makale

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

11

Investigation of Tensile Properties of Nonwoven Fabrics Produced from Recycled Staple Polyester and Core/Sheath Low Melting Staple Polyester Fibres by Using Carding, Needle Punching, Calendaring and Pressing Machines

Abstract

In this study, tensile properties of nonwoven fabrics produced from recycled staple polyester fibres and core/sheath low melting staple polyester fibres at 1%, 5%, 10%, 20% and 50% blending ratios by using carding, needle punching, calendaring and pressing machines were investigated. The recycled staple polyester fibres and core/sheath low melting staple polyester fibres were used as raw materials. The core/sheath low melting staple polyester fibres were blended with recycled staple polyester fibres at ratios 1%, 5%, 10%, 20% and 50%.

This mixing and web forming operations were carried out at laboratory type carding machine. These webs were bonded mechanically at needle punching machine. These needle punched fabrics were calendared and pressed at 120°C.

The weight per unit area, thickness and tensile properties of the needle punched, thermal bonded and pressed nonwoven fabrics were tested according to ISO and ASTM standards.

The results exhibit that the nonwoven fabric tenacity (cN/tex), tensile strength (MPa), specific strength (MPa/g/cm3) and other specific strength (N.m2/g) increase with the increase of core/sheath low melting polyester staple fibres ratio. It was found that nonwoven fabric thickness and elongation values decrease with increase of core/sheath low melting staple polyester fibres ratio.

Key Words: nonwoven fabric, needle punching, recycled polyester fibre, low melting fibre, calendaring technology, thermal bonding.

I. Introductıon

Nonwoven fibrous webs are mainly bonded by means of mechanical, thermally and chemical techniques depending upon the end product properties and cost. In mechanical bonding process, fibrous sheet or web is bonded together through the application of liquid or air jets, punching felting needles and by stitching with yarn. In chemical bonding, different types of chemicals or binders such as latex, synthetic rubber, acrylics, vinyl esters, styrene and different natural resins are sprayed to the nonwoven web. Other chemical bonding methods applied to nonwoven fabrics are coating, saturation, foam application and print bonding. Thermal bonding requires thermoplastic component to be present in the form of fibre, powder or as a sheath as part of a bi-component fibre. The heat is applied until the thermoplastic component becomes melts in an oven or with calendar cylinders. The thermal bonding process is more economic and environmental friendly. [1]

The rising cost of energy and greater awareness of the environmental impact of latex bonding led to a change in direction. As a result of this, the usage of thermal bonding instead of chemical bonding has increased. The high production rates possible with thermal bonding and the significant energy savings as compared to chemical bonding, due to the absence of significant water evaporation during bonding, makes the process economically attractive. In this method, bi-component and low melt fibres as a raw material are mostly used. [2]

In thermal bonding method, core/sheath bi-component and low melt core/sheath staple fibres are used for bonding fibrous web or for increasing breaking strength of nonwoven fabrics. Such fibres have a core/sheath structure with outer layer having a lower melting temperature that that of the core part. These kinds of fibres are blended and mixed with other staple at specific blending ratios. Bi-component and low melt core/sheath staple fibres have specific core/sheath ratio. In this study, low melt polyester staple fibres with 50/50% core/sheath by weight were used.

Bi-component fibres have been commercially available for years; one of the earliest was a side-by-side fibre called Cantrece developed by DuPont in the mid-1960s followed by Monsanto’s Monvel, which was a self-crimping bi-component fibre used by the hosiery industry during the 1970s. [2]

In Hayes (1992) patent, a melt-bondable bi-component fibre is described which is to be used in nonwoven. First component is a polymer with the capability to form a fibre while the second is a polymer with melting point at least 30°C below that of the first component and with the ability to adhere to the first polymer. Further Hayes recommends polyester as the polymer in the second component as polyester gives better adhesion than other polymeric materials. [3], [4]

Bi-component and core/sheath low melt fibres are made from two components distributed over the entire length of the fibre. They may either belong to the same type of polymer or be totally different polymer types. PET/low melt PET is the low melt polyester fibre consisting of same type of polymer. Polyethylene/polypropylene (PE/PP) is the bi-component fibre consisting of different polymer types. By co-extruding two polymers into one single fibre, the different properties of both polymers are combined. Bi-component fibres are classified according to the distribution of each component within cross-sectional area. Typical cross-section configurations include side-by-side, eccentric, core-sheath, islands-in-the-sea and segmented-pie. [5]

Core/sheath bi-component fibre and core/sheath low melt fibre are the most widely used and the most well-known binder fibre. The sheath part of bi-component fibre or low melt fibre is made from polymers with a low melting. The core part of bi-component fibre or low melt fibre is made from polymers with high melting point. When the fibre is heated, the sheath part of the fibre melts.

The eccentric configuration is used for providing self-crimping properties. The core part of eccentric core/sheath bi-component fibres is out of centre. When then fibre is heated, the fibre curl due to the different shrinking ratios of both polymers. Thus, it is possible to give volume to fibre.

In the side-by-side bi-component fibre, both polymers occupy an equal part of the fibre surface. The fibre may develop more crimp than the eccentric core/sheath configuration.

Segmented pie bi-component fibres are known splittable fibre. Splittables are fibres in which the two polymers share only one common interface and both polymer phases are also exposed.

Island/sea bi-component fibre consists of sea part and islands part. When the sea part of the fibre is dissolved, fabric is produced on the basis of very fine microfibers. These fibres (typically 37 islands) are used in the production of suede fabrics. The process is not often environmentally friendly because of the solvents employed in the removal of the sea part. Evolon® is the commercially spunbonded fabric made from island-in-the-sea polyester/nylon fibres with 16 segmented pie. The polyester and nylon fibres are split and bonded mechanically water-jet (hydroentanglement) technology with high pressure [7], [5]

In this study, the tensile properties of the nonwoven fabrics produced from recycled staple PET polyester fibres and core/sheath (50/50) low melt staple polyester fibres at specific blending ratios by using the carding, needle punching, calendaring and pressing machines were studied. In this regard, the effect of core/sheath low melt staple polyester fibre ratios on nonwoven fabric tenacity was investigated.

Iı. Experimental Study

II.1. Material and Method

In this study, 3 denier 51 mm recycled staple polyester fibres with white colour were used as carrier fibre. 4 denier 51mm core/sheath staple polyester low melting fibres with black colour supplied from Toray Company were used as binder fibre. These fibres are mainly used in the production of needle punched fabric and acquisition distribution layer/fabric (ADL). Table1 and Table2 present main properties of used recycled staple polyester fibre and core/sheath low melting staple polyester fibre.

Low melting polyester staple fibre is used as binder (a bonding agent) to combine staple fibres using heat in the manufacturing process of nonwoven fabric, and it is mainly used in nonwoven fabric used for acoustic insulation material for automotive, acquisition distribution layer (ADL) and cushions for mattress and other furniture. Manufacturers have been switching from the conventional chemical adhesive method using chemical agents, for manufacturing nonwoven fabric, to a thermo-bonding method given the rising awareness for environment-friendliness. Low melting polyester staple fibre is the eco-friendly material used in thermo-bonding and its global market is expanding at a rate of 8% a year. For this reason, the competition in the industry has been intensifying, as manufacturers with top market shares in the LM polyester staple fibre market invests in manufacturing facilities and other companies are newly entering into the market. [8]

The typical cross-section of core/sheath low melt staple polyester fibre is shown in Figure3.  The low melt staple polyester fibre was of core/sheath (50/50) type with a round cross section; core of conventional polyester and a sheath of co-polyester with a melting point of 110°C.

Core/sheath bi-component and low melt polyester staple fibres are utilized for sound absorption in vehicles. There is a rise in automobile applications in emerging economies, as market expands on expansion of requirements for lighter vehicles and for sound absorption. These fibres are used for mattresses, bed padding, sofa cushion materials and in quilt. The fibres are preferred high precision filter for purification. In construction applications, the fibres are used for sound, shock absorption, insulation and for preventing cracks. Other applications of these fibres are cloth interlining, inner soles and agricultural materials.

II.2. Production Method

In the experimental study, the nonwoven fabrics were manufactured at four steps. In the first step, the webs were produced from recycled staple polyester and low melting staple polyester fibres prepared at different blending ratios at carding machine. In the second stage, these webs were mechanically bonded at needle punching machine. In the third stage, needle punched nonwoven fabrics were thermally bonded at calendaring machine. In the fourth stage, thermally and mechanically bonded nonwoven fabrics were pressed. The tensile properties of nonwoven fabrics depend on needle punching machine parameters such as depth of needle penetration, needle type and needling density per cm2.

Wool type carding machine is the most used machine for web forming from staple natural and synthetic fibres. Carding is defined that a process for making fibrous webs in which the fibres are aligned parallel or to each other or random orientated. The fibrous web is produced at the end of the carding machine. In the study, laboratory type sample carding machine was used for making webs as you can see in following figure. [9], [10]

337A laboratory wool type sample carding machine of Mesdan S.P.A. was used for web forming operations. The machine has 4-5kg/h production capacity and 10-15m/min web delivery speed.

The machine is designed to assess the carding performance and quality of staple fibres as well as to produce webs. In addition to this, this machine is suitable for preparing homogeneous coloured fibre samples.

The equipment is composed by a wide conveyor, a pair of feed rollers, three pairs of workers and strippers, main carding cylinder, doffing roller, fancy roller and clearer together with a web collecting drum.

In the first step, the recycled staple polyester fibres and low melting staple polyester fibres were weighted according to blending ratio.

These fibres were mixture by hand before carding machine.

These fibre mixtures were run through the carding machine two times, first time for opening the fibres and second time for blending. Webs were produced at the end of the carding machine.

Needle punching technology was used to consolidate of fibrous structures (web).

Needle punching is a process of bonding nonwoven fibrous web structures by mechanically interlocking the fibres through the web. Barbed needles mounted on a board, punch fibres into the web and then withdraw leaving the fibres entangled.

By varying the stroke per minute, the advance rate of the web, and the degree of penetration of the needles, a wide range of fabric densities can be achieved. [9], [10]

The bonding of staple fibres in these webs was carried out at needle punching machine by using felting needles. 74.3punch needling density per cm2 and 12.5mm needle penetration depth at pre-needling machine was applied to webs. The pre-needled nonwoven fabrics were bonded in the second and third needling machines at 123punch/cm2 and 125punch/cm2 needling density and 10mm and 8mm needle penetration depth respectively.

Needle punched fabrics were thermally bonded by passing through the smooth calendar cylinders at 120°C. The needle punched and thermally bonded nonwoven fabrics were pressed at machine for better melting of low melting fibre at 120°C for 120second under 120bar pressure.

Thermally bonding is the process of using heat to bond or stabilize a web structure that consists of a thermoplastic fibre. Thermally bonding is known melt bonding or heat bonding. [12] The basic concept of thermally bonding was introduced by Reed in 1942. [2] The process is relatively simple. There are mostly used two kind of thermally bonding methods. One of them is bonding with calendar cylinders. Another method is through-air ovens. Hot calendaring and hot oven are the most frequently used methods for thermally bonding of nonwoven webs and fabrics. [9], [10]

II.3. Testing Methods

The weight, thickness and tensile properties of the produced mechanically needle punched, thermally calendar cylinders bonded and pressed nonwoven fabrics were done according to ISO ad ASTM standards.

II.3.1. Thickness Test

The thickness of fabrics is determined as the distance between the upper and the lower surfaces of the material, measured under a specified pressure. Thicknesses of nonwoven fabrics were measured at R&B Cloth Thickness Tester produced from James H.Heal&Co.Ltd Halifax England. Thickness test was done according to TS EN ISO 9073-2 standard. Thickness of nonwoven fabric was measured under 1g per cm2 and 5g per cm2 pressure respectively at the R&B Cloth Thickness Tester. Obtained results were averaged. It was seen that thickness of nonwoven fabric decreased with increase of low melting fibre ratio. [13], [14]

II.3.2. Tensile Strength Test

Instron 4411 tensile testing machine was used to measure the tensile and breaking strength of nonwoven test samples as specified in ASTM D5035-06 Standard Test Method for Breaking Force and Elongation of Textile Fabrics according to strip method. The nonwoven fabric tenacity (cN/tex) was determined according to following equation. Six samples were taken only machine direction (MD). The samples were cut and prepared at 50x175mm dimensions. Test length (the distance between the fixtures) was adjusted to 75mm. Test speed was 300mm per minute. A mean of six test results has been calculated in only machine direction (MD). All samples were conditioned at 65%±2°% relative humidity and temperature of 20±2°C prior to each test at physical testing laboratory of Marmara University Technology Faculty Textile Engineering Department.

The fabric density (g/cm3) was calculated by dividing fabric weight per area (g/m2) by fabric thickness (mm) [15] [16]

The nonwoven fabric tenacity (cN/tex) and specific strength was determined according to following equations.

Specific strength (MPa/g/cm3) is generally used for removing effects of the fabric thickness and fabric weight per unit area on tenacity and strength of nonwoven fabrics. Specific strength (MPa) can be calculated by dividing tensile strength (MPa) by fabric density (g/cm3).

Other specific strength (N/m2/g) was found by considering the breaking strength (N) and fabric areal weight (g/m2) of needle punched, thermally calendar cylinders bonded and pressed nonwoven fabrics. Specific strength was calculated by dividing breaking strength (N) by fabric areal weight (g/m2). Thus, it is possible to compare similar nonwoven fabrics with different basis weight. [17]

Results

Table3 presents the mean of measuring areal weight, thickness and breaking strength values. It was clearly seen that thickness of nonwoven fabric decreases with increase of low melting fibre ratio in the mechanically needle punched, thermally calendared and pressed nonwoven fabric.

The results clearly showed that low melt fibre percentage had a significant impact on nonwoven fabric thickness and thickness of nonwoven fabric decreases with increase of core/sheath low melt staple polyester fibre ratio.

The breaking strength test results of needle punched, thermally calendar cylinders bonded and pressed nonwoven fabrics show that increase of core/sheath low melting staple polyester fibre ratios from 1%, %5, 10%, 20% and to 50% increase the fabric tenacity by 4.57cN/tex, 5,25cN/tex, 5.28cN/tex, 5,46cN/tex and 5.58cN/tex respectively.  On the other hand, increase of core/sheath low melting staple polyester fibre ratios from 1%, %5, 10%, 20% and to 50% decrease elongation (%) values by 71,52%, 47,97%, 40,14%, 33,11% and 28,91% respectively.

Figure8 shows effect of core/sheath low melting staple polyester fibre ratio on nonwoven fabric tenacity (cN/tex). The results show that fabric tenacity (cN/tex) increases slowly with increase of core/sheath low melting staple polyester fibre ratio. This can be explained by the fact that the core/sheath low melting staple polyester fibres have high bonding force.

Figure9 indicates effect of core/sheath low melting staple polyester fibre ratio on breaking elongation (%). Elongation results show that breaking elongation (%) decreases considerably with increase of core/sheath low melting polyester staple fibre ratio.

Figure10 shows effect of low melting staple polyester fibre ratio on tensile strength (MPa). Results show that tensile strength (MPa) increases considerably with increase of core/sheath low melting staple polyester fibre ratio.

Figure11 shows effect of low melting polyester staple fibre ratio on specific strength (MPa/g/cm3).  Results show that specific strength (MPa/g/cm3) increases with increase of core/sheath low melting staple polyester fibre ratio.

Figure12 shows effect of core/sheath low melting polyester staple fibres ratio on specific strength (N.m2/g). Results show that specific strength ((N/m2/g) increases with increase of core/sheath low melting staple polyester fibre ratio.

Conclusion

This experimental study clearly shows the effect of core/sheath low melting polyester staple fibre on tensile strength test results of mechanically needle punched, thermally calendar cylinders bonded and pressed nonwoven fabrics. The recycled staple polyester fibres (r-PES) were blended with core/sheath low melting staple polyester fibre (bi-co PES). The core/sheath low melting staple polyester fibres were used at %1, 5%, 10%, 20% and 50% ratios. The nonwoven fabric production was carried out at carding, needle punching, calendaring and press machines. The following results have been obtained.

•Thickness of nonwoven fabric considerably decreases with increase of core/sheath low melting polyester staple fibre ratio.

•Fabric tenacity (cN/tex) increases with increase of core/sheath low melting polyester staple fibre ratio.

•Elongation values (%) decrease considerably with increase of core/sheath low melting polyester staple fibre ratio.

•Tensile strength (MPa), specific strength (MPa/g(cm3) and specific strength (N.m2/g) increase with increase of core/sheath low melting polyester staple fibre ratio.

Acknowledgement

I would like to thank to Hassan Group for support.

References

[1] [15] Nawab, Y.: “Textile Engineering”, Walter de Gruyter GmbH, Germany, (2016)

[2] Russell, S.J.: “Handbook of Nonwovens”, Woodhead Publishing in Textiles, CRC Press, (2007)

[3] Hayes, D.J.: “Melt-Bondable Fibers for Use in Nonwoven Webs”, 5082720, (1992)

[4] Lindström, K.: “Bicomponent Fiber in Sound Absorbent Production”, The Swedish School of Textiles, University of Boras, Master Thesis, (2014)

[5] Dasdemir, M.; Maze, B.; Anantharamaiah, N.; Pourdeyhimi, B.: “Influence of Polymer Type, Composition, and Interface on the Structural and Mechanical Properties of Core/sheath Type Bi-component Nonwoven Fibers”, Journal of Material Science, (2012), 45, pp.5955-5969.

[6] www.centexbel.be/bicomponent-fibres

[7] Anantharamaiah, N.; Verenich, S.; Pourdeyhimi, B.: “Durable Nonwoven fabrics via Fracturing Bi-Component Islands-in-the-Sea Filaments”, Journal of Engineered Fibers and Fabrics, Volume3, Issue3, (2008), 1-9

[8] http://www.toray.com/news/fiber

[9] Turbak, A.F.: “Nonwovens: Theory, Process, Performance, and Testing, Chatper2: Nonwoven Terminology Wlliam E.Houfek”, Tappi Press, (1993), pp. 11, 167.

[10] Akalın, M.; Özen, M.S.: “Tülbent Esaslı Dokunmamış Kumaşlar, (Nonwoven Fabrics)”, Nesil Matbaacılık, Istanbul (2010)

[11] Banerjess, P.K.: “Principles of Fabric Formation”, CRC Press, (2015), pp.398

[12] Kellie, G.: “Advances in Technical Nonwovens”, Woodhead Publishing with Textile Institute, (2016)

[13] Federova, N.: “Investigation of the Utility of Islands-in-the-Sea Bicomponent Fiber Technology in the Spunbond Process”, PHd Thesis, North Caroline State University, (2006)

[14] Demirci, E.: “Mechanical Behaviour of Thermally Bonded Bicomponent Fibre Nonwovens: Experimental Analysis and Numerical Modelling”, Loughborough University, (2011)

[15] Midha, V.; Mukhopadyay, A.: “Bulk and Physical Properties of Needle-Punched Nonwoven Fabrics”, Indian Journal of Fibre&Textile Research, Vol.30, June (2005), pp.219

[16] Ghali, L.; Halimi, M.T.; Hassen, M.B.; Sakli, F.: “Effect of Blending Ratio of Fibers on the Properties of Nonwoven Fabrics Based on Alfa Fibers”, Advances in Materials Physics and Chemistry, (2014), 4, pp.116-125.

[17] Wang, H.; Zhu, J.; Jin, X.; Wu, H.: “A Study on the Entanglement and High-Strength Mechanism of Spunlaced Nonwoven Fabric of Hydrophilic PET Fibers”, Journal of Engineered Fibers and Fabrics, Vol.8, Issue4, (2013), pp.63.