Permeable steel, commonly known as breathable steel or venting Steel, is a specialized functional material primarily used in the molding process. It is manufactured from high-quality stainless steel powder (316L) through an advanced powder sintering process. This results in a three-dimensional interconnected network of microscopic pores, which account for approximately 20–30% of the material's total volume. The core principle is that these controlled micropores allow trapped air or gases to escape freely during the molding process, while preventing the penetration of molten plastic due to surface tension and capillary action.

This material offers several key advantages in plastic and die-casting molds. It effectively eliminates common molding defects caused by trapped air, such as incomplete filling, burns, flow marks, and weld lines. Improving gas venting, it reduces pressure, shortens cycle times, and minimizes part warpage or internal stress. Additionally, permeable steel maintains the mechanical strength, hardness, and corrosion resistance required for demanding mold environments.

Products Specifications

Material: 316L
Size: 93*93*25mm
Porosity: 25-30%
Pore size: 10microns
Technique: Compression Molding

Advantages of Permeable Steel (Breathable Steel)

10 Microns Permeable steel Compression Molding 7

1. Solving Injection Molding Problems‌
Eliminates Gas‑Trapping Defects‌: The permeable structure allows air and gases to escape from the mold cavity, preventing defects such as ‌air traps, incomplete filling, burns (scorching), flow marks, and short shots‌.

Reduces Internal Stress & Warpage‌: Permeable steel enhances gas venting, lowering injection pressure and holding time, which minimizes residual stress in the molded part and prevents deformation.

Improves Surface Quality‌: Especially for textured or matte‑finish surfaces, permeable steel avoids glossy streaks or blemishes caused by trapped gas, meeting the aesthetic requirements of skin‑patterned plastic parts.

2. Enhancing Production Efficiency & Cost Savings‌
Shortens Cycle Time‌: Reduced injection pressure and faster gas release lead to shorter molding cycles, ‌improving overall production efficiency‌.

Lowers Energy Consumption‌: Smooth venting decreases the required pillow pressure, resulting in ‌reduced energy usage‌ during operation.

Minimizes Waste & Rework‌: By eliminating gas-related defects, permeable steel reduces the production of faulty parts, cutting material waste and the need for post-processing, thereby lowering overall manufacturing costs.

10 Microns Permeable steel Compression Molding 6

3. Simplifying Mold Design & Maintenance‌
Replaces Complex Venting Systems‌: It can substitute multiple ejector pins, inserts, or parting‑line vents, ‌simplifying mold structure‌ and avoiding issues like flash (burrs) from traditional exhaust channels.

Suitable for Challenging Geometries‌: Effective for molds with ‌offset gates, uneven wall thicknesses, or thin‑wall products‌, where conventional venting is difficult.

Easy to Process & Maintain‌: Permeable steel can be machined using standard methods such as cutting, grinding, and EDM, and its permeability is restored through soft-cutting, acetone cleaning, or nitric-acid soaking when pores are blocked.

4. Ensuring Dimensional Stability & Quality Control‌
Produces Dimensionally Stable Parts‌: By eliminating gas‑related defects, it ensures consistent product dimensions and ‌reduces the need for post‑molding corrections‌.

Maintains Mold Integrity‌: Reduces wear and damage to the mold caused by excessive pressure or gas buildup, ‌extending mold service life‌.

Applications of Permeable Steel (Breathable Steel)

1. Die Casting and Injection Molding
- Air Venting Inserts: Used in high-pressure die casting molds or plastic injection molds to allow trapped air and gases to escape during filling, improving surface finish and preventing voids or burn marks.
- Vacuum Interface Components: Installed in molds connected to vacuum systems to maintain uniform venting and stable pressure during injection.

- Ejector Pins and Core Pins: Replace solid pins to reduce soldering of molten metal, dissipate heat efficiently, and extend mold life.
- Thin-wall or Deep-rib Sections: Placed behind thin or complex areas of molds for targeted cooling and faster solidification.

2. Powder Metallurgy and Vacuum Sintering
- Gas Flow Control Elements: Used in sintering furnaces or reactors to evenly distribute or extract gases across powder beds.
- Support Plates and Fixtures: Provide stable, breathable platforms that allow gas circulation during heat treatment or sintering.

3. Vacuum Forming and Thermoforming
- Mold Surfaces and Cavities: Permeable steel inserts allow air to escape evenly through the surface during forming, ensuring sharp definition and smooth surfaces on plastic sheets.
- Tool Venting for Large Forming Tools: Improves cycle times and product quality by eliminating trapped air without external venting holes.

4. Aerospace and Automotive Manufacturing
- Precision Casting Dies: Used to avoid porosity and cracking in structural aluminum or magnesium parts.
- Thermal Management Inserts: Serve as internal heat sinks or cooling channels in molds for complex geometry components.
- Vacuum Valve Components: Control uniform venting in high-pressure forming tools or pressure-assisted composites molding.

5. Additive Manufacturing Tooling
- Integrated Porous Sections in Metal 3D Printed Tools: For combining cooling and degassing in one component.
- Hybrid Tool Design: Used alongside solid sections of molds to optimize thermal control and reduce cycle time.