Injection Mold WIKI

Injection molding defects the cause and solution

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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.

Plastic injection Mold Check Procedure

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Plastic injection mold check

  • Mold surface is free of pits, rust, extra unused rings, water fitting, gas, other defect which affect the appearance of the hole, etc.,
  • More than 1.5mm chamfer on all mold plates.
  • The cooling fitting should be upper than the mold surface,and is better to locate in unoperate side
  • Every lift ring should be marked their size if their weigh over 10 kg,or make sure the friendly use.
  • Make sure supporter is higher than blocks by 0.05-0.15mm.
  • All cooling should be marked “IN” and “OUT”,adding sequence number if needed, such as IN1, OUT1, IN2, OUT2.
  • Each plates should be marked with datum symbols and numbers ,position at 10mm away from the edge, writing should be clear, beautiful, neat, spacing evenly.
  • Small molds must have lifting holes in A plate and B plate, all plates of large mold must have lifting holes.
  • All four corners of the mold should have pry slot between two plates.

Find A Proper Injection Mold Factory

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If you want to make plastic parts or develop some product and looking for some mold factory,there are six principles as below
Principle I: reliable team and good attitude
the injection mold factory should have rich experience engineer and team work., the team is equipped to fly. When you find injection mold factory, you can not allow manufacturers to ignore you, probably because too many orders start at the same time, probably because they didn’t pay attention to detail and so on, so to make a phone call in two days or three days a week, take a look. To maintain a relationship with them.
Principle II: The ability of descripe a good prospect
Tell him your project have a good future, rather than ask him to help you do that. Let him know that you give the best products to him, but also it is his chance. In fact, in the final analysis, it is to your supplier but also as one of your investors, so that they have an idea with you success. Share with your mold factory your understanding of the industry, From the boss to tool makers, should be enough respected.
Principle III: ID-MD, mold making and injection molding in one stop

Industrial design and structural design are done in one factory , although there may be some small problems, but the advantages in one factory should be bigger. Mold making and injection molding should be done the same

 

Principle IV: Not the best,but the proper
Not the biggest and best mold factory is suitable for you, nor is it a small mold factory is simply not considered. Select mold factory, depending on your project, precision,development cycle and costs. Precision and cycle always conflict with the cost. Here you have a balance. Also not a small mold factory, we can help you save money. Small mold factory will often respond quickly. But where there will be a lot of such irregularities proplem.
Principle V: The standard is the key
To avoid unnecessary fighting and possible miscommunications. You should record every design change,all drawing,spec and reports should be written in paper and signed

 

Principle VI: patent application or NDA
Normally you should sign a NDA or Patent application before you make molds,it will protect your product not to be coppied.