Manufacturing Process of Nylon 6,6

Nylon 6,6 is one of the most important synthetic fibres used in textiles and industrial products. It belongs to the polyamide family and is produced by the reaction of two chemicals: hexamethylene diamine and adipic acid.

The name Nylon 6,6 comes from the fact that both the starting chemicals contain six carbon atoms. Hexamethylene diamine contributes six carbon atoms, and adipic acid also contributes six carbon atoms. When these two materials react, they form a long-chain polymer called polyhexamethylene adipamide, commonly known as Nylon 6,6.

Table of Contents

1. Raw Materials Used in Nylon 6,6
2. Chemical Reaction of Nylon 6,6
3. Manufacturing Process Flow
4. Polymerisation of Nylon 6,6
5. Melt Spinning of Nylon 6,6
6. Drawing of Nylon 6,6 Filaments
7. Important Process Control Points
8. Applications of Nylon 6,6
9. Nylon 6 and Nylon 6,6: Basic Difference
10. Frequently Asked Questions

1. Raw Materials Used in Nylon 6,6

The two main raw materials used in the manufacture of Nylon 6,6 are:

Raw Material	Chemical Nature	Role in Nylon 6,6 Formation
Hexamethylene diamine	Diamine compound	Provides amine groups required for amide bond formation.
Adipic acid	Dicarboxylic acid	Provides carboxylic acid groups required for amide bond formation.

For producing high molecular weight Nylon 6,6, the two raw materials must be combined in nearly equal molecular proportion. If one material is present in excess, the polymer chain may terminate early, resulting in lower molecular weight and weaker fibre properties.

2. Chemical Reaction of Nylon 6,6

Nylon 6,6 is formed by condensation polymerisation. In this reaction, the amine group of hexamethylene diamine reacts with the carboxylic acid group of adipic acid. During this reaction, amide linkages are formed and water is eliminated as a by-product.

The simplified reaction may be written as:

\( nH_2N-(CH_2)_6-NH_2 + nHOOC-(CH_2)_4-COOH \rightarrow [-NH-(CH_2)_6-NH-CO-(CH_2)_4-CO-]_n + H_2O \)

The important point is not merely the formula, but the formation of repeated amide linkages. These amide linkages are responsible for many characteristic properties of Nylon 6,6, such as strength, abrasion resistance, resilience and heat resistance.

Technical note: Nylon 6,6 is a polyamide. The word polyamide means a polymer containing many amide linkages in its molecular chain.

3. Manufacturing Process Flow

The manufacturing process of Nylon 6,6 may be understood in the following sequence:

Hexamethylene diamine + Adipic acid → Nylon salt → Polymerisation → Nylon polymer → Chips → Melt spinning → Cooling → Drawing → Winding

In industrial practice, the process is carefully controlled because fibre quality depends not only on the chemistry but also on melting, filtration, extrusion, cooling, drawing and winding conditions.

4. Polymerisation of Nylon 6,6

The first important stage is the preparation of nylon salt. Hexamethylene diamine and adipic acid are mixed in water to form a salt. This salt helps in maintaining the correct balance between the amine and acid groups.

The nylon salt solution is then concentrated by removing water. After this, it is heated under controlled conditions so that polymerisation can take place. As the reaction proceeds, long polymer chains are formed. Water produced during the reaction must be removed so that the reaction can continue in the forward direction.

The molten polymer may then be extruded and cut into chips. These chips are later used for fibre spinning. In some continuous processes, the molten polymer may also be taken directly for spinning.

Practical understanding: Polymerisation creates the fibre-forming material. Spinning converts that material into filaments. Drawing improves the strength and orientation of those filaments.

5. Melt Spinning of Nylon 6,6

Nylon 6,6 is generally spun by the melt spinning process. In melt spinning, the nylon polymer chips are first dried and then melted. The molten polymer is forced through a spinneret, which is a metal plate containing a number of very fine holes.

As the molten nylon comes out of the spinneret, it appears in the form of fine continuous filaments. These filaments are cooled by air and solidify quickly. The number, size and shape of spinneret holes influence the fineness and cross-sectional character of the filaments.

During spinning, the molten polymer should be protected from unnecessary contact with oxygen because oxidation and degradation can affect the quality of the polymer. For this reason, inert conditions such as nitrogen atmosphere may be used in some systems.

6. Drawing of Nylon 6,6 Filaments

The filaments obtained immediately after spinning are not fully strong. Their molecular chains are not yet sufficiently aligned along the fibre axis. Therefore, the filaments are drawn after spinning.

Drawing means stretching the filaments under controlled conditions. During drawing, the molecular chains become more oriented in the direction of the fibre length. This increases tensile strength, improves dimensional stability and gives the filament better textile performance.

In a typical drawing arrangement, the yarn passes through one set of rollers running at a lower speed and then through another set of rollers running at a higher speed. The difference in roller speed stretches the yarn. The draw ratio may vary depending on the required final properties of the fibre.

After drawing, the filament yarn may be wound on a package. Depending on the end use, it may also be twisted, textured or further processed.

7. Important Process Control Points

The quality of Nylon 6,6 fibre depends on several process control points. Some of the most important are given below:

Process Stage	Control Point	Why It Matters
Raw material preparation	Correct ratio of diamine and acid	Helps in forming high molecular weight polymer.
Polymerisation	Removal of water	Drives the condensation reaction forward.
Chip preparation	Drying of chips	Moisture can create defects during melt spinning.
Melt spinning	Temperature and viscosity control	Ensures smooth flow through the spinneret.
Cooling	Uniform quenching	Prevents uneven filament structure.
Drawing	Draw ratio and roller speed	Controls strength, elongation and molecular orientation.
Winding	Package tension	Prevents yarn damage and package defects.

8. Applications of Nylon 6,6

Nylon 6,6 is used in both textile and industrial applications. Its strength, abrasion resistance and resilience make it suitable for demanding end uses.

Area	Examples
Apparel	Hosiery, sportswear, linings and lightweight fabrics.
Home textiles	Carpets and upholstery fabrics.
Industrial textiles	Tyre cords, ropes, conveyor belts, nets and sewing threads.
Engineering uses	Moulded parts, gears, bearings and other components where strength and wear resistance are needed.

9. Nylon 6 and Nylon 6,6: Basic Difference

Nylon 6 and Nylon 6,6 are both polyamide fibres, but they are made from different raw materials. Nylon 6 is made from caprolactam, whereas Nylon 6,6 is made from hexamethylene diamine and adipic acid.

Point of Difference	Nylon 6	Nylon 6,6
Raw material	Caprolactam	Hexamethylene diamine and adipic acid
Polymer type	Polyamide	Polyamide
Manufacturing route	Ring-opening polymerisation	Condensation polymerisation
General character	Good toughness and dyeability	Good strength, heat resistance and dimensional stability

10. Common Student Mistakes

Students often remember only that Nylon 6,6 is made from two chemicals, but the more important understanding is that these two chemicals form amide linkages. These amide linkages make Nylon 6,6 a polyamide.

Another common mistake is to think that spinning alone gives full strength to the fibre. In reality, drawing is essential because it aligns the polymer chains and improves strength.

A third mistake is confusing Nylon 6 with Nylon 6,6. Nylon 6 is produced from one main raw material, while Nylon 6,6 is produced from two main raw materials.

Frequently Asked Questions

1. Why is it called Nylon 6,6?

It is called Nylon 6,6 because both of its main raw materials contain six carbon atoms. Hexamethylene diamine has six carbon atoms and adipic acid also has six carbon atoms.

2. What type of polymerisation is used for Nylon 6,6?

Nylon 6,6 is produced by condensation polymerisation. During this reaction, amide linkages are formed and water is eliminated.

3. Why is drawing necessary after spinning?

Drawing is necessary because freshly spun filaments have lower molecular orientation. When the filament is stretched, the polymer chains become more aligned along the fibre axis, improving strength and usefulness.

4. What is the function of the spinneret?

The spinneret converts molten polymer into fine continuous filaments. It contains small holes through which the molten nylon is extruded.

5. Why is Nylon 6,6 important in textiles?

Nylon 6,6 is important because it has good strength, elasticity, abrasion resistance and resilience. These properties make it useful for apparel, carpets and industrial textile products.

Summary

Nylon 6,6 is manufactured from hexamethylene diamine and adipic acid. These raw materials first form nylon salt, which is then polymerised to produce Nylon 6,6 polymer. The polymer is converted into chips or directly taken for spinning.

In melt spinning, the polymer is melted and extruded through a spinneret to form filaments. These filaments are cooled, drawn and wound. Drawing is a very important stage because it improves molecular orientation and gives the fibre its required strength.

Thus, the manufacturing process of Nylon 6,6 may be understood as a combination of chemistry and fibre formation: polymerisation creates the polymer, melt spinning creates the filament, and drawing develops the final textile properties.

Disclaimer

This article is intended for textile students, merchandisers and general readers. Industrial Nylon 6,6 manufacturing may vary depending on plant design, polymer grade, equipment configuration and end-use requirements. The explanation here simplifies the process for educational understanding.

Properties of Acetate Rayon

Properties of Acetate Rayon

55/20/3s means 55 denier yarn, 20 filament and 3 TPI S side.

Moisture content of sec. Cellulose acetate is 6.5% at 70 deg F and 65% RH.
( Moisture Content= Wt of water in a material /Total wt of material) ( Moisture Regain= wt of water in a material/ oven dry wt of material)
( RH= actual humidity/ humidity of air saturated in water).

Tenacity of Acetate rayon is 1.4 gpd at dry state and 0.9 gpd at wet state.

Elongation at break is 25% in dry state and 35% in wet state

Acetate Rayon is more sensitive to heat. It begins to weaken at 93 deg C. At 175 deg C it becomes sticky and melts at 260 deg C. Like nylon and polyester it is thermoplastic. Thus permanent crimp, pleats and creases can be imparted to the garment under carefully controlled conditions.

Acetate rayon is soluble in acetone, methyl ethyle ketone etc.

Some degeneration takes place when this fiber is exposed to light but not very serious.

It is stable to hot water.

It can also withstand treatment with soap or alkali solution having a pH of not more than 9.5 at temp upto 100 deg C. Therefore it can undergo normal scouring and dyeing operations without affecting the lustre.

It is unaffected by dilute solutions of weak acids but attacked by strong acids. Concentrated organic acids cause swelling

It is resistant to attack by bacteria and fungi. Its low moisture content contributes to resistance to mildew.

It is non toxic and non irritating to skin

Only a few striations ( 2-3) are present in the fibre as can be seen from the longitudinal view. The cross section of the fiber have individual lobes and are round and smooth. It is the smaller number of lobes or serrations of acetate fibres that distinguish the fibre from more numerous serrations of viscose rayon.

Manufacturing Process of Acetate Rayon

Acetate Rayon

We know that

Alcohol + Acid --> Ester

If the cellulose is treated with acetic acid under certain conditions the free hydroxyl groups of cellulose are converted into ester groups.

Manfacture of cellulose acetate

Unlike inthe case of viscose rayon and cuprammonium rayon, where cellulose is dissolved and regenerated, cellulose acetate is manufactured by converting cellulose into a chemical compound of cellulose ( or chem modified cellulose) which is then dissolved in a suitable solvent ( chloroform or acetone) and spun by evaporating the solvent. Thus while viscose and cuprammonium rayons are regenerated fibres, acetate rayon is regenerated modified fibre.

Raw Material

Cotton linters and wood pulp are the most common employed raw materials for the manufacture of acetate rayon

Acetylation Process



The pretreated purified cotton linters are fed into an acetylator ( closed vessel) containing a mixture of acetic anhydride, glacial acetic acid and a small amount of concentrated sulphuric acid. For every 100 kg of cotton linters, 300 kg of glacial acetic acid, 500 kg of acetic anhydride and 8-10 kg of concentrated su;phuric acid may be used. The acetylator consists of a metal tank having a circular door at the top. The door is sealed after adding the mixture of chemicals and cotton linters. A stirrer having many blades rotates in the acetylator to mix the ingredients thoroughly. The acetylation reaction is an exotherimic reation. Heat is removed by circulating cold water through a jacket fitted to the acetylator. The acetylation reation is completed in 7-8 hours at 25-30 deg c. Triacetate is formed at this stage and it is in the form of a suspension in the acetylation mixture called the acid dope.

Hydrolysis ( Partial Deacetylation)

The acid dope from the above process is stored in jars for ageing. Acetic acid, water and sulphuric acid are added and allowed to stand for 10-20 hours. During this period, called ripening period, partial conversion of acetate groups to hydroxy groups takes place. The mixture is then diluted with water and stirred continuously when white flakes of acetate rayon get precipated. The flakes are placed in a centrifuge and the excess water is forced out of the cage through perforations. The flakes are then dried.

Spinning Solution or Dope

Acetate rayon is manufactured by dry spinning. It is dissovled in a volatile solvent (Acetone) to form the spinning solution or dope. This solution is forced through a spinnerette into a chamber in which hot air is circulated. The solvent evaporates leaving filaments of acetate rayon.

The details are as follows. Dried acetate flakes are mixed with three times the weight of acetone in enclosed tanks which are provided with powerful stirrers. The acetate dissolves slowly in the solvent. It takes about 24 hours for the complete dissolution to give a thick clear liquid called dope. The solution is filtered and deareated.

Spinning Process



The dope is spun into acetate rayon filaments on the dry spinning process. The dope is fed from a spinning tank into spinning cabinets. The dope coming out of the spinnerette travels a distance of 2-5 meters vertically downwards to a feed roller, from where it is guided on to a bobbin at a much greater speed than the speed of spinning. This imparts twist to the filaments.

Some Online Resources in Silk: A Practical Guide to Silk Types and Market Terms

Silk is one of those fibres where the same word can mean different things to different people. A weaver may speak in terms of Korea silk, China silk, Desi silk, Katiya, Matka or Ghicha, while a textbook may classify silk into Mulberry, Tasar, Eri and Muga. A merchandiser, therefore, needs both languages: the scientific classification and the market vocabulary.

This note began as a search for useful online resources on silk, especially for terms that are frequently heard in Indian textile markets but are not always clearly explained in standard textile books. The most important lesson is simple: when somebody says “silk”, we must immediately ask: which silk, which yarn route, which cocoon source, and which fabric construction?

India is especially important in this discussion because it produces all four commercially known natural silks: Mulberry, Tasar, Eri and Muga. Tasar, Eri and Muga are generally grouped as Vanya silks, or non-mulberry silks. For a buyer or student, this classification is only the beginning. The real understanding comes when we connect the fibre source with yarn preparation, weaving practice, finishing and market terminology.

Table of Contents

• Why Silk Terms Are Confusing
• The Four Major Natural Silks
• Mulberry Silk
• Tasar or Tussar Silk
• Eri Silk
• Muga Silk
• Important Indian Market Terms in Silk
• Reeled, Spun and Waste-Based Silk
• Buyer’s Checklist Before Approving Silk Fabric
• Care of Silk Fabric
• Related Reading
• General Disclaimer

Visual 1: Silk understanding map showing fibre source, yarn route, fabric character and market terminology.

Why Silk Terms Are Confusing

Silk terminology is confusing because it comes from several worlds at the same time. Some terms come from biology, such as Mulberry, Tasar, Eri and Muga. Some come from yarn preparation, such as reeled silk, spun silk, noil silk and filature silk. Some come from market usage, such as Korea silk, China silk and Desi silk. Some come from Indian craft practice, such as Matka, Ghicha, Katiya, Balkal, Gajji and Mashru.

The problem starts when we treat all these terms as if they belong to the same classification system. They do not. For example, Mulberry is a silk type based on the silkworm and feed source. Matka is better understood as a spun silk yarn or fabric character. Dupion is related to double cocoons and slubbed yarn. Gajji is a fabric construction and market term, not a biological silk category.

A useful way to reduce confusion is to ask four questions. First, what is the fibre source? Second, is the yarn reeled, spun, drawn or waste-based? Third, what is the fabric construction? Fourth, how is the term used in the market? Once these questions are asked, silk becomes much easier to understand.

The Four Major Natural Silks

The four important natural silks in the Indian context are Mulberry, Tasar, Eri and Muga. Mulberry silk is generally associated with smoothness, fineness and lustre. Tasar silk is associated with natural texture, subdued lustre and earthy character. Eri silk is associated with softness, warmth and spun yarn character. Muga silk is associated with Assam, natural golden colour and cultural value.

Silk Type	General Source	Typical Character	Common Practical Use
Mulberry Silk	Bombyx mori silkworm feeding mainly on mulberry leaves	Smooth, lustrous, fine and regular	Sarees, scarves, dress materials, luxury fabrics
Tasar or Tussar Silk	Wild or semi-wild silkworms, often from the Antheraea group	Textured, earthy, slightly coarse and naturally rich	Sarees, dupattas, stoles, furnishing, dress materials
Eri Silk	Eri silkworm, often associated with castor leaves	Soft, warm, woolly and spun-silk-like	Shawls, stoles, winter textiles, comfort fabrics
Muga Silk	Associated strongly with Assam	Natural golden colour, lustrous and durable	Traditional garments, sarees, ceremonial textiles

Mulberry Silk

Mulberry silk is the best-known and most widely used type of silk. It is produced by the silkworm Bombyx mori, which feeds mainly on mulberry leaves. In general trade language, when people simply say “silk”, they often mean mulberry silk unless specified otherwise.

Mulberry silk is valued for its smooth handle, lustre, softness and drape. It is used in sarees, dress materials, scarves, furnishing fabrics, carpets and many traditional Indian textiles. From a merchandiser’s point of view, mulberry silk is usually associated with finer and more regular yarns compared to many wild silks.

However, final fabric quality depends not only on the fibre. It also depends on yarn denier, twist, degumming, weaving, finishing, dyeing and the skill of production. In simple terms, a fabric can be made from mulberry silk and still vary greatly in handle, lustre, strength, transparency and price.

Tasar or Tussar Silk

Tasar silk, also written as Tussar or Tussah, is a non-mulberry silk. In India, tasar is strongly associated with traditional and craft-based fabrics. It is often described as having a slightly coarse, textured, natural and earthy character.

Tasar does not try to imitate the smooth perfection of fine mulberry silk. Its beauty lies in its natural irregularity, subdued lustre and organic texture. Many tasar fabrics have beige, honey, coppery or dull-gold tones depending on source, processing and dyeing.

For merchandisers, Tasar is important because it frequently appears in sarees, dupattas, stoles and dress materials. The buyer should check whether the fabric uses reeled tasar, spun tasar, Ghicha, Katiya or other waste-based yarns, because each of these gives a different fabric character.

Eri Silk

Eri silk is another non-mulberry silk. The name is linked with the castor plant, as castor leaves are one of the important food sources of the Eri silkworm. Eri silk is often called a “peace silk” in popular language because, traditionally, the moth may emerge from the cocoon before the fibre is spun.

Unlike mulberry silk, Eri is generally spun rather than reeled. This is because the cocoon structure does not easily provide one long continuous filament in the same way as mulberry silk. The resulting yarn has a warm, soft, woolly and cottony handle rather than the slick smoothness of filament silk.

This makes Eri particularly interesting for shawls, stoles, winter textiles and fabrics where comfort and softness are more important than high lustre. A buyer should not reject Eri because it lacks the shine of filament silk. Its value lies in a different kind of silk experience.

Muga Silk

Muga silk is one of India’s most distinctive silks. It is associated with Assam and is famous for its natural golden colour, lustre and durability. Muga is not just another silk variety. It carries geographical, cultural and heritage value.

Among Indian silks, Muga has a special identity because it is closely tied to Assam’s textile culture. Its golden tone is natural, and the fabric is often prized for ceremonial and traditional garments. Because genuine Muga is rare and expensive, authenticity becomes very important.

In the market, one may hear expressions such as “Muga look”, “Muga finish” or “Muga colour”. These should not be confused with genuine Muga silk. A merchandiser must check whether the term refers to actual Muga fibre or merely to a colour and surface effect inspired by Muga.

Visual 2: Comparison of Mulberry, Tasar, Eri and Muga silk by source, handle, lustre and typical product use.

Important Indian Market Terms in Silk

Indian silk markets use many words that are extremely useful but not always standardized. Terms such as Katiya, Balkal, Matka, Ghicha, Dupion, Gajji, Mashru, Korea silk, China silk and Desi silk should be understood carefully. Some terms indicate yarn origin, some indicate cocoon condition, some indicate waste utilization, and some indicate fabric construction.

Katiya Silk

Katiya is an important trade term, especially in the tasar silk chain. It may be understood as yarn made from the portion of tasar cocoons left after the reelable silk has been removed. In many tasar production systems, the cocoon does not yield one continuous high-grade filament throughout.

The better reelable portion is taken first. The remaining portion, waste or partially reelable material may then be processed into spun or irregular yarn. Katiya usually implies more irregularity, more texture and a different price-quality position compared to fine reeled silk.

Balkal Silk

Balkal is another term connected with tasar. It is generally associated with the peduncle or anchoring portion of the cocoon. This portion is weaker and less suitable for fine reeling, but it can still be converted into useful yarn.

Balkal belongs to the family of yarns where silk waste or lower-grade cocoon portions are converted into fabric value. Such yarns may show unevenness, slubs, thickness variation and rustic appearance. These are not necessarily defects if the fabric is designed for that look.

Spun Silk

Spun silk is made from short lengths of silk fibre obtained from silk waste, pierced cocoons, floss or other non-reelable material. This distinction is important because not all silk yarn is filament yarn. Some silk yarn is produced in a spinning system, somewhat comparable in principle to cotton or wool spinning.

Spun silk may have less brilliance than continuous filament silk, but it can have a beautiful soft handle. It is useful where a slightly textured, less slippery and more fabric-like surface is desired.

Noil Silk

Noil silk is made from the shorter fibres removed during combing in the spun silk process. It is usually more matte, less lustrous and more textured than regular spun silk. It may resemble cotton or wool in surface character while still retaining the identity of silk fibre.

Silk Form	General Character
Reeled filament silk	Smooth, lustrous and made from continuous filament
Spun silk	Made from shorter silk fibres, softer and more textured
Noil silk	Made from very short fibres, more matte and irregular

Dupion Silk

Dupion silk is reeled from double cocoons, where two silkworms spin together and their filaments become interlocked. Because the filaments cannot be reeled as smoothly as regular cocoons, the yarn develops irregularities, slubs and thick-thin effects.

Dupion is an excellent example of a textile principle: what is technically irregular can become aesthetically valuable. The slubs and cross-lines in Dupion are often the very reason designers like it. It is used in sarees, lehengas, jackets, home textiles and occasion wear.

Filature Silk

Filature silk refers to raw silk reeled by machine, as distinct from silk prepared by hand in cottage or traditional settings. In practical buying, filature silk suggests more controlled reeling, better regularity and more standardized yarn quality.

However, the word “filature” should not be treated as a complete quality guarantee. One must still examine denier, evenness, cleanliness, twist, strength, gum content, dyeing behaviour and fabric performance.

Matka Silk

Matka silk is one of the most important trade terms in Indian silk fabrics. It is generally associated with textured silk yarn made from pierced or waste cocoons. Matka fabrics are usually thicker, textured and somewhat linen-like in appearance.

Matka is not meant to look perfectly smooth. Its charm is in the unevenness. It often carries a handspun quality and rustic elegance. In current trade, however, the term may be used broadly, and the exact production method should be verified with the supplier.

Mashru

Mashru is not always a pure silk fabric, but it is very important in the study of Indian traditional textiles. It is usually understood as a satin weave fabric with a glossy surface, traditionally involving silk or rayon in the warp and cotton in the weft.

Historically, Mashru is associated with a fascinating cultural logic: the fabric gives a silk-like appearance on the outside while keeping cotton in contact with the body. In modern markets, Mashru may be made with rayon, viscose, cotton, silk or blends depending on price and production context.

Gajji Silk

Gajji is commonly associated with a heavy satin weave silk fabric, especially used in Bandhani and tie-dye sarees and dupattas from Gujarat and Rajasthan. Gajji has a dense, smooth and lustrous surface.

It accepts tie-dye effects beautifully because the satin surface reflects colour strongly. In the market, “Gajji silk” may sometimes be loosely used, so the buyer must confirm whether the fabric is pure silk, art silk, viscose or a blend.

Korea Silk, China Silk and Desi Silk

Korea silk, China silk and Desi silk are useful market terms, but they must be handled carefully. They are not the same as the scientific classification of silk into Mulberry, Tasar, Eri and Muga. They may refer to yarn origin, denier range, texture, evenness or local trade convention.

For example, when a supplier says Korea × China, it may mean one type of yarn in the warp and another in the weft. But this should always be confirmed because trade language can vary by region and supplier. A merchandiser should convert such expressions into a technical specification before approving production.

Reeled, Spun and Waste-Based Silk

Many confusions in silk can be reduced if we separate silk into three broad routes: reeled silk, spun silk and waste-based silk. This classification is very useful because it explains why two fabrics can both be called silk but behave very differently.

One fabric may be smooth, lustrous and slippery. Another may be matte, thick, textured and almost linen-like. Both can be silk, but their yarn route and fabric construction are different.

Route	Meaning	Examples
Reeled silk	Continuous filament unwound from cocoon	Mulberry filament, filature silk, some tasar
Spun silk	Short fibres spun into yarn	Eri, spun silk, Matka
Waste-based or leftover silk	Made from pierced cocoons, peduncles, noil or cocoon waste	Katiya, Balkal, noil, some Matka and Ghicha-type yarns

A simple textile equation can be remembered as:

\( \text{Silk Fabric Character} = \text{Fibre Source} + \text{Yarn Route} + \text{Fabric Construction} + \text{Finishing} \)

This equation is not a mathematical formula in the strict scientific sense. It is a practical reminder that fabric character is never decided by the fibre name alone. A silk fabric becomes what it is because of the entire chain from cocoon to yarn to fabric to finishing.

Visual 3: Flow chart showing how cocoon quality and processing route lead to reeled silk, spun silk, noil, Matka, Katiya and Balkal.

Buyer’s Checklist Before Approving Silk Fabric

Before approving any silk fabric, a buyer should not rely only on the name given by the supplier. The name may be useful, but it is only the starting point. The buyer must convert the name into fibre content, yarn route, construction and performance expectations.

1. Is it pure silk, blended silk, art silk, viscose or polyester?
2. Is the yarn reeled, spun, handspun, drawn or waste-based?
3. Is the silk type Mulberry, Tasar, Eri, Muga or a trade-quality term?
4. What is the yarn count or denier?
5. What is the warp yarn and what is the weft yarn?
6. Is the fabric degummed, semi-degummed or gum-retaining?
7. What weave is used: plain, twill, satin, crepe or jacquard?
8. Is the irregularity intentional, as in Dupion or Matka, or is it a defect?
9. Is the colour natural, dyed, printed or finished?
10. What care method is recommended?

These questions help prevent one of the most common buying mistakes: comparing two silk fabrics only by price without understanding fibre source, yarn route, construction and finishing. In silk, a lower price may mean a different raw material, different yarn route, different fabric density or different authenticity level.

Care of Silk Fabric

Silk care depends on the type of silk, dyeing, finishing, embellishment and fabric construction. However, some general precautions are useful. Silk should usually be protected from harsh sunlight, strong alkalis, chlorine bleach, aggressive rubbing and high heat.

Many silk fabrics are best dry-cleaned, especially if they are expensive, heavily dyed, embroidered, printed or embellished. Washing should be done only when the care label or supplier confirms that the fabric is washable.

Risk	Why It Matters
Sunlight	Can weaken silk and fade colours
Alkali	Silk is a protein fibre and may be damaged by strong alkalis
Perspiration	Can affect colour and handle if not cleaned properly
Perfume	May stain or affect dyes and finishes
Rough rubbing	Can cause abrasion, fibrillation or surface damage
High heat	Can affect lustre, handle and dimensional stability

Quick Glossary for Merchandisers

Term	Simple Explanation
Mulberry silk	Silk from Bombyx mori fed mainly on mulberry leaves
Tasar or Tussar	Wild or non-mulberry silk, often textured and earthy
Eri	Spun non-mulberry silk, soft and warm
Muga	Golden silk associated with Assam
Katiya	Yarn from leftover tasar cocoon material after reelable portion
Balkal	Yarn from peduncle or anchoring portion of tasar cocoon
Matka	Textured silk yarn or fabric often made from pierced or waste cocoons
Noil	Short fibres removed during spun silk processing
Dupion	Slubbed silk associated with double cocoons
Filature silk	Machine-reeled raw silk
Gajji	Heavy satin silk fabric often used in tie-dye traditions
Mashru	Satin fabric traditionally with silk or rayon face and cotton back

A Small Note on Authenticity

Silk terminology in the market is not always standardized. Some names are scientific, some are regional, some are trade terms and some are marketing expressions. Therefore, a merchandiser should avoid accepting a fabric name at face value.

A better approach is to combine three forms of knowledge. First, understand the scientific classification: Mulberry, Tasar, Eri and Muga. Second, understand the production route: reeled, spun, handspun, waste-based, filature or cottage-made. Third, understand the market vocabulary: Korea, China, Desi, Matka, Gajji, Katiya, Balkal and Dupion.

When these three layers are combined, silk becomes much easier to understand. The buyer is then able to ask better questions, compare fabrics more fairly and avoid being misled by attractive but vague market names.

Related Reading on Silk Fabrics and Indian Textile Terms

• Silk Fabric Terms Explained — Part 1: A Practical Map for Understanding Silk Fabrics
• Silk Fabric Terms Explained — Part 2: Understanding Silk Yarns
• Silk Fabric Terms Explained — Part 5: Indian Silk Terms — Bafta, Kora, Ghicha and Matka
• How to Know Whether a Fabric is Pure Silk, Blended Silk or Part Silk
• Degummed Silk Yarn: How Raw Silk Becomes Soft and Lustrous

General Disclaimer

This article is intended for textile education, merchandising awareness and general understanding of silk terminology. Silk trade terms may vary by region, supplier and market practice. For commercial buying, quality approval, labelling, export documentation or legal claims, the fibre content, yarn route, construction, processing and care instructions should be verified through supplier declarations, laboratory testing and relevant standards wherever required.