In injection mold design, selecting the gate position is crucial for nearby injection molding factories. According to DAYIN Plastics, here are several key considerations when designing gate positions:
- Select the Parting Line: The gate position should ideally be set on the parting line, facilitating mold machining and making gate removal easier during use.
- Uniform Distance: The gate should be positioned equidistantly from all parts of the cavity, ensuring the shortest flow path for the plastic, which enhances injection efficiency.
- Smooth Injection: The gate position should allow the plastic to flow smoothly into the cavity, especially at thick-walled sections, to ensure proper filling.
- Thickness Priority: The gate should be located at the thickest section of the part’s cross-section, promoting smoother plastic flow and molding.
- Avoid Direct Impact: The design should prevent the plastic from directly impacting cavity walls, cores, or inserts during flow to reduce deformation risk and ensure the plastic quickly fills all parts of the cavity.
- Minimize Weld Lines: Efforts should be made to avoid weld lines on the product. If unavoidable, place them in less visible areas.
- Uniform Flow: The gate position and plastic flow direction should ensure that the plastic flows evenly along the cavity’s parallel direction when injected. This allows for proper venting of gases from the cavity.
- Easy Gate Removal: Lastly, the gate should be positioned where it can be easily trimmed without affecting the product’s appearance.
DAYIN Plastic Products Co., Ltd. specializes in the manufacturing of home appliance molds, offering OEM/ODM services as a comprehensive manufacturing solutions provider. Our products include robotic vacuum cleaners, plastic tableware, and electronic dartboards. With 30 years of mold development experience, over 50 R&D personnel, and more than 100 injection molding machines, we are committed to delivering high-quality manufacturing services and creating greater value for our clients.
Gate Placement: The Decision That Echoes Through the Part
Gate position is decided once, at design, and echoes into every property the part will ever have:
| Placement choice | What it improves | What it costs |
|---|---|---|
| Centre gate | Balanced fill, minimal warp | Gate vestige at a visible face |
| Edge gate | Cosmetic face kept clean | Asymmetric fill, warp watch |
| Submarine gate | Automatic degating | Restricted thickness window |
| Multiple gates | Flow length control | Weld lines where fronts meet |
The weld-line row is where gate decisions become quality debates. Every additional gate buys fill balance and pays in weld lines — the seams where melt fronts meet — and the question is never whether weld lines will exist but whether they land where the part can afford them: under a flange, along a stiffening rib, away from load paths. Simulation earns its cost here, because moving a gate in software is free while moving it in steel is a new tool. Operations that keep a record of gate choices per part build institutional memory too: the tool that warped until its gate was re-cut teaches the next design review more than any guideline document. Placement judgement is precisely the kind of quiet expertise that separates a mold supplier from a mold machine shop. The selection techniques are detailed in gate selection techniques, and the Vietnam-side system design in gating system design. Reference: gate configurations and weld line mechanics.