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Analysis of the weld mark of plastic product
Jan 24, 2018


(1) the injection pressure, the speed is too low, the temperature of the material cylinder and the mold temperature are too low, causing the melting of the material entering the mold to be cooled prematurely and the melting seam is present.

(2) when the injection pressure and speed are too high, there will be a spray and weld seam.

(3) increase the rotational speed and increase the back-pressure pressure to reduce the plastic viscosity and increase the density.

(4) the plastic should be dried well, and the raw material should be used less.

(5) reduce the clamping force and facilitate the exhaust.

2.Mold aspects:

(1) if the same cavity is overcast, the gate or symmetrical setting should be reduced or as close as possible to the welding seam setting.

(2) the exhaust system should be set up at the welding joint.

(3) the gate is too large and the size of the pouring system is improper, and the gate is opened as far as possible to avoid the melt flow around the hole, or to minimize the use of the embedded parts.

(4) the wall thickness changes too much, or the wall thickness is too thin, the wall thickness of the parts should be uniform.

(5) if necessary, a fusion well shall be opened at the melting joint to separate the welding seams.


(1) appropriate lubricant and stabilizer should be added to plastics with poor liquidity or heat sensitivity.

(2) there are many impurities in the plastic, and it is necessary to replace the plastic with good quality.

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