PUR Adhesive Description
There are actually many kinds of hot melt adhesives. For example, EVA hot melt adhesive for furniture edge banding is also a more commonly used hot melt adhesive, but today I want to share with you PUR hot melt adhesive. PUR is actually the abbreviation of Polyurethane Reactive, it contains chemical functional groups, when it is melted, it will react with the moisture in the air to form an irreversible substance, that is, it cannot be melted twice. Sometimes called thermosetting hot melt adhesive.
PUR adhesive is a molecular structure containing polar and chemically active urethane or isocyanate groups, stick with materials containing active hydrogen, it also have excellent adhesion. Such as wood, leather, fabric, paper, ceramics and other porous materials and plastics, metals, glass, rubber, etc. Smooth surface materials have excellent adhesion.
PUR hot-melt adhesive is heated and melted into a fluid for coating under the conditions of inhibiting chemical reaction; after the two adherends are bonded and cooled, the adhesive layer condenses to play a role of bonding; afterwards, it uses moisture and moisture in the air. The moisture attached to the surface of the adherend reacts with it to extend the chain to produce high polymer with high cohesion, which significantly improves the adhesion, heat resistance, and low temperature resistance.
PUR Adhesives Performance
Most hot melt adhesives are heated and can be reheated after bonding, which is reversible, while PUR is a moisture-reactive hot melt adhesive. After heating, it will react with moisture in the air after bonding, and the reaction is complete. After that, it is irreversible (that is, it will not melt when heated), so PUR is more resistant to high and low temperatures.
During the use of PUR glue, it is necessary to thoroughly clean the rubber rollers in the equipment after the production is completed every day. Once forgotten or incompletely cleaned, the glue will solidify and be difficult to clean, which will affect product quality.
Advantages of PUR hot melt adhesive
- PUR hot melt adhesive is an adhesive without any solvent/solution. It does not require a drying process like solvent-based adhesives, and it will not cause environmental pollution or poisoning. PUR hot melt adhesives are odorless and have been used in Europe many years ago. Started to use PUR hot melt adhesive, which is a green and environmentally friendly product.
- PUR hot melt adhesive, easy to operate. The two adhesives can be fixed in a short time without drying, which improves work efficiency and saves time.
- PUR hot melt adhesive has excellent heat resistance, cold resistance, water vapor resistance, chemical resistance and solvent resistance. Due to the irreversible characteristics of PUR glue once it is reacted (that is, it will not melt after being heated), the coated wire board can remain stable at -40°C to 150°C, and the product quality is more stable, which is more suitable for processing export products.
- The packaging of PUR hot melt adhesive is sealed in aluminum foil. The glue supply requires professional sealable equipment to better ensure the quality of the film. The hot melt glue machine heats and melts the PUR glue under the condition of isolating the air. In the custom furniture industry, currently PUR glue is mainly used in the edge banding of decorative panels, and the production of surface materials such as acrylic, PET, and PVC. In the application of edge banding, the quality and product performance of PUR glue seal are better than that of EVA glue.