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

2021/07/28

    Pur hot melt adhesives have different pasting properties in different applications. If pur hot melt adhesive wants to exert its maximum adhesive performance, it is necessary to understand its several major characteristics, and have a full understanding of the initial viscosity and the long-lasting viscosity. Today we will explain several factors that affect pur hot melt adhesive:

1. Color:

    For pur hot-melt adhesives, different colors have different viscosity, and yellow adhesive is better in many colors. If using colored glue has no effect on the bonded object, it is recommended to choose yellow pur hot melt glue, the paste effect is very good.

2. Temperature:

    Pur hot melt adhesive is very sensitive to temperature. When the temperature reaches the melting point, the adhesive begins to soften. When the temperature exceeds the normal use temperature, the pur hot melt adhesive will become brittle, which will seriously affect the bonding effect. The working temperature of pur hot-melt adhesive is lower than that of EVA hot-melt adhesive, so pur hot-melt adhesive machine should strictly control the working temperature of each glue when working, and also need to fully consider the environmental temperature change.

3. Curing time:

    Modern people have a very strong time concept, and customers are the same. After placing an order, they all hope that they can be delivered to themselves as soon as possible. This requires companies to complete with high production efficiency. Fast processing is a trend. The strength of pur hot melt adhesive is that its curing time is greatly shortened compared with other glues, usually about 6-20 seconds. However, if efficiency is pursued too much, insufficient curing time will still affect the bonding effect.

4. Viscosity:

    The viscosity of pur hot melt adhesive is divided into initial viscosity and holding viscosity. The initial viscosity represents the viscosity of the adhesive, and the holding viscosity represents the adhesive strength of the adhesive. It is usually better to choose a suitable adhesive. It is directly related. If the initial adhesion effect is not good, there is no need to talk about the holding viscosity in the later stage. The initial viscosity has a greater relationship with the environment in which the adhesive is located.