How to prevent product seam marks (stitching lines) 

Product seam marks are usually caused by low temperature and low pressure at the seam line.
 

1、Temperature problem

1). The temperature of the barrel is too low.

2). Nozzle temperature is too low.

3. The mold temperature is too low.

4). The mold temperature at the seam is too low.

5. Uneven temperature of plastic melt.
 

2、Injection problems

1). Injection pressure is too low.

2). Injection speed is too slow.

3、Mold problems

<1> Poor exhaust at the splice.

<2> Poor exhaust of parts.

<3> Too small manifold.

<4>Gates too small.

<5> Three-runner inlet diameter is too small.

<6>Nozzle hole too small.

<7>The gate is too far away from the seam, and the auxiliary gate can be added.

<8>The wall thickness of the product is too thin, resulting in premature curing.

<9> Core offset, resulting in thinness on one side.

<10>Mold offset, resulting in one-sided thinness

<11>Part is too thin at the splice and thickened

<12> Unequal mold filling rates.

<13> interruption of mold filling material flow.
 

4、Equipment problem

1). Plasticizing capacity is too small.

2). The pressure loss in the barrel is too large (plunger injection press).

(6) Material problems.

1). Material contamination.

2). Material fluidity is too poor, add lubricant to improve fluidity.