Abstract: A polypropylene composition, a preparation method thereof, and a film or a sheet prepared from the polypropylene composition and use thereof. The composition includes 45 parts to 75 parts of a polypropylene, 10 parts to 35 parts of an elastomer, 5 parts to 20 parts of a polyethylene, 0.1 parts to 0.5 parts of an antioxidant, and 0.1 parts to 0.5 parts of a lubricant. A half peak width of a crystallization peak of the polypropylene is 5° C. to 10° C., and a peak temperature of the crystallization peak of the polypropylene is 105° C. to 115° C. The polypropylene composition has a good tenacity, especially a?30° C. low-temperature impact performance. The film or the sheet prepared from the composition and applied to automotive interior parts, can enable the external accessories not only to be less likely to generate sharp fragments while being strongly impacted, but also to have a matte characteristic.

Abstract: A polypropylene composition, a preparation method thereof, and a film or a sheet prepared from the polypropylene composition and use thereof. The composition includes 45 parts to 75 parts of a polypropylene, 10 parts to 35 parts of an elastomer, 5 parts to 20 parts of a polyethylene, 0.1 parts to 0.5 parts of an antioxidant, and 0.1 parts to 0.5 parts of a lubricant. A half peak width of a crystallization peak of the polypropylene is 5° C. to 10° C., and a peak temperature of the crystallization peak of the polypropylene is 105° C. to 115° C. The polypropylene composition has a good tenacity, especially a ?30° C. low-temperature impact performance. The film or the sheet prepared from the composition and applied to automotive interior parts, can enable the external accessories not only to be less likely to generate sharp fragments while being strongly impacted, to guarantee the safety of people, but also to have a matte characteristic.

Abstract: A method of improving the appearance of foaming injection molding product includes closing the moving mold and the fixed mold and setting a clamping force on the closed mold, wherein a mold cavity is formed between the moving mold and the fixed mold. The method proceeds by inflating the mold cavity with high pressure and high temperature gas until the air pressure in the mold cavity reaches 2-25 MPa and the temperature of the high pressure and high temperature gas is between 60-200° C., then injecting molten resin that contains foaming agent into the mold cavity while continuously inflating high pressure and high temperature gas. After injection completed, stopping inflating high pressure and high temperature gas and simultaneously releasing pressure, wherein the step of releasing pressure includes the step of opening the mold.