Introduction


Quality is of prime importance for every industry or business, to get increased sales and better name amongst Consumers & fellow Companies. Generally Quality control Standards for export are set strictly, as this business also holds the prestige of the country, whose company is doing the export. Quality standards like ASTM, AATCC, BS, DIN and JIS & ISO must be recognized and agreed by all levels of management. However quality expectations for exports are related to the type of customer segments and the retail outlets. For textile and apparel industry product quality is calculated in terms of quality and standard of fibers, yarns, fabric construction, colours fastness, Surface designs and the final finished garments products. The present paper was aimed at investigating the important testing parameters for the textile products and the steps to be taken to improve these testing parameters.


Different testing parameters:


  1. Tensile Strength
  2. Tear Strength
  3. Seam Properties
  4. Pilling
  5. Color fastness to light


a) Tensile Strength


It is the strength of the fabric which denotes the breaking force required to rupture the fabric. A tensile tester is used to determine the strength in which central part of the width of the specimen is gripped in the clamps. It determines the effective strength of the specified width with the assistance of adjacent yarns. Fabric assistance depends on type of fabric & construction variables.


Recommendation for Improvement:


Tensile strength is a property that cannot be improved once a fabric is produced. For future production, a higher thread count or the use of stronger yarns should result in a fabric with better tensile strength properties.


b) Tearing Strength


The tear force required to propagate a single-rip tear of defined length from a cut in the fabric when a sudden force is applied. This test is performed by measuring the work done in tearing the fabric through a fixed distance on the tearing strength tester. This test is mainly applicable for woven fabrics not for knitted fabrics.


Reasons for poor tear strength:


Basically the yarn is weak; hence the fabric constructed with such yarns will produce a weak fabric with less strength. In rare cases during various treatments the fabric may become weak.


Recommendation for Improvement:


Tearing strength is a property that cannot be improved once a fabric is produced. For future production, yarns with longer fiber length and higher twist may result in higher tear strength properties. Since the core of the fabric is having problem there are no definite remedies to improve upon. Marginal improvements may be possible with washing or some treatment


c) Seam Properties


To determine the seam maximum force of sewn seams when the force is applied perpendicularly to the seam. The test applies to the standard seam applied to fabric samples or the Production seam as received in finished garments. The major contributors to seam strength are fabric type and weight, thread type and size, stitch and seam construction, stitches per inch and stitch balance. Seam Strength in woven and knit is same as fabric breaking and bursting strength respectively.


 

Reasons for poor Seam Properties:


The slippage of yarns in the fabric along a seam when stress is applied. The result is that the yarns pull out but the thread and the stitch doesn't rupture. Seam slippage is usually caused by poor fabric design (too loose of a weave) or too narrow of a seam margin. Not using enough stitches per inch and a poor stitch balance can also contribute to seam slippage.


Recommendation for Improvement:


If the fabric construction or weave is loose then drastic improvements are difficult. Seam Slippage can be marginally improved by increasing the SPI (Stitches per Inch) and Seam margin. If it is failing by Single needle stitch, then can try with Double needle stitch.


d) Pilling Resistance:


Pilling is the serious problem of the textile industry. A finished fabric may have pleasing handle and smooth surface but when converted into garment and while wearing and as well as washing pills are formed due to rubbing action. First entanglement of loose fibres which protrude from the surface takes place; this further appears like a ball anchored to the fabric surface through unbroken fibre.


Recommendation for Improvement:


Selection of fibres: Manufacturing of yarn and fabric based on low pilling tendencies. Prevention of abrasion during batch processing by using suitable lubricant in pretreatment as well as in dyeing process. Shearing and cropping with brushing to eliminate the surface fibre and protruding fibres Singeing on both surface to remove surface fibres


e) Colorfastness to Light:


It is the resistance to degradation of fabric dyes and prints due to light is an important requirement of a garment because without such resistance, the garment may change colour and such colour may not be acceptable to a consumer from an aesthetic point of view. The samples are placed in special holders and exposed to artificial daylight produced by a special light source which mimics the action of sunlight, but in a more intense manner so as to speed up the fading effect. A standard (blue wool reference) is also exposed with the sample and the colourfastness is being assessed by comparison of the colour change of the exposed portion to the unexposed portion of the test specimen using scale or blue references used.


Recommendation for Improvement;


Here regarding the color fastness to Light, there are certain controllable and uncontrollable factors. Uncontrollable factors are Light, Environmental factors such as temperature and relative humidity and controllable factors are Chemical reaction of fading reaction, Degree of dye association with the fiber, Diffusion characteristics of fibers, chemical nature of fibers, Contaminans, Delustrants, UV stabilizers and finishes. Thus by improving certain processing conditions and by using Good type of Stabilizers and finishes will improve the light fastness.


Acknowledgement: The authors would like to express profound gratitude to the management of the SGS India Private LTD., Gurgaon.


References:


  1. Testing and Quality Management, Vol 1 by Dr. V.K. Kothari.
  2. Textile: Causes and remedies by Dr. Naresh M.Saraf and Deepak V. Alat of Sarex form International Dyers.
  3. A Handbook on Light fastness testing of textile by Mr. Jayakumar Gopal Krishnan, Manager Technical Resource.


About the Authors:


The authors are associated with SGS INDIA Pvt. Ltd, Gurgaon, Harayana.