Saturday, October 5, 2019

Progressive Shrinkage and Methods of Control[1]
Art Resource

Marie-Therese Wisniowski


Preamble
This is the ninety-second post in the "Art Resource" series, specifically aimed to construct an appropriate knowledge base in order to develop an artistic voice in ArtCloth.

Other posts in this series are:
Glossary of Cultural and Architectural Terms
Units Used in Dyeing and Printing of Fabrics
Occupational, Health & Safety
A Brief History of Color
The Nature of Color
Psychology of Color
Color Schemes
The Naming of Colors
The Munsell Color Classification System
Methuen Color Index and Classification System
The CIE System
Pantone - A Modern Color Classification System
Optical Properties of Fiber Materials
General Properties of Fiber Polymers and Fibers - Part I
General Properties of Fiber Polymers and Fibers - Part II
General Properties of Fiber Polymers and Fibers - Part III
General Properties of Fiber Polymers and Fibers - Part IV
General Properties of Fiber Polymers and Fibers - Part V
Protein Fibers - Wool
Protein Fibers - Speciality Hair Fibers
Protein Fibers - Silk
Protein Fibers - Wool versus Silk
Timelines of Fabrics, Dyes and Other Stuff
Cellulosic Fibers (Natural) - Cotton
Cellulosic Fibers (Natural) - Linen
Other Natural Cellulosic Fibers
General Overview of Man-Made Fibers
Man-Made Cellulosic Fibers - Viscose
Man-Made Cellulosic Fibers - Esters
Man-Made Synthetic Fibers - Nylon
Man-Made Synthetic Fibers - Polyester
Man-Made Synthetic Fibers - Acrylic and Modacrylic
Man-Made Synthetic Fibers - Olefins
Man-Made Synthetic Fibers - Elastomers
Man-Made Synthetic Fibers - Mineral Fibers
Man Made Fibers - Other Textile Fibers
Fiber Blends
From Fiber to Yarn: Overview - Part I
From Fiber to Yarn: Overview - Part II
Melt-Spun Fibers
Characteristics of Filament Yarn
Yarn Classification
Direct Spun Yarns
Textured Filament Yarns
Fabric Construction - Felt
Fabric Construction - Nonwoven fabrics
A Fashion Data Base
Fabric Construction - Leather
Fabric Construction - Films
Glossary of Colors, Dyes, Inks, Pigments and Resins
Fabric Construction – Foams and Poromeric Material
Knitting
Hosiery
Glossary of Fabrics, Fibers, Finishes, Garments and Yarns
Weaving and the Loom
Similarities and Differences in Woven Fabrics
The Three Basic Weaves - Plain Weave (Part I)
The Three Basic Weaves - Plain Weave (Part II)
The Three Basic Weaves - Twill Weave
The Three Basic Weaves - Satin Weave
Figured Weaves - Leno Weave
Figured Weaves – Piqué Weave
Figured Fabrics
Glossary of Art, Artists, Art Motifs and Art Movements
Crêpe Fabrics
Crêpe Effect Fabrics
Pile Fabrics - General
Woven Pile Fabrics
Chenille Yarn and Tufted Pile Fabrics
Knit-Pile Fabrics
Flocked Pile Fabrics and Other Pile Construction Processes
Glossary of Paper, Photography, Printing, Prints and Publication Terms
Napped Fabrics – Part I
Napped Fabrics – Part II
Double Cloth
Multicomponent Fabrics
Knit-Sew or Stitch Through Fabrics
Finishes - Overview
Finishes - Initial Fabric Cleaning
Mechanical Finishes - Part I
Mechanical Finishes - Part II
Additive Finishes
Chemical Finishes - Bleaching
Glossary of Scientific Terms
Chemical Finishes - Acid Finishes
Finishes: Mercerization
Finishes: Waterproof and Water-Repellent Fabrics
Finishes: Flame-Proofed Fabrics
Finishes to Prevent Attack by Insects and Micro-Organisms
Other Finishes
Shrinkage - Part I
Shrinkage - Part II
Progressive Shrinkage and Methods of Control
Durable Press and Wash-and-Wear Finishes - Part I
Durable Press and Wash-and-Wear Finishes - Part II
Durable Press and Wash-and-Wear Finishes - Part III
Durable Press and Wash-and-Wear Finishes - Part IV
Durable Press and Wash-and-Wear Finishes - Part V
The General Theory of Dyeing – Part I
The General Theory Of Dyeing - Part II
Natural Dyes
Natural Dyes - Indigo
Mordant Dyes
Premetallized Dyes
Azoic Dyes
Basic Dyes
Acid Dyes
Disperse Dyes
Direct Dyes
Reactive Dyes
Sulfur Dyes
Blends – Fibers and Direct Dyeing
The General Theory of Printing

There are currently eight data bases on this blogspot, namely, the Glossary of Cultural and Architectural Terms, Timelines of Fabrics, Dyes and Other Stuff, A Fashion Data Base, the Glossary of Colors, Dyes, Inks, Pigments and Resins, the Glossary of Fabrics, Fibers, Finishes, Garments and Yarns, Glossary of Art, Artists, Art Motifs and Art Movements, Glossary of Paper, Photography, Printing, Prints and Publication Terms and the Glossary of Scientific Terms, which has been updated to Version 3.5. All data bases will be updated from time-to-time in the future.

If you find any post on this blog site useful, you can save it or copy and paste it into your own "Word" document etc. for your future reference. For example, Safari allows you to save a post (e.g. click on "File", click on "Print" and release, click on "PDF" and then click on "Save As" and release - and a PDF should appear where you have stored it). Safari also allows you to mail a post to a friend (click on "File", and then point cursor to "Mail Contents On This Page" and release). Either way, this or other posts on this site may be a useful Art Resource for you.

The Art Resource series will be the first post in each calendar month. Remember - these Art Resource posts span information that will be useful for a home hobbyist to that required by a final year University Fine-Art student and so undoubtedly, some parts of any Art Resource post may appear far too technical for your needs (skip over those mind boggling parts) and in other parts, it may be too simplistic with respect to your level of knowledge (ditto the skip). The trade-off between these two extremes will mean that Art Resource posts will hopefully be useful in parts to most, but unfortunately may not be satisfying to all!


Progressive Shrinkage and Methods of Control[1]

Thermoplastic Fibers
Thermoplastic fibers are stabilised by heat-setting. If properly heat-set fabrics will exhibit no progressive shrinkage and relaxation shrinkage will have been controlled also.



Wool Fibers
Washable wool is important in children's clothing, in skin-contact clothing, bed covers and in blends with washable fibers.



If wool fabrics are to maintain their position in the competitive market with fabrics made from wool-like fibers that have easy-care characteristics, they must be finished to keep their original size and surface texture with home cleaning methods. It might be assumed that people who can afford professional care will not be interested in washing wools. Another assumption might be that washable wools (those given a felting shrinkage control treatment) are poor-to-medium quality wools. Whether or not these assumptions are true, felting shrinking is important today, as evidenced by that fact that 250 patents for felt proofing wool were issued prior to 1957 and many more have been issued since.

Woolen felt proof hat.

To prevent felting shrinkage, the finish must alter the scale structure by "smoothing off" the free edges and thus reduce the differential friction effect that prevents wool fibers from returning to their original position in the cloth. The effectiveness of felting shrinkage treatments depends on the kind and amount of finish used, and on the yarn and fabric construction. Worsteds need less finish than woollens. Low-count fabrics and low-twist yarns need more finish to give good washability.



Treated wool fabrics are usually considered machine washable, but care should be taken to use warm, not hot, water and a short agitation period. Hand washing is preferable, since soil is easy to remove from the fiber and the hand washing process ensures lower temperatures and less agitation. Machine washing may cause more loosening of fibers, which results in fuzzy or slightly pilled surface.



Two methods are used to smooth off the free edges of scales; halogenation treatments and surface coatings.

Halogenation



Halogenation treatments are the most widely used - primarily chlorine. They are low in cost, can be applied to large batches of small items such as wool socks, do not require padding or curing equipment and are fairly effective. The processes are quite delicate and if not carefully done, are apt to damage the fibers. The scales are more resistant to damage than the interior of the fiber and should not be completely removed or there will be considerable reduction. in the wearing properties, there will be a loss of weight, and change in hand. The fabric will fell harsh and rough. To maintain the strength of the fabric, 18% nylon fiber is blended with the wool before weaving.

Surface coatings of a polyamide-type solution are applied to mask the scales. This is a very thin, microscopic film on the outside of the fiber. In addition to controlling shrinkage, the coating tends to minimise pilling and fuzzing (one of the greatest problems in wash-and-wear wools), give the fabrics better wash-and-wear properties and increases resistance to abrasion. This process carries the trade name Wurlan. It was developed in the USA.



Rayon Fibers
The shrinkage of regular rayon varies with the handling of the fabric when et. While it is wet, it can be stretched and it is difficult to keep from overstitching during the process. If it is dried in this stretched condition, it will have a high potential shrinkage and shrink when wet again and dried without tension, because the moisture in the fabric adds enough weight yo stretch it.



Shrinkage control treatments for rayon reduce the swelling property of the fiber and make it resistant to distortion. Resins are impregnated inside the fiber to form cross-links that prevent swelling and keep the fiber from stretching. The resin also fills up spaces in the amphora's regions of the fiber, making it less absorbent.



The non nitrogenous resins (the aldehydes) are superior to the other resins because they do not weaken the fabric and are non chlorine retentive and have excellent wash fastness. Treated rayons are machine washable, but the wash cycle should be short. High-wet-modulus rayon is also resin treated, primarily for wash-and-wear purposes, since its shrinkage can be controlled by the relaxation shrinkage control method of Sanforization.


Reference:
[1] N. Hollen and J. Saddler, Textiles, 3rd Edition, MacMillan Company, London (1968).

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