Analysis of flexible packaging bags adhesive selection

Analysis of flexible packaging adhesive selection – China YLTpacking packaging 1. Select adhesives according to the requirements of packaging products. The post-processing temperature of packaging products is different, and the selected adhesives will also be different. For example, common temperature classifications include cooking at 135°C for 30 minutes, cooking at 121°C for 30 minutes, boiling at 85°C for 30 minutes, room temperature, freezing and deep freezing. The selection principle is to consider the appropriate variety under the condition that the processing conditions are met. If the selection is too high, it will cause waste and increase the cost. If the product is 135°C for 30min, it is necessary to choose a product that can meet this temperature requirement; if the product only requires cooking at 121°C for 30min, it is not necessary to use a 135°C-resistant adhesive. 2. According to the structure of the composite packaging, there are various materials used for the adhesive composite packaging. The commonly used materials are BOPP (light film, pearl film, matte film), PET, BOPA, AL, aluminized film (VMPET, VMCPP, VMPE) etc.), CPP, PE, etc. Single PE film is very different. For example, the thickness of PE is different, the resin used is different, the characteristics of PE film are different, and the adhesive used is also different. For example, in the aspect of composite aluminized film, when using ordinary adhesives, the general peel strength is only (0.3-0.6) N/15mm, and the transfer of aluminum plating is serious. If such a packaging bag is used to package some irregular solids (such as tea leaves), and then vacuumed, after a period of time, it will be found that large air bubbles will appear on the surface of the packaging bag, that is, the aluminized composite film is delaminated. Therefore, it is necessary to find a way to improve the peel strength of the aluminized composite film and solve the problem of the transfer of the aluminized film. One of the methods is to use a special adhesive for the aluminized film composite. 3. According to the dry compounding equipment selected, such a phenomenon will be found in the dry compound production when the adhesive is selected. The same adhesive has different effects in different manufacturers. There are various reasons for this, one of which is the different equipment used. The grades of dry laminating machines used now are quite different. When choosing adhesives, you should choose adhesives according to your own equipment. Adhesives are selected based on the equipment tension system. If the level of the tension control system of the equipment is poor, the control accuracy of the tension is not high, and the tracking feedback is poor, then when selecting the adhesive, a good initial viscosity should be preferred, which can reduce the formation of tunnels. On the contrary, the tension control system Very good, then it doesn’t matter if the initial tack of the adhesive is poor, there will be no tunneling, and it will not affect the yield. Choose the adhesive based on the working speed of the equipment. If the working speed of the equipment is very high, the adhesive with a lower viscosity should be selected. If the viscosity is too high, the adhesive will generate a lot of air bubbles in the glue tank. Seriously affects the coating state of the adhesive, which in turn affects the quality of the product; on the contrary, the working speed is low, and the viscosity can be higher when the adhesive is selected. 4. Select the adhesive according to the working concentration of the adhesive under the same process conditions as the speed, etc.