Energy-saving foamed polypropylene bead and molded part thereof

Abstract

The invention belongs to the technical field of foamed polypropylene, and particularly relates to an energy-saving foamed polypropylene bead and a molded part thereof. The foamed polypropylene bead is prepared from composite particles through a high-temperature and high-pressure kettle type foaming method, and the composite particles comprise a core layer and a skin layer; the core layer is prepared from the following components in percentage by mass: 40 to 60 percent of polypropylene A, 20 to 40 percent of polypropylene B, 15 to 30 percent of polypropylene C, 0.05 to 2 percent of expanding aid, 0.05 to 0.5 percent of cell nucleating agent and 0.5 to 3 percent of maleic anhydride modified polypropylene; and the skin layer comprises the following components in percentage by mass: 90-100% of polyolefin D and 0-10% of other auxiliaries. The composite particle has a structure that the core layer is coated with the skin layer, and the skin layer matrix resin is low in melting point, easy to sinter and good in compatibility with the main base material resin used by the core layer; and the core layer resin adopts a specially selected mixture, and the expanding aid further promotes the molding expansibility, so that the EPP beads have more excellent molding expansion under the molding pressure of 1.4 bar, and the excellent apparent quality of a molded part is reflected while firm sintering is realized.

Description

technical field [0001] The invention belongs to the technical field of expanded polypropylene, and in particular relates to energy-saving expanded polypropylene beads and molded parts thereof. Background technique [0002] The expanded polypropylene beads (EPP) and its molded products produced by the kettle method have excellent resilience, better high temperature resistance (understood to be used at higher temperatures), and the production process is clean and pollution-free. It is a PU foam , EPS and EPE are ideal substitutes. At present, EPP has been widely used in the fields of thermal insulation, cushioning packaging and automobile lightweight. [0003] The inherent melting characteristics of EPP beads lead to the need for high steam pressure to achieve firm sintering during steam molding. Especially compared to the molding process of EPS, the high molding energy consumption of EPP beads is an obstacle to its further development. factors for development and promotion. ...

AI Technical Summary

Problems solved by technology

[0003] The inherent melting characteristics of EPP beads lead to the need for high steam pressure to achieve firm sintering during steam molding. Especially compared to the molding process of EPS, the high molding energy consumption of EPP beads is an obstacle to its further development. factors for development

[0004] Chinese invention patent CN101679662A uses polypropylene materials with a melting point of 115-135°C to obtain foamed polypropylene beads with a molding pressure lower than 0.18 MPa and molded products thereof; the inventors have repeatedly verified experiments and found that the products of this technology have anti-corrosion properties. Risk defect of low compression performance (soft hand feeling)

Chinese invention patent CN112457596A has obtained energy-saving foamed beads coated with low-melting point polyolefin and high-melting point polypropylene. The molding pressure is lower than 2.2bar, but there is poor sintering in the EPS molding machine mold (molding pressure is lower than 1.6bar). and the risk of poor apparent quality of the part

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