Metallocene Polyolefin / Pp Modification And Easy To Peel Polypropylene Cast Film (cpp) Developed

Flexible package is usually formed by the compound of barrier films and heat-sealing films. Due to its high barrier properties, Flexible package is helpful to prolong the storage life of products. In addition, the convenience and economy make flexible package be widely used in food, medicine, agriculture, chemical engineering and clothes industries. However, the Flexible package bag is difficult to be unclosed, which causes inconvenience in the actual application. Therefore, a nick is usually needed on the edge of the pack.Flexible package produced by easy-peeling PP cast film has a wide heat sealing temperatures window. Also its actual heat sealing temperatures is relatively low but the heat sealing strength can be under the control. The bag made of this kind of cast PP film can be easily opened from the sealing edge and very convenient for the customers to use it. Until now, the easy-peeling film is only used as the PE cover of jelly. The seal strengths of CPP film is even higher than PE film.Tt is very important to developing easy-peeling CPP film but it has not been produced in our country.In this paper, the production, application and development of the CPP film as well as the related studies on blending modification PP of metallocene polyolefin will be briefly introduced first. Next, influence of different metallocene polyolefin and its content on the thermal capacity and crystallization behavior of COPP will be investigated in details. It is found that adding of a butylene-ethylene copolymer reduces the seal initiation temperatures and also decreases the heat sealing strength. Quite differently, adding anther copolymer composed of propylene and butylene can only reduce the heat seal temperatures but has little effect on the thermal heat sealing strength. Therefore the butylene-ethylene copolymer is a preferable modifier to peelable CPP film. The relation between the content of butylene-ethylene copolymer and film heat sealing strength is studied and it is found that the film has a better peelable feature when the content of modifier is above 20 percent. For example, the peeling strength of the film is up to 9.2N/15mm as for the 30 percent content of the butylene-ethylene copolymer. After peeling, the separated surface is confirmed as between CPPs, which meets the requirement of the consumers.Moreover, the adding of heat sealing modifier also affects the antiblocking and friction coefficient of CPP cast film, then the kind of antiblocking additives and slip agents is carefully chosen and the effect is experimentally investigated. Considering the comprehensive properties of...