Custom gas-assisted injection molded parts engineered for structural rigidity, Class-A surface finish, and sink-mark elimination in thick-walled sections. By injecting high-pressure nitrogen gas into the molten polymer core during the injection cycle, internal hollow channels are formed without altering external aesthetics. This manufacturing method reduces part weight by up to 30%, eliminates warp-inducing volumetric shrinkage, and cuts cycle times for complex tubular geometries.
Technical Specifications
|
Parameter |
Specification Range |
|
Max Shot Volume |
Up to 4,500 cm³ |
|
Clamping Force |
160 Ton to 1,200 Ton |
|
Nitrogen Injection Pressure |
Up to 35 MPa (5,000 psi) |
|
Dimensional Tolerance |
±0.05 mm (Standard ISO 2768-m) |
|
Wall Thickness Range |
Nominal: 2.0–6.0 mm; Ribs/Bosses: 1.5–3.0 mm |
|
Surface Finish |
SPI-A2 to SPI-D3 / VDI 3400 texture |
Key Features
Sink-Mark Elimination: Core hollowing removes volumetric pull on thick ribs, bosses, and gussets, yielding unblemished exterior surfaces.
Rigid Tubular Geometry: Hollow sections increase the moment of inertia, delivering high structural stiffness with lower overall mass.
Reduced Clamping Tonnage: Internal gas pressure counteracts injection pressure, allowing larger parts to run on smaller tonnage presses.
Minimized Residual Stress: Controlled gas packing reduces internal part stress, preventing post-molding warpage.
Materials & Options
|
Material Grade |
Typical Application |
Key Characteristics |
|
ABS (Unfilled / GF) |
Appliance housings, interior bezels |
Balanced impact strength, good finish |
|
PP (Talc / GF Reinforced) |
Automotive ducts, structural frames |
Chemical resistance, fatigue endurance |
|
PC / ABS Blend |
Electronic enclosures, handles |
High impact resistance, dimensional stability |
|
PA66 + 30% GF |
Industrial brackets, mechanical arms |
High tensile strength, thermal resistance |
Post-Processing Options:
Ultrasonic welding and heat staking
CNC secondary machining for tight-tolerance features
Pad printing, laser etching, and EMI shielding coatings
Manufacturing Process & In-House Capabilities
Tooling & Mold Flow Analysis: Moldflow CAE simulation is performed prior to steel cutting to optimize gas channel paths, gas pin placement, and venting locations.
Injection & Gas Control: Multi-stage injection integrated with WIT (Water/Gas Injection Technology) units capable of precise pressure-time profiles.
Facility Scale: 25 injection molding cells equipped with central material drying systems, robotic part removal, and automated sprue trimming.
Quality Control
Hexagon Coordinate Measuring Machines verify critical GD&T features against 3D CAD data.
Destructive cross-sectional cut-tests monitor core hollow uniformity and wall thickness distribution.
Raw material lot certificates (CoA) archived per production batch; ISO 9001 certified production lines.
Customization & DfM Support
Design Engineering Support: Review of customer 3D models (STEP/IGES) focusing on draft angles, uniform wall transitions, and gas channel sizing.
Prototyping: Rapid CNC machining or 3D printed functional prototypes validated before production tooling investment.
Custom Tooling: Multi-cavity and family mold construction using P20, H13, or NAK80 tool steels.
Applications
Automotive:
Interior grab handles, door trim panels, roof rails, and structural seat components.
Industrial & Commercial:
Heavy-duty appliance frames, enclosure handles, and machine access panels.
Furniture:
Ergonomic office chair armrests, base components, and structural tubing replacements.
Packaging & Delivery
Packaging: Custom thermoformed trays or corrugated divider cartons to prevent transit abrasion on Class-A surfaces. Anti-static packaging available for electronics.
Logistics: Direct export via FOB/CIF shipping terms from major ports; vendor-managed inventory (VMI) agreements supported for recurring OEM schedules.
FAQ
Q: How do you prevent gas breakout or blow-through in thin-walled sections?
A: Moldflow simulation determines precise gas penetration thresholds. We control melt temperature, shot volume, and gas delay time to maintain a uniform polymer skin surrounding the gas channel.
Q: What file formats are required to initiate a DfM review?
A: STEP, IGES, or Parasolid 3D CAD files paired with 2D drawings specifying critical tolerances, surface finish requirements, and material grades.
Q: What is the typical tooling lead time for custom GAIM parts?
A: Standard tooling fabrication ranges from 4 to 7 weeks depending on part complexity and steel selection, followed by T1 sample submission.
Q: Can gas-assisted injection molding be applied to unfilled engineering plastics?
A: Yes. Materials such as ABS, PC, and unfilled PP process effectively, provided melt viscosity and temperature are tightly controlled during the gas injection phase.
Q: How is wall thickness uniformity verified on hollow sections?
A: Sample parts are cross-sectioned during First Article Inspection (FAI) and measured using optical comparators to verify minimum skin thickness across gas channels.
Q: What is the minimum production volume required for gas-assist tooling?
A: Due to specialized gas-pin integration and controller setup, GAIM is typically cost-effective for annual volumes exceeding 3,000 to 5,000 units.
RFQ Checklist
To help the technical and quoting teams provide an accurate evaluation within 24 hours, buyers are advised to include the following information with their inquiry:
1. 3D CAD Files
STEP / IGES format, including wall thickness and rib structure details.
2. 2D Engineering Drawings
Critical tolerances, GD&T, and appearance/Class-A surface requirements.
3. Material Grade & Performance Requirements
Such as ABS, PP+GF30, flame-retardant requirements, UV resistance, etc.
4. Estimated Annual Volume
Annual volume and batch delivery quantity.
5. Surface Treatment Requirements
Such as VDI 3400 texture, coating, or polishing grade.
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