Why do plastics need to be flame retardant

With the development of modern science and technology, plastic, synthetic rubber, synthetic fiber three categories of synthetic materials have been widely used, but their flammability as organic polymer materials also bring a lot of fire hazards to human beings.

Significance of flame retardant masterbatch production

In order to realize its application in military, aerospace, transportation, electric power and civil industries, flame retardant modification has become a new topic. The ideal flame retardant modification method for plastics is often to improve the fire resistance of plastics by adding products such as flame retardants or flame retardants.

In this context, the rapid growth of flame retardant production, its consumption and production are also growing, flame retardant materials have become the key basic materials widely used in today's social production and life.

Flame retardant masterbatch is also known as flame retardant masterbatch, fireproof masterbatch. It is in order to meet the requirements of plastic and rubber products to achieve fire prevention and a class of products.

Flame retardant masterbatch is a kind of granular product prepared by mixing, extrusion and granulation of twin-screw or three-screw extruder after organic combination, modification and synergism of various flame retardant ingredients on the basis of flame retardant.

Different from flame retardants, flame retardant master batch is easy to add in resin, clean and hygienic, high flame retardant efficiency, small amount of addition, little impact on the mechanical properties of resin, not easy to stratification, pattern, precipitation and other adverse phenomena after addition, saving manpower, material costs and time and many other advantages.

Generally speaking, the dispersion, fluidity, compatibility with the resin and thermal stability and weather resistance of the flame retardant masterbatch in the resin are greatly superior to ordinary flame retardants, and the flame retardant efficiency and effectiveness (cost performance) of the properly formulated flame retardants are also far superior to ordinary flame retardants. Therefore, the flame retardant masterbatch has become one of the best choices for flame retardant plastic products to achieve fire protection requirements, and has become an effective substitute for flame retardant powder.

Why do plastics need to be flame retardant

Although plastics have many excellent functions, the flame retardant function of most plastics is not very good, which often affects its use in some occasions with high flame retardant requirements, such as communication work, the automotive industry, construction materials, decorative materials, cables and electrical work. Most countries in the world have drawn up various regulations to rule the flame retardant standards of plastics, requiring that in some fields of application, plastics should have excellent flame retardant function. The good and bad of the flame retardant function of plastics are generally measured by the following two goals:

Oxygen index (OI)

The oxygen index (OI) is a goal to measure the combustibility of plastics, which refers to the low oxygen content necessary for the plastic sample to persist in burning in the air.

Different plastics have different combustion functions, and their oxygen indices are also different. The smaller the oxygen index of a plastic, the smaller the oxygen concentration required for continuous combustion, which indicates that its combustion is good, and it can continue to burn when there is little oxygen; On the contrary, the greater the oxygen index, the greater the concentration of oxygen required for continuous combustion, which indicates that its combustion is not good, as long as the oxygen concentration is large, it can continue to burn.

It is generally believed that OI<22 belongs to flammable plastics; OI=22~27 belongs to self-extinguishing plastic; OI>27 belongs to refractory plastics. The oxygen index OI value of most plastics is less than 27, and the general flame retardant occasions require the OI value of plastics to reach about 30, therefore, most plastics need to be flame retardant modified.

American UL Standard (UL-94)

The test method in the United States UL standard is to investigate the combustion of plastics when they are directly touched by the fire source, and to analyze their fire resistance.

(1) V-O continuously burns for 30 seconds, stops within 10 seconds after the fire, and does not ignite the cotton at 30mm below it.

(2) V-1 continuously burns for 30 seconds, stops within 10 to 30 seconds after the fire, and does not ignite the cotton at 30mm below it.

(3) V-2 continuously burns for 30 seconds, stops within 30 seconds after the fire, but ignites the cotton at 30mm below it.

Among the above two methods, our country mainly uses oxygen index method, which is intuitive and easy to compare; Compared with the two methods, generally OI>27 is equivalent to V-O level.

Classification of flame retardant masterbatch

Due to the advantages of flame retardant masterbatch used in plastics in flame retardant efficiency, environmental protection, improve production efficiency, convenience and many other aspects, it has become an effective substitute for traditional flame retardants and has been widely used in various aspects of plastic granulation, extrusion, injection molding and so on.

The flame retardant masterbatch that can be promoted and applied is mainly halogen series (Br, Cl), phosphorus series (red phosphorus, phosphorus compounds, etc.), nitrogen series (usually called expanded flame retardant masterbatch) and inorganic flame retardant masterbatch (aluminum hydroxide, magnesium hydroxide, etc.).

Halogen-based flame retardant masterbatch

Halogen-based flame retardant masterbatch is the flame retardant masterbatch that is respected in most resins today, because its own organic property makes it better affinity with plastics, so the mechanical properties of the finished product are reduced less and the flame retardant efficiency is high, the addition amount in the resin is less, and the cost performance is high. The disadvantage is that some of them are biotoxic and are prohibited in some international standards. And due to poor environmental performance, especially in Europe, there is a trend of elimination.

Phosphorous flame retardant masterbatch

Phosphate-based flame retardant masterbatch is also a more commonly used product, and its flame retardant efficiency is even higher than that of halogen in some resins, but it has many shortcomings such as poor color coordination, poor compatibility, low oxygen index, low applicability to processing technology, and often can only be used by special industries.

Polyethylene series flame retardant masterbatch

According to the different PE processing properties and processing technology, there are wire drawing grade, extrusion grade, film grade, coating grade, antistatic grade and other series of polyethylene flame retardant masterbatch. Completely replace the powder flame retardant, with high concentration, good dispersion, simplified production process, high cost performance. Thus, it can solve most of the flame retardant problems of PE molding and meet the needs of different products. It is widely used in polyethylene dense mesh building safety net, Christmas tree, artificial turf, polyethylene building threading pipe, mining pipe, cable, foam board, automobile wiring harness pipe, flame retardant cloth, flame retardant film, fireproof cloth coating, electronic packaging, etc.

Polypropylene series flame retardant masterbatch

According to the different processing properties and processing technology of PP, there are wire drawing grade, extrusion grade, film grade, antistatic grade, injection grade and other series of polypropylene flame retardant masterbatch. It has the advantages of high concentration, good dispersion, simplified production process and high cost performance, and completely replaces powdered flame retardants. Thus solving most of the flame retardant problems of PP molding to meet the needs of different products. Widely used in polypropylene high strength silk, flat silk, artificial wig, electrical safety belt, artificial grass, sports net, PP automotive wire harness pipe, plate, mining net belt, packing belt, electronic injection parts, electrical skeleton, electrical shell, European socket and so on.

Intumescent flame retardant masterbatch

Due to its low flame retardant efficiency and easy "foaming" and many other inadaptability, the application range of the expanded flame retardant masterbatch is more narrow. Inorganic flame retardant masterbatch, such as magnesium hydroxide. Its flame-retardant products have good environmental protection, do not emit toxic gases, small smoke volume, and high oxygen index of flame-retardant plastics, but due to the high addition amount to meet the ideal flame retardant standards and the natural incongrancy of inorganic substances and organic matter, although the finished products produced after modified treatment are still difficult to meet the needs of most industries, its promotion is subject to certain restrictions. It is believed that after the progress of the process, relying on its environmental advantages can also be gradually recognized by the market.

Ruize flame retardant masterbatch is mainly used in the plastic industry and chemical fiber, as long as the flame retardant masterbatch and the flame retardant resin mixed evenly according to the proportion can be used to process a variety of flame retardant products, when the addition of flame retardant masterbatch in the range of 6%-12% can be adjusted to give PP, HDPE, LLDPE and other polyolefin resin and other corresponding flame retardant effect.

Can be produced according to customer needs: polypropylene spunbonded non-woven masterbatch; Polypropylene melt-blown non-woven fabric masterbatch; Polypropylene SMS non-woven masterbatch; Polypropylene filament masterbatch; Polypropylene BCF masterbatch; Polypropylene short fiber color masterbatch and other kinds of polypropylene fiber color masterbatch, non-woven functional masterbatch, chemical fiber functional masterbatch, polyester color masterbatch, nylon color masterbatch.

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