The Difference between EVA Glue And PUR Glue

EVA edge banding refers to EVA adhesive, which is synthesized from ethylene (E) and vinyl acetate (VA). It is currently the most affordable and widely used edge banding method, and can be applied with ordinary edge banding machines. EVA adhesive looks like a bean. During the application process, it changes from solid to liquid and then back to solid to solidify. However, the curing process is reversible (unconventional environments) and is easily affected by external factors.

Processing principle: Apply adhesive by heating, and generally use twice the amount of adhesive from PUR edge sealing.

Advantages: Can be processed with ordinary edge banding machines; low construction cost.

Disadvantages: Not water-resistant, not heat-resistant, glue lines are relatively thick, and glue lines are prone to blackening. It is easily affected by temperature, requires a large amount of glue, and is prone to cracking and glue overflow; the glue lines are noticeable, resulting in poor flatness and aesthetics; the glue lines tend to yellow, accumulate dust, and turn black over long-term use, significantly diminishing the texture of light-colored boards!

PUR stands for "Polyurethane Hot Melt Adhesive". Its physical property is that it is irreversible after curing, making it the most cost-effective alternative to EVA.

Advantages: Relatively low adhesive application rate; resistant to high temperatures, water spray, heat fusion, both heat and cold; resistant to water vapor, chemicals, and solvents. Fine adhesive lines prevent mold growth. Application: Requires a dedicated PUR edge banding machine for precise edge banding, resulting in a fine, environmentally friendly, and durable finish.

PUR adhesive offers the following advantages:

1. Excellent initial bond strength, ensuring a perfect bond in one go.

PUR adhesive boasts high bond strength and excellent detail, providing a guarantee for beveled edge sealing and irregular curved surface sealing.

2. High bond strength; once sealing is complete, it is almost irreversible, ensuring the quality of the finished product.

Tensile strength exceeds 180N (equivalent to the arm strength of an archer), three times that of ordinary EVA hot melt adhesive.

3. Extremely fine adhesive lines, almost invisible (less than 0.1mm, more than 40% smaller than EVA hot melt adhesive).

Less pollution, reducing after-sales issues on the board surface.

4. Good temperature resistance.

Product use is not affected by temperature differences between -30℃ and 130℃.

5. Superior moisture resistance.

Its principle is based on the chemical reaction between the isocyanate (NCO) ions in its molecules and water in the air to achieve bonding and curing, producing polyurea and carbon dioxide gas. Therefore, it is unaffected by humid air, offering superior moisture-proof and mildew-proof performance.

6. Unique Irreversibility

Products using ordinary EVA hot melt adhesive are prone to delamination under high temperature and humidity environments. However, PUR adhesive, due to the participation of water molecules in the curing reaction to form a three-dimensional cross-linked network molecular structure, will not delaminate upon repeated exposure to high temperatures.