Nov 23, 2021
The length of the screw is specified exclusively in relation to the screw diameter.
Doing it like that allows to compare different screws much better.
The process-engineering effective length of the screw is specified as L.
This value represents the distance the granules/melt travels along the screw.
For the determination, the length from the front edge of the hopper to the backflow barrier is always used.
The effective length is set in relation to the diameter D of the screw.
Injection molding: Display of the L/D ratio on a screw
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This glossary of plastic industry is provided by PLEXPERT Canada Inc.
May 6, 2021
For the production of injection molded parts a mold is necessary to be placed on the injection molding machine.
It is commonly build out of steel or aluminum and is designed as a permanent form.
Depending on the plastic material used millions of parts can be created with one mold.
The complexity of a mold range from a simple two-plate molds up to a complex stack mold with sliders, etc.
To avoid additional costs it is important to think about the mold concept early in the concept phase of part design.
Injection
mold: 15 year old and more than 750000
parts produced.
Related topics:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Feb 15, 2019
In injection molding, during filling and packing phase the two mold halves are hold closed with the clamping force against the pressure of the melt. If the driving force of the cavity pressure is higher than the clamping force, the mold is pushed open by a few thousandths to hundreds of millimeters. This is known as the so-called mold breathing. Too large mold breathing can lead to flash formation, while too low mold breathing results to air compression with burn marks.
In order to optimize the required clamping force, dial gauges can be attached to the mold to determine the mold breathing. Permissible respiration depends on the quality requirements of the injection molded part, the material and the size of the machine.
Apr 6, 2021
Plates, which contain the part-cavity in the injection mold are called mold plates.
Usually there is one mold plate for the injection side and one for the ejection side.
Dependent on the complexity of the part, the cavity is carved directly into the mold plate or embeded with inserts into the mold plate.
The primary cooling system of the cavity is located in the mold plates as well.
Nov 27, 2018
A mold is usually divided into two sides according to their function.
The side which is moved for mold opening is called movable side.
This side contains the ejector pins, therefore another common name is “ejection side”.
