Introduction of Tie-Dye | How to Tie Dye on Fabric? | Procedure of TieDyeing

Tie-Dye

Tie-dye is a process of resist dyeing textiles or clothing which is made from knit or woven fabric, usually cotton; typically using bright colors. It is a modern version of traditional dyeing methods used in many cultures throughout the world. “Tie-dye” can also describe the resulting pattern or an item which features this pattern.

Why Tie?
The whole point of tie dyeing is to prevent the dye from reaching the fabric evenly. Any place that the dye can’t reach will stay white, or a lighter color, of course. The gradations of color from intense to light can be beautiful. You can accomplish this by folding the fabric, tieing it with string, using rubber bands, etc.

Another reason to tie is that it makes each garment of piece of cloth a small, neat bundle—much easier to handle if you have a lot to do. If you don’t tie, but just apply the dye directly, you need more space and can do fewer garments or pieces of fabric at a time.

Materials Needs for Tie-Dye: 

• Dyes – buy them at the craft store 
• White T-shirt or cotton material 
• Rubber bands 
• Plastic Bag  
• Plastic Tubs

How to Tie Dye?

Fold a piece of clothing in vertical pleats, and you’ll end up with horizontal stripes. Horizontal pleats result in vertical stripes (more slimming, you know). Diagonal pleats make a nice effect. Stitch a loose basting stitch in any shape you like, then pull the threads tight for another form of tie-dyeing that can have really cool results. For concentric circles, grab the cloth where you want the center to be, and pull, until you’ve more or less made a long tube of the garment, then apply rubber bands at intervals along the fabric. I also like the “scrunch” pattern, made by crumpling the fabric very evenly, so that ultimately it makes a nice flat disk when held with rubber bands. 

Tie-dyed Fabric

Tie dye procedure are given below as shortly:
1) Roll up t-shirt or cotton material in any type of design using rubber bands to hold it in place
2) Prepare dyes in buckets.
3) Dip the first rubber band section in one of your dye colors
4) Continue dying the shirt until you run out of white sections.
5) Place the tshirt in a ziplock bag and let sit for 24 hours
6) Remove rubber bands and hang dry
7) Wash with cold saltwater and check out your new GROOVY creation!!

What is Import? | Terms of Import | Types of Import | Types ofImporters | Requirements To Import Textile Goods From Abroad

Import

Normally import means bring (goods or services) into a country from abroad for sale.The term import is derived from the conceptual meaning as to bring in the goods and services into the port of a country. The buyer of such goods and services is referred to an importer who is based in the country of import whereas the overseas based seller is referred to as an exporter.Thus an import is any good (e.g. garments) or service brought in from one country to another country in a legitimate fashion, typically for use in trade. It is a good that is brought in from another country for sale.Import goods or services are provided to domestic consumers by foreign producers. An import in the receiving country is an export to the sending country.

This is an important subject and should be handled with extreme care and caution. It is advisable that before finalising the terms of Import Order, you should call for the samples or catalogue and other relevant literatures and the specification of the items to be imported. Once you are satisfied with the samples and the creditworthiness of the overseas supplier, you can proceed to finalise the term of the contract to be entered into. For this purpose, the Import Contract should be carefully and comprehensively drafted incorporating therein precise terms, all relevant conditions of the trade deal. There should not be any ambiguity regarding the exact specifications of the goods and terms of the purchase including import price, mode of payment, type of packaging, port of shipment, delivery schedule, etc.

Types of Import
There are two basic types of import:

1. Industrial and consumer goods
2. Intermediate goods and services

Companies import goods and services to supply to the domestic market at a cheaper price and better quality than competing goods manufactured in the domestic market. Companies import products that are not available in the local market.

Types of Importers

• Looking for any product around the world to import and sell.
• Looking for foreign sourcing to get their products at the cheapest price.
• Using foreign sourcing as part of their global supply chain.

Direct Import
Direct-import refers to a type of business importation involving a major retailer (e.g. Wal-Mart) and an overseas manufacturer. A retailer typically purchases products designed by local companies that can be manufactured overseas.

Indirect Import
In a direct-import program, the retailer bypasses the local supplier (colloquial middle-man) and buys the final product directly from the manufacturer, possibly saving in added costs. This type of business is fairly recent and follows the trends of the global economy.

Requirements To Import Textile Goods From Abroad

1. Product, Standards and specifications.
2. Import Quantity
3. Import Inspection
4. Total Contract Value
5. Terms of Delivery
6. Import Taxe, Import Duty and Charges payable at Exporting Country and payable in India on importation.
7. Period of Delivery/Shipment.
8. Import Packing, Import Labelling and Import Marking.
9. Terms of Payment-Amount, Import Mode & Currency.
10. Import Discount and Import Commission
11. Import License and Import Permit
12. Import Insurance.
13. Documentary Requirements.
14. Import Guarantee.
15. Force Majeure or Excuse for Non-performance of Contract.
16. Remedies
17. Arbitration

Introduction of Calendering Finishing | Working Process of CalenderingFinishing

Calendering
Calendering is a mechanical finishing process used on cloth where fabric is folded in half and passed under rollers at high temperatures and pressures. Calendering is used on fabrics such as moire to produce its watered effect and also on cambric and some types of sateens.

Calendaring is a high speed ironing process that primarily imparts lustre and is usually the final treatment for the fabrics in the finishing sequence. The basic principle of calendaring is to expose the cloth to the combined effect of moisture, heat and pressure until the fabric acquires a very smooth and light reflecting surface and gets a good lustre. The calendaring effect on the fabric is usually temporary and disappears after first washing. Semi permanent lustre is sometimes achieved by padding fabric in a sparingly soluble polyvinyl acetate emulsion before calendaring, where the solution acts as a binding agent. More permanent finish can be obtained by treating fabric with a solution of crease recovery reagent, followed by drying, calendaring and curing the fabric at about 150 ºC. The calendars are basically an assembly of heavy rolls, alternatively of iron and paper or cotton that are normally mounted in vertical frames. The rolls are bearing one on the other under a high pressure that is applied by compound levers or hydraulic or pneumatic equipment. 

Calendering

Paper or cotton rolls are made by compressing sheets of paper and cotton under heavy pressure of hundreds of tons and then finely turned to produce a smooth surface. The iron rolls are also called chilled rolls because these are hardened by sudden chilling of the red-hot rolls. These are hollow so as to allow passage of steam or sometimes gas-fire to heat these to different temperatures. 

Nipco-Flex Calender
The pressure application concept of this calender is different from the conventional calendering system. The pressing roller consists of a rotating shell that is covered with a highly elastic plastic material named as RACOLAN. The roller has fixed axels on which hydrostatic support elements are mounted that press the racolan shell against either steel or a cotton/paper roller. The hydrostatic pressure is applied with oil and is adjustable according to width of the cloth. The NIPCO roller can be arranged in vertical position or in L shape with a hot steel roller at top and a cotton bowl in front of it.

The main advantages of NIPCO calender over a conventional calender are;
1. Attainment of very high pressure.
2. Adjustment of pressure line according to width of cloth.
3. No over load at the fabric selvedge.
4. Easy installation and removal of the rollers.

Felt Calender
Felt calenders are mainly used for imparting lustre and smoothness to silk, rayon and cotton knitwear materials. These work at low pressure and temperature than used for cotton. The cloth is pressed between an endless felt blanket and a hot steel cylinder at a speed of 20 to 40 meters/minutes. By adjusting speeds of the feed and take up rollers the tubular knitwear can be compacted to some extent on this calender.

Introduction of Pressing Fastness Test | Color Fastness to Pressing

Color Fastness to Pressing:
Pressing fastness test of dyed and printed textile products is performed to determine of resistance of textiles to ironing and to processing on cylinders. Different tests are performed according to when the textile is dry, when it is wet, and when it is damp. 

Purpose and Scope:
This method is used for determining the resistance of the colour of textile of all kinds and in all forms to ironing and processing on hot cylinders. Tests are given for hot pressing when the textiles are wet, when it is damp, and when it is dry.

Apparatus and Reagent  

• Hand iron of proper weight to give a pressure of approximately 30g/sq.cm at the temperature indicated in the following ;

1. Cotton & Linen 190-200C˚
2. Wool, Silk & Viscose 140-160C˚
3. Cellulose acetate & Polyamide 115-120C˚

• White bleached cotton cloth weighting approximately 125g/sq.meter. Five pieces not less than 14×4 cm are required. 
• Gray scale by assessing change in colour and staining.(ISO scale)  
• The size of the specimen is 10×4cm

Working Procedure
Specimen preparation
Specimen of materials, which has been subjected to any heat or drying treatment, must be allowed to condition at 65% RH, temp. 20±2C˚, before they tested.

Dry Pressing
Place the specimen on the piece of dry cotton cloth on a smooth horizontal surface. Place the iron on the specimen and leave it for 15 Sec.

Damp Pressing: 

The adjacent fabric in dimensions of 100 mm x 40 mm is immersed into the water and, squeezed as 100% pick up. Dry specimen is placed onto the undyed cotton fabric on the filler and, the wet adjacent fabric is placed onto them. The top layer of the device is pulled down and, dry specimen is pressed for 15 seconds at the determined temperature. The change in color of the specimen is evaluated in two different ways according to grey scale.

a) Soon after the end of the test
b) After conditioning for 4 hours under standard atmospheric circumstances.
The staining to undyed fabrics is evaluated by grey scale.

Wet Pressing
Soak the specimen and cotton cloth in distilled water and squeeze or extract them to contain their own weight of water. Place the wet specimen on a piece of the dry cotton cloth and place the wet cotton cloth on the specimen, press by moving the iron to and fro over the wet cloth (without additional pressure) for 15 sec.

Assessment
Assess the change in colour of the specimen with appropriate grey scale.

Standard
Dry Pressing 4
Wet Pressing 3-4 

Introduction of Perspiration Test | Color Fastness to Perspiration

The color fastness to perspiration (acid and alkaline) shall be at least level 3-4 (color change and staining). This criterion does not apply to white products, to products that are neither dyed nor printed, to furniture fabrics, curtains or similar textiles intended for interior decoration. A level of 3 is nevertheless allowed when fabrics are both light colored (standard depth

Color Fastness to Perspiration
The garments a\which come into contact with the body where perspiration is heavy may suffer serious local discoloration. This test is intended to determine the resistance of color of dyed textile to the action of acidic and alkaline perspiration. Before knowing about the Color Fastness to perspiration you must have to know about Color Fastness to Wash and Color Fastness to Rubbing.

Perspirometer

Well, in today’s class you will know about the perspiration matters which affects on Color fastness.

Purpose and Scope
This method is used to determine the resistance of the colour of textile of all kinds and in all forms to perspiration.

Equipment For Fastness Measurement

1. Perspiration tester
2. Oven, Maintained at 37+-2 Degree centigrade
3. Multifiber test fabric
4. Grey scale
5. Color matching chamber
6. Acidic and Alkaline solution
7. Glass or Acrylic plat
8. Weight.

Reagent for Perspiration Test

1. Solution freshly prepared, containing 0.5g 1-histidine mono-hydrochloride mono-hydrate, 5g sodium chloride, and 2.5g disodium hydrogen ortho phosphate per litre brought to PH 8.0 with 0.1N sodium hydroxide.
2. Solution freshly prepared, containing 0.5g 1-histidine mono-hydrochloride mono-hydrate, 5g sodium chloride, and 2.2g sodium dihydrogen ortho phosphate per litre brought to PH 5.5 with 0.1N sodium hydroxide.
3. Two undyed cloths for each specimen each 6×6cm of the same kind of fibre as the sample. Place the specimen between the two pieces of white cloth and sew along one side to form a composite sample.

Working Procedure :
Thoroughly wet one composite sample in a solution of PH8.0 at the liquor ratio of 20:1 and allow it to remain in this solution at room temperature for 30min. pour off the solution and place the composite sample between two glasses plates measuring about 7.5×6.5cm under a force of about 4.5kg.

1. Treat the other sample in the same way but with the solution at PH 5.5.
2. Place the apparatus containing the samples in the oven for 4 hour at 37±2C˚
3. Separate the sample from the white cloth and dry them apart in air at the temperature not exceeding 60C˚
4. Assess the change in colour of the specimen and the staining of the white cloth with the greigh scale.

What is Pilling Formation on Fabric? | Pilling Resistance Test |Working Procedure of Pilling Resistance Test

Pilling
Pilling is a condition that arises in wear due to the formation of little ‘pills’ of entangled fibre clinging to the fabric surface giving it an unsightly appearance. Pills are formed by a rubbing action on loose fibres which are present on the fabric surface. Pilling was originally a fault found mainly in knitted woollen goods made from soft twisted yarns. The introduction of man-made fibres into clothing has aggravated its seriousness. The explanation for this is that these fibres are stronger than wool so that the pills remain attached to the fabric surface rather than breaking away as would be the case with wool. Figure 7.3 shows a pill on a cotton/polyester fabric.

The initial effect of abrasion on the surface of a fabric is the formation of fuzz as the result of two processes, the brushing up of free fibre ends not enclosed within the yarn structure and the conversion of fibre loops into free fibre ends by the pulling out of one of the two ends of the loop. Gintis and Mead consider that the fuzz formation must reach a critical height, which is dependent on fibre characteristics, before pill formation can occur.

Pilling Resistance Test:
Purpose and Scope:
This method is intended for the determination of the resistance of textiles of all kinds in all forms to the action of an applied resistive force. This causes pilling in the tested fabrics

Apparatus:
· Pilling tester
· Metal plates 4 inch diameter and 1 inch thick
· Standard for assessing the pilling grade

Working Procedure:
A piece of fabric measuring 10×10 inch is sewn to a firm fit when placed round a rubber tube. The out end of the fabrics is covered by cellophane tape and metal plates are placed on the tester .Run the tester for 300 cycles. Remove the sample and compare the sample with standard scale. 

Standard
Pilling Standard:              3-4 gray scale matching 

Biomedical Textiles | Biomedical Textile Products | Application ofBiomedical Textiles

 Introduction of Biomedical Textile

Biomedical textiles are fibrous structures designed for use in specific biological environments, where their performance depends on biocompatibility with cells and biological tissue or fluids.It is also branch of technical textile.Biomedical textiles are textile products and constructions, for medical and biological applications. It is related to medical textile. They are used for first aid, clinical or hygienic purposes. This type of textiles are manufactured from a wide range of processes. Extruded polymers can be further processed or used as filaments or tapes in dental floss and toothbrushes. Braided textiles are used for sutures and to replace damaged tendons and ligaments. Woven and knitted materials are used extensively in bandages, vascular grafts and hernia meshes. A specialised area of medical textiles is the extrusion of hollow fibre membranes used in extracorporeal devices. Non-wovens are primarily made from synthetic fibres and uses include wound dressings, hygiene products and protective clothing.

The design of a biomedical textile is driven by its end function. The main factors include:

Biodegradable Textiles : 

The textile needs to fulfil the purpose for which it was designed, for example swabs require an absorbent textile, sutures may require a biodegradable textile, while hospital bedding should be comfortable and durable.

Biocompatibility: 

This refers to the reaction of the textile with blood and tissue in the body. An implantable device has more potential for reaction than an external device and is, therefore, subject to tighter regulations. For example an artificial ligament is permanent and is able to react with blood cells and the surrounding tissue, compared to an external bandage that is temporary and only contacts the outer skin tissue.

Cost: 

This will depend on the raw materials, manufacturing process and product end-use; surgeons’ gowns and swabs should have a low production cost while vascular grafts and artificial skin will have a relatively high production cost.

Product approval: 

Each country has its own regulations and standards for medical textiles. However the European Union has introduced Community Legislation to govern medical devices. The three directives are: Active Implantable Medical Devices, Medical Devices Directive and In-Vitro Diagnostic Medical Devices.

Biomedical Textile Products
Biomedical textiles are textile products and constructions, for medical and biological applications. They are used for first aid, clinical or hygienic purposes. Examples of their application are: 

Protective and healthcare textiles
Surgeons’ wear, Operating drapes and Staff uniforms, etc. 

External devices
Wound dressings, bandages, pressure garments, prosthetic socks, etc. 

Implantable materials
Sutures, vascular grafts, artificial ligaments, etc. 

Hygiene products
Incontinence pads, nappies, tampons, sanitary towels, etc. 

Extracorporeal devices
Artificial liver, artificial kidney, artificial lung, etc.

Application of Biomedical Textiles
Since the 1960s, biomedical textiles have been used in cardiovascular medical devices, such as vascular grafts and heart valve sewing cuffs. However, the current wave of innovation is looking far beyond traditional materials and textile structures to enhance capabilities and performance in the repair of damaged or diseased cardiovascular tissue. In fact, the advent of new fabrics and geometries with greater variability of properties and performance characteristics, including the combination of resorbable and nonresorbable polymers, has enabled design developments previously unimagined.

Some uses are given below:
Protective and healthcare textiles: surgeons’ wear, operating drapes and staff uniforms, etc.
External devices: wound dressings, bandages, pressure garments, prosthetic socks, etc.
Implantable materials: sutures, vascular grafts, artificial ligaments, etc.
Hygiene products: incontinence pads, nappies, tampons, sanitary towels, etc.
Extracorporeal devices: artificial liver, artificial kidney, artificial lung, etc.