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How to achieve the self-extinguishing effect of PE flame retardant masterbatch?

Mar. 21, 2022

PE, or polyethylene, is a polymer with various structures and properties. It is mainly divided into low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), and ultra-high molecular weight polyethylene with special properties, low relative molecular weight quality polyethylene, high molecular weight high density polyethylene, very low density polyethylene, etc.

 

Generally speaking, polyethylene with a relative density lower than 0.920 is usually called low-density polyethylene; polyethylene with a relative density equal to or greater than 0.940 is called high-density polyethylene; polyethylene with a relative density in the range of 0.926~0.940 is called medium-density polyethylene density polyethylene.


HDPE Water Supply Pipe

 

Advantages of PE flame retardant masterbatch:

1. Good compatibility with resins: Generally, halogen-free flame retardant masterbatches (masterbatches) have been specially treated to improve their compatibility with plastic resins, so that even when the amount added to the resin is large It is also not easy to produce delamination, frosting, patterns, etc.

2. Easy to use: Halogen-free flame retardant masterbatches (masterbatches) are mostly tablet-shaped or strip-shaped particles, which are just the same size as ordinary plastic particles, which improves the mutual compatibility between them and makes it easier to disperse and add. And it is hygienic and reduces volatilization waste.

3. Reduce costs and increase the added value of products: often through the addition of halogen-free flame retardant masterbatch (masterbatch), general plastics have or are close to the application requirements of engineering plastics, which increases the added value of products and reduces the cost of raw materials.

 

The self-extinguishing principle of PE flame retardant masterbatch is as follows:

1. The PE flame retardant absorbs the heat generated during combustion and acts as a cooling to slow down the combustion rate. Such as aluminum hydroxide, the proportion of chemically associated water contained in its molecule is as high as 34%. This associated water remains stable at the processing temperature of most plastics, but begins to decompose when it exceeds 200 °C, releasing water vapor. And for every gram of aluminum hydroxide decomposed, 36 kcal of heat are absorbed.

2. Produce a gas that can smother the flame. Such as antimony trioxide, when it encounters HCL emitted by combustion in PVC, it reacts to generate a suffocating gas, that is, antimony nitrogen oxides.

3. PE flame retardant provides a coating that is isolated from oxygen. For example, the phosphide generated when the phosphate ester flame retardant is burned is the oxygen barrier coating.

4. Generate free radicals that can react with plastics and play a flame retardant role. The flammability of their reaction products with plastics is extremely poor.

 

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