Alternate Menu for incompatible browsers
This site is rated
Basic Plastic Injection Molding Machine Process
Injection Machine Controller Clamp & Ejectors Setting Descriptions and Function
In the custom injection molding process, the clamp settings control the distance the mold opens and closes to, where it slows down and speeds up, and other miscellaneous settings where you might perform other actions such as core pulling and ejection start points. Because of the large variety of machine types, I will not attempt to cover every possible setting but only the main ones that are common to most machines. Depending on the age and abilities of your machine, these could be digital settings in the controller interface on newer machines or limit switches on older ones, or in some cases a combination of both..
Clamp open fast – where you want to start opening the mold quickly
Clamp open slow – where you want to start slowing down the clamp before reaching full open.
Clamp full open - where you want the machine to clamp to stop after each cycle
Eject start – where you want to start your ejection movement if your machine has “eject on the fly capability”, otherwise it will usually be at the mold full open point.
Clamp close fast – where you want to close the clamp at high speed
Clamp close slow – where you want to slow down the clamp when closing (usually before engaging the guide or leader pins)
Mold safe – just before the mold halves first touch, usually a few thousandths of an inch before zero. This is the safety feature to help protect your mold from damage if it closes on a runner or part. The clamp is put into a low pressure state at this set point to protect your mold. This setting is one of the most critical to be set correctly and precisely.
Clamp fully closed – this is the point where the mold halves make contact and high pressure is applied to build full tonnage.
Clamp speeds and pressures – most of the above functions also have a speed and pressure setting. These will be set according to you needs and will vary somewhat for each mold.
The ejector settings control the distance and speed of the ejector rods during the part removal process from the mold. The settings are crucial to your molding process as they help determine a number of things such as whether or not the part is going to remain in place for robot or operator removal, or be ejected completely into a bin or chute. They can in some instances also help in determining part quality with how fast a part is removed in some more sensitive parts and molds, or ensuring the cores have been removed prior to ejection in order to protect the mold from damage. As with the clamp settings, depending on the age and abilities of your machine, these could be digital settings in the controller interface on newer machines or limit switches on older ones, or in some cases a combination of both.
Eject start position – where the ejectors start their forward stroke.
Eject forward position – the distance of travel the ejector rods will make during each stroke of ejection.
Number of strokes – the number of times the ejectors will make a an entire ejection stroke each cycle, usually limited to not more than 5 repeats.
Ejector dwell time or eject forward hold time – the length of time the ejectors will be held forward after reaching it’s forward limit. Usually only used with a single stroke condition.
Eject retract position – the position the ejectors must be in prior to closing the mold for the next cycle.
Eject speeds and pressures – most of the above functions also have a speed and pressure setting. These will be set according to you needs and will vary somewhat for each mold.
Written by: WM8C, August 8th, 2006. Not for use without written permission
This site Created with
Links & More