High-temperature anti-fog breathable polyethylene heat-seal film and preparation method thereof

Abstract

The invention belongs to the field of preparation of anti-fog heat-sealing films, and particularly relates to a high-temperature anti-fog breathable polyethylene heat-sealing film and a preparation method thereof. The heat-sealing film comprises a surface layer, a core layer and a heat sealing layer from top to bottom, a three-layer co-extrusion layer ratio structure is as follows: LDPE + LLDPE / (LDPE + LLDPE + an initial high-temperature antifogging agent + a long-acting high-temperature antifogging agent) / (LDPE + LLDPE + PBE + an initial high-temperature antifogging agent + a long-acting high-temperature antifogging agent + nano calcium carbonate); wherein the surface layer accounts for 10-30 wt%, the core layer accounts for 40-75 wt%, and the heat sealing layer accounts for 15-30 wt%. The anti-fog heat-sealing film prepared by the invention has the characteristics of better anti-fog durability, better air permeability, high heat-sealing strength and good comprehensive performance, isparticularly suitable for packaging of fruit and vegetable products, is particularly beneficial to market development, and promotes the progress of packaging materials.

Description

Technical field [0001] The invention belongs to the field of preparation of anti-fog heat-sealable films, and specifically relates to a high-temperature anti-fog, breathable polyethylene heat-seal film and a preparation method thereof. Background technique [0002] Anti-fog heat-sealing films are commonly used in food, fruit and vegetable packaging and other fields. At present, the commonly used anti-fog heat sealing film is polyethylene film. The plastic film for anti-fogging heat sealing has the following important performance requirements: (1) It has good initial anti-fog performance and anti-fog durability; (2) The addition of anti-fogging agent cannot have a greater impact on the film heat sealing performance The heat-sealing strength of the film cannot be reduced; (3) The film has good tensile strength and transparency; (4) It has good air permeability and meets the breathing requirements of fruits and vegetables. [0003] At present, most anti-fogging films on the market u...

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Problems solved by technology

[0005] In the present invention, an appropriate amount of initial high-temperature anti-fogging agent and long-term high-temperature anti-fogging agent are added to the heat-sealing layer and the core layer, and the two anti-fogging agents are compounded in a certain proportion to form a high-temperature compound anti-fogging agent. Among the sprays, one is more hydrophilic and has a better initial anti-fog effect, and the other is more lipophilic and has a long-lasting anti-fog effect, so that the film has a better initial anti-fog effect and a long-term effect. Anti-fog performance; adding a certain amount of nano-calcium carbonate to the heat-sealing layer can take advantage of the adsorption function of calcium carbonate to delay the precipitation of the anti-fogging agent, prolong the anti-fog time of the film, and use the granularity of nano-calcium carbonate to increase the thickness of the film. On the other hand, the inorganic material nano-calcium carbonate can increase the strength of the film, and solve the problem of film strength reduction caused by the addition of anti-fogging agents; add a certain proportion of propylene-based Elastomer (PBE elastomer), PBE elastomer has a thickening effect, which solves the problem of the decrease of film heat seal strength due to the increase of anti-fogging agent; and then uses three-layer co-extrusion blow molding technology to prepare a high-temperature anti-fog effect. , good air permeability, polyolefin film with good tensile strength and heat sealing strength

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