NEWS

The reasons for leakage in the production process are usually divided into the following points: heat sealing temperature is relatively insufficient: during the production process, the thickness change of aluminum foil bag affects the bag seal.

The reasons for leakage in the production process are usually divided into the following points: heat sealing temperature is relatively insufficient: during the production process, the thickness change of aluminum foil bag affects the bag seal. The main factors that cause changes in the combined parameters. For the same batch of products, it is assumed that the product thickness deviation is ± 10%, while the standard thickness of the aluminum foil bag is 80um, the thickness of the aluminum foil bag fluctuates between 72 and 88um, and the large deviation can reach 16um, which will bring problems to the control of sealing parameters. Difficulty. Following the aluminum foil bag manufacturer "Shanghai Yuhe Packaging Products Co., Ltd." Xiaobian to learn about it.

Sometimes the seal is good on the first roll of film, but part of the seal leaks after replacing another roll of film. This can also happen on the same roll of film. As the thickness increases, that is, the process of heat conduction increases, in order for the heat shield to reach a similar temperature, it is necessary to increase the time or set a lower temperature. In addition, it also affects the non-uniformity of the pressure. Especially when the two sides are thin and the lower part is thin, the temperature and pressure values should be set slightly to the upper limit. Of course, first of all, the thickness deviation of the composite film should be controlled within the allowable range. The most reliable way to check whether there is local leakage of the seal is to take samples at the highest temperature point within the temperature range, and take samples at intervals so that the samples can fully cover all parts of the mold in the longitudinal and transverse directions.

Problems in production equipment and operation: such as heat sealing film clamping foreign matter, heat sealing pressure is insufficient, or the mold surface is not flat caused by local pressure is too large, the temperature of different parts of the heat sealing mold may also be different, the heat sealing mold is also different. The temperature of the parts may also be different, the heat sealing mold is not installed in parallel, etc. Problems of packaging materials: such as corona damage, excessive slip agent in heat seal layer, resulting in improper heat seal, etc. Structural leakage seals: such as edge inserts, back seals, bottom bags, and leakage seals with sudden changes in thickness due to insufficient resin fusion in specific areas. It is generally difficult to appear at the side seal of the back seal of the four-layer or side seal bag or the overlap of the top seal. Due to local thickening, resulting in less heat sealing. In order to avoid this phenomenon, the temperature and pressure can be increased or local reinforcement can be used. method to solve.