Foaming type flame-retardant polypropylene granules and preparation method thereof

Abstract

The invention belongs to the technical field of new materials, and particularly relates to foaming type flame-retardant polypropylene granules and a preparation method thereof. The foaming type flame-retardant polypropylene granules comprise components in parts by weight as follows: 60-80 parts of polypropylene, 18-30 parts of polyethylene, 1-5 parts of a foaming agent, 1-5 parts of a flame retardant and 0-0.5 parts of color masterbatch. The preparation method comprises steps as follows: (1), polypropylene, polyethylene, the flame retardant and the color masterbatch in a formula ratio are mixed in a feeding system; (2), the component materials are sufficiently fused and mixed under the shearing action of a double-screw extruder; (3), the foaming agent in the formula ratio is injected; (4), a melt cut into granules on a template of an underwater granule cutting machine; (5), polypropylene granules obtained through cutting are screened by a sieve shaker, the screened granules are classified, and products with different granule diameters are weighed and packaged. According to the foaming type flame-retardant polypropylene granules, adverse factors in a foaming process of polypropylene can be overcome, and a foamed polypropylene material is produced successfully.

Description

technical field [0001] The invention belongs to the technical field of new materials, and in particular relates to foamed flame-retardant polypropylene particles and a preparation method thereof. Background technique [0002] Expanded polypropylene products have excellent shock resistance and energy absorption performance, high recovery rate after deformation, good heat resistance, chemical resistance, oil resistance and heat insulation. In addition, its light weight can greatly reduce the weight of items . Expanded polypropylene is also an environmentally friendly material, not only recyclable, but also naturally degradable, without causing white pollution, known as "green" foam. Due to its good mechanical properties, excellent heat resistance and environmental friendliness, expanded polypropylene is a new generation of foam materials after traditional polystyrene foam, polyurethane foam and polyethylene foam, and has a wide range of application prospects . However, at p...

AI Technical Summary

Problems solved by technology

However, at present, almost all polypropylene foamed material products in China are prepared and produced by imported expanded polypropylene. There is no technical method for industrialized production in China, and the price of foreign expanded polypropylene is very high, and the transportation cost is very high. bigger

Although polypropylene foam has good performance and application prospects, the development of polypropylene foam is very difficult. At present, the relevant core technology that can be industrialized has not been mastered in China. For foreign countries, the core technology of foamed polypropylene is also mastered. In the hands of a few large companies in a few countries, the main reason is: polypropylene is a crystalline polymer, which hardly flows below the crystalline melting point, but above the crystalline melting point, the melt viscosity decreases sharply, so in polypropylene The gas generated during the foaming process of propylene is difficult to be enveloped by the melt

In addition, the transformation of polypropylene from a molten state to a crystalline state will release a large amount of heat, and it takes a long time to transform from a melt to a solid

In addition, polypropylene has a high air permeability and foaming gas is easy to escape, so the temperature range suitable for polypropylene foaming is narrow, so it is difficult to obtain products with uniform and fine cells and high foaming ratio