1 too much injection materials.
Injection molding parts sticking.
5 incorrect design of draft.
If the injection molding machine is too large in size with a high speed screw great injection pressure and very long injection pressure holding time overfill will be caused making molding shrinkage smaller than expected thus leading to sticking sprues or parts.
The root causes of such sticking can be traced to one of several equipment or process issues.
Make a shot with no hold pressure where the largest part is only 80 full.
3 overhigh melt temperature.
The injection parts stick to the mold making it rather difficult for ejection.
Sticking might be caused by inadequate or no mold release in the resin.
For a processor finished parts sticking in the mold can be an absolute headache.
Parts sticking in the mold.
4 overlow or overhigh mold temperature.
Written by jeremy cooley on.
2 overhigh injection pressure overlarge dwell pressure and overlong dwell time.
The causes thereof comprise.
Parts sticking in.
Take time to do a proper short shot study.
Injection molding is a manufacturing process for producing parts by injecting molten material into a mould or mold injection moulding can be performed with a host of materials mainly including metals for which the process is called die casting glasses elastomers confections and most commonly thermoplastic and thermosetting polymers.
The reasons and corresponding solutions are described as follows.
The parts may be picked by a robot ejected off the mold to fall onto a conveyor system or hand picked by an operator after each cycle.
Material sticking in the mold can be a production killer whether it is the sprue or the formed part in the cavity.
Several process missteps can cause parts to stick.
If there are surface defects such as gouges nicks scars and dents in the mold cavity and sprue bush.
The surface of the mold cavity and sprue bush is rough.
Imbalanced filling especially in a multi cavity tool can cause over or under packing issues and subsequent part sticking.
Keep in mind that where the part sticks in the mold is not necessarily the area of the mold that is the cause.
The causes of parts sticking and sprue sticking are multifaceted among which mold failure is one of the main reasons.
Because injection mold buildup could also be an issue with sticking parts you could also try one of our mold cleaners like clean n run mold brite power clean kleen all and zap ox.
8 process missteps can cause parts to stick in injection molding published on august 7 2015 august 7.
