Making Fancy Denim- Amsler Slub, Multicount and Multitwist Yarn

Making Fancy Denim: Amsler Slub, Multi-count and Multi-twist Yarns

Denim is no longer only a plain indigo fabric with a twill weave. Over the years, denim has become a surface of expression. Different yarn effects, dyeing methods, washing techniques and finishing treatments are used to create denim that looks aged, rugged, irregular, vintage, fashionable or handcrafted.

One important route for creating such effects is the use of fancy yarns. Among these, Amsler slub yarn, multi-count yarn and multi-twist yarn are closely associated with cross-hatch and fancy denim effects. In denim practice, the word “Amsler” is often used almost as a shorthand for a controlled slub or fancy-yarn effect, even though the actual fabric appearance depends on yarn design, dyeing, weaving and washing together.

Table of Contents

1. What Is Fancy Denim?
2. What Is Amsler Slub Yarn?
3. Why Slub Yarn Is Difficult to Produce
4. Principle of Amsler Slub Formation
5. Important Slub Parameters
6. Slub Yarn and Cross-Hatch Denim
7. What Is Multi-count Yarn?
8. What Is Multi-twist Yarn?
9. Comparison: Slub, Multi-count and Multi-twist
10. Practical Points for Merchandisers and Buyers
11. Common Mistakes in Understanding Amsler Denim
12. Final Understanding

What Is Fancy Denim?

Fancy denim is denim in which the yarn itself contributes to the visual character of the fabric. In regular denim, the yarn count, yarn twist and yarn thickness are relatively uniform. The fabric surface therefore appears more even, except for the effect created by weave, indigo dyeing and washing.

In fancy denim, deliberate irregularity is introduced into the yarn. This irregularity may appear as thick and thin places, changes in count, changes in twist, or combinations of these effects. When such yarns are woven and later washed, the denim surface shows streaks, cross-hatch marks, uneven dye absorption and a more natural-looking texture.

This is why slub yarns became so important in fashion denim. They help create a fabric that does not look mechanically perfect. Instead, the fabric appears more alive, more casual and more vintage.

Visual 1: Fancy denim effect map showing how slub yarn, multi-count yarn and multi-twist yarn influence denim appearance.

What Is Amsler Slub Yarn?

A slub yarn is a yarn in which thicker portions are intentionally introduced at intervals. These thick places are called slubs. The slubs may be short or long, frequent or widely spaced, mild or prominent, depending on the desired fabric effect.

Amsler slub yarn can be produced on both ring spinning and open-end spinning systems. In denim, Amsler slub effects are commonly produced on open-end spinning because the attachment allows slub and multi-twist effects at a comparatively lower cost than true ring-spun fancy yarn.

The principle is simple but technically important: the spinning system is controlled so that more fibre is fed for a short period of time. This creates a thicker place in the yarn. The key is not merely to make a thick place, but to make it in a controlled way so that the yarn does not become too weak or too unpredictable during weaving.

Why Slub Yarn Is Difficult to Produce

Producing slub yarn is not just a matter of creating thick and thin places. If the slub is not properly controlled, it can create weak places in the yarn. One major problem is that a thick place may be followed by a thin place, instead of returning smoothly to the normal yarn count. This thin region becomes a vulnerable zone and may lead to yarn breakage during winding, warping, sizing or weaving.

Another issue is twist distribution. In a slub yarn, the thick and thin sections do not receive twist in the same way. The twist in different portions of the yarn is related to the linear density of that portion. In simple terms, when the yarn becomes thicker, the twist per unit mass and the compactness of that region may change.

A simplified way to understand this is:

\[ \text{Yarn linear density} \uparrow \Rightarrow \text{local yarn thickness} \uparrow \]

When the linear density changes suddenly, twist distribution and fibre binding also change. Therefore, slub design must be controlled carefully. A good slub yarn should create visible fabric character without making the yarn too weak, too irregular for processing, or too difficult to weave.

Principle of Amsler Slub Formation

The Amsler effect is created through controlled variation in fibre feed or drafting. In a normal yarn, the fibre feed and machine speed remain stable. In Amsler slub yarn, a microprocessor-controlled servo motor creates a programmed overfeed for a short period. This produces a thicker section in the yarn according to a pre-designed pattern.

In ring spinning, the servo drive system may be connected to the drafting rollers through a special gearbox. During normal yarn formation, the machine runs at the regular setting. When a slub is required, the servo motor changes the drafting conditions and introduces extra material into the yarn. The purpose is to create the slub without disturbing the normal yarn formation too severely.

In open-end spinning, the broad principle is similar: a controlled excess feed of fibre is introduced for a specific duration. This creates the slub effect. Since open-end spinning is already widely used for denim yarns, attaching a slub device to open-end spinning becomes a practical and economical route for fancy denim.

Visual 2: Amsler slub formation diagram showing normal yarn, programmed overfeed, slub formation and return to base count.

Important Slub Parameters

A slub yarn is defined not only by the presence of thick places, but by the design of those thick places. The important parameters are slub thickness, slub length, slub frequency, spacing, ramp and base yarn count. Each of these parameters influences how the denim finally looks after dyeing, weaving and washing.

Parameter	Meaning	Effect on Fabric
Slub thickness	How much thicker the slub is compared to the base yarn	Determines visibility and boldness
Slub length	Length of the thick portion	Short slubs give speckled effects; long slubs give streaky effects
Slub frequency	Number of slubs per unit length	Higher frequency gives a busier surface
Slub spacing	Distance between two slubs	Controls regularity or randomness
Slub ramp	Transition from normal yarn to slub and back	Affects smoothness and yarn strength
Base yarn count	Normal yarn count between slubs	Controls fabric weight and ground appearance

For denim, these parameters are selected according to the desired look. A subtle cross-hatch denim may need moderate and irregular slubs. A bold vintage denim may require more prominent slubs. A highly fashionable denim may use a combination of slub effects in warp and weft.

Slub Yarn and Cross-Hatch Denim

Cross-hatch denim shows irregular lines in both directions of the fabric. The effect may be created when slub or irregular yarns are used in warp, weft, or both. When the slub yarn is dyed with indigo and woven into denim, the thick and thin places absorb and reflect colour differently. During washing, abrasion also affects these areas differently.

The result is a surface that looks uneven in a controlled way. The fabric may show cloudy streaks, grainy texture, vintage character or handmade appearance. This is especially valuable in fashion denim, where perfect uniformity is often less attractive than controlled imperfection.

What Is Multi-count Yarn?

A multi-count yarn is a yarn in which the yarn count changes deliberately along its length. Unlike simple slub yarn, where short thick places are introduced, multi-count yarn has controlled count variation over longer lengths.

In simple terms, the yarn may run as a finer count for one portion and then become coarser for another portion. These changes are not random defects; they are planned effects. When woven into denim, they create variation in fabric density, appearance and handle.

Multi-count yarn is useful when the designer wants a more extended change in fabric character rather than small slub-like irregularities. It can give a fabric a natural, uneven and engineered look.

Feature	Slub Yarn	Multi-count Yarn
Main effect	Thick places at intervals	Controlled count changes over length
Length of effect	Usually shorter	Usually longer
Visual appearance	Specks, streaks, knots and irregular texture	Broader variation in surface density
Main control	Slub length, thickness and frequency	Count level and length of count zone
Denim use	Vintage, cross-hatch and rugged looks	Engineered unevenness and count variation

What Is Multi-twist Yarn?

A multi-twist yarn is a yarn in which the yarn count remains constant, but the twist level changes along the yarn length. These different twist levels influence dye intake, yarn compactness, surface hairiness and fabric appearance.

Twist affects compactness, hairiness, strength, absorbency and dye behaviour. A higher twist zone may behave differently from a lower twist zone during dyeing and washing. When such yarn is used in denim, the variation in twist can produce subtle shade and texture changes.

This is particularly important in denim because indigo dyeing is a surface dyeing process. Indigo does not penetrate the cotton yarn fully in the same way as many other dyes. Therefore, small differences in yarn structure, twist and compactness can produce visible differences after dyeing and washing.

A simple conceptual relationship is:

\[ \text{Twist variation} \Rightarrow \text{compactness variation} \Rightarrow \text{dye and wash variation} \]

In multi-twist yarn, the fibre mass may remain the same, but the internal arrangement of fibres changes because of twist variation. A higher twist portion may become more compact. A lower twist portion may be more open and hairy. These differences affect how dye is taken up and how the yarn surface abrades during washing.

Visual 3: Side-by-side comparison of slub yarn, multi-count yarn and multi-twist yarn with their denim surface effects.

Comparison: Slub, Multi-count and Multi-twist

Slub yarn, multi-count yarn and multi-twist yarn are often discussed together because all three create fancy effects in denim. However, the mechanism behind each effect is different. For a merchandiser, buyer or fabric developer, this distinction is very important. Two fabrics may both be described as “fancy denim,” but the yarn engineering behind them may be completely different.

Yarn Type	What Changes?	What Remains More Stable?	Main Fabric Effect
Slub yarn	Thickness changes locally	Base yarn count between slubs	Thick-thin streaks and vintage texture
Multi-count yarn	Yarn count changes over longer lengths	Twist may be controlled	Broader count variation and uneven surface
Multi-twist yarn	Twist level changes	Yarn count remains constant	Shade variation and subtle texture change

Practical Points for Merchandisers and Buyers

When sourcing fancy denim, it is not enough to say “Amsler denim” or “slub denim.” The fabric developer or buyer should ask for more specific details. The effect may be in the warp, in the weft, or in both directions. It may be a slub effect, a multi-count effect, a multi-twist effect, or a combination.

Question to Ask	Why It Matters
Is the effect in warp, weft, or both?	Determines direction and strength of surface effect
Is it slub, multi-count, multi-twist, or a combination?	Identifies the actual yarn engineering
What is the base yarn count?	Affects fabric weight and construction
What is the slub frequency?	Controls how busy the surface looks
What is the slub thickness ratio?	Controls boldness of effect
What is the slub length range?	Controls whether effect is speckled or streaky
Is the yarn ring-spun or open-end?	Affects handle, strength, cost and appearance
How does the fabric look after wash?	Final denim effect appears after processing

The most important point is that fancy denim should be evaluated after washing, not only in grey or loom-state fabric. Many yarn effects become visible only after dyeing, finishing and garment wash.

Common Mistakes in Understanding Amsler Denim

One common mistake is to treat all slub denim as the same. In reality, slub denim can vary widely depending on slub length, thickness, frequency and yarn count. A mild slub and a bold slub may create completely different garments.

Another mistake is to confuse slub defects with designed slub effects. A defect is uncontrolled and may weaken the fabric or create unacceptable irregularity. A designed slub is intentional, repeatable and planned for a visual purpose.

A third mistake is to judge fancy denim only by the yarn. Denim appearance is the result of yarn, weave, dyeing, finishing and washing. The same slub yarn may look different in two fabrics if the construction, dye depth or wash recipe changes.

Final Understanding

Amsler slub, multi-count and multi-twist yarns represent the engineering side of fashion denim. They show how a fabric effect begins not merely at the washing stage, but much earlier at the yarn-design stage.

Slub yarn creates thick-thin variation. Multi-count yarn creates controlled changes in yarn count. Multi-twist yarn creates changes in twist level while keeping the count constant. All three can create distinctive denim effects, especially when combined with indigo dyeing, twill weaving and garment washing.

For a merchandiser, the key lesson is simple: fancy denim should be understood from yarn to fabric to wash. The surface effect seen by the consumer is the final result of several controlled technical decisions made much earlier in the manufacturing process.

Related Reading on Denim Manufacturing and Processing

• Some Notes on Denim Washing
• Critical Process Parameters- Denim Manufacturing
• Finished Properties of some Common Denim Fabrics
• warp preparation for rope dyeing-1

General Disclaimer

This article is intended for educational and practical understanding of textile and denim concepts. Actual mill practices, machine settings, yarn parameters and fabric results may vary depending on machinery, fibre quality, yarn engineering, dyeing conditions, weaving parameters, finishing route and garment washing process. Readers should verify technical settings with machinery suppliers, mill technologists and relevant testing standards before applying them in production.

How to Stonewash Better

How to Stonewash Better

Traditionally Natural pumice stone is used in denim washing process. It has the following disadvantages:

1. Residual pumice is difficult to remove from washed fabric/garment.

2. There is always a danger of damage to the equipment by overload of tumbling stones and material.This can also clog the drains and sewer lines.

Thus enzymes like cellulase are used to achieve the desirable appearance and soft handle for the fabric.

The problem with using enzymatic treatment is that the removed indigo dye can be redposited on the white yarn of the denim fabric. this process is called back staining and it can mar the look of garment.

Industrially cellulase is used along with Pumice stone for stone washing.

The cellulase can be at ph=7, when it is called the neutrual cellulase or at a pH of 5.5, when it is called the acidic cellulase.

In general the cellulase added is for 60min at 55 deg C as a percentage of the weight of the garment. It can be 3%, 6%, 9% or 12% depending upon the appearance required.

Pumice stone is generally taken as equal in weight that of the garment.

According to a study , the best stone washing ( as measured by the lightness of the sample is achieved for treatment with Neutral cellulases with pumice stone, acid cellulases with pumice stone, neutral cellulases, acid cellulases and pumice stone, in that order.

In the same order tensile strength of the sample decreases.

However, degree of back staining increases in the order of treatment with pumice stone, acid cellulases, neutral cellulases, acid cellulases with pumice stone and neutral cellulases with pumice.

which means a balance needs to be achieved- and where the effort to increase one desirable leads to increase in another undesirable one.


Now that you've finished reading this post, what are you going do? You should go join the Forum.

Finished Properties of some Common Denim Fabrics

Finished Properties of Common Denim Fabrics: Understanding Weight, Yarn Count, Construction and Fastness

Denim is one of the most widely used fabrics in garments, especially for jeans, jackets, skirts, children’s wear and casual apparel. Although denim is often identified by its appearance, shade and wash effect, the real performance of denim depends on measurable fabric properties such as weight, yarn count, ends per inch, picks per inch, rubbing fastness and laundering fastness.

The original note listed finished properties for three common denim fabrics with ideal weights of 14.5 oz/sq yd, 13.75 oz/sq yd and 12.5 oz/sq yd. These values are useful because denim is often commercially discussed by weight category, but weight alone does not tell the full story. A merchandiser, fabric buyer or production person must also understand the relation between yarn count, fabric construction and finished performance.

Table of Contents

• Why Finished Denim Properties Matter
• Comparative Finished Properties of Common Denim Fabrics
• Understanding Fabric Weight in Denim
• Role of Warp and Weft Count
• EPI and PPI: Fabric Construction
• Rubbing Fastness and Laundering Fastness
• Practical Notes for Merchandisers
• Common Mistakes in Reading Denim Specifications
• Conclusion

Why Finished Denim Properties Matter

In denim manufacturing, the fabric that comes out of weaving is not the same as the fabric finally used in garments. Denim passes through finishing operations such as singeing, desizing, washing, sanforizing, softening, skew correction and sometimes special chemical or mechanical treatments. These processes change the fabric’s handle, dimensions, shrinkage, shade appearance and apparent fabric weight.

Therefore, when we say that a denim fabric is 14.5 oz, 13.75 oz or 12.5 oz, we should be clear whether we are talking about greige weight, finished weight or washed weight. Finished properties are especially important because the garment buyer and consumer experience the fabric after finishing, not at the loom stage.

Visual 1: Denim fabric properties map showing how weight, count, construction and fastness affect final performance.

Comparative Finished Properties of Common Denim Fabrics

Property	Heavy Denim	Medium-Heavy Denim	Medium Denim
Ideal Weight	14.5 oz/sq yd	13.75 oz/sq yd	12.5 oz/sq yd
Warp Count, Washed	6.9 ± 0.6	6.9 ± 0.5	6.9 ± 0.5
Weft Count, Washed	6.0 ± 0.4	6.9 ± 0.5	9.0 ± 0.5
EPI, Unwashed	70 ± 2	70 ± 2	70 ± 2
PPI, Unwashed	43 ± 2	43 ± 2	43 ± 2
Actual Weight	14.2 oz/sq yd	13.4 oz/sq yd	12.2 oz/sq yd
Rubbing Fastness, Dry	2–3	2–3	2–3
Fastness to Laundering	2	2	2

This small table contains an important technical lesson. The three fabrics have almost the same warp count, EPI and PPI, but the weft count changes. This means that the weight difference is mainly controlled through the weft yarn, while the face character of the fabric is kept broadly similar.

Understanding Fabric Weight in Denim

Fabric weight in denim is commonly expressed in ounces per square yard. Heavier denim generally feels thicker, stronger and more rigid, while lighter denim feels softer, more flexible and easier to wear in warm conditions. A 14.5 oz denim is usually perceived as a heavy and rugged fabric, while a 12.5 oz denim is closer to a medium-weight commercial denim.

Denim Weight	Practical Meaning	Typical Use
Around 14.5 oz	Heavy denim	Rugged jeans, workwear-inspired garments, structured bottoms
Around 13.75 oz	Medium-heavy denim	Regular jeans, casual bottoms, durable apparel
Around 12.5 oz	Medium denim	Comfortable jeans, fashion denim, lighter casual wear

In the data, the actual finished weights are slightly lower than the ideal weights. For example, the 14.5 oz fabric shows an actual weight of 14.2 oz/sq yd, while the 12.5 oz fabric shows 12.2 oz/sq yd. Such differences can occur because of yarn variation, weaving tension, finishing loss, moisture content and process conditions.

Role of Warp and Weft Count

The warp yarn count remains nearly the same in all three fabrics, around 6.9 Ne. This suggests that the main difference between the three denim qualities is not coming from the warp yarn, but from the weft yarn. The weft count changes from 6.0 Ne in the heavier fabric to 9.0 Ne in the lighter fabric.

In the English cotton count system, a lower count number means a coarser yarn. Therefore, 6s weft is coarser than 9s weft. This explains the weight difference clearly:

\( \text{Coarser weft yarn} \Rightarrow \text{more yarn mass per unit area} \Rightarrow \text{heavier denim} \)

\( \text{Finer weft yarn} \Rightarrow \text{less yarn mass per unit area} \Rightarrow \text{lighter denim} \)

This is a useful point for merchandisers. If EPI and PPI remain almost constant, but fabric weight changes, the change is often due to yarn count, especially weft count.

Visual 2: Relationship between weft count and denim weight, showing why coarser weft gives heavier fabric.

EPI and PPI: Fabric Construction

The construction shown in all three fabrics is approximately 70 × 43. This means that the fabric has about 70 ends per inch in the warp direction and about 43 picks per inch in the weft direction. Since EPI and PPI are the same across all three fabrics, the construction density remains largely unchanged.

EPI stands for ends per inch, or the number of warp yarns in one inch of fabric width. PPI stands for picks per inch, or the number of weft yarns in one inch of fabric length. In the given case:

\( \text{EPI} = 70 \pm 2 \)

\( \text{PPI} = 43 \pm 2 \)

This is a good example of how fabric properties should be read together. Looking only at fabric weight may not explain the reason for the difference. Looking at weight, yarn count and construction together gives a much clearer technical understanding.

Why Warp Count is Similar but Weft Count Changes

In conventional denim, the warp yarn is usually indigo dyed, while the weft yarn is generally undyed or lightly coloured. The warp gives denim its characteristic blue appearance, while the weft contributes strongly to weight, handle and body.

Keeping the warp count similar helps maintain a consistent denim appearance and surface character. Changing the weft count allows the manufacturer to create different weights without drastically changing the face appearance of the fabric. This is why three fabrics can look similar at first glance but behave differently in hand feel, stiffness and garment comfort.

Rubbing Fastness and Laundering Fastness

The dry rubbing fastness given for all three fabrics is 2–3. This indicates that colour transfer during rubbing is a concern. In denim, this is especially important because indigo dye is mainly present on the surface of the yarn rather than deeply penetrating the fibre.

A dry rubbing fastness rating of 2–3 means that some colour transfer may occur when the fabric rubs against another surface. This may appear as blue staining on light-coloured shirts, shoes, bags, upholstery or inner pocketing. For the merchandiser, this means care instructions and buyer expectations should be handled carefully.

The laundering fastness is shown as 2 for all three fabrics. This means that the fabric is likely to lose shade during washing. In denim, this is not always considered a defect because fading is often part of the desired denim character. However, from a quality-control perspective, this rating must be interpreted according to the buyer’s requirement.

Visual 3: Denim fastness performance map showing rubbing fastness, laundering fastness and consumer risk points.

Relationship Between Weight, Comfort and Durability

Heavier denim usually gives better body and ruggedness, but it may feel stiff and warm. Lighter denim gives better comfort and flexibility, but may not have the same rugged appeal. Medium-weight denim often becomes the commercial balance between durability and wearability.

Fabric Weight	Advantages	Possible Limitations
Heavy denim	Strong body, rugged look, durable feel	Stiffer, warmer, slower to break in
Medium-heavy denim	Good balance of strength and comfort	May still feel firm before washing
Medium denim	Softer, easier to wear, better drape	Less rugged appearance than heavy denim

Simple Weight Calculation Concept

A simplified fabric weight relationship can be understood as:

\( \text{Fabric Weight} \propto \text{Yarn Linear Density} \times \text{Fabric Density} \)

In practical terms:

\( \text{Weight} \approx f(\text{Warp Count}, \text{Weft Count}, \text{EPI}, \text{PPI}, \text{Crimp}, \text{Finishing}) \)

This means that the final denim weight is influenced by both yarn size and construction. In the present example, because EPI and PPI are constant, the difference in weight is largely explained by the difference in weft count.

Practical Notes for Merchandisers

A merchandiser should not approve denim only by looking at the weight. Two denim fabrics with the same weight can behave differently if the yarn count, twist, fibre quality, weave compactness, finishing route or shrinkage control is different.

Checkpoint	Why It Matters
Finished weight	Determines body, feel and product category
Warp and weft count	Explains yarn thickness and fabric mass
EPI and PPI	Indicates fabric density and construction stability
Rubbing fastness	Shows risk of colour transfer
Laundering fastness	Shows expected wash-down behaviour
Shrinkage	Critical for garment fit
Skew and bow	Important for leg twisting in jeans
Handle and stiffness	Affects consumer comfort
Shade consistency	Critical for bulk approval

Common Mistakes in Reading Denim Specifications

One common mistake is to assume that heavier denim is always better. This is not true. Heavy denim may be unsuitable for hot climates, fashion silhouettes or comfort products. Another mistake is to compare denim fabrics only by ounce weight without checking construction.

A third mistake is ignoring rubbing fastness. Denim may pass visual inspection but still create complaints if it stains other garments or accessories. Similarly, laundering fastness must be understood according to the intended wash effect. In denim, fading can be either a defect or a design feature, depending on the product brief.

Buyer’s Interpretation of the Given Data

The data suggests that the three denim fabrics are constructed with a similar warp system and similar fabric density. The main adjustment is in the weft yarn count, which changes the fabric weight. The heaviest fabric uses the coarsest weft yarn, while the lightest fabric uses the finest weft yarn.

The fastness ratings are similar across all three fabrics, which means that changing the weight has not significantly improved or reduced rubbing and laundering fastness. This is important because fastness depends more on dyeing, washing and finishing conditions than on weight alone.

Knowledge Nugget

In denim, the blue character comes mainly from the warp, but the body of the fabric is strongly influenced by the weft. Therefore, two denim qualities can have a similar face appearance but different weight and handle because of the weft yarn.

Conclusion

The original table is small, but it contains a useful technical lesson. Denim weight is not an isolated property. It is connected with yarn count, fabric construction and finishing. In the given examples, all three fabrics have nearly the same EPI, PPI and warp count, while the weft count changes. This change in weft count explains the difference between heavier and lighter denim fabrics.

For a merchandiser, this type of specification is very valuable. It helps in understanding why a fabric feels heavier, why one denim quality may feel more rigid, and why fastness ratings must be checked even when the construction looks acceptable. A good denim evaluation should always combine measurable data with hand feel, shade behaviour, washing performance and final garment requirement.

Related Reading on Denim, Fabric Construction and Finishing

• Some Notes on Denim Washing
• Critical Process Parameters- Denim Manufacturing
• Manufacturing Process of Denim
• How to calculate the weight of Fabric
• Count, Construction and Width of common Cotton Fabrics

General Disclaimer

This article is intended for educational and practical understanding of textile and denim concepts. Actual fabric properties may vary depending on fibre quality, yarn type, spinning method, weaving conditions, dyeing process, finishing route, testing method and buyer specification. Readers should verify production decisions with mill technologists, testing laboratories, buyer standards and applicable textile testing methods before applying these values commercially.

Denim of Polyester Cotton Blend

In such denims, the polyester used in warp is kept low about 20-25%, because the blend is harder to dye than cotton . Polyester can be used in much higher percentage in filling. It has the advantage of being strong, durable and even in appearance.

Receipes for different shades of Denim

Receipes For Different Shades on Denim


A) Black-on-Black
Black-on-Blue

Recipe

Liquid Sulphast Black= 200 gpl
Sodium Sulphide= 20 gpl
Sandozol HSI = 10 gpl
Soda Ash= 10 gpl

B) Blue-on- Blue

Receipe

Liquid Sulphar Navy Blue = 100 gpl
Liquid Sulphast Black= 50 gpl
Sodium Sulphide= 20 gpl
Sandozol HSI= 10 gpl
Soda Ash= 10 gpl

C) Reactive Series

Receipe

01) Ramazol Turquoise Blue G = 110 gpl
Urea= 100 gpl
Swanic 6L= 10 gpl

02) Sodium Silicate= 250 gpl
Caustic Soda = 10 gpl

Ratio of 01) and 02) = 3:1

D) Ramazol Coffee Brown G

Receipe
01) Coffee Brown G = 100gpl
Urea = 100 gpl
Swanic 6L= 10 gpl

02) Sodium Silicate = 250 gpl
Caustic Soda= 10 gpl

Ratio of 01) and 02) = 3:1

E) Ramazol Parrot Green

Receipe
01) Ramazol Turquoise Blue G = 90 gpl
Ramazol Yellow FG = 40 gpl
Urea= 100 gpl
Swanic 6L= 10 gpl

02) Sodium Silicate = 250 gpl
Caustic Soda = 10 gpl

Ratio of 01) and 02) = 3:1

F) Ramazol Blue

Receipe
01) Ramazol Black B = 70 gpl
Urea = 100 gpl
Swanic 6L = 10 gpl

02) Sodium Silicate = 250 gpl
Caustic Soda = 10 gpl

Ratio of 01) and 02) = 3:1

Denim Finishes

I came across these two websites while searching for images and description about denim finishes:

1. The website of cotton incorporated
2. The web site of Textile and Apparel Management at the University of Missouri

I would like to hear more about such websites giving Images and description about denim finishes.

BI-STRETCH DENIM MANUFACTURING

I have received a query from one of my blog readers who wants to know more about bi-stretch denim manufacturing. I feel there are some specific issues that need to be delt with while dealing with bi-stretch fabric at the manufacturing stage:

1. How to control yarns at the ball warping, rope dyeing and the rebeaming stage.
2. Changes in looms to be done to handle stretch warp and stretch weft. It includes issues such as width control and others.
3. Sanforisation and skew control at the finishing stage.

If someone can contribute to this blog regarding these questions, she/he is most welcome.

Indigo Dyeing on a 20 rope range

The softner used is cationic in nature and works best in acidic conditions.

Modification on plain loom for Denim

The following is the proposed modification on plain loom for weaving denim. The main problem of running denim on plain loom is the presence of width wide faults, problems of a strong beatup and prevention of starting marks among others.

Notes on Yarn for Rope Dyeing in Denim

Notes on Yarn for Rope Dyeing

* Yarn faces stress and stretch at ball warping, rope dyeing, rebeaming, sizing and loom shed so elongation of yarn should be more than stretch at (ball warping + Robe Dyeing+ Rebeaming + Sizing )= (2-3%) + Loom shed (about 5%)

* Tension at Ball warping should be less by 7-8% of single yarn strength.

* Strength CV should be within limits as it may give rise to weak points

* The tendency of yarn to migrate at rope dyeing can be countered by less micronaire of yarn ( should be around 3.8-4.2)

* More dropping of short fibers at long chain beaming is good

*The sensitivity settings for neps is set at +280 for rotor spun yarn and not +200 as in case of ring spun yarn. The reason for this is that the structure of rotor spun yarn is intrinsically different from that of conventional ring spun yarn. Neps in rotor yarn tend to be spun into the solid yarn body rather than remaining on the yarn surface, which is typical of ring spun yarns. Although embedded in the yarn core, these neps still represent a short mass defect and will therefore trigger the imperfection counter upon exceeding the preset value. However, compared to neps that are attached to the yarn surface, fully embedded neps are barely perceptible for the human eye. Thus, in order to balance the typical visual appearance of rotor spun yarn with the imperfection counts, +280 sensitivity setting is a common convention for rotor spun yarns.

Comparison of Ring Yarn with OE yarn at Ne 7

Denim Manufacturing Process- the presentation

Please refer to the following presentation for the denim manufacturing process

Proposed Inspection Process for Indigo Dyed Denim

* A four point system can be adopted, with 9 qualities ( from 9 to 1).

The point distribution is as follows:

upto 3"= 1 point
3-6"= 2 point
6-9"= 3 points
9" and above= 4 points

Any defect across full width = 4 point
All the above defects may be length or width wise.
Length wise one course or fine ends/ up to one meter=4
Starting mark (across the width)=4
Cuttable Defects
-moire
- continuous slub or slubbing weft
- thinck end more than one meter
- major shade variation
-burnt selvedge
- blanket impression
-width variation
-Jala-jerky-chira-wrong drawn- float-snarls-missing ends- more warp breaks- patti-holes-cuts-sever temple mark- more pick findings in short length, double pick
-Slack and tight ends >1m


* From qualities 3-9, only 2 pieces in a single roll are allowed and no piece should be less than 30 meters.

The qualities Criterian can be defineds as follows:

9--> 2 shades allowed, allow 20 points per linear meter which no greater than 2 to 3 4 points defects
8--> 3 shades are allowed, allow 36 points per linear meter no greater than 4, 4 point defects
7--> same as 8 but here we allow upto 5 shades
6--> Allow 72 points per linear meter, upto 3 shades -no greater than 5 to 6 , 4 point defects
5--> same as 6, but 5 shades are allowed.
4--> points should not be greater than 72, any number of shades, any number of 4 point defects. We do not allow patta ( width wide strips)
3--> Same as 4, we can allow patta
2--> same as 3, 5 pieces are allowed ( every piece 10-30 meters each)
1--> any continuous defect is allowed ( pack the piece less than 1 meter)

Shade gradation can be
Dark Shade--> D+
Normal Shade --> D
Light Shade --> D-

Relation between Manual and "l a b" grading system
l, a, b values
D- = 554,654,655
D= 454,555,656
D+= 455,456,556

Tolerance for l a b values--> L = +-0.5, a = +/- 0.5, b= +/- 0.5

Manufacturing Process of Denim

Manufacturing of Denim
For manufacturing Denim and Grey Fabric, the process is same up to the level of weaving, but in case of Denim Fabric, dyeing is done at the stage of sizing where as for Grey Fabric it depends upon the finished product. The details of each process are given below:
1. Fabric Weaving
a. Grey Yarn on ConesNormally yarns received for weaving in cone forms are either from ring spinning or from open end spinning in single or double fold as required. For weaving, yarn used is categorised into:
o Warp yarn
o Weft yarn
Normally for Weaving, yarn used as warp should be sufficiently strong to withstand stress and strains exerted during weaving operations. Hence they are having Count Strength Product(CSP) and further sized to increase its strength. The weft yarn is directly used on weaving machines and in some cases, if required, is rewound also so as to enhance its performance in weaving.
b. Warping on Sectional/ Direct Warping
The warp yarn is required to be fed into a sheet form to the weaving machines. At warping, the individual cones are put into the creel (the number of cones depends upon fabric construction) and yarn from individual cones is pulled together in sheet form, wound on a barrel called warping beams (for Direct warping) or on weaving beams (for Sectional Warping). Normally if warp sheet is with patterns of different coloured yarns it is processed on sectional warping machine.
c. Sizing of yarn in Set/ Beam to Beam Position
The object of Sizing is to improve the strength of yarn by chemically binding the fibres with each other and also improve upon its friction resistance capacity by chemically coating the surface of yarn/fibres. Further, number of threads in warpers beam sheet is very less against number of threads required in whole width of fabric. Hence multiplication of sheets by drawing yarns together from many warp beams and again making one sheet is also performed on sizing machine. On sizing, normally, 8-12 % size material on warp thread is applied. This improvement in strength and frictional resistance characteristic of warp yarn is essential because during weaving, yarn has to undergo severe strain & stress as well as frictional operations.
d. Drawing–in
Weaving is basically interlacement of two sets i.e. warp and weft threads in desired sequence and pattern. To obtain this interlacement, warp yarn sheet is bifurcated & opened in the form of two layers/ sheet and weft thread is inserted between so opened two warp sheets. This operation is called shedding. to perform shedding the warp yarn needs to be passed through heald eyes of the heald shafts, this operation is called as drawing-in.
e. Beam Gaiting or Knotting on Loom
The drawn weavers beams are fixed on weaving machines, threads are tied and heald shafts are coupled. This operation is called Beam Gaiting. If undrawn warp threads are directly knotted to the threads of finished beams, it is called Knotting. These operations are essential because normally weavers beam can carry only certain length of warp sheet on it and when so woven, whole length is converted to the fabric by weaving machine. Further warp length is required to be fed which can be done by knotting or gaiting other beams on weaving machine.
f. Weaving
As stated earlier, weaving is interlacing two sets of yarn and making fabric. One set is called warp thread which is in sheet form, the other one is called weft thread which is inserted between two layers of warp sheet by means of a suitable carrier i.e. Shuttle, Projectile, Rapier, Air current, Water current, etc. Depending upon the type of the weaving machines. The different types of technologies available for weaving machines are briefly explained as below:
o Conventional Shuttle Weaving System by Ordinary Looms or Automatic Looms.
o Shuttle less Weaving System by Airjet /Waterjet/Rapier/Projectile
Shuttle loom is a conventional Technology with much less production on account of slow speed and excessive wear and tear of machinery. This shuttle loom technology has now become obsolete. Denim is woven through Shuttle less Weaving System by using 96 ZAX-e Type Tsodakoma Corporation’s Airjet looms or rapier looms or projectile looms. These looms are distinguished by weft insertion method, which is briefly discussed hereunder.
Airjet Looms
These types of looms adopt the latest development in Weaving Technology where weft insertion is done with the help of compressed air. A very high weft insertion rate up to 1800 metre per minute is achieved. Compared to rapier and projectile looms, these looms are less versatile but are economical and are used in mass textile production unit like denim.
Finishing
a. Grey Fabric
The finally woven fabric or Grey Fabric, as it is popularly called, wound on a cloth roll is taken out from weaving machines at certain intervals and checked on inspection machines for possibilities of any weaving fault. If such faults are seen anywhere in fabric during inspection, certain corrective steps are taken at weaving, warping, sizing, etc so that they can be minimised in subsequent product. This is a quality control exercise.
b. Denim Fabric
Denim Fabrics woven of 100% cotton would be very strong and durable.
Traditionally Blue Denim is warp faced cotton fabric with 3 x 1 twill construction with warp being dyed in a solid colour and weft left un-dyed. The look and quality of the Denim Fabric shall improve after dyeing, the process of which differs from plant to plant. Normally the process of dyeing dictates the technology of Denim manufacturing.
The dyeing for Denim Fabric happens at the sizing stage. Generally there are two most popular methods of dyeing Denim Fabric. They are:
o Rope Dyeing
o Sheet Dyeing
A company can adopt any of the methods. In countries like India Sheet Dyeing Method is commonly used for manufacture of its Denim Fabrics, which has following advantages over Rope Dyeing Method:
o The technology is less capital intensive.
o The technology is a proven one.
o The cost of production is lower.
o The process time is lower.
o The Sheet Dyeing machines are very easy to operate.

The only defect in Sheet dyeing is that their is a problem of center to selvedge shade variation.
c. Sheet Dyeing Process
This process eliminates a few intermediate processes of the rope dyeing. The yarn sheet is washed with chemicals such as caustic and washing soda and after squeezing the excess water; the yarn sheet is allowed to pass through Dyeing Troughs one time for oxidation and development of dye on yarn. After dyeing, the dyed yarn is washed again with fresh water for two-three times and finalIy squeezed before allowing it to pass through six drying cylinders. The dyed yarn enters the starching device and sizing is done. After sizing, the sized warp beam goes for weaving. After weaving, the woven Denim Fabrics goes for various finishing processes consisting of brushing, singeing, washing, impregnation for dressing and drying. Brushing and singeing should eliminate impurities and help to even the surface of the fabric. Dressing regulates the hand and rigidity of the fabric while compressive shrinking regulates its dimensional stability.
Even today Denim Fabric without Indigo Dyeing is not called authentic Denim. Initially when Denim Fabric entered the fashion market, Denim manufacturers were using Natural Indigo Dye, which was costly and giving a natural finish. Though Synthetic Indigo Dye has gradually replaced Natural Indigo Dye, some unorganised manufacturers still prefer the latter and attract premium after branding them “Natural Dye Used”.
d. Making-Up
Weaving of fabrics on such multi sizes is not economical, hence a standard width fabrics is then sent to making up. Fabrics are cut into the desired width as per size required on this machine. Denim Fabric and Grey Fabric are thoroughly checked for various types of defects such as:
o Weaving Defects
· Uneven Dyeing
o Bleaching and Dyeing Defect
o Oil Stain
o Patches
Here the final product is categorised quality-wise. The products then found okay are segregated and sent to packaging department whereas defective ones are sent for correction. After inspection, the sets are wrapped with polythene covers and sent for despatch as per buyer’s specifications.
Despatch
Rolls and sets so formed and packed as per buyers’ requirements are then sent for final despatches.