Injection Mold Parting Surface
The parting surface of an injection mold is the contact plane between the fixed mold and the movable mold, serving as the interface where the mold opens and closes.
1. Functions of the Parting Surface
Mold Separation: The parting surface is the critical position where the mold opens and the finished product is removed.
Runner Design: The gating system's main runner, sub-runners, and gates are typically on the parting surface.
Venting Function: The parting surface allows air and gases to be evacuated from the mold cavity, preventing product defects.
2. Classification of Parting Surfaces
The parting surface can be categorized based on mold structure and product characteristics into the following types:
Flat Parting Surface: The most common type, suitable for simple-shaped products.
Inclined Parting Surface: Used for irregularly shaped products or those with certain inclines.
Curved Parting Surface: Applied to complex-shaped products but requires higher precision in machining and alignment.
3. Design Principles for Parting Surfaces
Avoid Damaging Product Appearance: The parting line should be concealed or placed in non-functional or non-decorative areas whenever possible.
Facilitate Ejection: Choose positions that enable the product to be easily removed from the mold.
Reduce Machining Difficulty: Avoid complex-shaped parting surfaces to minimize machining costs and time.
Ensure Mold Strength: Make sure the parting surface does not compromise the overall strength and durability of the mold.
4. Parting Surface and Venting
The parting surface is an essential pathway for mold venting. A well-designed parting surface effectively expels air and volatile gases from the mold cavity, preventing defects like burning and bubbles in the product. This is typically achieved by incorporating small gaps or dedicated venting channels.
