The last three common molding defects are here. They are following
• Flow lines
• Warping
• Mold stick
Common plastic injection molding defects
Flow lines and their preventative measures
Key preventative measures
 Make sure the form of the tool has a bowed corner wherever available.
 Development of the quickness and burden of the injection process
 Development of the climate of the mold and the molten plastic as the injection process
 development the amount of the gate to grant flawless mold filling
Warping and their preventative measures
What causes a warping?
Pervert appears when the part cools roughly and builds internal tension within the part. When the part is ejected from the tool, the part will warp as the internal tension is released.
Warping and their preventative measures
Key preventative measures
 assure the cooling time is calm to grant the plastic to solidify constantly, the valuable forcing authority would be cooling time and the cooling climate rate
 lower the climate of the element as injection and the climate of the mold
 Make sure the gate position allows the cavity to fill evenly as possible, if the cavity is filled in all extreme points the same, the solidification process is more even which helps eliminate warping of the part
 Choose a plastic element that is less likely to decrease and impair. Semi-crystalline element such as polyphthalamide (PPA), Polyetherketone (PEK), and High climate Nylon (HTN) are typically more level to pervert.
Part sticking in mold and their preventative measures
What causes a part to stick in a mold cavity?
When the molded part sticks to the mold, it fails to separate from the cavity or is held be a feature of the tool design which can occur for many reasons.
The Part sticking in the mold and their preventative measures
Key preventative measures
 assure the ejector pins are not defective, without ejector pins the part cannot accelerate out of the mold
 If the outline angle is too empty, there will be too much shallow friction amid the cavity shallow and the part preventing it from being ejected. In this case, The outline angle right to be expanded
 Surface finish too rough causing too much surface friction between the cavity surface and the part preventing it from being ejected. Two things to change in this instance, smooth and polish the surface of the cavity it a smooth surface is permissible in the design, if not, the outline angle right to be expanded to grant for the harsh outer to apart between the part and the cavity shallow
 Ensure there are no undercuts in the design, these would prevent the part being ejected as the part would hang on the undercut surface
 Cause clear there are no defects or scrape on the cavity shallow as these could act as undermine and carry the part during ejection
 assure a clear agent is tested to both parts of the tool between each injection cycle