BLEACHING WASHAuthor- Younus Miraj

Shanto-Mariam University of Creative & Technology

UTTARA-DHAKA

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Table of Content

Introduction

Bleach Refers to a number of chemicals which remove color, whiten or disinfect, often via oxidation. The bleaching process has been known for thousands of years. But the chemicals currently used for bleaching resulted from the work of several 18th century scientists. Chlorine is the basis for the most commonly used bleaches, for example, the solution of sodium hypochlorite, which is so ubiquitous that many people just call it "bleach", and calcium (bleaching powder). Oxidizing bleaching agents that do not contain chlorine most often are based on peroxides, such as hydrogen peroxide, sodium per carbonate and sodium per borate. While most bleaches are oxidizing agents, a fewer number are reducing agents such as sodium dithionite.

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Serial no Content Page no

01 Introduction 03

02 Bleaching 03

03 Item 03

04 Type of bleach with objective 03-05

05 Important factors affecting bleaching 05

06 Bleaching agent 05

07 General Recipe Steps 06

08 Standard Recipe for Bleaching washes 06

09 Types of machine 06

10 Example of denim pants 06-07

11 Bleach Warnings 07

12 Summary 07

13 Conclusion 07

14 Reference 8

Bleaching

Bleach is a laundry aid that helps remover dirt and stains from clothing. Bleach creates a chemical reaction with soil that breaks it down and removes it from clothing. Bleach also has whitening and brightening effect on clothing. There are two different types of bleach. Bleach is a product that makes it possible for laundry detergents to be more effective against stains. Bleach oxidizes food and other particles making them easier to remove from fabric.Item: denim.

Type of bleach

1. Chlorine bleach (common household bleach or sodium hypochlorite)2. Oxygen bleach (all fabric bleach)

Chlorine bleach

Usually comes in a liquid form, but can occasionally be found in a powder form. Chlorine bleach contains sodium hypochlorite diluted with water. This type of bleach is very powerful and can also disinfect laundry, but isn't safe for some fabric types.

Objectives:

All fabric bleach is considered safe for most clothing. Chlorine bleach should always be added to the washer water and mixed in well before

adding clothes. Never pour bleach directly onto fabrics. If using bleach for stain removal, bleach the entire garment to prevent spotting.

When chlorine bleach is used in the wash, it acts as a disinfectant on bacteria and viruses and generally whitens fabrics. Care must be taken to use it effectively by adding it at the correct time and temperature to the wash load. Liquid chlorine bleach has a limited shelf life. If more than six months old, it may have no effect on stains and should be replaced.

Test Items before Bleaching

Before you use chlorine bleach on a garment, test the fabric to see how it will react to the bleach. First, mix one part bleach to two parts warm water. Find an inconspicuous spot on the garment like an inside seam or pocket of the same fabric. Use a cotton swab dipped in the solution to dab the fabric. Allow the spot to dry completely before moving forward. If you see any change in color on the fabric or a transfer of color to the swab, do not use chlorine bleach on this fabric.

Never Mix Bleaches

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Never mix different types of bleach. You can cause a chemical reaction that is harmful to your clothing and, more importantly, your lungs. This also applies to other cleaning chemicals like ammonia.

Dilute for Best Results

Chlorine bleach should never be poured directly on clothing. It can cause weakening of fibers and extensive color removal. Mix 1 cup bleach is in one quart with warm water before adding it to the wash tub.

Wait to Add the Bleach

To allow the enzymes in the laundry detergents time to do their job of whitening and brightening, wait about 5 minutes after the wash cycle begins to add your diluted bleach.

Make it Hot, Hot, Hot

Chlorine bleach works most effectively in hot water. It can be used in warm and cold water but you won't see the results you expect.

Keep It Fresh

Chlorine bleach loses its potency once the bottle is opened. Bleach should be disposed of after about six months.

Oxygen bleach

 Is safe for use on most fabrics and is sometimes known as color-safe bleach or all-fabric bleach. Even this type of bleach may not be safe for all fabrics.

Objectives

Oxygen bleach is often called All-Fabric Bleach and is usually safe for all fabrics and colors. It works more slowly than chlorine bleach and may contain sodium per borate or sodium pre-carbonate. Oxygen Bleach is a popular ingredient in everything from dish soap to carpet cleaners to laundry detergent. Oxygen bleach contains hydrogen peroxide and is safe to use on many more surfaces than chlorine bleach.

Important factors affecting bleaching

Concentration of a chemical M: L ratio. Ph of the liquor. Temperature of a liquor Time of the treatment.

Bleaching agent

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A bleaching agent is a substance that can whiten or decolorize other substances. Bleaching agents essentially destroy chromospheres (thereby removing the color), via the oxidation or reduction of these absorbing groups. Thus, bleaches can be classified as either oxidizing agents or reducing agents.

Figure: chemical room.

Type of Bleaching Agents

There are different types of bleaching agent. These are-1. Oxidative Bleaching Agents2. Reductive Bleaching Agents3. Enzymatic Bleaching Agents

General Recipe Steps

Bleach wash generally involves steps. These are-

Desizing Stone wash Bleaching Neutralization Softner Application

Standard Recipe for Bleaching washes:

NaOH                               17ml/kg

SOAP (DTC)                    2ml/kg STABILIZER                    5ml/kg H2O2                               30ml/kg Reaction time                     25min. Speed                                50-70m/min

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Types of machine

There are different kinds of machine. These are-

Pad roll machine J-box machine Kier boiler machine

Bleach used machine

Figure: Wash machine.

Example of denim pants

Figure: Before wash.

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Figure: After wash.

Bleach Warnings

Always check for color fastness first, following the instructions on the container, before using either type of bleach.

Never pour full-strength bleach into a clothes-filled washer. Add bleach to washer water, mixing well, before adding clothes. Never mix bleach with ammonia which causes caustic fumes. Read and follow care instructions and any warnings on the fabric care label regarding

the use of bleach. Do not uses bleach on silk, acetate, wool, spandex, polypropylene foam, some flame

retardant fabrics or rubber? Repeated use of chlorine bleach can weaken cellulosic or cotton/ramie/linen fibers. Repeated use of chlorine bleach can cause yellowing of fabrics.

Summary

A process that is not physically removes color and adds contrast. A 20 yard roll of fabric, generally 62 inches in width, is put into a 250-pound washing machine along with chemical. The fabrics are rotated together for a set period of time. The washing time dictates the final color of the fabric- the longer the denim are rotated the white color becomes and one kind of contrast is achieved. The denim is then rinsed, softened and tumble dried.

Conclusion

This assignment is very importance thinks of ours future life. The bleach wash is the most important of the garments industry. Before the assignments we have do not idea about bleach wash. We complete the assignment about bleach wash. Finally we achieve some important information about this matter.

Reference

http://housekeeping.about.com/od/laundry/g/def_bleach.htm. http://laundry.about.com/od/laundrybasics/a/howtobleach.htm. http://www.answers.com/topic/bleach. http://textilelearner.blogspot.com/2011/03/textile-bleaching-process_5937.html.

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