Polyethylene Terephthalate Yarn Research Articles

Assessing PET composite prosthetic solutions: A step towards inclusive healthcare

The demand for affordable prostheses is particularly high in Low Middle-Income Countries (LMICs). Currently, sockets are predominantly manufactured using monolithic thermoplastic polymers, which lack durability and strength, or consumptive thermoset resin reinforcing with expensive composite fillers like carbon, glass, or Kevlar fibers. However, there exist unmet and demanding needs among amputees for procuring low-cost, high-strength, and faster socket manufacturing methods. We evaluate a socket made from a novel manufacturing technique utilizing an affordable and sustainable composite material called commingled PET (polyethylene terephthalate) yarn, along with a reusable vacuum bag, to produce custom-made sockets in a purpose-built curing oven. Our innovative fabrication methodology enables the production of complex-shaped patient sockets in under 4 h. To evaluate the efficacy and performance of the PET sockets, we conducted trials with both unilateral and bilateral amputees over a six-month period, in collaboration with Bhagwan Mahaveer Viklang Sahayata Samiti (BMVSS) in India. Utilizing a 6-min walking test, we measured various gait parameters, including ground reaction forces and flexion angle, for both unilateral and bilateral amputees.The gait analysis conducted on amputees using our PET-based sockets demonstrated their ability to engage in daily activities without interruptions, reaffirming the functional efficacy of our approach. By combining self-reinforced PET with our novel fabrication technique, we offer a unique and accessible solution that benefits clinicians and patients alike. This study represents significant progress towards achieving affordable and personalized prostheses that cater to the needs of LMICs.

Light transmission of weft-knitted fabrics for seamless garments

Knitted seamless sportswear offers ‘body-mapped’ comfort and support, but there is a risk of exposing the human body in public due to the low density and large fabric deformation of the sportswear when wearing it. This paper presents an experimental study on the light transmission behavior of different weft-knitted fabrics for seamless sportswear in different stretching modes to understand the light transmission principle. Three plain knit fabrics for seamless sportswear made from three yarn combinations were compared: a polyamide 6 (PA6) yarn, a combination of spandex and PA6 yarns, and a combination of spandex, PA6, and polyethylene terephthalate (PET) yarns. Three modes of stretching were performed on the three fabrics, namely uniaxially, uniaxially with transverse restraint, and biaxially, to simulate wear deformation. The stretched fabrics are analyzed in terms of cover factor, thickness, and light transmission. The results showed that light transmission increases with increasing tensile strain. The presence of restraint further increases the light transmission, and biaxially stretched fabrics have the greatest light transmission. The thinnest PA6 fabric has the lowest cover factor and the highest light transmission, while plating a spandex/PA6 covered yarn on a PA6 yarn shrinks and tightens the fabric, and therefore reduces the light transmission. Adding an additional PET yarn reduces shrinkage and thickness, increasing light transmission. Light passing through the fibers and loop meshes of a fabric accounts for total light transmission. Plating a coarser elastomeric yarn into weft-knitted fabrics for seamless sportswear is an effective way to increase the spaces in yarns and shrink the loop meshes, thereby reducing the light transmission.

Geotextile performance of fabrics woven by polyethylene terephthalate yarns prepared directly from drinking bottles

This research article describes the preparation and characterization of geotextile-reinforced embankment made from yarns produced from polyethylene terephthalate bottles by the bottle cutter and stretching yarn prototype. The yarns produced from plastic bottles were weaved to obtain fabrics with different pattern structures. Yarns and fabrics samples were characterized including yarn number, yarn tensile, fabric thread density, fabric weight, fabric thickness, fabric breaking strength, and fabric bursting strength. The performance of the fabric samples as a geotextile was evaluated by direct shear test, California bearing ratio, and water permeability. The results show that the fabric pattern structure plausibly was the main factor for geotextile performance. The fabric samples with low thread density could develop both interlocking and interbedding mechanisms resulting in higher shear stress and California bearing ratio. Lastly, PLAXIS 2D program simulation with finite element method was used to estimate the possibility of the use of fabric samples as geotextile-reinforced embankment. It was found that the predicted safety factor of soil erosion with fabric sample could reach the value of one which is higher than the safety factor of the soil erosion without fabric sample.

Sericin eco-friendly biomaterial as a spin finish in drawn textured PET yarn production

Purpose This paper aims to extracted sericin from the cocoons of Bombyx mori silkworms, and sericin powder was applied onto drawn textured polyethylene terephthalate (PET) yarns as a spin finish. The reactivity on the surface of PET yarns was analyzed through Fourier transform infrared spectrophotometry–attenuated total reflectance (FTIR-ATR) and dyeing with methylene blue as a reactive dye. Also, investigations were conducted on the effects of sericin, citrc acid (CA) (as a crosslinking agent), and sodium hypophosphite (as a catalyst) concentrations on some properties of false-twist textured PET yarns. Design/methodology/approach A false-twist texturing machine (Scragg-Shirley minibulk, England) was used with the draw ratio of 1.05, heating temperature of 120°C, texturing speed of 100 m min−1 and applied twist of 3,000 TPM. The aqueous extraction of sericin was carried out by the boiling of the raw silk in distilled water with L:R: 40:1 for 120 min. The aqueous solution was filtered with a filter paper to remove the impurities and insoluble fibroin. Finally, the sericin solution was freeze-dried to obtain the sericin powder. The sericin solution was applied on the drawn textured PET yarns using the “pad-dry-cure” method. Findings Sericin fixation onto the PET yarns was confirmed by FTIR-ATR. The results showed that there were no significant changes in the tensile strength, linear density, crimp contraction and crimp modulus, elongation at break and shrinkage. In contrast, a substantial increase was observed in moisture regain, vertical wicking, dye uptake and ultraviolet protection. There was also a reduction just in the electrical resistivity, in the presence of sericin. Originality/value Although sericin has been known to have numerous beneficial properties, its application in textile industry as a spin finish has not been reported yet.

Wear comfort and thermal insulation of ceramic-imbedded fabrics with different yarn structures by thermal manikin experiment

PurposeThis study examined the wear comfort and thermal insulation properties of Al2O3/graphite particle-imbedded sheath/core and dispersed fabrics via a thermal manikin experiment.Design/methodology/approachAl2O3/graphite sheath/core and dispersed polyethylene terephthalate (PET) yarn (POY 120d/24f) were spun using a pilot melt bi-component conjugated spinning machine, which was texturized as 75d/24f on the belt-type texturing machine. The woven fabric specimens were made using nylon 70d/34f in the warp with three types of weft yarn: Al2O3/graphite sheath/core, dispersed and regular PET yarns. Thermal insulation properties were measured and compared in terms of the heat retention rate (I) by KES-F7 apparatus and the maximum surface temperature by light heat emission equipment, as verified by the emissivity of various fabric specimens by far-infrared ray experiment. In addition, this study examined the thermal insulation (Clo value) characteristics of the clothes made of Al2O3/graphite sheath/core and dispersed fabrics using a thermal manikin apparatus, which were compared with the properties of regular PET clothing.FindingsThe thermal insulation of the dispersed fabric was superior to that of the sheath/core fabric, which was tentatively attributed to the higher emissivity of the dispersed yarn with Al2O3/graphite particles distributed over the whole yarn cross-section than that from the core of the sheath/core yarn. This result for the clothing measured using a thermal manikin was consistent with the higher heat retention rate (I) and the maximum surface temperature of the dispersed fabric than that of the sheath/core fabric. In addition, the thermal insulation of the dispersed and sheath/core fabrics was superior to that of the regular PET fabric, which revealed that the Al2O3/graphite particles imbedded in the dispersed and sheath/core yarns exerted a greater effect on the heat storage and release characteristics compared to that of the TiO2 particles in regular PET yarn. The Clo values of the dispersed and sheath/core fabrics under the light-on condition were much higher than those under the light-off condition, and furthermore, the difference of the Clo value between the sheath/core and regular PET fabrics under light-on condition was approximately 1.7 times greater than that under the light-off condition. These results revealed that the far-infrared rays emitted from the Al2O3/graphite particles imbedded in the sheath/core and dispersed yarns enhance the heat storage and release characteristics from the fabric under the light-on condition, i.e. under the sunlight.Originality/valueThe previously examined thermal wear comfort properties of the various inorganic particle-imbedded fabrics were measured with the fabric state, not clothing, which could not provide objective data related to the actual wearing performance of clothing.

Engineering hybrid textile braids for tendon and ligament repair application

AbstractChallenges involving tendon and ligament repair have motivated the investigation of new strategies to improve clinical outcomes. These have been mainly based on polymer constructs, which may be non‐biodegradable or biodegradable. The former typically fails due to lack of device integration and the latter demands a complex balance between biodegradability and tissue ingrowth, often failing due to insufficient mechanical properties. This work presents the development of hybrid braids based on polyethylene terephthalate (PET) and polylactic acid (PLA) yarns. A textile technique was used to fabricate braids based on 16 multifilament yarns of varying PLA/PET composition. The composition was varied to maximize biodegradability while ensuring mechanical performance. The braids' morphology, physical and mechanical properties were characterized. As production parameters and architecture were maintained, the braids exhibited similar porosity and wicking ability. The breaking force and stiffness decreased significantly as the number of PLA yarns increased, although strain levels remained constant. Braids containing 10 and 12 PET yarns (out of the total 16 yarns) demonstrated good creep and force‐relaxation behavior, as well as resistance to cyclic loading. These compositions were selected for future work, to be assembled into more elaborate structures to mimic the fibrous organization and tensile properties of different tendons/ligaments.

Creep Behaviour of Recycled Poly(ethylene) Terephthalate Non-Woven Geotextiles.

At the beginning of this century, due to well-established Brazilian recycling processes, geosynthetics’ manufacturers started to use recycled poly(ethylene) terephthalate (PET) yarns/filaments (from PET bottles) in geotextile production. Despite the fact that recycled products cannot act as reinforcement functions, geosynthetics are constantly under sustained tensile load and experiences evolutions of the axial strain (creep behaviour). Thus, this study aims to assess the influence of the structure of (needle-punched) non-woven geotextiles manufactured using recycled PET yarns on their creep behaviour. Two geotextiles with different fibre/filament production processes were investigated (short-staple fibres—GTXnwS—and continuous filaments—GTXnwC). Unconfined in-isolated conventional and accelerated (using the stepped isothermal method) creep tests were performed at 5%, 10%, 20%, 40% and 60% of geotextiles’ ultimate tensile strength. The geotextiles investigated provided similar creep behaviour to geotextiles manufactured with virgin PET material. The standard deviation of the axial strain tends to increase as the load level applied increase. The structure of the GTXnwS harms its tensile –strain behaviour, promoting axial deformation under sustained loads, at least 50% higher than GTXnwC for the same load level applied. The influence of the load level and geotextile structure in the initial axial strain is pointed out. Long-term predictions based on creep tests performed using the stepped isothermal method have proven to be conservative and they must be restricted for quality control of the investigated geotextiles.

HPT Türevi UV Absorblayıcıların PET İplik ve Kumaşların UV Dayanımı Üzerine Etkilerinin İncelenmesi

Morötesi (ultraviyole, UV) ışımanın tüm polimerler gibi tekstil malzemelerinin performansları üzerinde de olumsuz etkileri bulunmaktadır. Bu etkiler, dış ortam uygulamaları için üretilmiş ürünlerde daha da önem kazanmaktadır. UV ışımanın olumsuz etkisini azaltarak ürünlerin daha uzun süre kullanımını sağlayabilmek amacıyla UV absorblayıcı katkı maddeleri kullanılmaktadır. Bu katkı maddeleri masterbatch yöntemiyle, üretim sırasında lif yapısına katılarak tekstil ürünlerinin UV dirençleri arttırılabilinir. Polimerlerin açık hava koşullarındaki performanslarını belirleyebilmek amacıyla yapılan testlere dış ortam şartlandırma testleri denilmektedir. Bu testler, gerçek dış ortam şartlarında yapılabileceği gibi laboratuvar koşullarında dış ortam şartlarını simüle eden cihazlarında da gerçekleştirilebilinir. Laboratuvar ortamında yapılan testler hızlandırılmış yapay dış ortam şartlandırma testleri olarak adlandırılır. Açık hava uygulamarı için poliakrilonitril liflerinden yapılmış tekstil ürünleri yaygın olarak kullanılmaktadır. Ancak bu liflerin tedariklerinde çeşitli zorluklarla karşılaşılması ve maliyetlerinin yüksek olması bu tür uygulamalar için polietilen tereftalat (PET) liflerine olan ilgiyi arttırmaktadır. Bu çalışmada hızlandırılmış yapay dış ortam şartlandırma testleri, katkısız PET (referans PET) ve hidroksifenil triazin (HPT) türevi ticari bir katkı malzemesi olan Tinuvin 1577 ED ile UV ışımaya karşı direnci arttırılmış PET (katkılı PET) iplik ve bu iplikler kullanılarak dokunmuş kumaşlara 1000 saat süre ile uygulanmıştır. Her 250 saatte bir numunelerin kopma mukavemeti, kopma uzaması ve renk değişimi özellikleri kayıt edilmiştir. Şartlandırma testlerinden önce yapılan çekme deneyleri katkı maddelerinin PET ipliklerin kopma mukavemetlerini azaltıp, kopma uzaması değerlerini arttırdığını, dolayısı ile mekanik özellikler üzerinde olumsuz bir etkisinin olduğunu göstermiştir. Ancak 1000 saatlik dış ortam şartlandırma testlerinin sonunda bu katkı maddelerinin UV ışımanın PET iplik ve kumaşların mekanik özellik ve renk değişimi üzerindeki olumsuz etkisini belirgin bir oranda azalttığı tespit edilmiştir.

Surface modification of polymer textile biomaterials by N2 supercritical jet: Preliminary mechanical and biological performance assessment

Foreign Body Reaction (FBR) is a critical issue to be addressed when polyethylene terephthalate (PET) textile implants are considered in the medical field to treat pathologies involving hernia repair, revascularization strategies in arterial disease, and aneurysm or heart valve replacement. The natural porosity of textile materials tends to induce exaggerated tissue ingrowth which may prevent the implants from remaining flexible. One hypothesized way to limit the FBR process is to increase the material surface roughness at the yarn level. Supercritical N2 (ScN2) jet particle projection is a technique that provides enough velocity to particles in order to induce plastic deformation on the impacted surface. This work investigates the influence of ScN2 jet projection parameters like standoff distance or particle size on the roughness that can be obtained on medical polymer yarns of various diameters (100 and 400 μm) and woven textile surfaces obtained from a 100 μm yarn. Moreover, the mechanical and biological performances of the obtained modified textile material are assessed. Results bring out that with appropriate testing conditions (500 bars jet/500 mm distance between nozzle and PET textile) and particle size around 50 μm, it is possible to generate 20 μm large and 4 μm deep craters on a 100 μm monofilament PET yarn and fabric. Regarding the strength of the textile material, it is only slightly modified with the treatment process, as the tenacity of the yarns decreases by only 10%. Moreover, It is shown that the obtained structures tend to limit the adhesion and slow down the proliferation of human fibroblasts.

Development of a warming multi-functional fabric Part I: The analytic hierarchy process combined with the technique for order preference by similarity to an ideal solution for the optimization of the multi-quality melt spinning parameters in far-infrared functional yarn

This series study develops a multi-functional yarn with far-infrared emission, heating, and antistatic properties for winter clothing. In Part I, polyethylene terephthalate (PET) is used as the polymer matrix, and nano germanium powder is uniformly mixed with PET by the melt blending process for modification, in order that the PET composite has far-infrared function. Afterwards, the modified PET is made into 75d/72f fully drawn yarn (FDY) by melt spinning and melt drafting. The properties of the yarn, including tensile strength, elongation at break, yarn count (in denier), far-infrared emissivity, and far-infrared heating are discussed. In order to optimize the quality of yarn in the melt spinning process, this study designs process parameters consisting of germanium powder addition, melt temperature, mold temperature, nozzle temperature, gear pump speed, and take-up speed using the Taguchi method. Then, the analytic hierarchy process (AHP) is applied to obtain the weights of each quality, which will be used in the technique for order preference by similarity to an ideal solution (TOPSIS) to obtain the optimal processing parameters for multi-quality yarn. The results show that the tensile strength of the optimized modification PET yarn is 4.84 g/d, the elongation at break is 41.26%, yarn count is 74.39d/72f, the far-infrared emissivity is 89% and the far-infrared heating is 6.3℃. The properties of the optimized modified yarn are obviously better than general PET yarn.

The effect of dielectric barrier discharge plasma treatment on the air drag force of polyacrylonitrile, polyethylene, polypropylene and polyethylene terephthalate yarns

In this paper, atmospheric pressure dielectric barrier discharge (DBD) plasma was used to treat four kinds of chemical fiber yarns, namely polyacrylonitrile (PAN), polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET), for which the air drag force, moisture regain and yarn diameter were measured. Compared with untreated samples, the air drags of treated PAN, PE, PP and PET yarns increased maximally by 10.7%, 43.0%, 40.0% and 18.9%, respectively, in the present experiments. A two-way analysis of variance and correlation analysis were performed to study the effect of plasma treatment on air drag and other properties of these four chemical fiber yarns. The combination of X-ray photoelectron spectroscopy analysis and the determination of the DBD plasma component can further enhance the understanding of the difference between DBD plasma treatment processes among these four chemical fiber yarns. This study provided the experimental basis to improve the air-jet weaving efficiency of chemical fiber fabrics.

Preparation of Conductive Polyethylene Terephthalate Yarns by Deposition of Silver & Copper Nanoparticles

The assemblage of textiles and electronics in a single structure has led to the development of smart textiles for functional purposes and special products. Conductive yarn as a necessary component of smart textiles is being developed by a number of techniques. The objective of the current study was to impart conductivity to yarn by coating the silver and copper nanoparticles on the surface of multifilament polyester textile fibres. The surface morphology and electrical conductivity of the coated yarns were investigated. The wash ability of the conductive yarns developed was also studied. The yarns showed good retention of the nanoparticles, as proven by the very small loss of the conductivity of the material.

Research on the Effect of Dielectric Barrier Discharge (DBD) Plasma Remote Treatment on Drag Force of Polyethylene Terephthalate (PET) Yarns in Air Flow with Different Humidities

In this paper, long-lived free radicals in atmospheric-pressure DBD plasma were used to treat PET yarn surface. Subsequently, the drag force of treated yarns in air flow at four humidities (40 ± 3, 50 ± 3, 60 ± 3, 70 ± 3%) was measured. The results suggest that with the increase of flow humidity, the air drag force of untreated yarn decreased while that of plasma-treated ones on average increased gradually. The average growth rates of the drag force under each humidity were 5.33, 7.58, 10.08 and 12.28% respectively. Meanwhile, the air drag force of the yarns treated at different specific input energy (SIE) densities and treatment time varied obviously under different flow humidity. The X-ray photoelectron spectroscopy analysis was performed to characterize the yarn surfaces chemically. The topology and roughness of PET yarns were measured by atomic force microscopy. The tensile test was carried out to characterize the mechanical strength. The ozone, nitrate and nitrite radicals and total organic carbon in tail gas of plasma were also analyzed. The maximal atomic concentration of N element on PET surface could reach 8.0%. The obtained results can improve the understanding of the property of long-lived reactive species from DBD plasma source generated at different SIE and the difference in PET surface etching and modification during remote treatment at different SIE. Moreover, the results also provide an experimental guideline for the improvement of weaving efficiency in air-jet weaving.

Electrically controllable twisted-coiled artificial muscle actuators using surface-modified polyester fibers

As a new class of thermally activated actuators based on polymeric fibers, we investigated polyethylene terephthalate (PET) yarns for the development of a twisted-coiled polymer fiber actuator (TCA). The PET yarn TCA exhibited the maximum linear actuation up to 8.9% by external heating at above the glass transition temperature, 160 °C–180 °C. The payload of the actuator was successfully correlated with the preload and training-load conditions by an empirical equation. Furthermore, the PET-based TCA was electrically driven by Joule heating after the PET surface was metallization with silver. For the fast and precise control of PET yarn TCA, electroless silver plating was conducted to form electrical conductive layers on the PET fiber surface. The silver plated PET-based TCA was tested by Joule heating and the tensile actuation was increased up to 12.1% (6 V) due to the enhanced surface hardness and slippage of PET fibers. Overall, silver plating of the polymeric yarn provided a fast actuation speed and enhanced actuation performance of the TCA actuator by Joule heating, providing a great potential for being used in artificial muscle for biomimetic machines including robots, industrial actuators and powered exoskeletons.

Response of air drag force of the polyethylene terephthalate (PET) yarn treated via dielectric barrier discharge (DBD) plasma to its varying surface characteristics

In this paper, non-thermal plasma induced by dielectric barrier discharge (DBD) air discharging was used to treat the moving polyethylene terephthalate (PET) yarn samples and the motionless samples, respectively. The air drag force of the resultant samples was tested, and their surface characteristics were analyzed by X-ray photoelectron spectroscopy (XPS) for chemical composition and by scanning electron microscopy (SEM) for microscopic morphology. The results of the drag force of the samples indicated that, compared with the pristine yarn, the drag force of the samples treated via the two types of plasma treatment clearly varied under different processing conditions. The maximal drag force was 28.26cN for the moving sample treated at 34 V control voltage for 30 s in the discharge zone (zone A) and 27.81cN for the motionless sample treated at 36 V control voltage for 60 s in the long-lived plasma species treating zone (zone B), which increased by 18.9% and 17.0% over that of untreated sample (23.77cN), respectively. The fluctuation of the drag force probably depends on the change of the chemical composition and microstructure of the polyethylene terephthalate yarn surface, which implies that the feasibility of weaving efficiency improvement for an air-jet loom could be realized via controlling and optimizing the dielectric barrier discharge operating conditions.

Electrokinetic remediation of heavy metals contaminated kaolin by a CNT-covered polyethylene terephthalate yarn cathode

In the current study, carbon nanotube (CNT) covered polyethylene terephthalate yarns (PET-CNT) electrode has been investigated as a novel cathode material for the electrokinetic (EK) remediation of multi-metals (Cd, Cu, Ni, Pb, Zn) contaminated kaolin. The results of scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) showed that CNT was successfully covered on the surface of PET. The results obtained from EK process showed that PET-CNT as a cathode obviously elevated electric current and electro-osmotic flow (EOF), significantly decreased kaolin pH, and enhanced heavy metals removal efficiencies. The removal efficiencies of Cd, Cu, Ni, Pb, and Zn in PET-CNT treatment were 89.7%, 63.6%, 90.7%, 19.2%, and 88.7%, respectively. In comparison with the Pt/Ti and graphite treatments, the removal efficiencies of Cd, Ni, and Zn were improved at least about 30%, Cu and Pb were improved at least 16.6% and 6.9%, respectively. Our results demonstrated the PET-CNT was a good alternative cathode material for enhancing efficiency of EK remediation.

Similarities and Differences in Structure Formation Processes in Polyester Yarns During Orientational Drawing and High-Speed Spinning. Review

We demonstrate the similarities and differences between formation of structural and mechanical properties of polyethylene terephthalate (PET) yarns during drawing and during high-speed spinning (HSS). The orientational drawing process enables a targeted change in structural and mechanical properties of PET yarns. In high-speed spinning, a targeted change in the properties of the yarns to the level attainable in orientational drawing is not possible due to the non-isothermal nature of the process. Studies have shown that the structure formation conditions for the indicated processes need to match better in order to develop an optimized one-step process for obtaining PET textile yarns.

Moisture and thermal permeability of the hollow textured PET imbedded woven fabrics for high emotional garments

This study examined the effects of the total porosity, pore size, and cover factor on the moisture and thermal permeability of woven fabrics made from DTY (draw textured yarns) and ATY (air jet textured yarns) composite yarns with hollow PET (polyethylene terephthalate) yarns. The wicking of the hollow composite yarn fabrics was found to be superior to that of the high twisted yarn fabrics, which may be due to the high porosity in the hollow composites yarns, but this was not related to the cover factor. The drying characteristics of the hollow composite yarn fabric with high porosity were inferior compared to the high twisted yarn fabrics due to the large amounts of liquid water in the large pores, which resulted in a longer drying time of the fabric. The thermal conductivity of the hollow composite yarn fabrics decreased with increasing measured pore diameter due to the bulky yarn structure. The effects of the hollowness of the yarn on the thermal conductivity were more dominant than those of the yarn structural parameters. The air permeability increased with increasing measured pore diameter but the effects of the cover factor on the air permeability were not observed in the hollow composite yarn fabrics. The effects of porosity on the moisture and thermal permeability of the woven fabrics made from the hollow composite filaments were found to be critical, i.e., wicking and air permeability increase with increasing porosity. In addition, the drying rate increased with increasing porosity and the thermal conductivity decreased with increasing pore diameter, but were independent of the cover factor.

Polyester fabric with inherent antibacterial, hydrophilic and UV protection properties

Polyethylene terephthalate (PET) yarn with multifunctional properties such as UV protection, antimicrobial property and cotton-like moisture transport properties was fabricated in a semi-commercial melt spinning machine. Effects of chemical modifications and additives on PET yarn with polyethylene glycol (PEG) and zinc oxide (ZnO) were studied and reported. It was found that ZnO imparts UV protection and antimicrobial properties and PEG helps to improve moisture management. Bacteriostatic activity above 3.5 was observed with ZnO incorporation. High wicking length of 15 cm was obtained as against 2 cm for control PET fabric of same construction.

Embroidered electrode with silver/titanium coating for long-term ECG monitoring.

For the long-time monitoring of electrocardiograms, electrodes must be skin-friendly and non-irritating, but in addition they must deliver leads without artifacts even if the skin is dry and the body is moving. Today's adhesive conducting gel electrodes are not suitable for such applications. We have developed an embroidered textile electrode from polyethylene terephthalate yarn which is plasma-coated with silver for electrical conductivity and with an ultra-thin titanium layer on top for passivation. Two of these electrodes are embedded into a breast belt. They are moisturized with a very low amount of water vapor from an integrated reservoir. The combination of silver, titanium and water vapor results in an excellent electrode chemistry. With this belt the long-time monitoring of electrocardiography (ECG) is possible at rest as well as when the patient is moving.