Saturday, May 4, 2019

Finishes: Flame-Proofed Fabrics [1-2]
Art Resource

Marie-Therese Wisniowski

Preamble
This is the eighty-seventh 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

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!


Introduction
Some fibers are naturally fireproof. Mineral fibers such as asbestos and fiber glass cannot support combustion. However, they are a threat to health when they become friable. The term "friable" means that the asbestos is easily crumbled by hand, releasing fibers into the air. Sprayed on asbestos insulation is highly friable. Because it is so hard to destroy asbestos fibers, the body cannot break them down or remove them once they are lodged in lung or body tissues. They remain in place where they can cause disease. There are three primary diseases associated with asbestos exposure: (i) Asbestosis; (ii) Lung Cancer; (iii) Mesothelioma.



Protein fibers and some thermoplastics are fire retardant, as they ignite slowly and burn only for a very short time. However, thermoplastics melt as they burn; this melted substance can cause a severe burn if it sticks to the skin.



Today's post centres on flame-proofed fabrics.


Finishes: Flame-Proofed Fabrics
Most textile materials burn readily and rapidly. Whilst wool textile materials tend not to support combustion once a flame is removed, cellulosic textile materials will burn readily once they are ignited.

Wool-polyester after being burned.

The great danger with cellulosic fibers is afterglow, which may remain if the flame has been incompletely extinguished. Afterglow may often re-ignite a flame in a textile material.

Cotton-polyester afterglow.

Synthetic fibers may melt rather than burn.


However, acrylics will burn readily.



Hot molten thermoplastic fibers will cause severe burns and intense shock to the victim wearing clothes composed of such fibers. In fact, one major identifier of any fiber is to initiate a "burn test".



The construction of fabric determines the degree to which oxygen is made available to the fiber. Thick dense fabrics burn slowly, whereas thin open fabrics burn very rapidly. Fabrics with a fuzzy surface burn along the surface, before the base fabric catches fire.

Fabrics are divided into three groups according to their flammability.
(i) "Safe" fabrics that do not burn - fibreglass, wool etc.
(ii) "Borderline" fabrics that should be tested for flammability are sheer fabrics, such as organdie, lawn, voile and napped fabrics with a short nap.
(iii) "Dangerously flammable" fabrics - very sheer fabrics and nets, lining and/or irregular napped and pile fabrics with loose base construction, and fabrics with certain flammable finishes as well as cellulose fabrics.

Brushed rayons are easier to ignite than other napped fabrics and burn with greater speed and intensity.

V back light denim blue soft brushed rayon top.

Blending fire-resistant fibers with cellulose fibers will lower the flammability of cellulose fibers.
The high flammability of cellulosic fibers, particularly when in the form of loose-fitting garments such as nightdresses, has resulted in research to reduce their ease of ignition and flame propagation. The research has concentrated on preventing the occurrence of afterglow. When any of the cellulose fibers burn, they produce water, carbon-containing char, a tarry substance, and non-flammable vapor as combustion products. If the char is still very hot, even when the fiber has been extinguished, the cellulosic material may re-ignite.

Although many compounds have been developed over the years to minimise the flammability of textile materials, and in particular cotton, the only ones which have achieved commercial success are those based on:
(a) THCP - tetrakis-hydroxymethyl-phosphoniumchloride;i.e. Proban; (b) Pyrovatex CP - a phosphonoalkylamide (Phew!).

Flame-proofing of cellulosic materials can be achieved by the application of certain chemicals. Suggested reasons of the effectiveness of flame-proofing treatments are as follows:
(i) These chemicals alter the course of decomposition of the cellulosic fibers on burning. Less flammable tars and a reduced volume of flammable carbonaceous materials produced is increased (i.e. diminishing the fuel solid load).
(ii) These chemicals, may, on heating, yield inert gases. As these inert gases are non-flammable, they will act as flame retardants by reducing the concentration of atmospheric oxygen around the flame, thus limiting propagation of the flame.
(iii) The heat generated by the burning of textile materials may be dissipated by endothermic changes in the chemical applied to impart flame resistance. In so doing, these chemicals will conduct the heat away from the fiber. In other words, the chemical can absorb considerable amounts of energy without causing its temperature, or that of its surroundings, to rise. The withdrawal of heat limits the propagation of the flame.

There are still problems related to the use of flame-resistant finishes for cellulosic materials and these are:
(i) A harshening of the fabric handle; (ii) A break-down of the flame-resistant finish by laundering and dry-cleaning.

The disadvantages may in part be overcome by the use of specially manufactured, fire-retardant, man-made fibers. The addition of organo-phosphorous compounds to the spinning solution of acrylics, acetates, polynosic, polyesters, polypropylenes and viscose will make them fire retardant. However, a reduction in fiber tenacity, and hence durability, tends to occur more or less in direct proportion to the percentage of organo-phosphorous compound added. This treatment is not applied to nylon.

The presence of chlorine in fibers also acts as a fire retardant. Unfortunately, the relatively low softening point of chlorine-containing fibers, which causes them to wrinkle and distort badly, precludes their general use.

The industrial nylon, Nomex, is fire retardant owing to the aromatic groups in its polymer structure and the highly crystalline arrangement of its polymer system.

BDUS 1/6 Nomex IIIA.


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

[2] E.P.G. Gohl and L.D. Vilensky, Textile Science, Longman Cheshire, Melbourne (1989).

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