xufeng's brand talcum powder is used in EVA foaming
EVA foaming surface gloss and chemical stability is good, with anti-aging, ozone resistance, non-toxic and so on, in addition, EVA high foam sheet also has good softness and elasticity characteristics. Therefore, EVA foam inglis is widely used in shoes (slippers, sports shoes in the bottom), sports equipment sheath, floor mats, luggage materials.
EVA foaming formula generally consists of the following raw materials: main material, filler, foaming agent, bridge agent, foaming promoter, lubricant.
Main material: Very clear, it is EVA or PE. In order to improve the physical performance of the product, some other materials, such as rubber, POE, TPR, etc. can be added appropriately. EVA's main indicator is THE VA content, its high and low and eva foam products almost all performance has a direct relationship.
Filler: Talstone powder is currently commonly used. Talc powder with silicon content, particle size, whiteness as a quality index. The maximum amount in the formulation can be 40Phr (percentage of the main ingredient). Division I combined with the special needs of EVA foaming, through the selection of high-quality talcum, the use of advanced stand-grinding plus grading process produced by THE SPECIAL mid-range talc powder BHS-807, BHS-808A, the solution surface is smooth, with a uniform distribution of micro-powder fineness, uniform particle size span interval, larger than the surface area, The surface effect, volume effect and less dust impurity of ultrafine particles are characteristics.
Characteristics:
1. Adding talcum powder not only greatly reduces the cost;
2. Also play a role in increasing product performance, such as enhancing product rigidity, improve impact strength;
3. Ensure good fluidity of melts and improve processing performance;
4. Increase the molding rate, increase the yield of the finished product, reduce energy consumption;
5. Improve the melt strength of EVA foaming material and prevent the merging of bubbles
Foaming agent: generally used to use AC series of foaming agent, AC series foaming agent belongs to the high temperature foaming agent, decomposition temperature at 220 degrees C. There are also low-temperature foaming agents, such as AD-300, decomposition temperature at 140 degrees C, as well as medium temperature foaming agent. Because the price difference is not large, and high temperature foaming agent is relatively stable, so many do EVA to use high-temperature foaming agent. The amount of AC is based on the specific multiple.
Bridge agent: also known as cross-linking agent, is now the most used DCP, previously also used TAIC, PL400 and so on. The dystenage of the DCP is 1 minute at 180 degrees C and 10 minutes at 130 degrees C, so when the general exercise, the temperature is as controlled as far as possible below 120 degrees C. If the product is required for odor, another bridge agent BIPB can be used, BIPB generally and TAIC. The dosage of DCP, in the flat foam and in the mold small foam generally use 0.5-0.6Phr, shooting bubble generally add0.8-1.0Phr.
Foaming promoter: There are two more used now, zinc oxide powder and zinc stearate powder. The previous two combinations, now a single can also achieve results, and the stability of the product is better. Zinc oxide can reduce the decomposition temperature of AC to about 160 degrees C, which is convenient for production. General zinc oxide consumption does not exceed 0.2Phr, too many products shrink will be relatively larger, too little time foaming speed is too slow.
Lubricants: Generally with sic acid. In fact, it does not have much effect, is to let the practice material, non-stick machine. It's not good to use it too much because it reduces friction between components and reduces most physical properties.
In addition, in the EVA foaming formula will be added according to different needs of accessories, such as corner, anti-static agents, flame retardants, fast cooks, colorants and so on.
