Ejection Systems and Lifters in Injection Molds

The ejection system is a very important part of an injection mold design.  The ejection system must correspond to the stroke of the press, and work in perfect harmony with any auxiliary equipment utilized in the press.  The ejector pins must also be placed where they will eject the part without causing any damage to the part.  This can be tricky with small intricate molded product, it may be difficult to find the right angle to eject an oddly shaped part with critical dimensions or thin walls.  In some cases, lifters must be used just for this purpose, to eject the parts properly and without causing damage.

If lifters are required this must be apparent prior to building the mold.  This is where an experienced mold designer will determine the best placement of any required lifters in the ejection system.  A lifter is part of the ejector plate, activated during ejection.  They are usually angled and slide up when required during ejection, allowing the part to mold all dimensional features properly.  

If auxiliary equipment is attached to the press such as sprue pickers, the ejector system, whether it includes lifters or not, must always accommodate any automated auxiliary equipment.  Sprue pickers are automatic robots that reach into the mold when it opens to grab the sprue, also called the runner, and move it out of the way usually dropping into a bin or grinder to grind up and re-use the material.  A two-stage ejection system is sometimes used with a robot grabbing the sprue, and the parts falling onto a conveyor or into a bin below.  

Utilizing the latest technology with CAD/CAM software, Michiana Global Mold can design your complicated precision injection mold with an ideal ejection system.  We have experience designing and building precision molds requiring complex ejection systems, utilizing lifters, and accommodating the injection molder’s press specifications.  

Contact Michiana Global Mold today for an expert mold design and injection mold construction with quality steel and components.  We have been an integral supplier of injection molds for over 50 years, employing skilled designers and journeyman mold makers.   Michiana Global Mold is registered to ISO9001:2015, adhering all processes to our strict quality policy.  Contact us today for a free design consultation of your next mold building project.