Venting insert design of molded parts
In the thin-walled cavity, the end of the melt flow, the bottom of the blind hole of the mold cavity, the end of the solid column of the plastic part, the bottom of the plastic part rib and screw column, and the corners of the complex cavity are the most where it is easy to cause air trapping, the exhaust in these area mainly depends on the exhaust slot on the shut-off surface between the inserts and the exhaust slot.
Venting design of molded parts:
a. When the end of the material flow is not on the parting surface due to the restriction of the cavity structure, the matching gap between the molded parts can be used to exhaust;
b. Some parts of the forming parts that constitute the cavity, such as ejector rods, ejector pines, moveble parts, etc., the cavity or core are mostly used for clearance fit, and the matching gap is large, if it is designed in the end side of material flow, it can also serve as an exhaust gas, and there is no need to set up an exhaust system at this time;
C. When the exhaust rate cannot meet the requirements, an exhaust structure can be set on the corresponding parts to increase the exhaust rate (see the picture as below);
d. The transitional fitting inserts should have an exhaust slot at the end of the material flow in advance (see the picture as below);
e. The three-stage exhaust slot must be open to the outside of the mold and connected with the air;
f. The exhaust slot between the inserts is easily blocked by plastic powder or mark, and must be cleaned regularly.
The basic points of designing gas-assisted injection molding
Apr 17, 20221. Firstly, considering the suitable wall thickness areas needs to be injected and hollowed out, and then decide how to connect them with the gas channel; 2. The gas channel should be arranged in...viewPlastic injection mold cooling system design notice
Feb 14, 2022Design notice of designing the cooling system: 1. Normal molds can be quickly cooled to obtain a shorter molding cycle, and precision molds can be slowly cooled with a mold temperature thermometer; 2....viewDesign Tips of Vacuum Venting Mold
Mar 30, 2022There are some regular venting way which are parting surface venting, insert venting, insert pin venting and well-ventilated steel, but there is a special way is vacumm venting, it will need vacumm...viewThe T slot of slider and guider designing tips
Dec 18, 20231. The T slot of slot should be designed according to the picture 1, If there is a relatively high slider, the slider T slot is not high enough which will cause the center of gravity to be unstable,...viewGas-assisted injection molding product defects and solutions
Apr 28, 2022Common defects and solutions of gas-assisted injection moulding: 1. Gas blows out the melt like in picture 1. Reason: insufficient pre-filled amount. When the plastic part is a locally thickened...viewDesign principle of plastic injection mold cooling system
Feb 13, 2022Design principle of cooling system In order to improve the efficiency of the cooling system and make the cavity surface temperature distribution even, the following principles should be followed in...view