Finished product indicators

Appearance: brownish red liquid

Viscosity (25 ℃), cps: 90-300

Free formaldehyde content%:<0.1

Solid content%: ≥ 45

pH(25℃)：11-14

Curing time (100 ℃), min: 20-40

Storage conditions

The optimal storage temperature for glue is (-5 to 30) ℃, at which it can be stored for 60 days,

The adhesive should be stored away from direct sunlight, and the storage temperature should not be lower than -5 ℃. The viscosity increases with time, and the rate of increase mainly depends on the temperature at which the adhesive is stored.

Single board requirements

The surface of the veneer should be smooth, clean, free of dust and resin substances. The thickness of the veneer should be consistent. The recommended moisture content for the veneer is below 12%. A higher moisture content increases the risk of bubbling, delamination, glue infiltration, and missing glue.

Glue coating

According to the different quality of the veneer, the amount of double-sided adhesive coating is generally (290-320) g/m2. If the veneer is thick, the surface is rough, or the material is hard, it is necessary to increase the amount of glue applied.

Open aging time

The open aging time refers to the time from the beginning of billet assembly to before entering pre pressing. It is recommended that the open aging time should not exceed 40 minutes in summer, and if the ambient temperature is high, the open aging time should be shortened as much as possible. Winter does not exceed 60 minutes.

When the climate is dry and hot, and the moisture content of the veneer is low, maintaining a short open aging time is particularly important.

Pre pressing process

Pre pressing can improve the bonding quality, and it is more beneficial for repairing the slab and installing it during hot pressing. If there is no pre pressing, there is a risk of the adhesive layer drying too quickly.

The recommended preloading pressure is (7-12) kg/cm2. The preloading pressure of hard materials should be higher than that of soft materials. The pre pressing time should be determined based on the thickness of the veneer, the number of layers, and the effect after pre pressing. It is recommended that the pre pressing time be between 20-50 minutes.

Note: The pre pressed board must be fed into the hot press machine within 12 hours.

Hot pressing process

The optimal pressure for hot pressing is determined by the density of the veneer tree species. Usually (13-15)

kg/cm2, Hot pressing temperature (120-135) ℃

Hot pressing time for soft materials (1.0-1.2) min/mm (excluding exhaust time)

explain

Because the heat conduction rate depends on the tree species and moisture content, it is recommended to determine the hot pressing time through repeated experiments. The temperature of the innermost adhesive layer should be measured by a thermocouple to check if it has reached the desired value and has fully cured. To ensure that the adhesive layer is fully cured, it is recommended to reheat and stack the hot pressed board for several hours after it comes out of the hot press machine.

clean

Before the glue is cured and dried, the glue mixing machine and the glue coating equipment must be cleaned. Hot water cleaning is better. Once the adhesive has solidified and hardened, it will no longer dissolve and must be scraped off. If residual glue and cleaning water are discharged into drainage ditches and rivers, it will cause pollution and should be properly treated according to the requirements of the local environmental protection department.