What is Flow Mark？
Flow marks refer to the obvious flow cracks of melt that can be found near the gate. […]
Introduction to Ejection Flow Mark
It is a snake-shaped squirt flow formed upon the melt’s entering the cavity with thick walls and large section with excessively high injection rate. […]
Introduction To Wheel Wave Flow Mark
When melt with unsteady flow is injected into the mold cavity through the runner and gate in semi-solidified state, […]
introduction to Turbulence Flow Mark
When the melt flows from a runner with narrow section into a cavity with large section or when the runner is very narrow and the surface roughness is rather poor, turbulence flow will form within the runner (including the cavity), thereby resulting in the turbulence flow mark on the surface of plastic parts. [...]
Introduction to Nebulous Flow Mark
The volatile gas produced from the resin in the melt and the lubricating agent under processing temperature is stored in between the melt flow and surface wall of cavity and interferes the flow of melt, […]
Shrink Mark, Depression and Shrinkage Porosity
Both the shrink mark and shrinkage porosity are defects of injection products due to the molding shrinkage at thick walls where no sufficient follow-up compensation is made. During the injection molding process, the surface layer of products often condenses first, followed by the center layer, which will cause sinking on the surface of parts with [...]
Optimize the structural design of injection products
The injection products should not be too thick and when necessary the stiffening rib can be added to reduce wall thickness; the wall thickness must be kept as uniform as possible and the shape and structure should be simple and symmetric; […]
Optimize prescription of plastics
Optimize prescription of plastics and preferably use resins with low shrinkage; […]
Optimize injection technics
Properly improve injection and dwell pressure as well as the injection rate to increase melt’s compression tightness; prolong time of injection and dwell (the freezing of gate should not occur too early) to realize sufficient shrinkage compensation; […]
Optimize mold design
Properly increase section dimension of gate and runner; the position of gate is set at thick walls of the plastic parts and should be as symmetric as possible; improve mold exhausting condition; […]