E0 grade phenolic resin adhesive

Finished product indicators

Storage conditions

The optimal storage temperature for the glue is (-5 to 30)℃, under which it can be stored for 60 days. When storing the glue, it should be kept out of direct sunlight, and the storage temperature must not fall below -5℃. The viscosity increases over time, and the rate of increase mainly depends on the storage temperature of the glue.

Mixing ratio

The recommended production rubber mixing ratio is:

Stir the glue for 10-15 minutes when mixing, ensuring the mixture is thoroughly blended before use. The viscosity of the mixed glue is adjusted according to the amount of filler, with the filler ratio determined as follows.

1) Temperature changes of the adhesive caused by seasonal variations

2) The active period required by the factory and the open maturation time

3) The quality of the flour used by the factory and the protein content in the flour (only flour without talc must be used)

Note: After adding the filler and stirring, the adhesive viscosity should be (18000-28000) cps. The glue must be used within 2 hours after preparation.

Requirements for the single board

The surface of the veneer should be smooth and clean, free of dust and resinous substances. The veneer thickness should be consistent. It is recommended that the veneer moisture content be below 12%. Higher moisture content increases the risk of bubbling, delamination, glue seepage, and glue deficiency.

Apply adhesive

Depending on the quality of the veneer, the typical amount of adhesive applied on both sides is (290-320)g/m2. If the veneer is thicker, has a rougher surface, or is made of harder material, the adhesive quantity needs to be increased.

Open ageing period

The open ageing time refers to the period from the start of assembly failure to before pre-pressing.

It is recommended that the open maturation time in summer should not exceed 40 minutes, and if the ambient temperature is high, the open maturation time should be shortened as much as possible. In winter, it should not exceed 60 minutes.

When the climate is dry and hot and the moisture content of the veneer is low, it is particularly important to maintain a shorter open ageing time.

Pre-pressing process

Pre-pressing can improve the bonding quality, as it is more beneficial for the repair of the board blank and the loading during hot pressing. Without pre-pressing, there is a risk of the adhesive layer drying too quickly.

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

Note: The pre-pressed panels must be placed in the hot press within 12 hours.

Hot pressing process

The optimal hot-press pressure is determined by the density of the veneer species, generally (13-15) kg/cm2

Hot pressing temperature (120-135)°C

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

Explanation

Since the rate of heat conduction depends on the wood species and moisture content, it is recommended to determine the hot pressing time through repeated trials. The temperature of the innermost adhesive layer should be measured with a thermocouple to check whether it has reached the required value and is fully cured. To ensure the adhesive layer is fully cured, it is recommended to stack the boards for several hours after they come out of the hot press.

Cleaning

Before the adhesive cures and hardens, the adhesive mixer and coating equipment must be cleaned. It is preferable to use hot water for cleaning. Once the adhesive has cured and hardened, it will no longer dissolve and must be scraped off.

If residual glue and cleaning water are discharged into drains and rivers, it will cause pollution and should be properly treated in accordance with the requirements of the local environmental protection authorities.

Not applicable

Linear speed: Not applicable

High frequency and current: Not applicable