The heat sealing technology of the composite bags

When heat sealing material was determined, composite bag heat sealing quality is directly related to heat sealing process, usually is the main control of heat sealing temperature, pressure and time. Heat sealing theory? Composite bags above the heat sealing temperature when heat sealing, make plastic film adhesive flow; And heat sealing pressure can make the plastic film in the viscous flow of interface between molecules produce mutual penetration, diffusion, external power; Certain heat sealing time can make the plastic film interface molecular mutual penetration, diffusion as soon as possible, make the interface disappeared and as a whole, thus has good sealing. Heat sealing temperature heat sealing materials of minimum heat sealing temperature depends on the material melt temperature, heat sealing temperature should be higher than the melting temperature of the heat sealing materials, however, is higher than many, want to consider to be sealing material is single film or composite film, film thickness, heat sealing pressure, heat sealing speed and other technical indicators. Generally, high heat sealing pressure; Heat sealing was slow; Film thickness is big, the heat sealing temperature can be lower, and vice versa. Heat sealing pressure heat sealing the size of the effect of the heat sealing is big, the influence of heat sealing pressure should be appropriate, heat sealing pressure too low, by heat sealing of the two materials are difficult to achieve the real convergence, or difficult to catch all the seal in the middle of the gas, so that cause local seal leakage. Heat sealing pressure, and then when heat sealing temperature is a bit high, easy to heat sealing when heat sealing DaoHui molten material from the joint sealing edge out, cause & other; Eager & throughout; Phenomenon. Light reduce the heat sealing strength of sealing to seal the resistance to impact strength decreased. In general, high heat sealing temperature; Heat sealing was slow; Thin film materials, heat sealing pressure can be smaller, and vice versa. Heat sealing at the same time the heat sealing temperature and heat sealing pressure, heat sealing, the longer the heat sealing layer interface combined with the stronger, but the heat sealing time is too long from resin sealing joints oxidation, reduce heat sealing effect. At the same time, heat sealing time is too long also easy to cause joint sealing wrinkle deformation, affect the appearance and cause leakage bag. Summary in a word, different heat sealing materials and adding different additives and composite bags for heat sealing materials of different processing methods ( Corona, printing) , such as the characteristics of the heat sealing material is different. According to the different packing materials and packing technology choose carefully. Temperature, pressure and time are the three important parameters of heat sealing process, should according to the different heat sealing of composite packaging materials and packaging process properly determined, in order to get the best heat sealing effect.