Reasons for woodworking glue to open:

1. Moisture content of the bonding substrate

White latex is a water-soluble adhesive, and its bonding principle also relies on wood fibers to absorb the colloid and then integrate it. If the moisture content of the bonding material is greater than 12%, the bonding surface will reduce the bonding effect.

2. The flatness of the bonding substrate

The flatness of the bonding substrate is the premise of bonding, and the wood flatness error is required to be controlled within 0.1mm. Protrusions at local edges can also lead to failure to bond because other bonding surfaces cannot be tightly bonded.

3. Is the amount of glue applied scientific?

If the amount of glue is too large, the adhesive will not be strong due to the excessive residual colloid that cannot be cured, and even the board will be deformed and mildewed. Phenomenon, the scientific standard for the amount of rubber cloth is generally 250–300 g/m2, and there should be uniform granular rubber extrusion between the two pressurized board surfaces when viewed with the naked eye.

4. Whether the pressure is standardized

The pressure of the press is not uniform or the pressure is not in place is also the main reason for the opening of the glue. The easiest but very standard method to check whether the pressure of the press is balanced is: put four A4 sheets on the four corners of the press, and place the press Put it all down and see if the four A4 sheets can be taken out. The most standard press cannot pull out any corners of the A4 sheets.

5. The colloid painted on the bonding surface before pressing has been dry

During construction, the workers use the same press to press the plates in batches. The first board is coated with glue until the last board is coated with glue and the press is put down. This time period may last for more than half an hour, or more than half an hour. The time is long enough for the glue on the glued plate below (the first glued plate) to solidify, that is, when the press is put down, the glue on the lower pressure plate has been solidified, which means that no addition is made. Pressing, this phenomenon of surface drying before pressing is most common in summer. Due to the glue-opening phenomenon that occurs when the surface is dry before pressing, pry open the two bonding surfaces, usually there will be glue on one side and no glue on the other. is in the “mesh” state.

6. Use low glue content

The degree of softness and hardness of the bonded wood directly determines the quality of the glue used. The harder the wood, the higher the quality of the glue required. If the wood is harder but the effective substance content of the glue used is not up to the level, the bonding effect cannot be guaranteed.

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