Adnan Mazari

Tensile Properties of Sewing Thread and Sewing Needle Temperature at Different Speed of Sewing Machine

Needle heatup is a big issue for apparel industry especially for automobile industry seat covers where a lot of synthetic materials are used which get damaged by needle heat at high speed of sewing machine,in this article thermocamera and thermocouple are used to measure the precise temperature of needle eye and then 100% polyester 35x3 Tex thread is taken for sewing,the lockstitch sewing machine is run at 1000rpm,2000rpm and 3000rpm respectively and the both methods are used to obtain the accurate needle temperature and finally thread tensile properties are measured before the sewing and taking out the thread from the seam precisely to get the tensile properties of thread after 10,30 and 60 seconds of continuous stitching,the article is very helpful in predicting the exact temperature of needle in lock stitch machine and getting the damage to thread by the needle heat at different speeds and different stages of sewing process.

Review: Radiation Heat Transfer Through Fire Fighter Protective Clothing

A fire fighter garment is multilayer protective clothing with an outer shell, moisture barrier and thermal barrier, respectively. Fire fighters encounter different levels of radiant heat flux while performing their duties. This review study acknowledges the importance and performance of fire fighter protective clothing when subjected to a low level of radiation heat flux as well as the influence of air gaps and their respective position on the thermal insulation behaviour of multilayer protective clothing. Thermal insulation plays a vital role in the thermal comfort and protective performance of fire fighter protective clothing (FFPC). The main emphasis of this study was to analyse the performance of FFPC under different levels of radiant heat flux and how the exposure time of fire fighters can be enhanced before acquiring burn injuries. The preliminary portion of this study deals with the modes of heat transportation within textile fabrics, the mechanism of thermal equilibrium of the human body and the thermal protective performance of firefighter protective clothing. The middle portion is concerned with thermal insulation and prediction of the physiological load of FFPC. The last section deals with numerical models of heat transmission through firefighter protective clothing assemblies and possible utility of aerogels and phase change materials (PCMs) for enhancing the thermal protective performance of FFPC.

Effect of Perforated Polyurethane Foam on Moisture Permeability for Car Seat Comfort

Polyurethane (PU) foams are the most essential part of a car seat cushion. PU foams are durable and easily moldable according to the shape of the car seat, but they are poorly permeable to moisture. This impermeability of PU foam causes wetness of the microclimate between the person and car seat and makes it uncomfortable. In this research PU foams with two different thicknesses and three different hole sizes were obtained from industry by the moulding process. The foams were tested for moisture permeability by the standard cup method to determine the effect of the size of the hole on the overall moisture permeability. The foams were further tested with 11 of the most common top layer fabrics to check the effect of the top fabric layer on the overall moisture permeability of the car seat. All the top layers were first tested by means of a sweating guarded hot plate (SGHP) to measure the water vapour resistance (Ret) and then 4 materials with the minimum Ret values were tested with the most permeable foam. The results shows that the perforation of PU foam causes a significant increase in moisture permeability, whereas the top layer with the minimum Ret value decreases the overall moisture permeability and a maximum of 40g/m2 of moisture per hour is obtained with the most permeable foam with the least Ret value of the top layer. This research is an initial work on replacing the car seat with perforated PU-foams.

Adsorption Kinetics of Acid Red on Activated Carbon Web Prepared from Acrylic Fibrous Waste

In this work, activated carbon (AC) web was prepared using physical activation under the layer of charcoal in high temperature furnace. The carbonization of acrylic fibrous waste was performed at different temperatures (800 °C, 1000 °C, and 1200 °C) with heating rate of 300 °C/h and at different holding time. At 1200 °C, the heating rate of 300 °C/h and no holding time provided better results of surface area as compared to carbonization at 800 °C and 1000 °C. The activated carbon web (AC) prepared at 1200 °C was used for removal of Acid Red 27 dye from aqueous media by varying different parameters like initial concentration of dye, stirring speed, adsorbent dosage, and pH. The results were evaluated using non-linear forms of Langmuir and Freundlich isotherms. The Freundlich isotherm was found to describe the results more effectively because of non-homogenous surface of activated carbon web. Further, the kinetics of adsorption was examined using linear and nonlinear forms of pseudo 1st order and pseudo 2nd order.

Liquid Moisture Transportation Properties of Functional Underwears: Part 1

Abstract This study investigates the effect of material composition on moisture management properties. Fiber type has significant influence on the moisture management properties of knitted fabrics. In this article, single jerseys knitted fabric samples with different yarn compositions were prepared. Liquid moisture transportation properties including wetting time, absorption rate, spreading speed, one-way transportation capability, and OMMC were evaluated by Moisture Management Tester (MMT) and vertical wicking was evaluated using thermography system and image analysis. Knitted sample having fine cotton yarns with coolmax and micro denier multifilament polypropylene showed best liquid transportation properties. There is a strong co-relation between OMMC and accumulative oneway transport index with vertical wicking of knitted samples.

Thermal Absorptivity Model of Knitted Rib Fabric and its Experimental Verification

Abstract Thermal absorptivity is an indicator of warm and cool feeling of textile materials. An equation based on thermal absorptivity of polyester in solid form, porosity of a fabric, and relative contact area of human skin and fabric surface has been developed to characterize thermal absorptivity of fabric. For verification of suggested model, 15 knitted rib fabrics were produced using 100% polyester yarn and having different surface profile. ALAMBETA semiautomatic non-destructive instrument has been used for measuring the effective thermal absorptivity of knitted rib fabric. It was found that the suggested simple theoretical model exhibits significant agreement with the measured thermal absorptivity values of knitted rib fabric, which endorsed the approach applied.

Development of V-Shaped Compression Socks on Conventional Socks Knitting Machine

Abstract The aim of this study was to develop V-shape compression socks that should exert graduated lateral compression around the leg. For the development of socks, three types of yarns: main yarn (MY), plaiting yarn (PY) and inlaid yarn (IY) were used. Each yarn contained spandex yarn as the core. Machine adjustments were optimized to achieve the special V-shaped compression socks according to size of the wooden leg. Eighteen socks samples were developed and quantified for pressure exertion at ankle and calf portions using the MST MKIV, Salzmann pressure measuring device. Consequently, only two socks samples were accepted, which had the pressure exertion values of 21 mmHg and 23 mmHg with graduation percentage of 73% and 80%, respectively.

Analyzing the effects of special washing processes on characteristics of sewing threads

Abstract In recent years, wet (washing, bleaching, etc.) and dry (abrasive, laser shaping, rodeo, etc.) operations applied on fashion denim products have become an important factor to increase the added value. However, these wet and dry processes applied to the denim products may have adverse effects on the strength of the fabric and other supplementary materials of denim products. For example, thread breakages affect the repair ratios and quality of products, which causes time and profitability losses in companies. The main objective of this study is to analyse how the types of washing affect the strength of the sewing threads that are commonly used in the production of denim trousers. In this study, 100% cotton denim fabric with a weight of 11.5 ounces and two different sewing threads were used. The fabrics are sewn as trouser legs with chain and lock stitch. Five different washes were applied to the trouser legs. The obtained data were evaluated in the R statistical program. As a result of the analyses made it is proven that the washing techniques used have an effect on the sewing threads’ tensile strength and elongation at break. The tensile strengths of lock stitch and chain stitch decrease averagely 35% and elongation at break of lock stitch decreases %22 and chain stitch decreases 29.8%.

Effect of a Superabsorbent for the Improvement of Car Seat Thermal Comfort

The use of super absorbent polymers (SAP) for moisture absorption and comfort is still unexplored. The aim of this work was to observe the application of super absorbent fibres in car seats for comfort purposes. In this research the efficiency of different SAP fibrous webs were determined under different moisture percentages to examine the sorption and desorption efficiency. A SAP fibrous web with low thickness and high moisture absorption were tested with a multilayer sandwich structure of a car seat cover to determine moisture absorption through the cover material. The standard Cup method was used to determine the moisture permeability of different car seat covers with a superabsorbent layer closed with impermeable polyurethane foam. It was observed that the SAP fibrous layers are very effective in absorbing and desorbing water vapour under extremely high and low moisture percentages. In extreme humid conditions (95%RH), 20g of the SAP layer absorbs nearly 70% of its weight in water vapour, reaching the maximum absorption capacity in 6 hours.

Prediction of needle heating in an industrial sewing machine

In industrial sewing, needle heating is a key problem that limits the further increase of sewing speed, and hence the productivity. Heat is generated during the sewing process because of friction between the needle and the sewing thread as well as between the needle and the fabric. The high temperature of the needle affects the quality and productivity of the sewing. The problem of needle temperature rise due to friction heat generation is considered in this paper and a simple analytical model is developed to predict needle temperature. The predicted needle temperature is compared with the experimental results by the inserted thermocouple method. Some of the process parameters, used as input variables, were also measured experimentally and experimentally observed values of needle temperature were compared with the theoretical prediction. It was observed that the temperature of the needle increases significantly with the presence of the sewing thread. Both the theory and the experimental results show that the needle temperature increases linearly with the machine speed within the ranges studied.