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Fire retardants & textiles: past, present and future
15-16 February, 2016 Torino - Italy
HISTORY AND EVOLUTION OF FIRE RETARDANTS FOR TEXTILES
S. Giraud, F. Rault, A. Cayla, F. Salaün
Université Lille Nord de France, F-59000 Lille, France
Ecole Nationale Supérieure des Arts et Industries Textiles (ENSAIT)/Laboratoire Génie des
Matériaux Textiles (GEMTEX), F-59100 Roubaix, France
Abstract: Textiles are materials that exhibit extremely varied forms and are used for a variety of applications
where fire protection is essential.
Textile with wood was historically one of the first flame-retardant materials. FR
products for textile materials presented the same evolution as those of general polymeric materials even though
adaptations are necessary to meet the specific characteristics of the fibrous material and its industrial
specifications.
Keywords: Textile, Flame Retardant, History, Industrial Requirements
The fibrous materials exhibit extremely varied forms for application domains that are not limited only to
clothing. Some of these high-value products are multifaceted, ie multifunctional (protection against all
types of threats), intelligent (integrating sensors), reinforcing structures for composites, insulation for
buildings, implants for medical, etc. Heatproof and flame retardant (FR) textiles have applications not
only for protective clothing, but also in areas where fire protection is essential, i.e. public transport, or
places open to the public. These materials fall into the composition of multiple products for furniture,
bedding, seat covers, housing (wall coverings), structural composite materials, filters, acoustic and
thermal insulation panels, etc. The textile fire behavior
1,2
and the associated fireproofing principles
2-4
have already been the subject of numerous bibliographic summaries.
From a historical perspective, the first patent with FR use was deposed in 1735 by Obadjah Wyld and
concerned the textile and paper. In 1820, Gay-Lussac suggested a mixture of ammonium phosphate,
ammonium chloride and borax to increase the fire retardance of textiles used in French theaters.
During the twentieth century, advances in chemistry have obviously revolutionized the textile industry.
Synthetic fibers appear and some have intrinsic properties of fire resistance (eg marketing in 1961 of
Nomex® the first polyaramide). The major classes of FR products have been adapted and formulated
to treat various fibers and meet the specific requirements of the textile material (eg development in
1955 of the first sustainable flame retardant cellulosic fabric via Proban®). The use of FR products
have undergone changes as the abandonment of certain brominated components for their
environmental impact. These evolutions have of course also affected the treatment of textile materials.
The fire behavior of fibrous materials has number of peculiarities. Textiles compared to plastic
materials generally have a large surface area, thus promoting exchange with oxygen. Thereby textiles
have short ignition time and high flame propagation speeds. Their propensity to initiate and propagate
the fire makes "hazardous", even if their heat release rate could be quite small due to their low
density. The fire performance of a textile substrate depends mainly on the polymeric nature of the
fibers. Mineral fibers as glass by the non-combustible nature and fibers from thermostable polymers
as polyaramide are inherently fire resistant. The other categories, i.e natural or artificial (cellulose,
protein) and synthetic (polyolefin, polyester, polyamide, etc.) exhibit various fire behaviors. Cellulosic
are among the most easily ignitable fibers while protein (wool) hardly burn. Both types of fiber are
naturally charring. Synthetic fibers present a low charring behavior (polyamide) or no charring effect
Fire retardants & textiles: past, present and future
15-16 February, 2016 Torino - Italy
(polyolefin). In addition, synthetic fibers tend to escape the flames, and generate the hazard of falling
material in the molten state or inflamed with risk of direct burning and fire spread.
Industrial requirements on FR textiles are related to legislation and standards which define the
required levels of fire resistance specific to the application sectors. Fireproof textiles must also meet
the requirements and specific industrial constraints. In addition, many features need to be compatible
with fireproofing, i.e. (i) Dry or high temperature cleaning resistance; (ii) maintain comfort (color, touch,
management of heat and mass transfer); (iii) mechanical resistance for protective clothing, seat
covers, structures for buildings, or otherwise; and (iv) specific properties to an application area
(filtration, sound insulation, weather resistance, resistant to fungal growth, etc.). Thus, the main
industrial challenges for flame resistant textile development can be namely summarized in four points,
(i) to reach the level of fire retardancy at lower cost; (ii) to design in the context of sustainable
development; (iii) to make the textile a fire resistant protective layer; and (iv) maintain the FR
properties with other expected features.
Figure 1 : summary diagram of textile fireproofing strategies
The main classes of flame retardants for polymeric materials are also in the fibrous materials with
certain adaptations. Figure 1 summarizes the different strategies for fireproofing a fibrous material.
None of the existing commercial strategies not yet fully meet the challenges outlined above.
The first option to design a FR fibrous material is the selection of fibers having this property. Mineral
fibers are for very specific applications (eg reinforcement materials), while they are inherently non-
combustible and have high mechanical properties. Their lack of comfort and high cost of manufacture
and / or implementation mean that they are never used directly for traditional applications (eg furniture
cover), or while being hidden and in combination with other fibers. The thermostable fibers, fire
resistant and mechanically efficient, are also limited in their use by their cost, low comfort (hard color
management) and their aging problem (particularly UV). FR fiber from polymers chemically modified or
containing fillers have a better compromise (cost, comfort, implementation, washing resistance) but
does not ensure alone protection and fire resistance equivalent to the heat-stable fibers. The three
main commercial examples are the Lenzing viscose FR® the Modacrylic (Kanecaron) and polyester
Trevira CS®.
The second way to give FR properties to a textile is to add a surface treatment. This is the only
possible strategy for natural fibers. Thus, for several decades, many R&D efforts have focused on
cellulosic textiles including cotton which remains one of the most used fiber in the world. Surface
treatments can be divided into two categories, i.e. the non-reactive and reactive. The former are
Fire retardants & textiles: past, present and future
15-16 February, 2016 Torino - Italy
mainly based on phosphorus and nitrogen compounds, inorganic or organic, which are fixed by weak
bonding on the substrate, or blocked by a polymer resin (binder). These treatments are generally
inexpensive and simple to implement, but have the disadvantage of being at best semi-durable.
Among these treatments, there is the principle of back coating, ie depositing a layer of flexible polymer
(acrylic, polyurethane) FR (especially with an intumescent formulation) on the non-visible face of the
textile. Although the durability of this technique is not optimal, it has the advantage of being used on
any textile nature including mixtures of fibers. The reactive treatment, as Pyrovatex® and Proban® the
two most famous processes for cellulose, are permanent (resistant to washing). However, their
implementation remains complex and alteration of mechanical properties of textile is sometimes
observed.
Among the most recent developments in research on fireproofing textiles, two processes have been
studied, the Layer-by-Layer (LbL) method and sol-gel process. Alongi et al.
5
have summarized all the
work for the processes applied fireproofing primarily cellulosic textiles. The LbL process seems for
now difficult to apply industrially since it has little durability (FR product loss by simple manipulation of
the textile). The sol-gel process, more promising (10 washes resistance), requires extremely long
implementation times, incompatible with industrial production. For ten years, our laboratory contributes
to the development of solutions in the field of fireproof of textiles in connection with the expected
industrial challenges. The main strategies developed are (i) the reformulation and / or improvement of
fire retardant for textile applications through the microencapsulation process
6-7
, (ii) the incorporation of
fillers (micron or nanometer) during the melt-spinning in particular for polyester to develop upholstery
fabrics able to withstand the heat and to protect the whole of the material
8-10
, and (iii) the use of
additives and / or bio-based polymers for the development of flame retardant textile
11-12
.
REFERENCES
1. Lewin M, Flame retardance of fabrics, 1984, Handbook of fiber science and technology: Volume II. Edited by Lewin M and
Sello S B, Marcel Dekker, New York.
2. Horrocks A R, Kandola B K,Textiles, 2004, Plastic Flammability Handbook : Principles, Regulations, Testing, and Approval.
Edited by Troitzsh J, Carl Hanser Verlag GmbH & Co KG, Munich.
3. Weil E D, Levchik S V, Flame Retardants in Commercial Use or Development for Textiles, 2008, J Fire Sci, 26, 243-281.
4. Horrocks A.R., Flame retardant challenges for textiles and fibers: New chemistry versus innovatory solutions, 2011, Polym
Degrad Stab, 96, 377-392.
5. Alongi J, Carosio F, Malucelli G, Current emerging techniques to impart flame retardancy to fabrics: An overview, 2014,
Polym Degrad Stab, 106, 138-149.
6. Vroman I, Giraud S, Salaün F, Bourbigot S, Polypropylene fabrics padded with microencapsulated ammonium phosphate:
Effect of the shell structure on the thermal stability and fire performance, 2010, Polym Degrad Stab, 95, 1716-1720.
7. Salaün F, Creach G, Rault F, Almeras X, Thermo-physical properties of polypropylene fibers containing a
microencapsulated flame retardant, 2012, Polym Adv Technol, 24, 236-248
8. Didane N, Giraud S, Devaux E, Lemort G, Capon G, Thermal and fire resistance of fibrous materials made by PET
containing flame retardant agents, 2012,Polym Degrad Stab, 97, 2545-2551.
9. Didane N, Giraud S, Devaux E, Lemort G, Development of fire resistant PET fibrous structures based on phosphinate-
POSS, 2012, Polym Degrad Stab, 97, 879-885.
10. Didane N, Giraud S, Devaux E, Lemort G, A comparative study of POSS as synergists with zinc phosphinates for PET fire
retardancy, 2012, Polym Degrad Stab, 97, 383-391.
11. Giraud S, Rault F, Rochery M, Gaquere L, Lemort G, Use of bio-based carbon source to develop intumescent flame
retardant polyurethane coating for polyester, 2013, 14th European Meeting on Fire Retardancy and Protection of Materials,
Lille, France, 01-04 July
12. Cayla A, Rault F, Giraud S, Salaün F, Campagne C, Fierro V, Celzard A, Interest of wood wastes (lignin) as flame retardant
fillers in bio-based polymers (PA11 and PLA), 2015,Eurofillers Polymer Blends, Montpellier, France, 26-30 April