Sharing the preparation and application of integrated wood splicing adhesive:

Plywood is a type of wood made from small-diameter logs as assembly material,经过 a series of processes such as machine cutting, board drying, trimming, material selection, finger jointing, splicing, and subsequent treatment, to form a certain width, thickness, and length. Since different materials have different requirements for laminated wood adhesive, here, Anhui Lichao Building Materials Company shares the knowledge of preparation and application of integrated wood splicing adhesive:

1. Adhesive ratio and pot life
High-strength integrated wood is mainly composed of two-component adhesive, with the curing agent containing isocyanate. The reaction speed with the main agent depends on the amount of curing agent, ambient temperature and relative humidity, and the uniformity of mixing of the two components. Our Jincheng adhesive series integrated wood adhesive has a mass ratio of main agent : curing agent = 100:12-15. Pot life: 50 minutes at 25°C, requiring manual stirring for at least 2 minutes; electric stirring for not less than 30 seconds. After mixing, the effective usage time of the splicing adhesive will be relatively shortened due to increased temperature, and its performance will decrease as time increases.

2. Glue application amount for laminated wood adhesive
The amount of glue applied directly affects the thickness of the adhesive layer, the evaporation rate of water, the filling effect of uneven glue lines, and the curing speed, ultimately affecting the bonding strength. Our Jincheng adhesive series laminated wood adhesive generally has a glue application amount of about 180-240 grams.

3. Open air drying time
The length of open air drying time directly affects the evaporation of moisture from the adhesive layer, the film formation speed, and the relationship between surface adsorption and bonding strength. Under the premise of mass production, the bond should be closed immediately after glue application, otherwise the glue will form a film (although the film has good adsorption, its bonding strength is very low). For integrated wood adhesive, there are many opportunities for water removal; it can transfer and evaporate into the atmosphere along the internal channels of the wood, or be consumed in the reaction with isocyanate. Therefore, the drying time of integrated wood adhesive should be as short as possible. Generally, the closing time is controlled within 4 minutes. In dry and hot environments, for wood with loose texture, the bond can be closed immediately after glue application.

4. Pressing time
Plywood after batch production cannot be placed on the press at the same time. This leads to a significant difference in stacking time between the first and last piece. The surface of the adhesive layer of the first piece has already初步 formed before final pressing, which is不利 for the elimination of moisture and bubbles, resulting in low bonding strength and directly affecting the final strength. Therefore, after applying the integrated wood adhesive, you must grasp the timing of pressing, that is, the maximum stacking time should not exceed 8 minutes.