SCF Microcellular Injection Mold
1:1 Rib-to-Wall Ratio No Sink | Enhanced Venting |
Optimized Gating | One-Stop Custom Service
SCF Microcellular Injection Mold
SINOMOULD specializes in the R&D and manufacturing of SCF microcellular injection molds. Every detail—from gate location to vent depth, from hot runner type to rib-to-wall ratio—is deeply optimized for the microcellular foaming process. With in-group mold trial support from DKM microcellular injection molding machines, SINOMOULD molds undergo process validation before delivery, ensuring seamless integration between machine and mold. This helps you achieve mass production goals with lightweighting, high precision, and high efficiency.
SCF Microcellular Mold Core Design Principles
1. Gate Design — Start from the Thinnest Section
The gate location of a microcellular mold directly affects melt flow and bubble nucleation. SINOMOULD positions the gate at the thinnest section of the part, ensuring that the melt fills the thin-wall areas first and gradually expands into thicker sections—avoiding underfill caused by premature foaming. Gate dimensions are optimized to ensure sufficient pressure drop rate for uniform nucleation.
2. Venting — 50% Deeper
Bubble growth requires gas to escape from the cavity. The vent depth in SINOMOULD molds is increased by 50% compared to traditional molds. Vent width and depth are precisely calculated to ensure rapid gas evacuation while preventing melt from entering the vent channels. Enhanced venting capability avoids backpressure that could inhibit bubble growth, ensuring a uniform, closed-cell structure.
3.Rib-to-Wall Ratio — 1:1 No Sink
In traditional mold design, rib thickness is typically limited to within 60% of the main wall thickness to avoid surface sink marks. The microcellular foaming process compensates for shrinkage with internal bubbles. SINOMOULD molds achieve a 1:1 rib-to-wall ratio—ribs can be as thick as the main wall without surface sink marks. This brings revolutionary freedom to structural design, significantly increasing part stiffness without adding weight.
4.Hot Runner — Valve Gate Required
The microcellular foaming process imposes strict requirements on the hot runner system. SINOMOULD recommends a valve gate hot runner system to avoid pressure loss and premature foaming that can occur with valveless hot runners. The valve gate is precisely coordinated with injection timing: high pressure is established before the valve opens, ensuring the melt enters the cavity in a single-phase state for instantaneous nucleation.
5.Wall Thickness Variations — No Longer Restricted
Traditional injection molding often requires uniform wall thickness to eliminate sink marks. The microcellular foaming process allows for greater variation in wall thickness, enabling designers to design for function rather than compromise for the process. SINOMOULD molds fully support this freedom, optimizing flow and cooling in thick-to-thin transition areas to ensure uniform bubble distribution.
SCF Microcellular Mold Manufacturing Process
Precision Machining
- High-speed milling and EDM ensure complex surfaces and high-precision details.
- Hardness HRC 48–52: High-quality mold steels such as 2738, H13, S136 are selected; wear-resistant steels are chosen based on glass fiber content in the material.
In-Group Mold Tryout & Validation
- Mold trials on DKM microcellular injection molding machines validate mold performance under real process conditions—no outsourcing needed.
- Cell structure analysis: Sectioning to observe cell diameter (10–200μm) and distribution uniformity.
- Dimensional and warpage inspection: CMM measurement ensures compliance with drawing specifications.
SINOMOULD, together with the DKM process team, will provide you with a professional integrated solution for microcellular molds and machines.
