Dyeing of textile material book pdf free download

New York, NY: Rodale. It centers on how the atmosphere is very thin and how greenhouse gases such as carbon dioxide are making it thicker. The thicker atmosphere traps more infrared radiation, causing warming of the Earth. He includes several examples of problems caused by global warming. Penguins and polar bears are at risk because the glaciers they call home are quickly melting.

Coral reefs are being bleached and destroyed when their inhabitants overheat and leave. For example, many highways in Alaska are only frozen enough to be driven on fewer than 80 days of the year. In China and elsewhere, recordsetting floods and droughts are taking place. Hurricanes are on the rise. It is useful because it relies on scientific data that can be referred to easily and it provides a solid foundation for me to build on.

For example, it explains how carbon dioxide is produced and how it is currently affecting plants and animals. This evidence could potentially help my research on how humans are biologically affected by global warming.

It will also help me structure my essay, using its general information to lead into the specifics of my topic. For example, I could introduce the issue by explaining the thinness of the atmosphere and the effect of greenhouse gases, then focus on carbon dioxide and its effects on organisms. A concise description of the work. Relevant commentary. If you write an evaluative bibliography, your comments should be relevant to your purpose and audience.

To achieve relevance, consider what questions a potential reader might have about the sources. Consistent presentation. All annotations should be consistent in content, sentence structure, and format. If one annotation is written in complete sentences, they should all be. Decide what sources to include. Though you may be tempted to include every source you find, a better strategy is to include only those sources that you or your readers may find useful in researching your topic.

Is this source relevant to your topic? Is it general or specialized? Are the author and the publisher or sponsor reputable? Does the source present enough evidence? Does it show any particular bias? Does the source reflect current thinking or research? Decide whether the bibliography should be descriptive or evaluative. Read carefully. To quickly determine whether a source is likely to serve your needs, first check the publisher or sponsor; then read the preface, abstract, or introduction; skim the table of contents or the headings; and read the parts that relate specifically to your topic.

Research the writer, if necessary. In any case, information about the writer should take up no more than one sentence in your annotation. Summarize the work. Sumarize it as objectively as possible: even if you are writing an evaluative annotation, you can evaluate the central point of a work better by stating it clearly first. You may find, however, that some parts are useful while others are not, and your evaluation should reflect that mix.

Ways of organizing an annotated bibliography. Depending on their purpose, annotated bibliographies may or may not include an introduction. State scope. List first List second List third List final alphabeti- alphabeti- alphabeti- alphabeti- cal entry, cal entry, cal entry, cal entry, and anno- and anno- and anno- and anno- tate it. Sometimes an annotated bibliography needs to be organized into several subject areas or genres, periods, or some other category ; if so, the entries are listed alphabetically within each category.

Category 2 alphabetically, and annotate them. List entries Explain category 2. To read an example annotated bibliography, go to digital. You may be required to include an abstract in a report or as a preview of a presentation you plan to give at an academic or professional conference. This chapter provides tips for writing three common kinds: informative, descriptive, and proposal. That one paragraph must mention all the main points or parts of the paper: a description of the study or project, its methods, the results, and the conclusions.

Here is an example of the abstract accompanying a seven-page essay that appeared in in the Journal of Clinical Psychology: The relationship between boredom proneness and health-symptom reporting was examined. The results suggest that boredom proneness may be an important element to consider when assessing symptom reporting. Implications for determining the effects of boredom proneness on psychological- and physicalhealth symptoms, as well as the application in clinical settings, are discussed.

They usually do not summarize the entire paper, give or discuss results, or set out the conclusion or its implications. The findings and their application in clinical settings are discussed. You prepare them to persuade someone to let you write on a topic, pursue a project, conduct an experiment, or present a paper at a scholarly conference; often the abstract is written before the paper itself.

Titles and other aspects of the proposal deliberately reflect the theme of the proposed work, and you may use the future tense to describe work not yet completed. Here is a possible proposal for doing research on boredom and health problems: Undergraduate students will complete the Boredom Proneness Scale and the Hopkins Symptom Checklist.

A multiple analysis of covariance will be performed to determine the relationship between boredom-proneness total scores and ratings on the five subscales of the Hopkins Symptom Checklist ObsessiveCompulsive, Somatization, Anxiety, Interpersonal Sensitivity, and Depression.

An informative abstract includes enough information to substitute for the report itself; a descriptive abstract offers only enough information to let the audience decide whether to read further; and a proposal abstract gives an overview of the planned work. Objective description. Abstracts present information on the contents of a report or a proposed study; they do not present arguments about or personal perspectives on those contents. Unless you are writing a proposal abstract, you should write the paper first.

You can then use the finished work as the guide for the abstract, which should follow the same basic structure. Copy and paste key statements. Copy and paste those sentences into a new document to create a rough draft. Pare down the rough draft. Introduce the overall scope of your study, and include any other information that seems crucial to understanding your work. Conform to any length requirements. In general, an informative abstract should be at most 10 percent as long as the original and no longer than the maximum length allowed.

Descriptive abstracts should be shorter still, and proposal abstracts should conform to the requirements of the organization calling for the proposal. Ways of organizing an abstract [An informative abstract] State conclusions of study. State Summarize nature of method of study. State implications of study. To read an example abstract, go to digital. We read cookbooks to find out how to make brownies; we read textbooks to learn about history, biology, and other academic topics.

And as writers, we read our own drafts to make sure they say what we mean. In other words, we read for many different purposes. Following are some strategies for reading with a critical eye. It always helps to approach new information in the context of what we already know.

List any terms or phrases that come to mind, and group them into categories. Then, or after reading a few paragraphs, list any questions that you expect, want, or hope to be answered as you read, and number them according to their importance to you. Finally, after you read the whole text, list what you learned from it. Preview the text. Start by skimming to get the basic ideas; read the title and subtitle, any headings, the first and last paragraphs, the first sentences of all the other paragraphs.

Study any visuals. Think about your initial response. Read the text to get a sense of it; then jot down brief notes about your initial reaction, and think about why you reacted as you did. What aspects of the text account for this reaction? Highlight key words and phrases, connect ideas with lines or symbols, and write comments or questions in the margins.

What you annotate depends on your purpose. One simple way of annotating is to use a coding system, such as a check mark to indicate passages that confirm what you already thought, an X for ones that contradict your previous thinking, a question mark for ones that are puzzling or confusing, an exclamation point or asterisk for ones that strike you as important, and so on. You might also circle new words that you need to look up. Play the believing and doubting game.

Analyze how the text works. Outline the text paragraph by paragraph. Are there any patterns in the topics the writer addresses? How has the writer arranged ideas, and how does that arrangement develop the topic? Identify patterns. Look for notable patterns in the text: recurring words and their synonyms, repeated phrases and metaphors, and types of sentences.

Does the author rely on any particular writing strategies? Is the evidence offered more opinion than fact? Is there a predominant pattern to how sources are presented?

As quotations? In visual texts, are there any patterns of color, shape, and line? Consider the larger context. What other arguments is he or she responding to?

Who is cited? Be persistent with difficult texts. For texts that are especially challenging or uninteresting, first try skimming the headings, the abstract or introduction, and the conclusion to look for something that relates to knowledge you already have.

As a critical reader, you need to look closely at the argument a text makes. Does his or her language include you, or not? Hint: if you see the word we, do you feel included? So learning to read and interpret visual texts is just as necessary as it is for written texts. Take visuals seriously. When they appear as part of a written text, they may introduce information not discussed elsewhere in the text. It might also help to think about its purpose: Why did the writer include it? What information does it add or emphasize?

What argument is it making? How to read charts and graphs. A line graph, for example, usually contains certain elements: title, legend, x-axis, y-axis, and source information. Figure 1 shows one such graph taken from a sociology textbook. Other types of charts and graphs include some of these same elements.

But the specific elements vary according to the different Legend: Explains the symbols used. Here, colors show the different categories. X-axis: Defines the dependent variable something that changes depending on other factors. Women in the labor force as a percent of the total labor force both men and women age sixteen and over. For example, the chart in Figure 2, from the same textbook, includes elements of both bar and line graphs to depict two trends at once: the red line shows the percentage of women who were in the US labor force from to , and the blue bars show the percentage of US workers who were women during that same period.

Both trends are shown in two-year increments. To make sense of this chart, you need to read the title, the y-axis labels, and the labels and their definitions carefully. Research Research is formalized curiosity. It is poking and prying with a purpose. We search the web for information about a new computer, ask friends about the best place to get coffee, try on several pairs of jeans before deciding which ones to buy.

Will you need to provide background information? What kinds of evidence will your audience find persuasive? What attitudes do they hold, and how can you best appeal to them? If so, which media will best reach your audience, and how will they affect the kind of information you search for? Is there a due date? How much time will your project take, and how can you best schedule your time in order to complete it? If the assignment offers only broad guidelines, identify the requirements and range of possibilities, and define your topic within those constraints.

As you consider topics, look to narrow your focus to be specific enough to cover in a research paper. Reference librarians can direct you to the most appropriate reference works, and library catalogs and databases provide sources that have been selected by experts. General encyclopedias and other reference works can provide an overview of your topic, while more specialized encyclopedias cover subjects in greater depth and provide other scholarly references for further research.

Some databases include documentation entries in several styles that you can simply copy and paste. Generate a list of questions beginning with What? Who should determine when and where fracking can be done? Should fracking be expanded? Select one question, and use it to help guide your research.

Drafting a tentative thesis. Here are three tentative thesis statements, each one based on a previous research question about fracking: By injecting sand, water, and chemicals into rock, fracking may pollute drinking water and air. The federal government should strictly regulate the production of natural gas by fracking.

Fracking can greatly increase our supplies of natural gas, but other methods of producing energy should still be pursued. A tentative thesis will help guide your research, but you should be ready to revise it as you continue to learn about your subject and consider many points of view. Which sources you turn to will depend on your topic.

For a report on career opportunities in psychology, you might interview someone working in the field. Primary sources are original works, such as historical documents, literary works, eyewitness accounts, diaries, letters, and lab studies, as well as your own original field research. Secondary sources include scholarly books and articles, reviews, biographies, and other works that interpret or discuss primary sources.

Whether a source is considered primary or secondary sometimes depends on your topic and purpose. Scholarly and popular sources. Popular sources, on the other hand, are written for a general audience, and while they may discuss scholarly research, they are more likely to summarize that research than to report on it in detail. Catchy, provocative titles usually signal that a source is popular, not scholarly. Scholarly sources are written by authors with academic credentials; popular sources are most often written by journalists or staff writers.

Includes an abstract. Multiple authors who are academics. Author not an academic. Consider how much prior knowledge readers are assumed to have. Are specialized terms defined, and are the people cited identified in some way? Look as well at the detail: scholarly sources describe methods and give more detail, often in the form of numerical data; popular sources give less detail, often in the form of anecdotes.

Scholarly sources are published by academic journals, university presses, and professional organizations such as the Modern Language Association; popular sources are published by general interest magazines such as Time or Fortune or trade publishers such as Norton or Penguin.

Scholarly journal articles often begin with an abstract or summary of the article; popular magazine articles may include a tag line giving some sense of what the article covers, but less than a formal summary. Scholarly sources have URLs that end in. Keep in mind that searching requires flexibility, both in the words you use and in the methods you try. For some topics, you might find specialized reference works such as the Film Encyclopedia or Dictionary of Philosophy, which provide in-depth information on a single field or topic and can often lead you to more specific sources.

Many reference works are also online, but some may be available only in the library. Wikipedia can often serve as a starting point for preliminary research and includes links to other sources, but since its information can be written and rewritten by anyone, make sure to consult other reference works as well. You can find bibliographies in many scholarly articles and books. Check with a reference librarian for help finding bibliographies on your research topic.

You can search the catalog by author, title, subject, or keyword. Many books in the catalog are also available online, and some may be downloaded to a computer or mobile device. Indexes list articles by topics; databases usually provide full texts or abstracts.

While some databases and indexes are freely available online, most must be accessed through a library. EBSCOhost provides databases of abstracts and complete articles from periodicals and government documents. InfoTrac offers full-text articles from scholarly and popular sources, including the New York Times. JSTOR archives many scholarly journals but not current issues. Humanities International Index contains bibliographies for over 2, humanities journals.

MLA International Bibliography indexes scholarly articles on modern languages, literature, folklore, and linguistics. PsycINFO indexes scholarly literature in psychology. Because it is so vast and dynamic, however, finding information can be a challenge. Google, Bing, Yahoo! Yippy, Dogpile, and SurfWax let you use several search sites simultaneously. They are best for searching broadly; use a single site to obtain the most precise results.

For peer-reviewed academic writing in many disciplines, try Google Scholar; or use Scirus for scientific, technical, and medical documents. Following are a few of the many resources available on the web. You can find information put together by specialists at The Voice of the Shuttle a guide to online resources in the humanities ; the WWW Virtual Library a catalog of websites on numerous subjects, compiled by subject specialists ; or in subject directories such as those provided by Google and Yahoo!

News sites. Many newspapers, magazines, and radio and TV stations have websites that provide both up-to-the-minute information and also archives of older news articles. Through Google News and NewsLink, for example, you can access current news worldwide, and Google News Archive Search has files extending back to the s.

Government sites. Many government agencies and departments maintain websites where you can find government reports, statistics, legislative information, and other resources.

Audio, video, and image collections. Your library likely subscribes to various databases where you can find and download audio, video, and image files. AP Images provides access to photographs taken for the Associated Press; Artstor is a digital library of images; Naxos Music Library contains more than 60, recordings. Digital archives. You can find primary sources from the past, including drawings, maps, recordings, speeches, and historic documents at sites maintained by the National Archives, the Library of Congress, the New York Public Library, and others.

Three kinds of field research that you might consider are interviews, observations, and surveys. If you wish to record the interview, ask for permission. Some writing projects are based on information you get by observing something.

How does this observation relate to your research goals, and what do you expect to find? Also note details about the setting. Then analyze your notes, looking for patterns. What did you learn? Did anything surprise or puzzle you? One way of gathering information from a large number of people is to use a questionnaire.

Multiple-choice questions will be easier to tally than openended questions. Be sure to give a due date and to say thank you. A Google search on the same topic produces over ten thousand hits. How do you decide which ones to read? This chapter presents advice on evaluating potential sources and reading those you choose critically. What kinds of sources will they find persuasive? How well does it relate to your purpose?

What would it add to your work? To see what it covers, look at the title and at any introductory material such as a preface or an abstract. Has the author written other works on this subject? Is he or she known for a particular position on it?

If the credentials are not stated, you might do a search to see what else you can learn about him or her. Does the source cover various points of view or advocate only one perspective?

Does its title suggest a certain slant? If the source is a book, what kind of company published it; if an article, what kind of periodical did it appear in? Books published by university presses and articles in scholarly journals are reviewed by experts before they are published. But books and articles written for the general public do not undergo rigorous review or fact-checking. Is the site maintained by an organization, an interest group, a government agency, or an individual?

Look for clues in the URL:. Can you understand it? Texts written for a general audience might be easier to understand but not authoritative enough for academic work. Scholarly texts will be more authoritative but may be hard to comprehend. Check to see when books and articles were published and when websites were last updated.

If a site lists no date, see if links to other sites still work; if not, the site is probably too dated to use. If so, you can probably assume that some other writers regard it as trustworthy. Is there a bibliography that might lead you to other sources? How current or authoritative are the sources it cites?

Pay attention to what they say, to the reasons and evidence they offer to support what they say, and to whether they address viewpoints other than their own. Assume that each author is responding to some other argument. Does he or she present several different positions or argue for a particular position?

What arguments is he or she responding to? How thoroughly does he or she consider alternative arguments? Does it seem objective, or does the content or language reveal a particular bias? Are opposing views considered and treated fairly? Does it support a different argument altogether?

Does it represent a position you need to address? Is the main purpose to inform readers about a topic or to argue a certain point? This chapter focuses on going beyond what your sources say to inspire and support what you want to say. What makes them so strong? The dyes which belong to this category are logwood and sappan wood. Logwood, a natural dye, produces dark black shade on silk, wool and cotton.

The natural dye carajurin belongs to this category. The blue and orange shades are obtained from this class. Different natural colourants contain different chromophoric and auxochromic groups. Depending on the presence of a particular group in the dye structure, the chemistry of the dyes can be explained in terms of their chromophoric groups. The different dye structures and chromophoric groups are as explained. The quinoid-based dye structure can be overviewed as three chemical structures a benzoquinone, b naphthoquinone and c anthraquinone.

The natural colourant carthamine belongs to benzoquinone group, and juglone and lawsone are having naphthoquinone structure. Alizarine dye possesses anthraquinone structure. The red colourant carthamine is present in safflower Natural Red In dyeing, the water-soluble yellow dye safflor yellow is extracted [ 18 ] by cold water, and then red safflorcamin is extracted by diluted sodium carbonate solution.

After the neutralisation of extracted solution, it can be used in dyeing of wool, silk and cotton. Structure of carthamine. Lawsone and juglon natural dye belongs to this category. Lawsone is extracted from hina plant; the leaves also contain flavonoid colourants lutcolin.

It is cultivated in countries like India, Africa and Australia. Naphthoquinone is present in glycosidic [ 19 , 20 ] form named as Hennosid A, B and C. The quantitative analysis of lawsone can be performed by high-performance liquid chromatography on reverse-phase C 18 column.

Chloroform extracted hina leaves were analysed by high-performance thin layer chromatography Figures 22 and Lawsone 2-hydroxy, 1,4 naphthalene. Juglone 5-hydroxy, 1,4 naphthoquinone. The better dye uptake is obtained at pH 3. Agarwal et al.

Hina can be used for dyeing of cotton, polyester, polyamide and cellulose triacetate as the structure of dye molecules are similar to disperse dyes [ 22 , 23 , 24 ]. Juglone is representative of natural dye with naphthoquinone structure. The dyestuff is extracted from different part of nut trees. Juglone is present as a glycoside form in trees and plants. Wool dyed with juglone are having good resistance with moths and insects.

Mordanting treatment further enhances the fastness properties. Dyeing of textile materials with aqueous walnut extract yields brown shade. Wide range of textile fibre, e.

It possess biggest group of anthraquinone dyes. Rhubarb CI Natural Yellow 23 is extracted from the root of the plant. The extracted dye contains emodin, chrysophenol, aloe emodin and pyscion Figure Rhubarb extract is used in dyeing of wool fibre [ 25 ].

It produces yellow to orange shade after mordanting with alum. The mordanting treatment improves light fastness of dyed materials. Different representative structurers of anthraquinone group-based dye molecules. Natural dye alizarin, pseudo purpurin and purpurin Figure 25 belongs to plant of Rubiaceae family and has an anthraquinone structure [ 26 ]. The dye is obtained from the root of plant. Structures of alizarin, pseudo purpurin and purpurin.

Madder C. I Natural Red 8 natural dye produces red colourant; the cultivation of madder is done as a source material for red colour in Europe, Asia and Northern and Southern America. The dyestuff is extracted from the dried roots of the plant. The roots of the plant contain 2—3. Carotenoids are red, yellow and orange pigments present in plants and animals [ 17 ]. It has a polyisoprenoid structure with a series of centrally located conjugated bonds.

The bright colours of many fruits and vegetables are due to carotenoids. Carotenoids are polyisoprenoid structure Figure 26 which contain conjugated double bonds, which acts as chromophore and responsible for characteristic absorption spectra. Carotenoids are divided into two parts: Hydrocarbon carotenoid. Structural changes by hydrogenation, double bond migration, isomerization and chain lengthening and shortening resulted in many carotenoid structure.

Pyron dyes contain flavonoids and anthocyanins having structure as shown in Figures 27 and The pyron structure is bound to various sugars by glycosidic bonds [ 17 ].

Flavonoids are classified as flavonols, flavones, anthocyanidins, isoflavones, flavon-3,4-diols and coumarins. Yellow flavones and flavonols are used as vegetable dyes. The valuable and very popular flavonoid is yellow quercetin which possess several bio effect.

Structure of anthocyanins. Structure of quercetin. Anthocyanins are found in fruits and vegetables; some are grape wine, sweet and sour cherries, red cabbage, hibiscus and different varieties of oranges.

There are more than varieties of anthocyanins that produces red, pink, violet and orange colours. There are some important anthocyanins which are cyaniding, delphinidin, pelargonidin, malvidin, peonidin and petunidin. Many plants besides anthocyanins also contain quercetin and chlorophylls, and the resulted colour is a mixture of all these.

Violet and purple colours were generally obtained from molluscs and shellfish, and they were source of dyestuff from ancient to the beginning of the Middle Ages. Royale purple and Tyrian purple were the name of the colour obtained originally from molluscs [ 27 ]. Lichens and mushrooms are source of natural dyes, and they produce violet and purple colours. Lichens are found in coastal areas and were easier to collect. The dyeing methods with lichens are easy; however, disadvantage associated with lichens is poor light fastness.

Therefore, the dyeing of lichens are limited to cheap quality fabrics. Fungi are also used for dyeing of textiles. In America and India, red colour is obtained from fungus Echinodontium tinctorium.

In Italy and France, fungi obtained from Polyporales were used to dye the wool. The colourants in lichens and fungi are benzoquinone derivatives, especially terphenylquinone. Some of these species possess compounds such as Sarcodon , Phellodon , Hydnellum and Thelephora [ 28 , 29 ]. Orchil and litmus are the colourants that are responsible for the colour in lichens. Then some pre-compounds are lecanoric acid, atranorin and gyrophoric acid which take part in the formation of orchil and litmus as shown in Figure Structures of different colourants occurring in fungi and lichens.

In the past, the extraction of colourants from lichens were performed by keeping the lichens in water with ammonia for several days. The reaction occurred through enzymatic hydrolysis in which non coloured compounds such as lecanoric acid are converted into orcinol by hydrolysis and decarboxylation. Orcinol after oxidation forms purple orceins or litmus.

The colour of both litmus and orchil depend on the pH of the solution [ 30 ]. In acidic pH dyestuff forms red cation, and in basic pH, it forms bluish violet anion.

The lichens which belong to species Parmelia , Xanthoria parietina , Ochrolechia tartarea and Lasallia pustulata are capable to produce yellowish, brownish and reddish brown colours in dyeing of wool with lichens [ 31 ]. The dyeing is done by boiling the wool with lichen solution either premordanted or without mordanted wool in presence of ammonia. The mushrooms which belongs to species Sarcodon , Phellodon and Hydlnellum contain terphenylquinone compounds as a main colourants which produce blue colour in mushrooms.

They are benzoquinone derivatives. The Cortinarius species mushrooms are richly coloured in brown, red, olive green and violet. They are anthraquinone derivatives.

Tannins are polymeric polyphenols with typical aromatic ring structure with hydroxyl constituents and have relatively high molecular weight. In plants two different groups of tannins are found, a hydrolysable tannins and b proanthocyanidins condensed tannin [ 32 , 33 ].

Tannins are present in plant cell and are concentrated in epidermal tissues. Tannins are found in wood, leaves, buds, stems, florals and roots [ 34 ].

The hydrolysable tannins are concentrated in the roots of several plants. The plants are the source of different variety of tannins. The three major tannins hydrolysable tannins are grouped as gallotannins [ 35 ] or ellagitannins and which are gallic acid or ellagic acids.

The most widespread gallotannins are pentagalloyl glucose. Ellagitannins are esters of hexahydroxydiphenic acids. Gallic acid and hexahydroxydiphenic acid occur together in some hydrolysable tannins [ 36 ]. The complex chemical nature of tannins makes the biosynthesis and polymerisation a difficult task; however, there are some established pathways for bio synthesis.

The precursor for biosynthesis of hydrolysable tannins is shikimic acid. The direct aromatization of 3-dehydroshikimic acid produces gallic acid, which upon esterification forms polyol. The bio synthesis of condensed tannins occurs through two different ways a by phenylpropanoid and b by polyketide. The polyketide pathway takes malonyl moieties for aromatic ring formation in flavonoid biosynthesis.

The phenylpropanoid pathway takes aromatic amino acid, L-phenylalanine, which is non-oxidatively deaminated to E-cinnamate by phenylalanine ammonia-lyase. The classification of natural dyes are also done according to the hue of the colour. Some important natural dyes giving primary and secondary colours are: Red: Colour index has 32 red natural dyes. The prominent members are maddar, manjistha, Brazil wood, Morinda , cochineal and lac dyes.

Blue: There are four natural blue dyes. Some prominent colours are indigo, Kumbh and flowers of Japanese Tsuykusa. Natural indigo blue is known from very ancient time to dye cotton and wool. Yellow: There are 28 yellow natural dyes available which are used in dyeing of wool, silk and cotton. Prominent examples are barberry, tesu flowers, Kamala, turmeric and marigold.

Green: Plants that yield green natural colour are very rare; they are made by mixing yellow and blue primary colours. Woad and Indigo produce green colour. Black and brown: There are six black natural dyes. Cutch is used to produce brown shade; for getting black shade lac, carbon and caramel are used. Orange: Natural dyes which produce red and yellow colour are used to produce orange shade. Barbeny and annatto are the examples of orange colour. Vat dyes: Indigo is a water-insoluble dye, and before application it is solubilised in water.

The solubilisation of natural indigo is done with the help of sodium hydrosulphite and sodium hydroxide.

After solubilisation, it is applied on cellulosic fibre, and after dyeing the development of colour is done by oxidation with hydrogen peroxide.

Indigo dye is the representative of indigoid class of vat dyes. Direct dyes: The natural dyes which are water soluble and have a long and planar molecular structure and presence of conjugated single and double bonds bonds can be applied by direct dyeing method.

The dye molecules may contain amino, hydroxyl and sulphonic groups. Turmeric, Harda, pomegranate rind and annatto can be applied by direct dyeing method. Common salt is used to get better exhaustion of dyes. Acid dyes: The dye molecules possess sulphonic or carboxylic groups in their structure, which produce affinity for wool and silk fibre. The dyeing is done at acidic pH of 4. After dyeing the fastness improvement is done with tannic acid. The dyeing of wool and silk with saffron is done by acid dyeing method.

The presence of common salt in dye bath produces levelling effect. Basic dyes: The dye molecules produce coloured cation after dissolution in the water at acidic pH. The dye bath pH is kept 4—5 by adding acetic acid. The amount of natural dyes present in natural products are very less [ 11 , 37 ].

They need specific technique to remove dye from their original source. Here there are some methods which are suitable for extraction of natural dyes from their source materials [ 28 ]; the different extraction methods are as follows:.

In this method, the dye containing materials are broken into small pieces or powdered and then soaked in water overnight. Basically a grab test. June 21, testextextile Textiles Test Industrial Info 1 Comment Introduction : The human use the textiles materials made of fibers with different forms has been used for thousands of years, and the earliest records of textiles are traced back to fabrics, baskets, and nets on small ceramic tablets 27, years ago.

What is Textile Testing? Why do you need Textile Testing? The Purpose and Significance of Textile Testing. The main purpose and significance of textile testing are: To check the quality and suitability of raw material To monitor the production process control To assess the quality of the final product To investigate the faulty materials To set standards or benchmarks For research and development purpose For new product development Basic Conditions and Method of Textile Testing 1 First of all, we should understand the test purpose and determine the test standards.

Analyze and sort out the data and get the test results. Prepare test report and file it. Classification of Textile Testing Items 1 Classification according to the textile application From fiber to yarn, from yarn to fabric, from fabric to textile finished product, every step of the textile product production process cannot be separated from testing.

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