Injection molding knowledge

Dent products:

A mold cavity plastic material shortage, caused by contraction

1 filling in the material shortage or insufficient, increase the feeding or open the gate

The 2 gate location or improper gate asymmetry. All limit the sprue gate into the melt, not into the other gate

3 flow channel, gate is insufficient or too small, increase the flow of the runner or increase the size of the gate

4 product wall thick Rong thin wall is not uniform, in the back of the wall thickness at the dents easily. The mold mold to modify or increase the injection pressure.

Two technological parameters of the improper regulation

1 the plastic pressure is small, the injection speed is slow.

2 short shot time

3 time protection time is short

4 cooling time is short

Three plastic overheating

1 the material barrel overheating, Wen Taigao

2 mold temperature is too high

3 parts of the mold or mold heat release

Four material temperature is too low or poor plastic, so that the flow of molten material

Dissatisfaction with the finished product

1 the material in the hopper bridging to insufficient feeding

2 the amount of injection is not enough, the lack of plastic and the remaining material is insufficient, the amount of injection is reduced to maintain the amount of material and the ability of the plastic.

The 3 runner or gate. Add or expand the runner gate size

4 cannot melt flow into the multi cavity mold properly balanced.

The 5 cavity melt volume greater than the amount of injection molding machine

6 die casting system of large flow resistance, the feed port location is not out, the small form of small, long process and winding.

7 air can not discharge the mold cavity

8 plastic moisture content, volatile matter, dissolved in the material in the air

9 nozzle temperature is low, the material barrel temperature is low, cause the blockage.

10 injection pressure is small, the speed is slow

11 shooting time is short

12 time protection time is short

13 material flow is too bad, resulting in excessive discharge of the flying side, the correction of temperature, to prevent overflow

14 mold temperature is too low cooling too fast

15 release agent used too much; cavity with water, etc.

16 the product wall is too thin, the shape is complex and the area is large, the complexity is reduced.

Product Phi Feng

1 the projection area of the product is more than the maximum permitted by the injection molding machine, and the large injection molding machine or the appropriate die should be used.

2 die installation is not correct or one-way force

3 injection molding machine template uneven or tie rod deformation

4 die in parallel with bad or mold side has hindered

5 die parting surface adhesion, cavity or core offset or sliding parts of the gap is too large

6 material and too much liquidity too large amount

7 cavity high temperature material, the mold temperature is too high. To control the heating barrel and die temperature

8 injection pressure is too large, the injection speed is too fast

9 clamping force is not constant or uneven

Bad welding

1 gate system is not the gate, the gate is small, the diversion channel is small, the process is long, the material flow resistance is big, the material temperature drops quickly.

2 material temperature is too low or the mold temperature is too low

3 poor liquidity, there is a mixture of cold material, cooling fast

4 in the mold has the moisture or the lubricant, the molten material is inflated, the mold release agent is too much

5 injection pressure is too small or injection speed

The 6 form of bad products, uneven of the wall thickness, the molten material in the book at the confluence, improve the product form or injection molding cycle time

7 improper cooling system or exhaust

8 plastic containing insoluble material, oily or improper release agent

Product crack

1 plastic has pollution, dry bad or volatile

2 the proportion of plastic and recycled material is large, which makes the plastic shrinkage of large or uneven distribution

3 inappropriate mold design, the wall is thin, the draft is small, sharp corners and gaps, easy to produce stress concentration

The 4 thimble or ring bit, or improper molding conditions, stress is too large, the top side

5 the mold temperature is too low or uneven temperature

6 injection pressure is too low, the speed is too slow

7 injection time or time to protect the time is too short

8 cooling time is too long or too short

9 after the product release or postprocessing cooling is not uniform, or the use of improper release agent

Deformation

1 plastic uneven, filling excess or insufficient

2 improper gate position, asymmetric or insufficient

3 die strength is not enough, easy deformation, the accuracy is not enough, there is wear, positioning or top out

4 material temperature is too low, the mold temperature is too low, the mouth aperture is small, the injection pressure, the speed is high and the shear stress is big

5 the design of the release system is not good or bad, so that the force of the release is not all

6 high temperature material, high mold temperature, filling over, packing feeding too large, shoot rubber pressure is high residual stress is too large. To lower the temperature of the melt cylinder, reduce injecting pressure and holding pressure feeding

7 product thickness, improper parameters, cooling and contraction. Check mold heating is uniform, or modify mould thickness or adjusting the parameters

8 the cooling time is too short to make the release deformation, or postprocessing improper and improper preservation

9 the mold temperature is not, the cooling is not all, the wall thickness cooling is slow, the thin cooling is quick.

Product silver pattern