Definition and classification of gating systems

2025,11,06

1、Definition and classification of gating systems

Composition：It consists of a gating system (gating cup), a sprue, a runner, an ingate, a buffer recess, an air outlet, and a filter screen.

Main functions：Drainage, shrinkage repair, wax removal, venting, slag removal, heating, auxiliary equipment.

Classification: Generally, there are four types: top injection, side injection, bottom injection, combined injection.

2、Design principles of gating system

Solidification principle: The design of each part of the gating cup (sprue and riser), runner and ingate should comply with the solidification principle to ensure good shrinkage. The ingate solidifies later than the hot spot of the product, the runner solidifies later than the ingate, and the gating cup or riser solidifies later than the runner.

Filling principle: The molten metal fills the cavity in a short time and provides the necessary pressure head to accurately replicate the shape of the cavity, avoiding incomplete filling or cold shut defects.

Stable principle: The molten metal flow should be stable to prevent defects such as gas entrapment and oxide inclusions caused by turbulence.

Slag blocking and venting principle: It has good slag blocking, venting and slag discharge capabilities.

3、Design principles of gating system

Temperature distribution principle: The temperature distribution should be reasonable during solidification and shrinkage to avoid excessive temperature differences in different parts of the casting, which could lead to thermal cracking or deformation.

Dewaxing principle: The dewaxing process should be smooth to avoid dewaxing cracks or wax residue.

Strength principle: It must have sufficient strength to support the wax model and the shell.

Economic principle: It is conducive to improving the output rate of the process.

Other principles: Facilitate operations such as mold taking, tree assembly, coating, drying, dewaxing, shell picking, pouring, shell vibration, cutting, rough and fine grinding, etc.

Author:

Mr. Karl cao

E-mail:

caoyongjun@enon-cn.com

Phone/WhatsApp:

+86 15965270117