Topics

31

Environmental Science and Disaster Management / 3D effect on Denim

« on: September 08, 2013, 06:36:33 PM »

Resin ( Formaldehyde free ) being used for achieving 3D effect ( 3 Dimensional ), Rigid Look etc. This process can be done by spraying or dipping the garments in to Resin, Catalyst, Silicone & PU solution in right combination according to the fabric strength & desired effect needed.
After application of resin solution in right proportion, make manual designing as needed on the thigh, hip & back knee area to get 3Dimentional effect. After making it , it should be manually dried with hot press or hair dryer & then must be cured in oven at right temperature, time as mentioned in resin product manual.If resin not cured properly , 3 D effect will not be permanent & can cause skin irritation/rashes to the wearer.

32

Environmental Science and Disaster Management / Textile and Nanotechnology

« on: September 08, 2013, 06:32:00 PM »

Nanotechnology came into existence around 2600 BC in China when people started dyeing fabrics and since then it has been unknowingly used to impart different colors, shapes and strength to fibers and fabrics. People started understanding that nanoparticles and nanofibres have exclusive properties which can be used to add different properties to fabrics. Nanotechnology has gained popularity in the last 15 years and the textile industry has benefited greatly from it. This is a complex process.

The use of nano-fibres has increased over the last five years. It has become an area of interest academically as well as commercially. Surface modification techniques have proved very beneficial in manufacturing. Incorporation of nano-particles can be used to create anti microbial and electrically conducive fibers. Whether it's a natural fabric or a synthetic one, different nanomaterials are used in textile manufacturing because of the properties they impart.Textiles are getting smarter, and much of this is being enabled by nanotechnology. "Smart Textiles and Nanotechnologies: Applications Technologies and Markets" provides the most in depth look to date at the impact of nanotechnology on the global textile industry, looking at technologies and applications from geographer to smart homes.
This report provides an in-depth presentation of recent developments in nanotechnology applied to smart textiles and provides market opportunities to 2022.

The market is segmented by
• Clothing & Apparel
• Home Textiles
• Military Textiles
• Medical Textiles
• Sport Textiles
• Technical and Smart Textiles

33

Environmental Science and Disaster Management / Vintage garments by Resin treatment

« on: September 08, 2013, 06:27:01 PM »

In 80’s we have seen Resin being used to give non press , iron free trousers & now we are using in Denims to make wrinkles & creases to look natural vintage which stays after multiple home laundries.

The present invention relates to processes and methods for treating Denim garments. In particular, the invention relates to the treatment of denim made of cotton, cotton blends and synthetic fabrics for the purpose of imparting no press properties thereto.

Typical Resin treatment process for Non denim garments for Durable Press finish:

Lets talk about wrinkle free, durable press or crease free finish on non denim trousers. A variety of techniques and additives have been suggested for use in the treatment of cotton fabrics to obtain durable press properties. A typical process suggests the use of a low-formaldehyde glyoxal resin (10%), a non-ionic wetting agent (0.2%), an amino functional silicone (3%), a polyethylene emulsion (2%), and acetic acid to maintain pH in aqueous solution wherein water comprises the remaining 84%. Then load the machine with the garments prior to the addition of the liquid mix components. Once the mixture components are added, the garments be allowed to soak for between six and ten minutes without agitation. The offload & do hydro extract & semi dry.

The amount of time required to reach the target moisture level will depend on the weight of the fabric, the temperature of the dryer, the duration of the drying cycle, and the extent to which the garments are tumbled. However, it is important to keep the drying temperature below a temperature which will cause the resin to set.

Once the garments have been dried to the proper moisture level, they are ready for the pressing and final cure steps. It is important to press and finally cure the garments without substantial delay, i.e. delay of more than approximately 12 to 24 hours, depending upon the weight of the fabric comprising the garments. Denim fabrics can be held between the drying and the pressing steps longer than lighter weight fabrics, because they tend to more readily retain moisture. Pressing of the garments in accordance with the present invention is done with a garment press capable of exerting a vacuum on the garment through the lower plate of the press. Initially, the garments are positioned with the aid of a vacuum to eliminate wrinkles and they are subsequently subjected to a steam treatment for approximately five seconds with the vacuum turned off. Steam is then applied to the garment through the top plate of the press for approximately 5 seconds. Finally, the garments be pressed for non denim to get wrinkle free, durable press finish or crunched for denim where ever 3D effect needed and cured.

The  current technology of post cure being introduced for non denim garments process gives an option to produce a garment with smooth drying and wrinkle resistant properties along with sharp creases that are durable for the life of the garment. In this process the resin is padded onto the fabric and dried at low temperature. The fabric is then cut, garment constructed and creases pressed into the garment. A high temperature cure in this configuration is given to cross-link the resin. This process, though giving excellent results, has not been too successful with garment manufacturers owing to obvious limitations of colors, styles and fabric weight, and the need for a direct interface between mills, garment manufacturers and retailers.

34

Textile science, events, trade and issues / Effluent Treatment: A burning issue for dyeing industry

« on: September 08, 2013, 05:55:25 PM »

Effluent is an out flowing of water or gas from a natural body of water or from a human made structure .Effluent is defined by the United States Environment protection Agency as “wastewater, treated or untreated that flows out of treatment plant, sewer or industrial outfall. Generally refers to wastes discharged into surface waters”. The compact oxford English Dictionary defines effluent as “Liquid waste or sewage discharged into a river or the sea.

Waste water discharged from a textile wet processing plant contains various types of impurities depending on the types of dyes, chemicals, auxiliaries and process used. Some of these impurities are considered toxic while some are not. Off course the toxicity or harmless also depends on the amount present in a certain amount of wastewater. various countries have different standards for acceptable level of toxicity .For example water is used for drinking purposes, irrigation  in the fields, in various types of textile, chemical, food processing ,leather processing and pharmaceutical industries, and also to maintain the aquatic life in the canals and rivers. In all these cases different level of purity in terms of toxicity and harmfulness is required. this is mainly intended for wastewater generated in the various textile wet processing industries. Therefore, the present discussion will mainly be concentrated on wastewater generated in various types textile processing industries.  This is Bangladesh govt.standard .the level of toxicity was considered for water intended to be discharged into river or canals. the wastewater generated in a textile wet processing industry can be recycled back for consuming in the plant as raw influent or even can be used for drinking purposes but this is expensive enough. So wastewater as generally discharged into the river or canals.

Characteristics of waste water to discharged into the environment. (Recommended by the dept. of environment, Government of Bangladesh).
                                           
PH    7-8
BOD   <50 PPM or mg/.L
COD   <200 PPM or mg/L
TSS   <100 PPM or mg/L
TDS   <2,500 PPM or mg/L
OIL & GREAS   <10 PPM or mg/L
COLOUR   CLEAN
TEMPERATURE   <300 C

35

Textile science, events, trade and issues / Ozone: A Tool for Denim Processing

« on: September 08, 2013, 05:51:06 PM »

Ozone is tri-atomic oxygen, it exists in nature within the stratosphere (from a height of 10 kms to 50 kms), small amounts of ozone is constantly being produced by the action of sun's UV radiation that splits oxygen (O2) to from single oxygen atoms. These atoms combine with the remaining oxygen molecules to form Ozone (O3) molecules, which are very effective at absorbing suns UV rays.

Ozone is also formed from the pollution from burning fossil fuel which creates smoke and carbon monoxide, and lighting creates nitrogen oxides. All of these chemicals, combined together with unstable compounds and in the presence of sunlight, form ozone as a by-product. At ground level, ozone at atmospheric conditions is very unstable, due to this unstable nature; it reduces to oxygen within a very short span of 60 min. in air and 20 mins. in water. This reduction reaction releases one atom of oxygen with act as a very powerful oxidizing agent as a very powerful disinfectant, on the principle of oxidation the garments are treated and the color, look appears on the treated garments.
Even today, many manufacturers  feel that by using Ozone Gas their denim garments they would simply bleach them to lighter blue only. This is true since the Indian denim manufacturers and users are used to the brighter colour of Indigo achieved with the help of optical brighteners that sometimes it is difficult for them to accept the duller colours achieved through Ozone processing.

Though it changes the colour of the Indigo dye, Ozone eliminates tinting from the reverse of the denims as also from the sewing thread, pocket fabric, labels, zippers, buttons etc. giving the garment a cleaner look. Ozone also destroys all air borne micro-organisms including bacteria, virus, mold, fungi, spores, etc. It also oxidizes the volatile organic chemicals, including aromatic chemicals reducing them into lower molecular organics which are no more aromatic in nature; hence the hand-feel in garments is enhanced after the treatment. Furthermore, the discharge of the Ozone purifies the atmosphere by adding freshness and giving clear, pollution free-oxygen rich air.

Since ozone has the bleaching property, low ozone dosage helps in avoiding bleaching action, while enabling the washed clothes come out brighter it also sanitized them at the same time. Ozone's sanitizing property makes it very relevant to the hospitals as also the hotels. The use of ozone reduces the requirement of detergents and also the wash can be achieved at lower temperatures. Thus, a specially designed Ozone system helps in reducing the use of water as well as energy cost for heating, resulting in large savings. Besides this, the added advantage is that the waste water from the laundry has much lower detergent contents which requires very little or no waste water treatment prior to letting it out in to the sewage system.