20 ways to improve injection molding machine:
1. Explanation of the starting circuit of the oil pump motor
The starting of the oil pump motor is star-delta starting.
2. There are more than a dozen old and new machines in a certain factory, and the oil seal often leaks. After a period of time, it leaks again?
Too high oil temperature makes the oil seal easy to age and damage the oil leakage, and the cylinder core is worn out, causing the oil seal to be scratched and leaking.
3. Explanation of the principle of power saving pump
The power-saving pump is a variable flow pump. When the machine is in motion, the pressure oil will push the mechanical action through the oil valve cylinder and then return to the fuel tank. When the machine is not in motion, the pressure oil will return to the fuel tank directly.
4. Explanation of output and input of electronic circuit board.
Signals such as various motion sensing switches and electronic rulers are input to the electronic board, and the computer passes calculations and then outputs to the oil valve to perform actions.
5. Reasons and prevention of stubborn oil leakage of oil seal
The oil cylinder core is worn and scratched and the oil seal is stubbornly leaking. Keep the oil cylinder core clean to avoid wear and prevent the oil seal from being scratched and causing oil leakage.
6. The influence of pressure and flow linearity on injection molding process
The pressure is linearly proportional to the flow rate, which is of great significance to the accuracy and stability of the parameters of the injection molding process.
7. Reasons for the slowdown in production during the same period and improvement measures
The main reasons for the slower production cycle are the extension of the cooling time and the longer the return time of the screw due to wear. Improve the cooling effect of the mold, shorten the cooling time, replace the worn screw, shorten the return time and speed up the production cycle.
8. Reasons and solutions for screaming when melting glue
The screaming sound when melting glue is caused by the friction between the screw and the material or the friction with the barrel. Polishing or electroplating the screw to make the surface smooth and reduce friction. Adjust the center of the screw so that it does not rub against the barrel.
9. Detection and adjustment method of clamping parallelism
Use four dial gauges to measure the stretched length of the Collin column when the machine is clamping the mold, to see if it is within the allowable tolerance, and the degree of clamping of the Collin column is not tested. Then adjust the big nut of the coring column to adjust the parallelism of the clamping mode.
10. Reasons and preventive measures of the broken column
The reason for the broken column is due to the imbalance of the mold clamping. Adjust the parallelism of the clamping to prevent the column from breaking.
11. Analysis of the causes of elbow wear
The cause of elbow wear is caused by poor lubrication of the elbow.
12. Reasons and prevention of broken screw and glue head
The reason for the breakage of the screw and the dispensing head is that the plastic has not reached the melting temperature or there is an iron block in the barrel that jams the screw, and the screw and the dispensing head are twisted due to the high pressure when the material is returned.
13. Analysis of the easy leakage of the cooler
Due to the excessive acidity or saltiness of the cooling water, it will corrode the pipes of the cooler and cause the cooler to leak water easily.
14. Installation and application of nitrogen injection
Nitrogen injection is an additional device installed in the injection oil circuit. During injection, the nitrogen rapidly expands and squeezes the hydraulic oil to increase the flow rate of the hydraulic oil to achieve rapid injection.
15. Application of gas auxiliary equipment
When the gas assist is a beer-plastic product, inflating the product to make the product empty, which can reduce the plastic material.
16. Comparison of open loop and closed loop oil circuit
The comparison between the open-loop and closed-loop oil circuit is that the closed-loop oil circuit adds a pressure sensor to the nozzle. When the set parameter deviates from the actual data, the pressure sensor will feedback the signal to the computer, and the computer will correct the deviation value to make the setting The fixed value is equal to the actual value.
17. The impact of levelness on the injection molding machine
The levelness of the injection molding machine is of great significance to the balance of opening and locking of the machine, and it plays a role in ensuring the smooth operation of the machine.
18. Causes and preventive measures for the rupture of the template (head board, second board, and tail board)
The main reason for the template rupture is that there is stress in the template. Under the action of the stress, the template ruptures. The stress should be eliminated in time when the template is processed to prevent the template from rupturing.
19. When using engineering plastics, the solution to insufficient melting torque and insufficient injection pressure
When using engineering plastics, insufficient melting torque may be solved by increasing the first-stage glue motor, and insufficient injection pressure can be solved by reducing the diameter of the screw.
20. Reasons and solutions for the high temperature in the middle of the material pipe
The high temperature in the middle of the material pipe is mainly caused by insufficient surface smoothness of the screw and friction between the screw and the material. The surface of the screw should be polished or electroplated. Measures such as reducing the back pressure of the return material.
Injection molding process:
1. Filling. The time is calculated from when the mold is closed and the injection is started, until the mold cavity is filled to about 95%. In theory, the shorter the filling time, the higher the molding efficiency; but in actual production, the molding time (or injection speed) is restricted by many conditions.
2. Pressure holding stage. Continue to apply pressure to compact the melt and increase the density (densification) of the plastic to compensate for the shrinkage behavior of the plastic. During the pressure holding process, the back pressure is relatively high because the mold cavity has been filled with plastic. During the packing and compaction process, the screw of the injection molding machine can only move forward slightly slowly, and the flow speed of the plastic is relatively slow. The flow at this time is called the packing flow.
3. Cooling stage. Because molded plastic products can only be cooled and solidified to a certain rigidity, the plastic products can be prevented from being deformed due to external forces after demolding. Since the cooling time accounts for about 70% to 80% of the entire molding cycle, a well-designed cooling system can greatly shorten the molding time, increase injection molding productivity, and reduce costs.
4. Demolding is the last link in an injection molding cycle. Although the product has been cold-formed, demolding still has a very important impact on the quality of the product. Improper demolding method may cause uneven force on the product during demolding, and cause defects such as product deformation when ejected.
There are two main ways of demolding: ejector pin demoulding and stripping board demolding. When designing the mold, choose the appropriate demoulding method according to the structural characteristics of the product to ensure the quality of the product.