Method for improving stability of polypropylene melt

Abstract

The invention relates to a principle and a method for improving the stability of a polypropylene melt. The method and the principle are characterized in that: by adding a tetrafluoroethylene polymer with a polypropylene melt strength enhancing function and a flaky component with a melt die swell control function, the melt die swell phenomenon is significantly reduced, and the obtained polypropylene modified material is suitable for thermal forming of various large parts, thus meeting the requirements for extrusion of hollow plates and large-diameter pipes. During extrusion blow molding of large hollow products, the melt dimensional stability can also be ensured. The method and the principle also have the advantages of enhancing the processing speed and reducing the cost.

Description

technical field [0001] The invention relates to a principle and method for improving the stability of polypropylene melt, which is characterized in that by simultaneously adding tetrafluoroethylene polymer with the function of enhancing the strength of polypropylene melt and a sheet-shaped polymer with the function of controlling the die expansion of the melt components, which significantly reduces the melt die expansion phenomenon, and meets the requirements of melt strength and dimensional stability for thermoforming and extrusion blowing processes. Background technique [0002] Polypropylene is cheap and has good overall performance. It is widely used in the fields of thermoforming, hollow extrusion, and hollow blow molding. However, ordinary polypropylene has low melt strength and high viscoelasticity, resulting in variable dimensions during thermoforming and extrusion. The controllability is very poor, which reduces the qualified rate of products and limits the increase...

AI Technical Summary

Problems solved by technology

In fact, simply increasing the melt strength often leads to an increase in viscoela

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