Detailed knowledge of flame retardant fabrics–An Lintian

1.What is flame retardant fabric

2.Classification of flame retardant fabrics

3.The production process of flame-retardant cloth and the introduction method of additives can be divided into:Flame retardant treatment of fiberandFlame-retardant finishing of fabrics

4.Finishing process and commonly used additives for flame retardant fabrics

1.What is flame retardant fabric

Flame-retardant fabrics are flame-retardant treatments based on dyed fabrics, or flame retardants with flame-retardant functions are added to the fibers through technologies such as polymer polymerization, blending, copolymerization, composite spinning, and extrusion modification. , making the fiber flame retardant. The finished product can not only effectively prevent the spread of flames, but also protect the original properties of the fabric. It can automatically extinguish or effectively slow down the spread of flames, making theThe fabric is carbonized to form an isolation layer. It also has the characteristics of not melting or dripping when exposed to fire and not burning, and has a good flame retardant effect. (Flame-retardant fabrics are not inflammable. Even if they are ignited by an open flame, they can still be lit after leaving the open flame12 Automatically extinguishes within seconds)

2. Classification of flame-retardant fabrics

Flame retardant Fabrics can be divided into:

1.Permanently flame-retardant fabric (Weaved with flame-retardant fiber, the flame-retardant effect does not change no matter how many times it is put into the water)

2.Washing resistance (50 times or more) Flame retardant fabric

3.Semi-washable flame retardant fabric

4.Disposable flame retardant fabric (Decoration, curtains, cushions, etc.)

3.The production process of flame-retardant cloth and the introduction method of additives can be divided into:Flame retardant treatment of fibersandFlame-retardant finishing of fabrics

Flame retardant treatment of fiber:

1. The flame retardant mechanism refers to adding a certain flame retardant to some inherently flammable raw fibers (such as polyester, cotton, and acrylic) to inhibit free radicals during the combustion process; or to change the thermal decomposition process of the fiber. , promote dehydration and carbonization; some flame retardants decompose and release non-flammable gas to cover the fiber surface, which acts as an air barrier.

2. Flame retardant treatment method

1)Improve the thermal stability of fiber-forming polymers

2)Precursor silk flame retardant modification

Flame-retardant finishing of fabrics:

Flame retardant mechanism

Covering layer theory: Flame retardants can form a glass-like or stable foam covering layer at high temperatures, which can insulate heat, oxygen, prevent flammable gases from escaping outward, and play a flame retardant role.

2)Non-combustible gas theory: The flame retardant decomposes into non-combustible gas when heated, and the concentration of combustible gas decomposed from cellulose is diluted below the lower combustion limit.

3)Endothermic theory: Flame retardants undergo endothermic reactions at high temperatures, lowering the temperature to prevent the spread of combustion. In addition, the heat can be quickly transferred out after fabric finishing, so that the cellulose cannot reach the temperature at which it ignites and burns.

4)Chemical reaction theory (catalytic dehydration theory): The flame retardant acts as a Lewis acid and reacts with the fiber at high temperatures, causing the fiber to catalytically dehydrate and carbonize, reducing flammability Generation of gas

2. Flame-retardant finishing method

1)Padding and baking method: a widely used flame retardant finishing process. The process is padding–Pre-baked–Baked–Post-treatment is generally made of flame retardant.It consists of agents, catalysts, resins, wetting agents and softeners, and is configured into an aqueous solution or emulsion for finishing.

2)Dipping and baking method (absorption method): The tissue is immersed in the flame retardant liquid for a certain period of time, and then dried and baked to make the flame retardant liquid absorbed by the fiber polymer.

3)Organic solvent method: uses non-water-soluble flame retardant. Its advantage is low energy consumption during flame retardant finishing. However, in actual operation, attention should be paid to the toxicity and flammability of the solvent.

4)Coating method: Mix the flame retardant into the resin, and the flame retardant is fixed on the fabric by the adhesion of the resin. According to the difference in mechanical equipment, it is divided into blade coating method and pouring coating method.

4.Finishing technology and common additives for flame-retardant fabrics

At present, the mainstream flame retardant processes include promethazine fumigation process andCPfinishing process. The Prubenzene process is allowed for formaldehyde that is not suitable for clothing that is not worn close to the body. The advantage is that it has little loss of breaking strength of the fabric. , the relative fastness of fabrics made from the same gray fabric after finishing is much higher, and Prubenzene can basically reach GB8965.1-2009B-level standard requirements, and CPcan only meet this standardC Level standard, it is basically difficult to achieve theBlevel standard. However, it is not recommended to use prophenyl for flame retardant clothing that is close to the skin. It is recommended to use fabrics with low formaldehyde contentCPCP or permanently flame-retardant fabrics such as acrylonitrile and aramid are also recommended for customers with higher color and feel requirements.CPProcess or acrylonitrile and aromaticFor flame-retardant fabrics made of polyester, most customers currently use flame-retardant workwear made of flame-retardant fabrics finished with polybenzene on their coats.

（The addition of formaldehyde-removing additives to the pluben process can control the formaldehyde content within 75PPmbelow)

Process flow:

1. Pluben: padding flame retardant finishing liquid→pre-baking→Ammonia smoke→Washing→Drying→Preshrinking→Finished product (Requires hot air blowingBottom machine and ammonia fumigation machine）

2. CP: padding flame retardant finishing Liquid→Pre-baking→Baking→Washing→Drying→Preshrinking→Finished product (General dyeing factories can do it)

Commonly used additives:

According to the application method, it is divided into additive flame retardants and reactive flame retardants. According to the composition, additive flame retardants mainly include inorganic flame retardants and halogen flame retardants(Organic chlorides and organic bromides), phosphorus flame retardants(red phosphorus, phosphate esters and halogenated phosphates, etc. font>)and nitrogen-based flame retardants, etc.