Factors affecting the heat sealing effect of stretch wrap film

When using stretch wrap film, it is sometimes necessary to perform heat sealing, but many friends do not know much about stretch wrap film heat sealing, and some problems often occur during use. Below, the editor summarizes some factors that affect the heat sealing effect of stretch wrap film? The details are as follows:
What is the impact of heat sealing time on the effectiveness of use?
The heat sealing time of automatic packaging machines or old bag making machines is determined by the machine speed. When the heat sealing temperature and pressure remain constant, the longer the heat sealing time, the stronger the bond between the heat sealing layers. However, if the heat sealing time is too long, wrinkles and unevenness will appear in the heat sealed part of the composite stretch wrap film, seriously affecting the appearance quality of the product.
What is the impact of heat sealing pressure on the effectiveness of use?
In order to ensure the heat sealing strength of plastic composite flexible packaging, there must be a certain heat sealing pressure. Therefore, during the heat sealing process, it is required that the heat sealing pressure be moderate and uniform. If the heat sealing pressure is insufficient or uneven, bubbles will form in the heat sealing area, and false welding will lead to poor heat sealing. If the heat sealing pressure is too high, the sealing part will deform. When the heat sealing temperature is high, some composite materials will be squeezed off, resulting in brittle cracking of the heat sealing edge and a decrease in heat sealing strength.
What is the impact of heat sealing temperature on the effectiveness of use?
The heat sealing temperature of stretch wrap film has a significant impact on the heat sealing strength. The thickness of the film that affects the heat sealing effect of the outer layer of the product will play a decisive role in its heat sealing effect. When the temperature is relatively low, the surface of the heat sealing layer melts, and the outer layer thickness of the thin film participating in the heat sealing is relatively thin, resulting in a lower contact temperature. When the temperature is too high, it may melt the stretch wrap film of the heat seal layer or pose a risk of peeling off the bottom layer of the heat seal layer, causing the bottom layer of the upper and lower stretch wrap films to participate in heat sealing, and also leading to a decrease in heat sealing strength. Therefore, when heat sealing the surface wrapping film, it is necessary to choose an appropriate heat sealing temperature, which cannot be too high or too low. In addition, the viscosity of stretch wrap film is also a major factor affecting its effectiveness. It can be said that the higher the viscosity, the better the usage effect, which can play a role in rain and dust prevention. Moreover, the packaged products will not be blown away by the wind during long-distance transportation, making them very unsightly. Therefore, in the market, the thickness of this film is about 0.02mm.
Stretch wrap film is not only affected by many factors in terms of its effectiveness, but its cost of use is also affected by its quality. At present, with the development of modern cast film technology, the thickness of stretch wrap film can become thinner and the strength can become higher, and the tensile and puncture resistance have been greatly improved. However, many customers do not understand and continue their previous inertia, or are concerned about whether the strength will decrease after the winding film becomes thinner, so they dare not try to use such protective films.