The reasons for the bubbles are as follows: (1) because the plastic film is a material with high air tightness structure, the CO2 generated along with the curing of the adhesive will remain on the surface of the adhesive as bubbles. (2) The water mixed into the adhesive or absorbed by the film will lead to bubbles after compounding. Solutions: (1) select the adhesive with less proportion of curing agent (polyisocyanic acid system) in the main agent (polyol system). (2) Reduce the amount of adhesive coating. (3) After compounding, avoid rapid heat aging. (4) Do not compound in a high temperature environment similar to rainy days. (5) Do not use adhesives with curing agent (polyisochlorate system) exceeding the ratio standard. (6) The diluting solvent of adhesive should be completely sealed to avoid mixing with water. (7) Pay attention to the management of film to avoid moisture absorption of film (especially cellophane, nylon, vinylon, etc.). 3. The causes of irregular wrinkles and bubbles in the composite film are as follows: (1) the apparent quality of the film is not good, such as wrinkles and uneven thickness. (2) The film is deformed by absorbing moisture. (3) There is ink flow on the printed film. Solution: (1) select the film with good apparent quality. (2) Avoid moisture absorption of film in printing and storage, pay special attention to cellophane, nylon, vinylon, etc. (3) Consider changing the print pattern or reducing the amount of ink. (4) Reduce the winding tension after printing. 4. The causes of regular wrinkles and bubbles in the composite film are as follows: (1) the holes of the coated roller are blocked. (2) The cot is deformed. (3) The steel roller is not clean. (4) Composite and printing speeds are not synchronized. (5) The film was deformed and relaxed. (6) The guide roller is not well balanced, resulting in wrinkles and relaxation of the film. Solution: (1) clean the anilox roller and replace it if necessary. (2) Replace the cots. (3) Clean the steel roller in time after each compounding. (4) Measure and adjust the rotation speed of each drum to keep the combination and printing synchronized. (5) Do not use films with poor apparent quality. (6) Adjust the balance of guide roller. 5. There are impurities in the composite film, and the causes of bubbles are as follows: (1) dust and other impurities are mixed into the adhesive. (2) Dust and other impurities are attached to the film. (3) The film has pinholes. (4) Dust mixed in the hot air. Solution: (1) adhesive, diluted solvent should be fully sealed storage. (2) Use a circulating pump and filter the adhesive at the same time. (3) Eliminate static electricity and prevent foreign matters due to static electricity, especially to completely eliminate static electricity at the air inlet. (4) Because the existing processing conditions can not solve the problem of film pinhole, high quality film must be selected. (5) Prevent powder from flying. (6) Clean the oven regularly. In addition to the above typical failures, the following points are also worth noting: (1) the excessive viscosity of adhesives or the use of gelatinous adhesives will lead to poor homogenization and uneven coating, resulting in bubbles. At this point, the viscosity of the adhesive should be reduced and gel adhesives should not be used. (2) Anilox roller wear will also lead to uneven coating, lack of homogenization, and even bubble. At this time, check whether the anilox roller is blocked or worn.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service.
The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries.
We uphold the integrity of cooperation, good quality, good service business philosophy, won the industry's approval, products sold to all over the world; welcome friends from all walks of life to inquire, visit our factory to investigate guidance and business negotiations.