1, filling defect
It always show uncomplete filling or edge collapse,it will dective product,waste material,labor and time.ther are many possible reason, such as nozzle temperature is too low,not enough supply,flowablity not good,injection pressure is low,the gate is too small or not right position,the mold surface is not smooth enough,nozzle is blocked,venting problem
2,flash or burr
It always happen in parting line,it will increase the difficulty of machining or dishape,even defective.the possible reason such as:nozzle temperature too high,injection too much material,flowbility is very good,injection pressure too high,clamping force too small
3,sink mark
It always caused by material shrink after injection molding,possible reason such as:nozzle temperature too high,resin supply not enough,shrinkage is too big,injection molding pressure too low,holding time too short,injection speed too slow,mold teperature too high,cooling time too short,the thickness of product is uneven,gate too small
4,welding line
It always happen in product which have holes or other shape,possible reason such as:nozzle temperature too low,material is not dry up enough,injection speed is too slow,gate too small,venting is not good,injection pressure too lowor other reason
As we can see the types and causes of injection molding defects, almost every kind of defect is formed by the combined effects of many factors. All these reasons are performance and molding machines, molding material character, mold design structure and material, filling control systems and different operating processes related. office for rent . Although injection molding technology development in some areas is very quickly, technology is relatively mature, but accompanied with increasing difficulty defect control, which requires us to to reduce and eliminate injection molding defects with the help of advanced theory and advanced technology tools.