The temperature of self sealing plastic mold is about 10 ~ 30 ℃ lower than that of parison mold. Pressure. Injection pressure and holding pressure. The injection pressure can be adjusted within the additional pressure range of the injection machine. Lack of injection pressure, uneven surface of parison, lack of melt filling modulus, easy to create parison gap, bottom leakage, lack of thread size and so on; If the injection pressure is too high, it is easy to show parison mandrel deflection and parison flash. The injection pressure can be controlled at (2.0 ~ 2.5) x105pa. After the melt is injected and filled, the injection machine still needs to adhere to the pressure holding pressure to obtain the parison with accurate scale, flat and bright appearance and low specific volume value.
At the same time, the mold locking equipment also needs to adhere to the mold locking force to prevent mold expansion. The clamping force of the mold is related to the injection pressure and the projected area of the cavity. Inflation pressure. The blowing pressure refers to the compressed air pressure that blows the parison into a container in the blow mold. Yin Yang self sealing bag? The compressed air pressure is usually controlled within the range of 0.8 ~ 1.ompa. Improving the blowing pressure can reduce the defects such as lack of parison blowing, shoulder deformation and bottle body depression; Increasing the volume flow (inflation speed) of compressed air can improve the production power and improve the surface gloss and wall thickness uniformity of the container.
Moment. Injection blow molding cycle is the induction of the time required for each technical process. It includes material mixing and plasticizing time, injection time, mold waiting time, blow molding time and mold opening and closing interval, usually 10-20s. Forming cycle is the inductive balance result of obtaining high production power under the condition of ensuring container quality. Accelerating the plasticizing time of materials can shorten the forming cycle, but it does not affect the plasticizing quality of materials; Extending the injection time, pressure holding time and inflation time is conducive to improving the quality of the container, but will reduce the production power. The start-up operation of self sealing bag injection blow molding shall be carried out according to the following process.
Turn on the power supply and heat the barrel according to the technical requirements. After reaching the set temperature, keep the temperature constant for 1h to make the temperature of each point uniform and common. Turn on the cooling water switch of the hopper base to cool the hopper base to prevent the feeding port from showing the appearance of "bridging". Select manual air injection to investigate the plasticization of materials. If the materials are plasticized evenly, the production can start. Through several cycle operations, the temperature of the mandrel, cavity and blow mold tends to be appropriate, and the active operation of the injection machine can be started.
The demoulding station shall conduct sampling inspection on the products to see whether their quality and scale meet the requirements, and whether there are flash, material shortage and holes. If any part of the mandrel is attached with plastic, the wall thickness of the container will be uneven. Therefore, each mandrel shall be sampled and sent to the quality inspection part for inspection. If it is qualified, it can be produced normally. The parking operation of injection blow molding shall be carried out according to the following process. Change the operation method selection switch to manual position.
Close the feeding baffle and stop the continuous feeding to the barrel. Place the mold in the semi closed state. Push the injection seat back. For the remaining materials in the finishing barrel, the resin that is easy to differentiate in processing, such as PVC, shall be cleaned with special materials for screw cleaning. Put all operation switches and buttons in the off position to cut off power, water and gas. After parking, scrub the machine parts and clean the environment.