Common faults of book printing and laminating process

Uneven coating ① Part of the adhesive in the glue tank solidifies. Replace or add new adhesive. ② Low compound pressure. Compound pressure should be increased. ③ Swelling and deformation of cots. Replace the rubber roller. ④ The thickness tolerance of plastic film is large. The film shall be replaced and the film with small thickness tolerance shall be selected. ⑤ Film relaxation. The traction should be adjusted. Wrinkle film ① The film transfer roller is unbalanced. The transfer rollers should be adjusted. ② The tightness of both ends of the film is inconsistent, with wavy edges. The qualified film shall be replaced in the book printing. ③ The adhesive layer is too thick and the solvent evaporation is not complete, which affects the viscosity of the adhesive. It is squeezed by the pressure roller and slides between the paper (printed matter) and the film. The gluing amount shall be adjusted to increase the drying channel temperature ④ The two ends of electric heating roller and rubber roller are uneven, the pressure is inconsistent, and the linear speed is not equal. Both rollers shall be adjusted ⑤ Insufficient tension will cause uneven film speed, which will cause film wrinkling. The pressure should be adjusted to make it normal. ⑥ If the surface of the coating layer on the film is not completely dry, it will also cause the film to wrinkle. It can be solved by increasing the drying temperature. ⑦ The temperature is too high, causing the film to wrinkle when feeding. In the film coating process, the purpose of heating is to soften the film and bond the paper with the plastic film. Therefore, the fan should be used for cooling, and the electric heating wire or other heating equipment should be turned off to restore the temperature to normal as soon as possible. Corrugated paper Coated paper is generally coated paper, offset paper and whiteboard. The paper wrinkling occurs when laminating. Generally, there are the following situations. ① Improper temperature and humidity control in the workshop. When the relative humidity is too high, the paper absorbs moisture and has a "lotus leaf edge", resulting in paper wrinkling in the film covering process of book printing. The temperature and humidity of the workshop must be strictly controlled. ② If the ambient temperature is too high or the coating temperature is too high, the paper will tighten and wrinkle. The pressing plate can be used to flatten, increase the times of knocking and kneading the paper before laminating, and reduce the environment and laminating temperature. ③ Uneven roller pressure causes paper wrinkling during film covering. In this case, the pressure shall be corrected first, and then the machine shall be started for operation. ④ If the cots are uneven, resulting in paper wrinkling in the lamination, replace them with new cots or grind the old cots flat for reuse. ⑤ There is dirt on the cot, which causes the paper to wrinkle when laminating. The cot should be cleaned in time to keep it clean.