The heat-seal material should have good heat-sealability, stable chemical properties, meet hygienic requirements, and have certain barrier properties. Mainly polyethylene, polyethylene co-extruded film, polyethylene copolymer, polypropylene and so on. Evaluate the performance indicators of the heat seal material generally have tensile strength, elongation at break, right angle tear strength, surface roughness, haze, impact strength, friction factor, puncture resistance and so on. The indexes for evaluating the heat sealability of the heat seal material include low temperature heat sealability, hot stickiness, heat seal strength, heat seal stretch state, and anti-pollution heat sealability. In order to meet the requirements of various packaging, to meet the requirements of packaging machinery, to meet the requirements for the production and storage of contents, it is necessary to choose different heat sealing materials. Cast polypropylene film (CPP) is more transparent, rigid, oil-resistant, moisture-blocking, gas-barrier, and high-temperature resistant than polyethylene film, and is widely used in transparent food packaging and cooking bags. For continuous automatic filling of liquids, consider the use of metallocene polyethylene (mPE) ionic resin (Surlyn) with good thermal tack and good anti-pollution and heat seal properties. Because the low temperature resistance of polyethylene film is better than CPP, it is widely used in frozen food packaging.