1、热封温度 1, the heat sealing temperature 复合膜的热封温度的选择与复合基材的性能、厚度、制袋机的型号、速度、热风压力等有密切关系，直接影响热封强度的高低。 The choice of heat sealing temperature of the composite membrane and the performance of the composite base material, thickness, bag making machine model, there is a close relationship between speed, air pressure, etc, which directly affect the heat sealing strength of high and low. 复合薄膜的起封温度是由热封材料的黏流温度或熔融温度决定，热封的温高温度不能超过热封材料的分解温度。黏流温度与分解温度之间的温度即为热封材料的热封温度范围，它是影响和控制热封质量的关键性因素。热封温度范围越宽，热封性能越好，质量控制越容易、越稳定。 The sealing temperature of the composite film is determined by the viscous temperature or molten temperature of the hot sealing material, and the temperature of the hot sealing temperature cannot exceed the decomposition temperature of the heat sealing material. The temperature between the viscous temperature and the decomposition temperature is the temperature range of the heat sealing material, which is the key factor in the influence and control of the heat seal quality. The wider the temperature range, the better the heat sealing performance, the easier and more stable the quality control. 同时复合薄膜热封温度不能高于印刷基材的热定型温度。否则会引起热封部位的收缩、起皱，降低了热封强度和袋子的抗冲击性能。印刷基材的耐温性好，如BOPET，BOPA等，提高热封温度能提高生产速率；印刷基材的耐温性差，如BOPP则尽量采用较低的热封温度，而通过增加压力、降低生产速度或选择低温热封性材料来保证热封强度。 At the same time, the heat sealing temperature of the composite film is not higher than that of the printed substrate. Otherwise, it will cause the shrinkage and wrinkling of the heat sealing area, reducing the heat seal strength and the impact resistance of the bag. The high temperature of the printed substrate, such as BOPET, BOPA, etc., increases the rate of production by raising the heat seal temperature. Printing substrate temperature resistance is poor, such as BOPP, using low heat sealing temperature as far as possible, and by increasing the pressure, reduce the production speed or choose low temperature heat sealing materials to ensure that the heat seal strength. 2、热封压力 2, heat sealing pressure 热风压力由制袋机上的压力弹簧提供。热封压力的大小与复合膜的性能、厚度、热封宽度等有关。极性热封材料有较高的活化性能，升温对其黏度的下降影响较大，因而所需的热封压力较小，防止热封部位的熔融材料被挤出，影响热封效果。而PE，PP为非极性材料，活化性能极小，所需压力较高，对热封强度、界面密封性有利。 Hot air pressure is provided by the pressure spring on the machine. The size of the heat sealing pressure is related to the properties, thickness and thickness of the composite membrane. Polarity, heat sealing materials have higher activation temperature on the viscosity of the decline in influence is bigger, so the required heat sealing pressure is small, prevent heat sealing parts out of the molten material, heat sealing effect. Whereas PE, PP is non-polar material, the activation performance is very small, the pressure is higher, it is advantageous to the heat seal strength, the interface sealing property.