Science of Denim

Sample is a product which represents a group of product or lot or batch, in order to assess their quality, style or design or any other characteristic of the product. Based on the samples, the buyer will give approval or comments for any alteration in design or style or quality. Samples will reflect the quality and workmanship of the exporter or manufacturer. Samples are made to make sure to get a desired style design or fit and good quality in the particular order.           Samples may be made before start of the production or can be taken from the finished goods. For every order or style, separate samples are to be made. Samples help in to procure or get the orders from the buyer. In a particular order, samples are made at different stages to make sure that all parameters are maintained properly. A good sample will make good first impression to the buyer on the exporter or manufacturer. Special care should be taken while making the samples. Types           In apparel m

Can you please briefly explain about Red Seal sample? A sample with red tag is an identification of a sample that buyer had approved and sealed that particular sample for production. A sealed sample means approved garment construction, approved trims attached to the garment. Receiving a Red tag sample from buyer is the approval for production go ahead to the factory. Buyers attach colored tags to approved samples and send back to the suppliers. Buyer uses different color tags for different sample type, like Green tag is used for Size set samples and Red Tag is used for PP samples (Pre-Production sample). Once attached these tags can not be removed easily from the sample garment. Sealed sample with Red Tag Tag is  attached to a sample (some buyers also include comment sheets) so that suppliers can not replace sealed sample or can not show any other garments as a approved sample. Tags are attached to sample to ensure that no unapproved sample is referred in production. Secondl

There are three broad classes of samples, one for each phase. These sequential phases are design, sales and production. Design related samples are to model design ideas and (ideally) finalize the pattern for production. Sales related samples are used to predict orders from buyers. The last type of samples are intended to test consistency in production. Technically (and optimally) speaking, all sampling should take place during the first phase of design (R&D) because you can’t get to selling (second phase) if you don’t have production (third phase) lined up. I’m aware practices are all over the map these days but I have tried to cover every contingency. This list may be overwhelming because I’ve attempted to be all inclusive but it does not mean you will need to have all of these kinds of samples produced. There is also quite a bit of overlap depending on your operation.  By way of example are fit samples. If you’re managing your product development and having samples ma

Definition           Sample is a product which represents a group of product or lot or batch, in order to assess their quality, style or design or any other characteristic of the product. Based on the samples, the buyer will give approval or comments for any alteration in design or style or quality. Samples will reflect the quality and workmanship of the exporter or manufacturer. Samples are made to make sure to get a desired style design or fit and good quality in the particular order.           Samples may be made before start of the production or can be taken from the finished goods. For every order or style, separate samples are to be made. Samples help in to procure or get the orders from the buyer. In a particular order, samples are made at different stages to make sure that all parameters are maintained properly. A good sample will make good first impression to the buyer on the exporter or manufacturer. Special care should be taken while making the samples. Types      

Development Sample: Which sample make by available fabric & accessories and send to buyer to collect order from the buyer that is called development sample. Fit sample: Medium or large size have to send buyer for checking fits of dummy that is called fit sample Pr-production sample (PP Sample): which sample make by actual fabric & accessories and send to buyer for final approval to start production. Lab test: Which sample make by actual fabric & accessories and send to local laboratory (Buyer Nominated) to check fabric structure such as-GSM, Color fastness, Rubbing, Shrinkage, printing,& embroidery. Size set sample: send to local buying house all size sample made by according to order, style & color& get them approved from buying house Counter sample: To reserved with pattern for future order from buyer that is called counter sample Production sample: First production garment will be send buyer for buyer satisfaction. Shipment sample: according t

It is most basic wash for denim garment. Such type of wash is also used in dyeing frequently. To clean dyeing machine rinse wash also used. Typically named, Dark Wash, the only purpose of this wash is to make the garment wearable. During the construction of denim fabric, starch is applied to strengthen the Warp. This makes the fabric pretty stiff and harsh to skin. In rinse wash the garment is desized and some softening agent is applied to improve the hand feel of garment. In some cases Potassium Permanganate is applied on blasted area with spray gun of paint brush. This is commonly used where the fading effect is desired to high intensity. Rinse Washed Jeans Purpose of Rinse Wash: The main reason to rinse jeans before wearing them is that they simply will last longer, as starch (and chemicals) is removed. This softens the fabric. The purposes of rinse wash are Rinse wash is required for the following reasons: To remove dust, dirt, oil spot, impurities from the garments To r

LYCRA® is a man-made elastic fibre invented and produced only by DuPont . It is INVISTA's trademark for a synthetic fabric material with elastic properties of the sort known generically as "spandex". Lycra is commonly used in athletic or active clothing. Lycra as a clothing material is fetishized by some people, perhaps on the basis that the garment forms a "second skin" that acts as a fetishistic surrogate for the wearer's own skin. This is known as lycra fetishism. Lycra is normally one of the fabrics in leggings. Lycra Yarn LYCRA can be stretched four to seven times its initial length, yet springs back to it’s original length once tension is released. While Lycra appears to be a single continuous thread, it is in reality a bundle of tiny filaments. Properties of Lycra Yarn: >Heat : Sticks at 350-390F. Melts above 500F. >Bleaches &Solvents : Good resistance to oxidizing agents. Poor resistance to bleaches. >Acids & Alkalis : Goo

Laboratory Tests The main purpose of laboratory tests is to obtain prior knowledge of the performance of textile products in service. The assumption is made that when such tests are carried out, there is some relationship between the results of the laboratory tests and the performance of the items in use. In order to design laboratory testing procedures that correlate with end use performance the conditions of actual use must be carefully analysed so that they can be simulated as closely as possible in a controlled setting. Since actual wear is such a complex phenomenon, however, laboratory tests are usually designed to evaluate only one or a limited number of variables at a time. Advantages of Laboratory Tests : 1. They are rapid. Most tests can be completed within a day. 2. They are designed to give objective results. A numerical result or rating allows one fabric to be ranked as being better or worse than another fabric even when the differences between them are small. 3. Th

Introduction: The GSM of fabric is one kind of specification of fabric which is very important for a textile engineer for understanding and production of fabric. ‘GSM’ means ‘Gram per square meter’ that is the weight of fabric in gram per one square meter. By this we can compare the fabrics in unit area which is heavier and which is lighter. Objectives: >To determine the GSM of the given samples of fabric. >To compare the GSM of them. Theory: The weight of a fabric can be expressed in two ways, either as the ‘weight per unit area’ or the ‘weight per unit length’; the former is self explanatory but the latter requires a little explanation because the weight of a unit length of fabric will obviously be affected by its width. In woven fabric, the weight per unit length is usually referred to as the ‘weight per running yard’. It is necessary therefore to know the agreed standard width upon which the weight per running yard is based. Usually this width depends upon the widt

Introduction: Sampling is one of the most important processes in garments industry which has a vital role in attracting the buyers. Normally buyers are placed an order after satisfying with the quality of samples. As its importance on garments industry, today I will discuss about the different kinds of sample used for completing an order. Different Types of Garments Samples Types of Samples Required for Completing a Garments Order: There are mainly eight types of sample needed for completing a garment order. Those ares- Proto sample, Fit sample, Size set sample, Counter sample, Salesman sample (SMS), Pre-production sample (PPS), Top over production sample (TOP), Shipment sample. All the above garments samples are discussed in the below: 1. Proto sample: It is the very first sample given into the buyer. It is prepared according to the buyer’s specification. It is a trial sample prepared on product development department. Buyer wants to see here that how its look

Introduction Yellowing of textile fabrics is one of the oldest and most widespread quality problems known. The yellowing can be seen directly in the case of market whites, pastel shades or even after-washed denims. However, shade change noticed in darker colored fabrics can often be attributed to chemical change or degradation of the fiber or some chemical agent either purposely applied to the fabric in finishing or inadvertently absorbed by the fabric in its storage and shipment to market or during its end use. As a general statement, yellowing of textile materials is an indication of unanticipated chemical degradation. Very often, as colorless chemicals decompose, they form light to moderate yellowish colors. Of course, if this chemical is a textile finish or additive or has been absorbed by a textile product, this color formation is noted as fabric or garment yellowing. It should also be noted that continued chemical decomposition could form moderate to dark brown colors or, in so

Hypochlorite Bleaching: Hypochlorites as bleaching agents are still popular despite the anti-chlorine lobby and environmental pressures. Some of these salts which are used for the bleaching of textiles are Calcium hypochlorite (Bleaching powder), Sodium hypochlorite, Lithium hypochlorite and chlorinated trisodium phosphate etc. Bleaching with Peroxide: Hydrogen peroxide was discovered in 1818 and its use in bleaching textiles was first suggested in 1866. However, its high cost limited its use in cotton bleaching until 1935. The problem was partially solved by the process using barium peroxide and phosphoric acid. In 1926 hydrogen peroxide was manufactured by an electrolytic process based on the decomposition of persulphuric acid (H2SOs). Advantages and Disadvantages of Peroxide over Hypochlorite Bleaching Advantages : 1. Peroxide is an universal bleaching agent and can be employed for wool, silk as well as cotton. It is specially suited to the bleaching of union fabrics cont

Bleaching: Textile Bleaching is chemical treatment employed for the removal of natural coloring matter from the substrate. The source of natural color is organic compounds with conjugated double bonds, by doing chemical bleaching the discoloration takes place by the breaking the chromophore, most likely destroying the one or more double bonds with in this conjugated system. The material appears whiter after the bleaching. Chemical Requirements in Bleaching Process: 1. The oxidation of the impurities and the coloring matters on the surface and in the lumen of the fibers has to be performed at a rate, which is much faster than the rate of the oxidation of the cellulose. The parameters of the bleaching process have to chosen so as to increase the difference between these two rates and to ensure the slowest possible rate of the cellulose oxidation such parameters are the pH, the concentration of the bleaching liquor, the liquor ratio, temperature and the presence of additives such as

Solvent Scouring: Solvent scouring is the treatments of fabrics in organic solvent medium to remove impurities such as lubricating oils and spin finishes. Certain organic solvents will readily dissolve oils fats and waxes and these solvents can be used to purify textiles. Removal of impurities by dissolution is called Extraction. Suitable Solvents: It is found that waxes are removed by solvents like chloroform, benzene, carbon tetra chloride etc. But those are not used industries because of their high cost and toxicity. Now a days widely used trichloro ethylene, perchloro ethylene etc. Solvent Properties: Boiling Point: Temperature at which solvent is converted from liquid to a gas. Specific Heat: The amount of energy needed to raise one gram of solvent one degree centigrade (Calories/gram/0C). Latent Heat of Evaporation: The amount of energy needed to vaporize one gram of solvent (Calories/gram). Solvent Scouring Process: There are commercial processes where textiles are

Sodium Chlorite(NaClO₂) Bleaching Process Sodium chlorite, anhydrous is in the form of slightly hygroscopic crystals or flakes, soluble in water.The hydrated material is in the triclinic leaflets. The chemical formula is NaClO2, and molecular weight is 90.45. The molecular weight of hydrated product is 144.5. Bleaching with Sodium Chlorite (NaClO₂) The sodium chlorite is available as a powder , and it is applied under strongly acidic conditions to textiles. Its application produce a toxic and corrosive gas. 1. Bleaching Mechanism Sodium Chlorite is an oxidant particularly adapt for synthetic fibre bleaching (polyamidic, acrylic, polyester) and cellulosic (man-made and natural, particularly for linen). Its oxidant action works thanks to Chlorine Dioxide which develops through an acidification process: therefore it is highly recommended to work with closed equipment and to furnish the bleaching departments with aspiration systems.A general guideline for bleaching bath at M:L=1:1

Hypochlorites are salts, chiefly important as powerful oxidizing and bleaching agents; not, however, when pure, but when containing chlorides. The chief hypochlorites, or at least the complex substances which contain hypochlorites, are bleaching-powder, and the bleach liquors made with potash and caustic soda/soda. Bleaching Powder Calcium hypochlorite is a chemical compound with formula Ca(ClO)2,Molecular weight: 143 .Calcium hypochlorite is usually a white or grayish-white powder free from lumps , contains about 35-37% active chlorine, but it is also available as tablets. It is a strong oxidizer and is considered more stable than sodium hypochlorite. It is also believed to provide more chlorine. Bleaching powder is partially soluble in water, the hypochlorite dissolving and being responsible for oxidizing and bleaching powers.Available chlorine is a measure of the oxidizing power of the hypochlorite ion. Chemical Properties of Bleaching Powder Reaction with Water Ca(OC)Cl

The ion exchange water softener is one of the most common tools of water treatment. Its function is to remove scale-forming calcium and magnesium ions from hard water. In many cases soluble iron (ferrous) can also be removed with softeners. A standard water softener has four major components: a resin tank, resin, a brine tank and a valve or controller. Ion exchange is an effective, versatile means of conditioning boiler feed water. The term “ion exchange” describes the process: as water flows through a bed of ion exchange material, undesirable ions are removed and replaced with less objectionable ones. For example, in softening processes, calcium and magnesium ions (hardness) are exchanged for sodium ions. In dealkalization, the ions contributing to alkalinity (carbonate, bicarbonate, etc.) are removed and replaced with chloride ions. Other dealkalization processes utilizing weak acid cation resin or strong acid cation resin in a split stream process, exchange cations with hydrog

Desizing: The purpose of a desizing process is to remove sizes that have been attached to warp yarns during a weaving process. Prior to the desizing process, therefore, the size analysis should be performed in order to set desizing conditions suitable for the sizes. Desizing Methods: Different methods of desizing are: A desizing method is selected on the basis of analysis of size , type of fabric , eco friendliness , ease of removal , cost of desizing and effluent treatment. Different methods of desizing are: 1. Enzymatic desizing 2. Oxidative desizing 3. Acid steeping 4. Rot steeping 5.Desizing with hot caustic soda treatment, and 6.;Hot washing with detergents The most commonly used methods for cotton are enzymatic desizing. This desizing process consists of three main steps: application of the enzyme, digestion of the starch and removal of the digestion products. The common components of an enzymatic desizing bath are as follows: >Amylase enzyme >pH stabilis