What are the factors that affect the stickiness of pur hot melt adhesives?

2021/03/17

        Pur bulk melter  has different sticking performance to different bonding materials. If pur hot melt adhesive wants to exert its maximum adhesive performance, the following factors must be carefully considered:


1. Color: different colors of pur hot melt adhesives have different viscosities, usually yellow adhesives are more viscous. If the adherend does not require high glue color, it is recommended to choose yellow pur hot melt adhesive, the paste effect is very good.

2. Viscosity: The viscosity of pur hot melt adhesive is divided into the initial viscosity and the later holding viscosity. The initial viscosity is the adhesive strength of the adhesive. It is usually better to choose the appropriate adhesive. The latter holding viscosity is directly related to the initial viscosity. If the initial adhesion effect is not good, you don’t need to talk about the later holding viscosity, but the viscosity has a greater relationship with the environment in which the adhesive is located.

3. Temperature: Pur hot melt adhesive is very sensitive to temperature. When the temperature reaches the softening point, the adhesive begins to soften. At a certain temperature, the pur hot melt adhesive will become brittle, which will seriously affect the bonding effect. The working temperature of pur glue is lower than that of EVA glue, so the pur hot melt glue machine should strictly control the working temperature of each glue when it is working, and also need to fully consider the environmental temperature change.

4. Curing time: Modern technology has very high requirements for production efficiency. Fast processing is also the strength of pur hot melt adhesives. Compared with other glues, the curing time is greatly shortened, usually about 15 seconds. However, if the efficiency is too high, the curing time of less than 15 seconds will still affect the bonding effect.