PUR Adhesives
PUR prepolymer adhesives or PUR glues are one-component, duroplastic adhesives that react with the surrounding humidity and the workpieces that are to be bonded. They are part of the most modern adhesives for carpenters and cabinet makers and are excellent for particularly demanding connections.
No matter if you want to bond two absorbent materials or an absorbent and a non-absorbent workpiece - PUR adhesives form an excellent bond without further heating.
liquid vs pasty
PUR adhesives are available in different viscosities. These range from liquid to pasty and have to be chosen according to the purpose. The more pasty adhesive for example is particularly suited for vertical bonding and is very popular for mobile use on construction sites. The more liquid variant is rather used for greater surfaces and in the workshop.
Both variants can be applied by using a putty. For liquid adhesives, it is possible to use a glue roller as well. Keep in mind to clean the application tool immediately after use with acetone or cellulose thinner, before the adhesive hardens.
Fibre-reinforced? For what reason?
Some PUR adhesives are, in addition, fibre-reinforced. They are particularly suited for the construction of loadbearing, glued finger joints for interior and exterior areas. Due to the fibres, a particularly high bond strength is achieved.
Humidity and foaming
For bonding with one-component PUR adhesives, a chemical reaction with water is indispensable. In case the adhesive cannot draw the humidity from the materials or the surrounding air, you can carefully wet the workpieces with water.
The different foaming reaction is mentioned for each PUR adhesive in the technical data sheet. Adhesives with greater foaming reaction for example are particularly suited to bond uneven surfaces that the adhesive can then seep into.