A Study Of Assistants On Properties Of Polyethylene Micropore Films

In this paper, I use expandable functional granules as raw material, and prepare a new ventilate and moisture-penetratable polyethylene films by blow molding. Compare with current high filling blow film of PE and machine penetrating hole film, it has remarkable difference in principle of forming micropore, process-control and use properties. This experiment uses lime carbonate, kaolin clay and starch as filler, uses sorbitol, ethanediol and chitosan as hygroscopic agent, under without foaming and foaming systems conditions, study filler and hygroscopic agent affect on tear strength, tensile strength, moisture coefficient and gas permeability of this film, and research mechanics of ventilation and moisture-penetrability of experiment preparing PE film by SEM.This article includes three chapters: 1. under without foaming system condition, calcium carbonate, kaolin clay and starch of filling and sorbitol, ethanediol and chitosan of hygroscopic agent affect on tear strength, tensile strength and moisture coefficient of polyethylene micropore film;2.under foaming system condition, calcium carbonate, kaolin clay and starch of fillings and sorbitol, ethanediol and chitosan of hygroscopic agent affect on tear strength, tensile strength and moisture coefficient of polyethylene micropore film;3. Analysis of microscopic structure of film.It can draw the following conclusions form this experiment:1. Calcium carbonate, kaolin clay and starch of filling have greatly influence on properties of PE film. Tear strength and tensile strength of PE film will decline with increasing of content of filling, but moisture coefficient and gas permeability will increase.2. sorbitol, ethanediol and chitosan of hygroscopic agent has evidently affect on properties of PE film. When increasing content of hygroscopic agent, which willlead to drop of ear strength and tensile strength of PE film, moreover improve moisture coefficient and gas permeability.3. The filling has greater effect on mechanical properties and gas permeability than hygroscopic agent.4. Filling has obvious influence on film forming, even if less content filling has distinct effect on film forming of PE. Colchicum carbonate is best among of colchicum carbonate, kaolin clay and starch.5. This experiment shows PE film of without foaming system hasn't gas permeability; even filling added, this film hasn't gas permeability. Only PE film of foaming system has gas permeability, foaming system has definitively action on gas permeability. In general, filling added can improve gas permeability, but increased extent is inconspicuous.6. Different assistant has different effect on gas permeability of PE film. When system has blister, film has good gas permeability, and foaming system has greater influence on gas permeability than filling and hygroscopic agent.7. SEM analyses indicate the microcellular polyethylene films are prepared by common blow molding. The surfaces of these films are lots of minute pores, the inner of films is distortion globosity, and the connectivity between pores form microcellular network structure. Microcellular shape of film surface, microcellular network structure and distribution connect its basal body composition, confectioning technology, foaming system and filling system.8. The osmotic mechanics of the microcellular polyethylene films is: (1) Adsorption, beneficiation and adhesion of osmotic gas molecule on the surface of films; (2) Solution, absorbing and diffusion, the osmotic gas molecules change saluting in the pores of films surface change the osmotic gas consistency of the pores by osmotic gas chemical potential action; (3) The osmotic gas beneficiation on another surface of films and diffusion in the air.