To obtain the best processing melts for any plastic, one starts with the plastic manufacturer’s recommended heat profile and/or one’s own experience.
There are different starting points for the various types of plastics, which have to be interfaced with the different capabilities of injection molding machine to be used. The time and effort expended on startup make it possible to achieve maximum efficiency of performance vs. cost for the processed plastics.
Electric injection molding machine can provide higher process capabilities with quick startup and setup without the oil heating required in hydraulic injection molding machine. Specialty injection molding machine have their own procedures. Under practical operating conditions process takes place in stages:
- The first stage covers the running of an injection molding machine.
- The second stage involves setting molding conditions on a prescribed set of parameters for a specific plastic material and a specific mold that will produce acceptable parts.
- The final stage is devoted to problem solving and fine-tuning of the operation, which will lead to high productivity and part quality.
Injection molding machine checklist
- Preset the heat controllers on the barrel and nozzle.
- Start the machine motor and screw motor when the heat controllers indicate that the proper temperature has been reached.
- While the equipment is in manual operation, close the safety gate and the press to lock.
- Check to see that the resin feed hopper gate is closed, and adjust the flow control valve down to zero.
- Turn the plunger switch to the out position. Adjust the flow control valve until the screw rotates. (If it will not rotate, the heat has not been on long enough, so shut down the machine and try again in 10 or 15 min.)
- As the screw rotates, open the feed (off and on) to allow small amounts of resin to feed into the screw. Watch the screw load, and if it exceeds 100%, reduce the screw rotation rate.
- Continue opening and closing the feed hopper until the machine is pumping well and the load is holding fairly even.
- Open the feed to the screw, and let it purge until the melt appears to be consistent (adjust the back-pressure valve to hold the screw in the forward position).
I hope you liked and got useful information from the above article now it’s your turn to share your thought on this through comment.