The quality and characteristics of the raw materials are crucial to the thickness uniformity of the matte laminating film. If the viscosity of the base material such as the resin is unstable, it will be difficult to form a uniform film layer during the coating process, resulting in thickness differences. For example, a resin with a lower viscosity may flow too fast during coating, thinning some parts of the film; while a resin with too high a viscosity may be unevenly coated, resulting in uneven thickness. In addition, the impurity content in the raw materials will also affect the thickness uniformity. Impurities may hinder the uniform distribution of the resin and cause local thickness abnormalities.
The coating system is a key link that affects the thickness uniformity of the matte laminating film. The design and precision of the coating head directly determine the amount and uniformity of the resin applied on the substrate. For example, a high-precision slit coating head can more accurately control the flow rate and coating width of the resin, making the film thickness more uniform; while wear or blockage of the coating head will cause unstable coating amount, which in turn affects thickness uniformity. In addition, whether the feeding system of the coating system is stable is also important. If the feeding pressure or flow fluctuates, the amount of resin applied will be uneven, resulting in deviations in film thickness.
The surface flatness of the substrate is the basis for ensuring the uniformity of the thickness of the matte laminating film. If there are defects such as unevenness, wrinkles or impurities on the surface of the substrate, it will affect the degree of adhesion between the resin and the substrate, resulting in uneven film thickness. For example, a tiny protrusion on the surface of the substrate will reduce the amount of resin coating in that part, forming a thin spot; while the depression will accumulate more resin, causing the film thickness to increase. Therefore, the substrate needs to be strictly surface treated before production to ensure its flatness and cleanliness.
The drying and curing process also has a significant impact on the thickness uniformity of the matte laminating film. During the drying process, if the temperature, wind speed or drying time is uneven, the resin will cure at different speeds in different parts, which will cause changes in film thickness. For example, in areas where the temperature is too high or the wind speed is too high, the resin will dry and cure quickly, which may cause uneven shrinkage of the film layer and produce thickness differences; while insufficient drying time may cause the resin to not be completely cured, affecting the overall quality and thickness uniformity of the film.
Production speed is also a factor that affects the thickness uniformity of the matte laminating film. When the production speed is too fast, the coating system may not be able to evenly coat the resin on the substrate in time, resulting in uneven film thickness. At the same time, too fast a production speed may also shorten the drying and curing time relatively, and the resin will not have time to cure evenly, thus affecting the uniformity of the film thickness. On the contrary, too slow a production speed will reduce production efficiency and increase production costs.
The tension control system plays an important role in the production process of matte laminating film. Appropriate tension can keep the substrate flat and stable during coating and drying and curing, which is conducive to uniform coating of the resin and uniform curing of the film. If the tension is uneven, the substrate will be loose and tight, resulting in different coating amounts and curing degrees of the resin in different parts, which in turn affects the uniformity of the film thickness.
Regular maintenance and cleaning of production equipment should not be ignored for the uniformity of the thickness of matte laminating film. During the long-term operation of the equipment, resin or impurities may remain in the coating head, feed pipe, drying oven and other parts. These residues will affect the coating and drying effects and cause uneven film thickness. Therefore, it is necessary to clean and maintain the equipment regularly to ensure the normal operation of the equipment and the stability of coating, drying and other processes.
