Insufficient amount of glue, drying is not complete, will make composite products appear white spots.
There are two main reasons for the occurrence of white spots in composite products, and they have different solutions.
Water-based glue generally contains 50% water, in a short period of time to completely volatile clean, it requires adequate temperature and wind speed.
There are two reasons which make the Compound product appearance appears white spot, one is on glue quantity insufficient, two is dry not thoroughly.
Can be a short time of aging and the disappearance of white spots, that is not completely dry, because aging can further help moisture evaporation; otherwise, it is insufficient glue.
To avoid the condition of incomplete drying, it is necessary to adjust the temperature of drying passage and wind speed. The temperature of drying passage can be set as 70 °C as ——80 °C as -- 90 °C. I found that the actual temperature of many composite equipment is much lower than the set temperature, so the conditions must be corrected to avoid too much error. The wind speed is very important to the drying of water-based adhesive. It is necessary to ensure the wind speed above 6m/s and clean the air outlet and air inlet of the equipment to prevent blockage.
In addition, the temperature of the composite roll also affects the appearance of the Composite Roll and the initial adhesion. The actual temperature of the composite roll should be above 50 °C.