Multi-layer hollow blow molding machine may present abnormal phenomena similar to extrusion blow molding, but also may present two abnormal phenomena unique to multi-layer extrusion blow molding.
I. Products present delamination phenomenon
The melt temperature of the bonding layer is too low, and the material blend is not good. Improve the temperature of the bonding layer appropriately to improve the bonding performance.
The melt temperature of the adhesive layer is too high, and the adhesive layer is attached to the adjacent layer so that the adhesive layer is uneven, and the temperature of the adhesive layer is decreased appropriately.
The temperature of the blow mold is too low, the adhesive layer in the product cools too fast and the adjacent layer is not firmly bonded, and the cold is controlled.
II. Products within the barrier layer uneven
If the barrier melt temperature is too low or too high, adjust the corresponding extruder temperature and extrusion rate.
Extrusion blow molding machine, pressure fluctuation, extrusion speed is not stable or screw structure is not appropriate.
There is retention or degradation in the nose, improve the flow channel of the nose for the flow of materials to avoid retention.
The failure of multi-layer extrusion blow molding machine is mainly related to blow molding machine and die head, so the screw structure and control precision are required to be higher, in addition, the flow design of die head is also very important.
Multi-layer extrusion blow molding machine is fully automatic computer control, equipped with accurate integrated PID temperature control system, real-time detection of each screw extrusion pressure, can realize centralized control, interlock protection and warning functions, with automatic deflash system, and optional 100-point wall thickness control system.
Multi-layer extrusion blow molding machine through accurate control in the product without affecting the impermeability of the condition to reduce the small medium thickness, thus greatly reducing the cost of composite bottles, currently close to the level of glass bottles. The composite bottle itself has the advantages of light weight, not easy to break, so it can be an ideal substitute for glass bottles, and has broad market prospects.
Working process of automatic extrusion blow molding machine
1. the operator needs to go through technical training to the job control, otherwise can not control the hollow automatic blow molding machine.
2. Check whether the machine is normal before starting.
3. Check whether the mixer is working properly. Turn off the power before mixing, put in the prepared material, and then turn it on again.
4. Check around the machine every day to prevent blockage of foreign matter in the machine and ensure stable production environment.
5. blow molding machine in the mold removal and opening operation, to do outside the stable area, so as to avoid injury.
6. Before heating the blow molding machine, check whether the cooling water part of the pipe is connected smoothly.
7. the material produced by the blow molding machine should meet the drying requirements.
8. the pressure of the machine system has been set before the factory, except for special circumstances, generally can not be adjusted at will, otherwise it will affect the normal operation of the machine.
9. When the automatic blowing and molding machine is operating normally, it is forbidden to manually cut off the switch, so as to avoid being burned by high temperature feeding and electric cutting knife and mould injury.
10. Select the appropriate head and install it according to the product size.
11. It is strictly prohibited to let workers on the stage to add materials, so as to avoid the risk of electric shock or scald fall.
12. In case of emergency, do not press the red emergency button slowly to prevent accidents.
Blow molding machine can be divided into extrusion blow molding machine, injection blow molding machine and special structure blow molding machine three categories. Stretch blow molding machines can be classified into the above categories. Extrusion blowing molding machine is a combination of extruder and blow molding machine and mold mechanism, which is composed of extruder and mold head, blowing device, mold closing mechanism, mold thickness control system and driving mechanism.
Blank die head is one of the important parts to decide the quality of blow molding products, usually there are side feed die head and center feed die head. Storage cylinder type blank die head is used in blow molding of large products. Storage tank volume of 1kg, up to 240kg. Billet thickness control device is used to control billet wall thickness, control points up to 128 points, generally 20 ~ 30 points. Extrusion blow molding machine can produce volume range of 2.5ml ~ 104l hollow products.
Injection blow molding machine is a combination of injection molding machine and blow molding mechanism, including plasticizing mechanism, hydraulic system, control electrical appliances and other mechanical parts. The common types are three - station injection blowing molding machine and four - station injection blowing molding machine. The three-station machine has three stations of preforming billet, blowing and demoulding, each station is separated by 120°. Four stations are more than one preforming station, each station is 90° apart. In addition, there are two stations separated by 180° injection blow molding machine. The plastic container produced by injection blowing molding machine is accurate in size, without secondary processing, but the mold cost is relatively good.
Special structure blow molding machine is a blow molding machine that uses sheet material, molten material and cold billet to blow hollow body with special shape and purpose. Because of the different shapes and requirements of the products produced, the structure of the blow molding machine is also different.