Along with the rapid development of food,book,toys, pharmaceuticals and other industries, the demand for POF shrink film is very increasing in the world, and the quality requirements for POF shrink film are also increasing. Packaging users not only pay attention to the aesthetics and logistics performance of the packaged products, but also pay attention to the heat-sealing strength of the packaged products. Because the POF shrink film heat seal of the packaged product directly affects the packaging speed, transportation and marketing. In actual production, as POF shrink film Chinese leading manufacturer Prettylift industry company controls the heat seal strength as one of the most important quality indicators for automatic packaging lines. In the following, combined with our prettylift customers experience in actual production, a simple analysis of the factors affecting the heat seal strength of the heat shrinkable film is made: 1. POF shrink film Heat sealing temperature: The heat sealing temperature directly affects the heat sealing strength of plastic composite packaging products.The different thickness POF shrink film have different the heat sealing temperature,the more thick thickness POF shrink film like 25mic,30mic and 38mic POF shrink film which need higher heat sealing temperature. our standard POF shrink film film heat sealing temperature is 150 -240 degrees,you can adjust this to your suitable Heat sealing temperature when you use POF shrink film to package products. 2.POF shrink film heat sealing time: the heat sealing time of the automatic packaging machine is determined by the machine speed. In the case where the heat sealing temperature and the heat sealing pressure are constant, the longer the heat sealing time, the stronger the bonding between the heat sealing layers. However, if the heat sealing time is too long, wrinkles and unevenness may occur in the heat-sealed portion of package product, which seriously affects the appearance quality of the product.The different thickness POF shrink film have different the heat sealing time, our standard POF shrink film film heat sealing time is 3-5 seconds.as normal the automatic packaging machine have their own suitable heat sealing time, if you want package more perfect, you can adjust it, then find your more suitable heat sealing time 3.POF shrink film heat sealing pressure: In order to ensure the heat sealing strength of plastic composite flexible packaging, a certain heat sealing pressure is essential. Therefore, the heat sealing pressure is required to be moderate and uniform during the heat sealing process. If the heat sealing pressure is insufficient or uneven, bubbles will be generated in the heat-sealed portion and the welding will be performed, resulting in poor heat sealing. This POF shrink film technolgy copyright by Prettylift Industry Co.,LTD,Our company web: www.prettylift.com If you want buy POF shrink film or Polyolefin shrink film from China, the PRETTYLIFT INDUSTRY shrink film is your best choice,We have more 20 years manufacture experience, and export many countries and place, and know all place customers requirements for shrink film,our email address:info@prettylift.com,our company web: www.prettylift.com