems with their wide use at every stage of modern life. Nonwoven surface products offer manufacturers the advantage of simplicity in the manufacturing process and the ability to apply desired qualities (absorbent/retaining, soft/stretched etc.) to nonwoven surface products as they require a manufacturing process simpler than the conventional textile fabrics. [1]

Nonwoven surface products, which are manufactured in a fashion both faster and cheaper, are being used more ever day in new areas. Especially the increase in the practical use and usage habits of disposable products allow mobility in the nonwoven surface industry and caused the market to grow. When examining Turkey’s 22 main product groups in the technical textiles export, it is observed that nonwoven surface products constitute the most exported product groups of Turkey’s technical textile exports. Nonwoven surface products which form 30,9% of Turkey’s total exports of technical textiles (nonwoven) exports in 2017 were valued at approximately 479 million dollars, increasing by 9,5%. When examining the technical textiles imports in Turkey’s 22 basic product groups, it is seen that nonwoven surface products are the second imported products with 11,5% after glas fiber and their products. In 2017, imports of nonwoven surface products increased by 12% to approximately $ 220 million. [1, 2]

Demand for nonwoven surface products is increasing day by day and it is predicted that over the coming years the numbers will exceed today’s value. [3]

In the field of nonwoven products, products with a high degree of flexibility at low cost is constantly needed. these nonwoven products are being produced especially for disposable diapers, sick cloths and also areas such as lining, and filtration. They are preferred for flexibility, softness, durability, good stretch-backing properties and high tearing elongation features. [4]

There are also literature studies on elastic nonwovens –an important issue in innovations which have taken place in the nonwoven surface area in recent years.

In a study by Srinivas et al., they treated polypropylene homopolymer and thermoplastic elastomer (TPE) under the same conditions and observed a marked difference in elongation properties. The polypropylene homopolymer is only 35% elongated, while the surfaces produced with thermoplastic elastomer (TPE) can be elongated up to 360%. According to Srinivas et al., molecular parameters such as molecular weight, molecular weight distribution, composition, melting temperature and crystallinity grade affect the elastic behavior of the polymer. The elasticity of the web is related to the molecular weight and the specific elastomeric composition. As expected, low crystallinity requires high elasticity. As the level of crystallinity increases, the mechanical behavior of the polymer changes from an elastomeric character to a plastic one.[5]

Zhao states in his work that the industry focused on the meltblown process to develop unique fiber and surface properties using special polymers, and that many factors are needed to develop high-value meltblown products, among which polymer properties, targeted areas of use of the product, and properties and capabilities of meltblown equipment are mentioned. Polypropylene nonwovens produced with the meltblown method have attracted more attention in areas such as hygiene, medical and personal care products with high flexibility of nonwovens made of elastic raw material, although they may have one-sided stretching properties. [6]

Dharmarajan et al., used the meltblown method in their work for surface preparation and have blended thermoplastic elastomer (TPE) and classical polypropylene on some samples. Inclusion of polypropylene thermoplastic elastomer increases the elongation of the nonwoven surface. Surface elasticity increases with increasing TPE ratio. Even 30% weight of TPE content makes the surface softer and drapery than polypropylene. In the light of these results, they have stated that meltblown elastic nonwovens containing TPE polymers have offered a new elastomeric product, which can be used in hygiene, personal care, medicine and industrial applications. [7]

Li et al. used the thermoplastic elastomer in their study to produce a surface with the meltblown method. According to Li et al., the elastic meltblown nonwovens have incomparable advantages over ordinary meltblown surface. Therefore, they have stated that this material is the new favorite in the nonwoven industry and elastic nonwovens produced with the meltblown method using TPE are high elastic materials which can solve the low elasticity problem of the conventional nonwovens. [8]

 

  1. ELASTIC NONWOVENS

Materials imposed to deformeation under pressure (elongation/ change of form) and reverted to its original state when unpressured are called elastic materials, and such deformations are called as elastic deformation. Mechanical creep (almost) does not occur. [9]

Elastic nonwovens are products, which exhibit superior elongation/reversibility compared to conventional nonwoven surfaces. While the elasticity on the conventional nonwoven surfaces is around 30%, it can reach 300% on elastic nonwoven surfaces. [5]

The limited resilience of the surfaces produced using conventional synthetic raw materials causes limitations in their usage and application. On surfaces produced using special thermoplastic elastomers (TPE), this problem can be avoided and highly elastic surfaces can be created (Figure 1). This will allow limitations and combine with the advantages of meltblown method to find a more common and convenient area of use. [6]

Elastic nonwoven surface before stretching     Elastic nonwoven surface after stretching

Figure 1. Elastic nonwoven surface before and after stretching [10]

2.1. Elastic Nonwoven Production Methods

Elasticity can be achieved in the texture in different ways. The most important ones are:

2.1.1. Customized voluminous design for nonwoven web structure

Voluminous web structure can be achieved by needle method in particular. In this method, the fibers are laid smoothly on top of each other to form a surface and fixed with special needles to form a web surface. However, the surfaces produced in this method can be too thick and show little flexibility.

2.1.2. Achieving elasticity in materials using crimp fibers

As the crimp fibers on surfaces produced by using crimp fibers are opened under pressure, the surface will stretch and revert to its original state when unpressured. However, the flexibility obtained by this method is very insufficient.

2.1.3. Production using special meltblown method with raw materials

The meltblown method does not require a special preparation process to form the surface, nor does it need to prepare any solution to draw fibers. Fibers are taken directly from the polymers.

In the meltblown method, the special thermoplastic material (TPE) is heated in the extruder and melted up to the temperature and viscosity to provide the fiber formation. The melt is sprayed through the nozzle holes at high speed with a flow of hot air, and these micro-sized fibers become cool and solidify as they move towards the pick-up cylinder. The solidified fibers randomly orientated in the picking cylinder create the elastic nonwoven surface. [11]

2.1.4. Production with finishing operations such as coating

The nonwoven surface is created by covering one or both sides of the surface with a chemical substance. The chemical materials are applied on the surface in the form of powder, paste or foam to form a film layer on the ground. [12]

2.1.5. Production with composite technology

Composite materials are a group of material, which are created by bringing together at least two different materials for a specific purpose. The purpose in this three-dimensional assembling feature is to create a feature, which is not present in any of the components alone. In other words, it is aimed to produce a material with superior properties for the desired components. [13]

The elasticity of the web produced with the first two methods is limited while they have excessive thickness. Flexibility of the web obtained with the coating method is not at the desired level. It has been seen that problems are solved in the web produced using TPE chips. [8]

  1. THERMOPLASTIC ELASTOMER (TPE) – RAW MATERIAL FOR ELASTIC NONWOVENS

Crosslinked rubbery polymers, or rubbery webbands, which exhibit very high elongation under tensile force and revert to their original initial length when the force is lifted, are called elastomers. The most commonly used and known elastomers are polyisoprene (or natural rubber), polybutadiene, polyisobutylene and polyurethane.

Thermoplastic elastomers (TPE’s) are polymers that exhibit elastomer behaviors, even though they do not have chemical cross-links between their molecules.

The physical cross-links in the TPEs constitute the webbing structure by interlocking the flexible molecules together. They can be processed as thermoplastics at high temperatures and exhibit elastomeric behavior when cooled (Figure 2). The transition from thermoplastic behavior to elastomeric behavior is completely reversed, i.e. unlike conventional elastomers, thermoplastic elastomers can be processed repeatedly, so they can be recycled. [14]

Thermoplastic elastomers contain two distinct phases in their texture:

  • Elastomeric phase with rubber features
  • Rigid phase with thermoplastic features. [14]

Figure 2. Temperature change in the thermoplastic elastomer structure [15]

 

  1. APPLICATION AREAS OF ELASTIC NONWOVENS

Elastic nonwovens find use in the fields of filtration, medicine and hygiene as soft protective cap, lining and gloves.

  • Medicine and Hygiene

Research and development studies in both fiber types, in which materials used in medicine and hygiene applications are produced, and in the production techniques of such materials, cause the increase in the use of medicine and hygiene textiles in all technical textiles every day. [16]

The fastest developments in medicine and hygiene textiles have occurred after the discovery of synthetic fibers. Rapid developments have been achieved with the invention nonwoven products in the 1960s, and improving a 56% reduction in the risk of infection transmission with the use of disposable products in 1985. [17]

 

The most important use of nonwovens is the hygiene industry. In a report published by  EDANA – European Nonwoven Producers Association, 35 billion products have been sold in the European hygiene market in 1997, 90 billion in 2004 and 211 billion in 2013 (Figure 3). [18]

Figure 3. The number of nonwoven products sold in the European hygiene market

 

Especially the elastic nonwoven medical bandages exhibit excellent stretching, wrap the wound well, hel healing quickly and leave only a small trace. Patients using them feel comfortable and at ease.

Its porous structure allows skin moisture to penetrate and the skin to breathe. Its elastic structure easily conforms to body folds and joints.

 

In addition, these elastic nonwoven materials also find use in areas such as patients and diapers (Fig. 4), menstrual pads, and in hospital equipment such as surgical disposals and gowns that require disposability, non-slipperiness and elasticity. [8]

Figure 4. Patient diaper with elastic nonwoven materials [19]

 

  • Soft Stretching Caps

It significantly increases comfort, safety and work efficiency for workers. It is non-irritant, soft-textured and has high tensile strength with low shrinkage force. They have a breathable structure for perfect comfort and ease. It provides excellent barrier treatment and filtration performance (Figure 5).

  • For use in construction, mining, health and waste management to prevent dirt, dust, airborne particles and airborne liquids,
  • For protection against dust, bacteria and harmful chemicals in laboratories and factories,
Figure 5. Caps with elastic nonwoven material [10]
  • For shielding against outdoor activities, wind and rain,
  • In order to provide good bacteria and particulate filtration in medical use,
  • It can be used for undercoating in hard caps, emergency respiratory masks and other face protection equipment. [10]

Undercoating

A study conducted by researchers at the University of Tennessee, USA, of Materials Science and Engineering reveals that the use of elastic nonwoven as a primer in military apparel shows better filtering features against chemical and biological threats.

Also, undercoating made of such structures in sportswear and women’s clothing helps show the body better. [8]

  • Filtration

These structures, produced using microfiber fibers, have great market share thanks to their superior filtration performance.

These elastic nonwovens, which can also be used in production of masks, provide protection against gas, dust and bacteria in the medical field by preventing harmful granules (Figure 6). Also these filters can be used in AC units, automobiles and engines[8].

 

Figure 6. Mask with elastic nonwoven material [20]

  • Gloves

Elastic nonwoven gloves are used in pharmaceutical factories and research laboratories, where high protection is required thanks to their excellent stretching, absorbing and filtering features. [8]

  1. CONCLUSION

Elastic nonwovens provide balanced mechanical features thanks to better elongation for increased flexibility, higher impact strength, higher melt flow rate for easier machining, lower cost and higher performance in comparison with conventional nonwovens. Especially on machine applications, they exhibit better breaking resilience and tearing prolongation. [21]

Thanks to these features, the application area for elastic nonwovens is growing day by day. The studies conducted in this area is also increasing every day. Interest and researches in the elastic nonwovens, which is considered to be one of the important branches in nonwoven industry, are increasing thanks to the improvements in living standards rising with awareness on the importance of  disposable products especialy for health, advanced level of improved product performances and the R&D activities conducted by the leading companies to grow their market domination.

RESOURCES

[1]KDR Tekstil, http://www.kdrtekstil.com.tr/bilgi-3.php (Erişim tarihi: 13.05.2016)

[2]ITKIB, Teknik Tekstil Sektörüne İlişkin Güncel Bilgiler, Mart 2015, http://www.itkib.org.tr/ihracat/DisTicaretBilgileri/raporlar/dosyalar/2015/TEKNIK_TEKSTIL_SEKTORUNE_ILISKIN_GUNCEL_BILGILER-MART_2015.pdf (Erişim tarihi: 05.04.2016)

[3]Textotex, Hijyen Uygulamalarında Nonwoven Teknolojisi, http://www.textotex.com/haber/tekniktekstil/hijyen-uygulamalarinda-nonwoven-teknolojisi.html (Erişim tarihi: 03.11.2015)

[4]Boggs L., Elastic polyetherester nonwoven web, 1987, US 4707398 A.

[5]Srinivas, S., Cheng, C. Y., Dharmarajan, N. and Racine G., 2005, “Elastic Nonwoven Fabrics from Polyolefin Elastomers”, http://faculty.mu.edu.sa/public/uploads/1426341765.4035Elastic_Nonwoven_Fabrics.pdf (Erişim tarihi: 10.10.2015)

[6]Zhou R., 2004, Stretching the Value of Melt Blown with Cellulose Microfiber and Elastic Resins, Biax Fiberfilm Corporation, 13p.

[7]Dharmarajan R., Kacker S., Gallez V., Westwood A.D. and Cheng C.Y., Meltblown Elastic Nonwovens from Specialty Polyolefin Elastomers, ExxonMobil Chemical Company, 3p.

[8]Li L., Zhang J., Li S. and Qian X., 2011, Research Progress of Elastic Nonwovens with Meltblown Technology, Advanced Materials Research, Vols. 332-334, 1247-1252pp.

[9]Yalçınkaya E., Elastisite Teorisi(Stress-Strain) Gerilme-Deformasyon İlişkisi, https://iujfk.files.wordpress.com/2013/09/3-ders-elastisite.pdf, (Erişim Tarihi: 28.04.2016)

[10]Vitaflex, http://vitaflexllc.com/index.html, (Erişim Tarihi: 19.10.2015)

[11]Atul Dahiya, M., Kamath, G. and  Raghavendra, R., 2004, Meltblown Technology, http://www.engr.utk.edu/mse/Textiles/Melt%20Blown%20Technology.htm (Erişim tarihi: 13.10.2015)

[12]Bulut Y., Sülar V., 2008, Kaplama veya Laminasyon Teknikleri ile Üretilen Kumaşların Genel Özellikleri ve Performans Testleri, Tekstil ve Mühendis, Sayı:70-71, 5-16.

[13]Kompozit Malzemeler Hakkkında Her şey, http://www.bilgiustam.com/kompozit-malzemeler-hakkinda-hersey/(Erişim Tarihi: 21.09.2016)

[14]Esen, M., “Termoplastik Elastomerler”, http://www.kimyam.net/2012/09/elastomer-nedir.html (Erişim tarihi: 26.10.2015)

[15]Deniz V., Karakaya N., Karaağaç B., Aytaç A. ve Gümüş S., 2008, Stirenik Termoplastik Elastomer Malzeme Geliştirilmesi, TÜBİTAK MAG Proje 107M412, 58s.

[16]Ilgaz S., Duran D., Mecit D., Bayraktar G., Gülümser T. ve Tarakçıoğlu I., Medikal Tekstiller, Tekstil Teknik Dergisi, Şubat 2007, Yıl-23, Sayı 265, 138-162.

[17]Güney S., 2009, Peristaltik Hareket Sağlayan Tıbbi Tekstil Materyalinin Geliştirilmesi ve Bilgisayarlı Kontrolü, Süleyman Demirel Üniversitesi, Yüksek Lisans Tezi, Isparta, 70s.

[18]Anonim, 2010, Nonwoven Tekniği ile Hijyenik, http://www.bilgilerforumu.com/forum/konu/nonwoven-teknigi-ile-hijyenik.630333/,  (Erişim Tarihi: 10.02.2016)

[19]Can Kimya, http://www.tamtut.com/tr/fullbond-urunler/20/yetiskin-ve-hasta-bezi-hotmelt-yapistiricilari, (Erişim Tarihi: 30.09.2016)

[20]ASM Medical, http://www.asmmedical.com/cat/aile-hekimligi-sarf-malzemeleri/sayfa/2, (Erişim Tarihi: 30.09.2016)

[21]ExxonMobil Chemical, 2010, Vistamaxx™ propylene-based elastomer,

http://www.ktron.com/News/Seminars/Plastics/Houston/Vistamaxx_-_PBE-An_innovation_for_the_masterbatch_industry.cfm, (Erişim Tarihi: 24.09.2015)

Investigation of Mechanical And Morphological Performance Properties of Cotton Fabric Coated With Copper Oxide Particles

Aslıhan Koruyucu, A.Özgür Ağırgan Namık Kemal University; Çorlu Engineering Faculty, Textile Engineering Department, Çorlu, Tekirdağ, Turkey

 

Abstract
Gaining antibacterial protection in fabrics is one of the increasingly important functional properties. In this study, the development of fabrics for specific application areas was foreseen using copper oxide, which is the center of attention of the whole world because of its economic status. The purpose of this article is to produce cotton fabrics with enhanced antibacterial functions using copper oxide particles and It is planned to investigate the possibilities of using these fabrics in the technical textiles field. Thus, it is aimed to reduce the microbial infections originating from the surfaces that people have contacted many times during the day. In this article, when different particulate copper oxide chemical substances applied to the textile industry for antibacterial purposes are used changes in the performance characteristics of cotton fabrics have been investigated. For this purpose, cotton fabrics are coated with antibacterial Cu (I) O, Cu (II) O particles and isocyanate and glycidimethacrylate structures with cross-linkers. The selection of copper oxide particles as antibacterial was made by examining previous studies. Another benefit of the use of copper oxide particles in the presence of an antibacterial property it is an attempt to form an alternative to the antibacterial property provided by silver, zinc oxide and titanium oxide in previous studies. Besides, the silver used is expensive compared to other used antibacterial materials is an important problem. Zhang et al.(2008) refered to strong evidence that silver ions show cytoxidic and genotoxic effects for high organisms (including humans). After coating with Cu(I)O and Cu(II)O antibacterial agent, the tensile strength properties of cotton fabric samples increased and mechanical effects after coating with isocyanate crosslinker because it damages the fabric structure reduction in tear strength was achieved. In the FTIR spectra of the fabric after coating, the new bands would be a sign of a modification due to coating processes are occurred.

1.Introduction
Substances or environments that inhibit bacterial growth and inhibit are defined as antibacterial. Due to the harmful and bad smell of the bacteria; the use of antibacterial materials, especially in garments and fabrics , are becoming even more important. Antimicrobial agents are defined as those that kill microorganisms such as bacteria, mold, yeast and fungi. On the other hand, it is also defined as a natural, synthetic or semisynthetic chemical that inhibits growth, proliferation or activity. The importance of the antibacterial based functional textiles is given below: In the study of transferring silver nanoparticles from antibacterial fabric to artificial sweat are connected to on amount of silver transferred artificial sweat to the initial coating, fabric quality, pH and artificial sweat formulation. In this study, the effects of silver molecules on human health were examined(1). Silver nanoparticles, silver ions exhibit bacteriocidal action when are used alone or in various combinations. By increasing the permeability of the bacterial cell membrane, the energy requirement of the cell is triggered. At this point, there is a flow of phosphate, cellular contents leak, and DNA proliferation is interrupted (2). Kathirvelu et al. (2008) investigated the self-cleaning, antibacterial and UV protection functions of the fabrics coated with TiO2 NPs at different temperatures and concentrations produced with a hydrolytic reaction starting with HNO3 and titanium tetrachloride. They found that there was no change in the self-cleaning activities of the prepared sample fabrics. However, they found that the UV protection effect was higher in PES / Cotton fabrics, woven fabrics and fabrics coated with small NPs. It was determined that woven fabrics, 100% cotton fabrics and fabrics coated with small NPs exhibited antibacterial properties at a higher level. When examined for all three functions, it was observed that the use of TiO2 in coatings made with ZnO and TiO2 is more advantageous than the use of ZnO (3). In previous studies; There is strong evidence that silver ions show cytoxidic and genotoxic effects for high organisms (including humans) (4). Performance changes and antimicrobial activity amounts of chemicals known to antimicrobial activity such as silver, triclosan, dichlorophenol, quarternary ammonium and chitosan, which are frequently used in the industry, on 100% cotton fabrics have been compared comparatively. In working with this, however, the antimicrobial fabrics produced with the specified chemicals, antimicrobial performance values after 1, 5, 10, and 20 washings were compared (5). In previous studies; antibacterial agents bonded with aluminum or titanium compounds, antibacterial surfaces treated with cotton fabrics. One of the metal compounds, oxytetracycline, tetracycline, pyrithione, or the antibacterial agent to which the process is applied by passing the same through different baths, is effective against Staphylococcus aureus bacteria. Some of the tetracycline treated fabrics continue to exhibit antibacterial activity even after 20 washes. Because of some problems encountered during the application of titanium compounds, the antibacterial activities of the aluminum compounds have been found to be more satisfactory (6).

2. Materials and Methods
In the experiments; The cotton fabric used as the material was supplied by Bossa. In the experiments; The characteristics of cotton fiber as material are given in the Table. In the study, copper(I) oxide and copper (II) oxide were used as nano and micro particle size materials in order to provide antibacterial property.

ekran-resmi-2016-12-09-12-21-16
In this study, as coating chemicals; two different polyurethane binders, the cross-linker in two different structures, a antifoaming for cutting the foam formed in the coating path, an emulsion to provide homogeneous distribution of copper oxide particles in the path, dispersion material; a thickener was used to adjust the flow of the path. One of the binders is of an aliphatic polyester polyurethane structure, the another one is; the coating should contain a polysiloxane compound to increase the resistance to hard water salts and washing of the path. In this study; for the purpose of improving the activity of antibacterial treated cotton fabrics, crosslinkers were used in the coating recipe for isocyanate and glidimethacrylate structures. Antibacterial finish treatment was applied to the fabric samples according to the knife-over-roller coating method. Physical tests such as breaking strength, tear strength and abrasion resistance were applied to the fabric samples after the coating process. Besides, SEM image for the purpose of examining the morphological changes occurring on the fabric sample surfaces after coating, FTIR analysis was carried out to examine the changes in bond structure of the post-coating fabrics. Physical tests applied to sample fabrics are given in the table.

ekran-resmi-2016-12-09-12-22-30
3. Conclusions and Discussion 3.1. Breaking, tearing and abrasion resistance properties of treated fabrics
It is thought that antibacterial finishing will cause a change in the strength of the positive or negative fabric breaking. The results of the tensile strength test for cotton fabrics are given in Figure 3.1. Based on the weight of the specimen, the pre-tension applied during the test was set at 5N. As shown in the figure, Cu (II) O in nano particle size was found to cause the greatest strength increase in the warp and weft direction of the coating with glidimethacrylate crosslinker.

By applying glycidemethacrylate as a cross-linker to the cotton fabric, there is more cross-linking between the fiber and the coating. Since this gives extra strength to the coated cotton fabric, no overall loss of tear strength was observed. As a result; the chemical substances containing the isocyanate group in the coating path, oxide release the CO2 gas during reactions with water, the resulting pressure of this carbon dioxide gas causes the foam to form in the polymer, which leads to reduced cross-linking in the coating and reduces the breaking strength of the coating.

abric
Tear strength measurements were made in the weft and warp directions on each fabric sample, the percent change values of the tear strength according to the control groups are calculated and shown in Figure 3.2. Tearing in the weft direction, breaking of the warp fibers, while tearing in the warp direction corresponds to the break of the weft fibers. The highest strength loss was observed for the 1st fabric and 2nd micro particle size after coating with Cu(I)O, Cu(II)O antibacterial agent and isocyanate crosslinker 29,26% and 20,15% respectively. Particle size is constant; the highest strength loss was observed after coating with the isocyanate cross-linker. Mechanical effects after coating with antibacterial agent particle size and isocyanate cross-linker, resulting in loss of tear strength as it damages the fabric structure. The highest strength loss was observed in the first and second cumulative microparticle sizes after coating with Cu (I) O and Cu (II) O antibacterial agent and isocyanate crosslinker were calculated as 31.53% and 19.66% respectively. Particle size is constant; maximum loss of strength was observed after coating with isocyanate cross-linker. Mechanical effects after coating with antibacterial agent particle size and isocyanate cross-linker resulting in loss of tear strength as it damages the fabric structure.

fabric

ekran-resmi-2016-12-09-12-29-453.2. SEM properties of treated fabrics
In the figure, SEM images of micro and pure Cu (I) O applied fabrics are given. Polyurethane binders used in coating process, blocked isocyanate and cross-linkers in glycidmethacrylate structure has been observed that polymerization is carried out with the surface.

3.3. FTIR properties of treated fabrics
FT-IR analysis was used to investigate the presence of the chemical bonds in the coating path structure in the applied cotton. The FT-IR spectra of the cotton fabrics pretreated in the formulations were given in blue color. The characteristic peaks of the cotton fabrics pretreated in the spectra are summarized in Table 4.1. Pre-treatment followed by micro Cu (I) O and two ekran-resmi-2016-12-09-12-30-25different crosslinkers FTIR spectra of the antibacterial coated cotton fabric are shown in Figure 4.14.a and 4.14.b. Cu (I) O and two different cross-linkers FTIR spectra of antibacterial coated cotton fabric the characteristic absorption band indicating the presence of the C = O groups in the ester groups has changed in the range of 1732-1750 cm-1. In addition, the shear characteristic band of -CH- groups is in the range of 1374-1383 cm-1 ,the strain range for C-O groups is 1083-1088 cm-1, the strain range for C-O groups is 1083- 1088 cm-1, the ekran-resmi-2016-12-09-12-31-17tensile vibrations of the -OH groups of the cotton fiber structure give wide and severe bands at 3325 cm-1. Glicidmethacrylate cross-linker with antibacterial coating path when the FTIR spectrum of the coated cotton fabric is examined; aliphatic esters in the structure of glycidmethacrylate carbonyl groups in the isocyanate structure at 1740 cm-1 appears to give a sharper peak. This gives us the antibacterial Cu (I) O chemical shows better binding of cotton fiber together with the coating path.

ekran-resmi-2016-12-09-12-32-19Pre-treatment followed by micro Cu (II) O and two different crosslinkers FTIR spectra of the antibacterial coated cotton fabric are shown in Figures 4.15.a and 4.15.b. O-H and C-H stretching in the spectrum (3333, 2910 and 2161 cm-1) O-H and C-H bending (1645, 1428 and 1315 cm- 1), C-C and C-O stretching (1160, 1107 and 1030 cm-1) The change in the transmittance band at 1645 cm -1 is due to the deformation vibration of the hydroxyl groups. After the antibacterial coating process, new bands emerged which would be a sign of modification. Particularly after coating with glidimethacrylate crosslinker the shear characteristic band for the -CH- groups is 1374-1383 cm-1, the strain range for CO groups is in the range of 1083-1088 cm-1 , while the tensile vibration bands of –CH– groups show more in the range of 2940-2949 cm-1, the stress vibration bands of CH- groups show more in the range of 2940-2949 cm-1. This holds the antibacterial Cu (II) O chemical of the glycidylmethacrylate cross-linker, indicating that the coating material is better maintained to the fiber.

4.Results
ekran-resmi-2016-12-09-12-33-07
Antibacterial treated textile materials are mainly medical, aesthetic and hygienic applications are spreading rapidly in various industrial fields. In this study, coating method was used to impart antibacterial activity to cotton fabrics as material and the effects of the processes are examined step by step. In the FTIR spectra after coating, new bands emerged that would indicate a modification due to coating processes. Carbonyl groups are formed on the surface of the cotton fabric after coating and copper oxide particles in the microparticle size are cross-linked to these groups. It has been observed that the breaking strength of the fabric samples increases after the coating. The binders used in the coating form a lm layer on the surface of the yarn, therefore it sticks all layers of yarn together. In case of polysiloxane based polyurethane; forming a lm layer on the outer side of the yarn, penetrates into the ekran-resmi-2016-12-09-12-34-36bers, as it allows the bers to stick together, causing an increase in the breaking strength. As a result, the copper oxide particles used in coating path depending on the glycidyl methacrylate cross-linker structure are further increases in the breaking strengths in the weft and warp direction of the fabric. In other words; chemical substances containing the isocyanate group of the coating lm, in the reactions with water, emit CO2 gas, the pressure created by the resulting CO2 gas causes the foam to form in the polymer. This causes a decrease in cross-linking in the coating and reduces the breaking strength of the coating. The H atom after coating, substituted with other atoms or groups, it forms as a C=0 functional groups. At the same time, due to the groups formed on the surface and containing oxygen, oxihijyen dation occurs in fabrics. This has been quite effective on fabric strengths. According to ISO 13937-1 test method, in the tear test on the Elmendorf device it was observed that the rupture of coated fabrics more easily than the untreated fabrics.

Reference:
1.Kornphimol Kulthang, Sujitra Srisung, Kanittha Boonpavanitchakul, Wiyong Kangwansupamonkon and Rawiwan Maniratanachote, Determination of Silver Nanoparticle Release from Antibacterial Fabrics into Articial Sweat. Particale and Fibre Toxicology 7:8, (2010).
2.Catalino Marambio-Jones,Eric M.V.Hoek, “A review of the antibacterial effects of silver nanomaterials and potential implications for human helath and the environment”,Journal of Nanoparticle Research, June 2010, Vol.12,Issue 5,pp 1531-1551.
3. Kathirvelu, S, DSouza, L, Dhurai, B, A Comparative Study of Multifunctional Finishing of Cotton and P/C Blended Fabrics Treated with Titanium Dioxide/Zinc Oxide Nanoparticles, 2008, Indian Journal of Science and Technology, 1, 7,1-12
4.X.Wang, Y.H.Zhang, Q,Li, Z.J.Liu, “Study of the Morphology and Antibacterial Properties of Nano Silver Films Prepared on Regenerated Cellulose Substrate”,Advanced Materials Research, Vol 79-82, 2091-2094,2009.
5. Palamutçu, S, Sengül, M, Devrent, N, Keskin, R., Hasçelik, B., İkiz, Y., Farklı Antimikrobiyel Bitim Kimyasallarının % 100 Pamuklu Kumaslar Üzerindeki Etkinliklerinin Araştırılması, 3. Uluslar arası Teknik Tekstiller Kongresi,İstanbul, 2007, s 412-421 6.Morris, C. E, Welch, C. M, 1983, Antimicrobial Finishing of Cotton with Zinc Pyrithione, Textile Resource Journal, December 1983, s 725-728

Biodegradable Nonwovens And Application Areas

Deniz Duran1, Hatice Aktekeli2

1,2 Ege University – Faculty of Engineering – Textile Engineering Department.

Abstract

The rapid increase in the world population leads to the depletion of our natural resources and to the increase of environmental pollution. In recent years, many studies have been carried out to produce alternative solutions to these problems. Community awareness is growing and accordingly, interest is growing towards safe, biodegradable synthetic materials that are either recyclable or that do not harm the environment. In this study, the researches about the polylactic acit(PLA), which are obtained by using natural based raw materials which are self-destructive in natüre, and PLA’s usage areas.

1.Introduction

Population growth and industrialization in the world has brought environmental problems. For this reason, sustainability has become an important issue of the whole world in recent years. The textile industry is also in search of solutions that support sustainability, from raw material selection to production methods, like many other industrial areas(Erten, 2004; Kalaycı et al., 2016).

Petroleum-derived raw materials, which take many years of decay in nature and when they start to deteriorate, causing to emit harmful chemicals to the environment and slowly pollute our food chain, as well as the non-renewable energy, are a serious threat to their living life as well as environmental pollution. In this context, the use of natural based raw materials instead of petroleum based synthetic fibers is one of the methods that can create an alternative to sustainable textile production. For this reason, biodegradable polymers which do not harm the environment and which can disappear without leaving waste in nature are important(Kalaycı et al., 2016; Çebin, 2016).

Polylactic acid (PLA) is the most commonly used biodegradable polymer in textile industry.

2.Polylactic Acid (PLA)

Polylactic acid(PLA), a repeating unit of lactic acid, is a polymer entering the group of aliphatic polyesters. One of the most important characteristics is that it is a biodegradable and compostable thermoplastic polymer produced from starch rich vegetable sources such as corn, sugar cane and wheat.

The lactide monomer forming the polylactic acid can be produced by carbohydrate fermentation or chemical synthesis. Produced lactic acids today are produced by fermentation. PLA polymer is made by ring opening polymerization mechanism. By this method, high molecular weight PLA is obtained(Ray, 2005).

General Features of PLA

  • PLA is synthesized from renewable sources.
    • PLA is a 100% biodegradable polymer. In nature, it disappears spontaneously in a short period of time such as 0-2 years.
    • PLA is an ecological polymer that can decompose in nature without any danger and does not contaminate the soil during its degredation.

PLA Degradation

The degradation of the PLA in nature takes place in 2 steps:

  1. High molecular weight (Mn> 4000) chains are hydrolyzed to low molecular weight oligomers (the reaction continues by accelerating with the addition of acid or alcali and the effect of temperature and humidity).
  2. When Mn <4000, the microorganisms in the environment continue to deteriorate by releasing smaller molecular weight compounds such as carbon dioxide,  water and humus(Farrington et al., 2005).

3. Nonwoven Surface Production Techniques

Polylactic acid polymers can be applied to the surface with nonwoven surface technologies and they are widely used. For this purpose, needling and melt blowing methods are mostly used.

3.1. Needle punching method

In the needle punching method, fiber bundles are fed to the cards by air flow after opening and blending. After the carding, with the structure called camel back, the web comes to the laying and folding band and is laid on top according to the desired thickness. Needling is carried out throughout the thickness of the web which is formed by the unbonded fiber. The notched needles move the fibers from one face of the web to the other face to form a complex structure, during the needling, some of the fibers and filaments move up to the needles and another part remains in place and the fibers are pulled down with repeatedly immersed needles. In this way, mechanical bond of the fibers is carried out.

3.2. Meltblowing method

The most common and current definition used for the meltblown method is the one-step process, also it is surface forming method by the way of the thermoplastic raw material is melted in the extruder and self-bonded by spraying the microfibers onto the cylinder from nozzle with high-speed air flow.

Polymer material being melted in the extruder, is sprayed through the nozzle holes with high speed hot air flow and the micro-size fibers are cooled and solidified as they move towards the collection cylinder. The solidified fibers form a randomly oriented non- woven surface in the collection cylinder. Due to the turbulence created by the air flow, the fibers are placed highly complex. Usually a vacuum placed in the collector retracts hot air(Duran, 2004).

4.Usage Areas of Biodegradable Nonwovens

Nonwovens produced by biodegradable PLA which is obtained by using needling and melt blown techniques find a wide range of applications. Textile fibers can be used for growing different human organs. This process involves the planting and  cultivation of cells living in human organs on a textile scaffold. This skeleton consists of biodegradable polymers made of biocompatible and degradable polymers and fibers such as biodegradable PLA.

Apart from these, applications where PLA fibers are used in medical field are given below:

  • Special membranes for use in nerve injuries,
    • In parts which can be implanted to the body,
    • In controlled drug release systems,
    • Bandage, wound closure etc. materials (Farrington et al., 2005). It is also used as top layer and additive layers in the diaper and women’s hygiene market due to its elastic properties.

PLA has the opportunity to be applied in the automotive field.

  • In 2003, PLA was used as a floor covering for Toyota Raum and Prius models. Here, the last group of PLA was closed to prevent hydrolysis.
    • In 2008, PLA fiber was used for the Mazda door sill.
    • Mitsubishi used a floor covering with Nylon 6 and PLA fibers in a special production vehicle (Auras et al., 2010)

In the agricultural field, PLA is used in applications such as sandbags, weed prevention networks, plant nets and pots. Important features for such applications; it is the process of maintaining structural integrity during use and degradation under the soil after use (Üner and Koçak, 2012).

  • Conclusion

In recent years, many studies have been carried out in order to generate alternative solutions to the rapid growth of the world population, the depletion of our natural resources and the increase of environmental pollution. Accordingly, there is growing interest in safe, biodegradable synthetic materials that are either recyclable or that do not harm the environment.

In the production of nonwovens can be produced in a short time and at a more affordable cost since it does not contain the stages such as yarn preparation, warp preparation, finishing process and so on. In recent years, the importance of biodegradability in the production of nonwovens with the use of mostly petroleum-derived raw materials has started to be used in the self-destructing raw materials in nature.

In the result of these, researchers are conducting research on the use of these environmentalist raw materials in a wider field. Thanks to their superior fiber properties, the use of these environmentally friendly fibers, which are expanding day by day, is expected to become more widespread.

References

Auras, R., Lim, L.T, Selke, S.E.M., and Tsuji, H., 2010, Poly(lactic acid): Synthesis, Structures, Properties, Processing, and Applications, A John Wiley & Sons,Inc., Publication.

Çebin B., 2016, Plastik Poşet Kullanımının Çevreye Verdiği Zararlar, (Erişim Tarihi: 10 Mayıs 2017).

Duran, K., 2004, Dokusuz Yüzeyler, Teknik Fuarcılık Yayınları, İzmir, 408s.

Erten, S., 2004, Çevre Eğitimi Ve Çevre Bilinci Nedir, Çevre Eğitimi Nasıl Olmalıdır?, Çevre ve İnsan Dergisi, Çevre ve Orman Bakanlığı Yayın Organı, 65-66.

Farrington, D. W., Lunt, J., Davies, S., Blackburn, R. S., 2005, Biodegradable Sustainable Fibers, Chap-6,Poly(lactic acid) fibers, 191-220.

Kalaycı, E., Avinc, O. O., Bozkurt, A., Yavaş, A., (2016). Tarımsal atıklardan elde edilen sürdürülebilir tekstil lifleri: Ananas yaprağı lifleri. Sakarya Üniversitesi Fen Bilimleri Dergisi, 20(2), 203-221. Ray S.S., Bousmina M., 2005, Biodegrable Polimer/Layered Silicate Nanocomposites, Progress in Materials Science, Vol. 50, No. 8. Tipper, M., Gullemois, E., 2016, Advances in Technical Nonwovens, Developments in the use of nonofibers in nonwovens, 115- 132.

Üner, İ., Koçak, E.D., 2012, Poli(Laktik Asit)’in Kullanım Alanları ve Nano Lif Üretimdeki Uygulamaları, İstanbul Ticaret Üniversitesi Fen Bilimleri Dergisi, 11(22), 79-88.

URL-1: www.total-corbion.com/about-pla/pla-lifecycle/, (Erişim Tarihi: 29 Ağustos 2018). URL-2: www.nptel.ac.in, (Erişim Tarihi: 17 Ağustos 2018).