Method for improving low-temperature impact resistance of PPR pipe

Abstract

Provided is a PPR pipe resisting to low-temperature impact. The PPR pipe is composed of, by mass, 1.5-3 parts of color master batches, 3-6 parts of toughening agents and 93-98 parts of PPR. A manufacturing method of the pipe comprises the steps that (1) the materials are evenly mixed together and subjected to smelting, fusion and modification through an internal mixer, and a fused blank enters a single-screw extruder to carry out extrusion pelletizing; (2) the modified grains are extruded through a single-screw extrusion host and a mold, and then are subjected to cooling sizing through a sizing water tank; (3) after cooling sizing is carried out, the grains pass through a dragger, a cutting machine and a plate turning frame and then are discharged, so that the PPR pipe is obtained; and (4) the pipe is subjected to annealing treatment, then cooled quickly and finally cooled to the room temperature in a natural mode. The raw materials of the method are easy to obtain, and cost is reduced; and by placing the pipe in an annealing tank for annealing, internal stress generated in the forming process of the pipe can be released, and the impact resistance of the pipe is improved.

Description

technical field [0001] The invention belongs to the field of plastic building materials, and in particular relates to a method for improving the low-temperature impact resistance of PPR pipes. Background technique [0002] Random copolymerized polypropylene (PPR) Since the ethylene monomer is randomly distributed in the long chain of propylene during the synthesis process, the ethylene monomer is controlled between 3% and 5%, and the ethylene content and the polymerization method of ethylene and propylene determine the Low temperature brittleness characteristics of PPR. When the temperature is below 5°C, especially in winter, the flexibility and toughness of the pipe will decrease at low temperature, and brittle problems such as pipe cracking will occur under external impact or load. [0003] Generally, there are three ways to improve the low-temperature impact strength of PPR, namely, blending elastomers, adding β-nucleating agents, and blending nanoparticles. Considering...

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