There are three elements of TPU hot melt adhesive film hot pressing, none of which is missing.
In addition to controlling the temperature of the TPU hot melt adhesive film, there are two other factors that need attention, namely pressure and time. Temperature, pressure, and time are the three elements of hot pressing that we often say. In the process of bonding, none of these three elements can be missing.
2023-02-21
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There are three elements of TPU hot melt adhesive film hot pressing, none of which is missing.
In addition to controlling the temperature of the TPU hot melt adhesive film, there are two other factors that need attention, namely pressure and time. Temperature, pressure, and time are the three elements of hot pressing that we often say. In the process of bonding, none of these three elements can be missing.
The hot pressing pressure can make the TPU hot melt adhesive film diffuse better after being heated and melted. Without pressure, the TPU hot melt adhesive film cannot fully contact the adherend after melting, resulting in poor adhesion. Then too much pressure will not work. On the one hand, it will cause the problem of film penetration, and on the other hand, it may destroy the characteristics of the bonded object itself. For example, if the adherend is foam or a foam material, excessive pressure can crush the substrate itself and lose its useful value.
The heat pressing time is the same, neither too short nor too long. It should be adjusted according to the parameters of the specific TPU hot melt adhesive film, and an appropriate time should be selected. Too long will cause the film to melt excessively, and too short a time will cause poor bonding.
Pay attention to the characteristics of the remnants themselves.
There are also some cases of poor adhesion, which are caused by the fact that the adherend has its own characteristics, and the user does not notice these characteristics when bonding.
If some materials have a high moisture content, there will be water vapor during the hot pressing process, and the water vapor cannot be released well under pressure, forming air bubbles, resulting in poor adhesion. At this time, it may be necessary to adopt the method of segmented pressurization during compounding, appropriately release the pressure at a specific time, remove air bubbles, and then repeat the pressurization.
Some materials are not very flat or have a certain thermal stress during hot pressing, so there will be a certain degree of rebound after the pressure is released. The TPU hot melt adhesive film needs to wait for the film to cool and harden before it can form the bonding strength, so once the rebound occurs, the TPU hot melt adhesive film has not cooled and hardened, which of course causes poor bonding. At this time, it is necessary to add a cold pressing step after hot pressing, so that the TPU hot melt adhesive film can be cooled rapidly to form a good bonding strength.
The above points to pay attention to when using the TPU hot melt adhesive film. The key point is that everyone needs to flexibly adjust their own process according to the materials they are bonding, in order to explore a better process. If everyone can pay attention to this point, it will definitely help you to compound more firmly.
