In dry compounding, if too much thinner is added to the adhesive as in the case of printing, the dry basis coating weight is neglected, which will result in insufficient dry coating weight, resulting in a composite film. The strength and performance will not meet the requirements and the losses will be enormous. In dry compounding, if the working concentration of the adhesive is very low, in order to ensure the dry-base adhesive amount of the adhesive, only the amount of adhesive applied when the adhesive is coated is selected, that is, a lower number of screens is selected. To guarantee. This will bring a series of problems. We will add the following discussion below.
In the actual production of dry composite adhesives, there is an optimum working concentration. The so-called optimal working concentration is the maximum working concentration of the adhesive under a certain environment, a certain speed, and the like, in a state where the adhesive can be well coated. The so-called optimal working concentration is the maximum working concentration of the adhesive under a certain environment, a certain speed, and the like, in a state where the adhesive can be well coated.
Selecting the adhesive to work under the optimum working concentration has many benefits. First, it can reduce the amount of ester and reduce the production cost.
For example: a general-purpose two-component polyurethane adhesive, the solid content of the main agent A and the curing agent B is 75%, the main agent A: the curing agent B = 5:1, the unit price of the adhesive is 19.00 yuan/kg The unit price of ethyl ester was 7.00 yuan/kg. The product to be produced requires a quantity of 3.0 g/m2 (dry basis).
As can be seen from the above figures, with the reduction of the amount of ethyl ester, the working concentration is increased, and the coating cost per unit area is decreasing.
Second, reducing the amount of ethyl ester can reduce energy consumption.
The ethyl ester in the adhesive is transferred to the substrate after the adhesive has been leveled. It is useless. In order to dry the adhesive thoroughly, the ethyl ester must be transferred to the adhesive on the substrate film. Completely volatile. If too much ethyl ester is used in the preparation of the adhesive, the ethyl ester to be volatilized will also be too much and the energy consumption will be too much. Conversely, the amount of ethyl ester is small, the working concentration is high, and the energy consumption is reduced.
Third, reducing the amount of ethyl ester can increase production efficiency.
The drying capacity (heating rate, air flow rate, wind speed, etc.) of any equipment is limited. If the binder is formulated with too much ethyl ester and the working concentration is too low, under the condition of limited drying capacity, The amount of ethyl ester in the binder can increase production efficiency.
Fourth, reducing the amount of esters can improve product quality.
By reducing the amount of ethyl ester, the amount of adhesive on the substrate is reduced (Fig. 3), the coating thickness is reduced, the problem of surface crusting of the adhesive in the drying process is avoided or reduced, and the transparency of the film can be improved. .
To sum up, after the selection of a certain adhesive, the composite processing should be performed under the condition of the optimum working concentration. Doing so can help reduce costs, reduce energy consumption, increase efficiency, and improve product quality.
Thermal CTP Plate,Positive PS Plate,CTCP Plate Co., Ltd. , http://www.thermalctpplate.com