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Chemically recycled polyester fibers consisting of a core and sheath layer were used to produce nonwoven fabrics for ecofriendly automotive interiors. The density and thermal shrinkage of the recycled polyester nonwoven fabrics were higher than in virgin polyester nonwoven fabrics, irrespective of the heat-setting temperature and time, but the air permeability was lower. The wicking property of the recycled polyester nonwoven fabrics decreased significantly above 180℃. The tensile stress and modulus of the recycled polyester nonwoven fabrics increased gradually with increasing heat-setting temperature. However, the strain at maximum stress of the recycled polyester nonwoven fabrics decreased rapidly. The abrasion strength of the recycled polyester nonwoven fabrics improved above a heat-setting temperature of 200℃. The impact strength of the recycled polyester nonwoven fabrics was higher than that of virgin polyester nonwoven fabrics. As the heat-setting temperatures used for the nonwoven fabrics were higher than the melting temperature of chemically recycled and virgin polyester fibers, thermal bonding occurred between fibers. The lightness of the recycled polyester nonwoven fabrics decreased with increased heat-setting temperature and time. The recycled polyester nonwoven fabrics also showed slight yellowing. The thermal bonding between the fibers in the recycled polyester nonwoven fabrics was generated at a lower heat-setting temperature than for virgin polyester nonwoven fabrics, and therefore it is considered that under more relaxed heat treatment conditions, the recycled polyester nonwoven fabrics would show a performance similar to that of the virgin ones.

This study was performed in order to investigate the effects of tandem and conventional vacuum steaming on the physical properties of 100% cotton and 100% viscose yarns. The yarns with different twisting coefficients and numbers were twisted and exposed to tandem and conventional vacuum steaming at different temperatures. Tenacity, unevenness, hairiness, twist liveliness, package hardness values, and spirality of knitted fabrics produced from these yarns were measured before and after vacuum steaming. The results obtained were assessed by means of COSTAT statistical analysis program. Variation analysis and SNK test were carried out at 5% (0.05) level of significance. The findings of this study indicate that the effects of vacuum steaming methods on the tenacity, unevenness, hairiness, twist liveliness and package hardness values of yarns are statistically significant. Although the effects of tandem vacuum steaming vary depending on the temperature applied and the raw material used, decreases are observed in unevenness, hairiness, twist liveliness and package hardness values of yarns. Apolteks Textil San. Tic. A.Ş Epiriler Textil San. Tic. A.Ş

In this study, the effect of vacuum steaming temperature and time on the physical properties of polyamide (PA) 6 yarns has been investigated. Also, the effect of vacuum steaming temperature and time on twist liveliness and package hardness of PA 6 yarns has been studied and the results obtained have been evaluated using statistical methods. Further, the effect of vacuum steaming on dyeability properties of PA 6 yarns has been examined and the effect of vacuum steaming temperature and time on dye absorption properties of PA 6 yarns has been analyzed. As a result of this study, it has been seen that vacuum steaming temperature and time have significant effects on the tenacity properties, twist liveliness, package hardness, and dyeability properties of PA 6 yarns.

In this study, PA 66 and PA 6 fibers are heat set at temperatures between 25 and 200°C. Fractional recovery ( f) depends on heat setting temperatures and crystallinity, which provides partial crosslinking that delays the onset of the flow regime and increases the time constant of relaxation at a given temperature. Mechanical properties are examined with an Instron tensile tester, and the effect of heat setting temperatures on mechanical properties is correlated with crystallinity changes. The terminal modulus and extension at break show a direct correlation with crystallinity, while there is no noticeable effect on initial modulus with crystallinity changes.

Moulding is a method of inducing a permanent three-dimensional shape in ther moplastic materials by heat setting. Using polyurethane foam moulding for brassiere pads as an example, the most essential problem is to predict the optimum conditions that result in the best cup shape conformity with the most efficient use of heat energy. To study the best moulding quality, a response surface method is used to examine the relationship between a measured response (shape conformity) and a number of input variables (moulding temperature and time). The optimum moulding conditions for individual foam types can be found by examining the contour plots of response sur faces. A relationship between the moulding temperature and time is then derived. The heat energy required for optimum moulding can be expressed in terms of these two moulding variables and three other foam attributes ( mass, specific heat, and thermal conductivity).

This study of single-jersey knit fabrics is the first to examine the basic properties of staple-core knits. Prior studies revealed certain functional and aesthetic advantages of woven staple-core fabrics when compared to 100% cotton or intimate-blend fabrics of the same construction. In this study, nominal 20s count staple-core yams have been spun on a ring spinning frame that incorporates patented modifications. The staple-core yams contain a high tenacity polyester core and a cotton sheath comprising two-thirds of the yam. The fabrics are knitted on a single-feed jersey knitter with a 88.9 mm (3.5-inch) diameter, 20-gauge cylinder. Fabric properties are examined after five home-laundering cycles, in the greige state, after scouring, and after scouring and heat setting. The staple-core knits are stronger, less permeable, and significantly more abrasion resistant than the cotton controls. They also show less differential shrinkage and look consistently better than the controls after laundering. Greater spirality is evident in the greige staple-core knits than in the cotton knits, but the skewness of all fabrics decreases with additional processing. Skewness is substantially eliminated by substituting S- for Z-twist staple-core yam. Relaxed S-twist staple-core fabrics are also denser and greatly more abrasion resistant than comparable Z-twist knits. This suggests that a reduction of yam torque might further improve the superior properties and performance of staple-core knits. Additional study is required to optimize heat setting procedures and provide meaningful discussion of the dimensional stability of staple- core knit fabrics.

This work investigates the degree and stability of flat set for a series of plain weft knitted structures made from ring and rotor spun yams produced from cotton, poly ester, and polyester blends. While the flat set of cotton fabrics shows more or less similar values following bleaching and dyeing, for polyester fabrics a lower value follows scouring and heat setting. Of the various methods used to study the degree of flat set, curling couple merits consideration in view of its sensitivity.

Texturing conditions were systematically adjusted in a factorial experiment to create twenty-four yarn items that varied in their respective bulk levels. Following a heat- setting treatment by one of three methods (one dry, the Suessen at a tunnel temperature of 200°C, and two wet, the Superba at tunnel temperatures of 129.4°C and 137.8°C), each item was implanted as a triple tuftline into two carpet backgrounds that also differed in their respective levels of bulk. Forty-eight such implanted streaks from each heat-setting method—144 streaks in all—were then rated by shade and intensity and contrasted by method of heat setting. The relative intensity of the low-bulk dark streaks was worst for the Suessen-set treatment and best for those Superba-set at the higher temperature. Suessen heat setting enabled smaller bulk differences to be seen in the carpet.

Dynamic mechanical properties of commercial nylon, polyester and polypropylene carpet yarns are measured with a Rheovibron, and the tan δ] values are used as a measure of yarn resiliency. The effects of fiber drawing, fiber crimp, yarn structure, yam heat setting, and moisture on yarn resiliency and modulus as measured by the Rheovibron are investigated. In this exploratory study, dynamic mechanical mea surements on carpet pile yarns are compared with carpet appearance retention per formance. Rheovibron measurements of yarn resiliency may be related to carpet ap pearance retention during the initial stages of carpet walkout.

Poly (ethylene terephthalate) partially oriented yarn (PET POY) was heat set at 100 to 220°c in a fixed state and then treated with hydrazine. Although crystallinity of the heat-set PET POY increased with increased heat-setting temperature, weight loss from the hydrazine treatment initially decreased at a temperature up to 120°c and subsequently increased above 120°c. The hydrazinolyzed POY fiber is dyeable with acid dyes because of the hydrazide groups incorporated by hydrazinolysis. Nitrogen content and dye exhaustion with CI acid orange 7 showed trends similar to the weight loss of the hydrazinolyzed POY fibers. On the other hand, the dyeability of the hydrazinolyzed POY fibers with CI disperse violet 1 was lower than that of the untreated fibers. Many cracks appeared on the surface of the hydrazinolyzed fibers, and they were smallest on the fibers that were heat set at 120°c.

The effects of dry heat setting conditions on streaks in finished carpets made from nylon 66 staple yams are considered. Two different polymers were subjected to con trolled variation in heat-set temperature, residence time, and chamber steam pressure on a Suessen machine according to a factorial design. Yarns from some of the items were made into finished carpets, and other items were implanted into these carpets using two adjacent creel positions. Streak intensity grades were assigned to these im plants, and then an empirical model was fit to the data relating streak intensity to the differences between the background and implant items in heat setting conditions. Streaks caused by variation in heat setting conditions are associated with differences in dye uptake rather than with physical or textural differences between tuftlines. If the Suessen is operated at a nominal temperature of 200°C, then surprisingly large dif ferences in heat setting conditions are required in order to cause an objectionable streak. Furthermore, the effect of heat-set temperature differences on carpet streaks depends on the dyeing system used. For a continuous dyeing system, which has a dye uptake minimum at 200°C, any tuftline-to-tuftline heat-set temperature variation from 200°C causes dark streaks. On the other hand, the Beck system has a linear rather than a U-shaped dye response to heat-set temperature, and increases considerably above 200°C cause light streaks when that tuftline is implanted within a group of tuftlines having experienced a 200°C temperature.

Plain and twill weave fabrics produced with unique 67/33 cotton covered, high tenacity polyester staple-core yams in the warp and filling directions were appropriately finished without difficulty. The greige fabrics were desized, heat set, bleached, union dyed, and treated with different levels of dimethyloldihydroxyethyleneurea (DMDHEU) resin finish to assess the effect on important properties, including durable press rating, wrinkle recovery angle, dimensional stability, Stoll flex abrasion resistance, pilling resistance, breaking strength, and tearing strength. The test results show that the staple-core-yam fabrics attain satisfactory durable press and dimensional stability after an ordinary process of heat setting at 190°C for 65 seconds. DMDHEU resin slightly improves the durable press rating and wrinkle recovery angles, but more resin does not necessarily improve the properties proportionally; resin as low as 1% in solution gives acceptable DP results and improves pilling resistance. The DMDHEU resin finish diminishes flex abrasion resistance, breaking strength, and tearing strength, but the deterioration is much less than with similar 100% cotton fabrics. The breaking and tearing strengths remain especially high.

Experiments were carried out on monofilaments to determine the role of the magnitude and mode of deformation on heat setting efficiency of nylon 66 and polyester. In single mode deformations, setting efficiencies increased consistently as the temperature and the magnitude of that single imposed deformation were raised. In double and triple mode deformations, however, an increase in level of imposed strain (in any single mode) generally led to an increased residual heat set in one mode, but decreased set on the other mode. The nylon 66 monofilaments evidenced significantly higher twist setting efficiency (often exceeding 100%) than did the polyester specimens. On the other hand, the polyester bend setting was significantly greater than that of the nylon.

The structural changes on heat-setting and friction-twisted texturing of commercial nylon 6 multifilament yarn have been studied over a range of heater temperature and heater-contact time. Both heat-setting and texturing result in increase of crystalline content and decrease of crystallite orientation. The changes in these structural parameters, when plotted as functions of heater temperature and heater-contact time, show important differences. An attempt is made to explain the temperature- and time-dependence of the structural changes. The likely effect of these structural changes on some mechanical properties is discussed.

A study has been made of the in service fading of a numher of blue anthraquinone dyes on nylon carpot yarns before and after heat setting. Samples were exposed to indoor and outdoor atmospheres in various parts of the U. S. A. The importance of the atmospheric humidity and temperature in the fading, suggested by laboratory testing, was confirmed. The laboratory test was shown to rank dye/fiber combinations in order of resistance to fading, and such a ranking was reproduced in the fading of samples exposed outside the houses. Inside the houses the laboratory ranking was less accu rate, illustrating the difficulties of using laboratory tests to predict the service life of a dyed nylon carpet.

Longitudinal swelling in water of nylon 66 multifilament yarn and fabric has been measured before and after heat setting. It is shown that relatively large increases in longitudinal swelling of the nylon occur as a result of setting. The swelling produced is to a large extent of reversible nature, which results in considerable stresses being produced in heat-set specimens dried at constant extension.

Anionic modified and normal poly(ethylene terephthalate) yarns were heat set at temperatures from 100 to 220°C and times from 3.75 to 45 seconds. Tensile properties, critical dissolution times, and dye sorption of these yarns were examined as a function of time and temperature of heat stabilization. Melting behavior (DSC thermograms), thermal stress, and critical dissolution times vary as a function of time and temperature of heat setting in the same way for both cationic dyeable and normal PET yams.

Knitting machine settings and their effect on fabric distortion are examined, and this information is related to finishing procedures involving heat setting and chemical finishing systems. Experiments with a cotton/polyester double knit show that acceptable shrinkage values can be achieved by a combination of careful yarn selection and controlled knitting and finishing procedures.

A study has been made of the in service fading of a numher of blue anthraquinone dyes on nylon carpot yarns before and after heat setting. Samples were exposed to indoor and outdoor atmospheres in various parts of the U. S. A. The importance of the atmospheric humidity and temperature in the fading, suggested by laboratory testing, was confirmed. The laboratory test was shown to rank dye/fiber combinations in order of resistance to fading, and such a ranking was reproduced in the fading of samples exposed outside the houses. Inside the houses the laboratory ranking was less accu rate, illustrating the difficulties of using laboratory tests to predict the service life of a dyed nylon carpet.

Using the method of resolving overlapping peaks, wide angle x-ray scattering data for relaxed heat set poly(ethylene terephthalate) (PET) filaments were analyzed and the characteristic parameters of some main crystal peaks were obtained precisely. The relative lattice strains of the filaments treated at different heat setting temperatures were thus determined. With the help of a thermomechanical analyzer, the thermal shrinkage stresses were also measured. Analysis of these experimental results indicated that the crystal structure of polymer fibers differs from that of low molecular weight substances, in that the unit cell parameters of the former are much more influenced by the internal stresses left in the fiber during the heat setting of the drawn polymer fibers. The series model is suitable for explaining these phenomena.

It is shown in this paper that protein and cellulosic fibers can be heat set at tempera tures above 100° C and moisture regains varying from that corresponding to 65% RH to the saturated value providing the moisture regain is kept constant during the treatment. No chemicals need to be added before or during the treatment.

Progress in developing cotton fabrics having high recoverable stretch, durable loft, warmth, and other highly desirable properties is reported. Three general methods for making stretch and bulked cotton yarns and fabrics are described: (i) use of cross- linking agents to set or maintain crimp in cotton yarn; (ii) slack mercerization of cotton fabrics to cause shrinkage; and (iii) the crimping and heat setting of thermoplastic cotton yarns (ethers and esters of cotton cellulose). The first method employs the chemical reactions of the type widely used by industry in manufacturing wash-wear products. Stretch and bulked cottons might present opportunities equal to those already provided by wash-wear products.

Polyvinyl alcohol applied to cotton/polyester fabrics was dried, then heat-set using temperatures ranging from 95 to 165°C. The samples were washed in water baths ranging in temperature from 45 to 85°C. Measurements of the amount of size removed during washing showed that the heat-setting temperature altered the ease of removal. Insight into the film structure of PVA which has been heat-set was gained using differential thermal analysis.