Injection Molding

High-volume production of precision plastic parts. From prototype tooling to full-scale manufacturing with multi-cavity molds, insert molding, and overmolding.

What is Injection Molding?

Injection molding is a manufacturing process where molten plastic is injected into a steel or aluminum mold cavity under high pressure. Once cooled and solidified, the part is ejected. It is the most cost-effective process for producing plastic parts at medium to high volumes, offering exceptional repeatability and surface finish.

Moldkey connects buyers with experienced injection molding suppliers across China who specialize in automotive, medical, consumer electronics, and industrial components. Whether you need a single-cavity prototype mold or a 32-cavity production tool, we have the supplier network.

Key Specifications

ParameterStandardPrecision
Clamping Force80–1,600 tonsUp to 3,000 tons
Part Weight1 g – 2,000 gUp to 20,000 g (large parts)
Max Part Dimensions800 × 600 × 400 mmUp to 2,000 mm
Tolerance (plastic)±0.10 mm±0.02 mm
Surface FinishSPI-C1 (VDI 30)SPI-A1 (mirror polish)
Typical MOQ500–5,000 pcsAs low as 100 pcs (prototype mold)
Mold Lifespan (steel)500,000 – 1,000,000 shotsUp to 3,000,000 shots
Lead Time (mold)25–40 business days15–20 days (expedited)

Molding Types We Cover

Standard Injection Molding

Traditional thermoplastic molding for a wide range of part geometries. Most common and cost-effective.

Insert Molding

Metal or plastic inserts placed in the mold before injection for threaded inserts, connectors, and reinforcement.

Overmolding

Two-material molding for soft-touch grips, seals, and multi-color parts. Requires specialized tooling.

Gas-Assist Molding

Nitrogen gas injected into the melt for hollow sections, reducing weight and warpage on large parts.

Two-Shot Molding

Sequential injection of two materials on a rotary platen. Ideal for multi-material parts without secondary assembly.

Micro Molding

Ultra-precision molding for sub-gram parts used in medical devices, electronics, and micro-optics.

Common Materials

CategoryMaterialsTypical Applications
CommodityABS, PP, PE, PS, PVCConsumer goods, packaging, toys, housings
EngineeringPC, Nylon (PA6, PA66), POM, PMMAAutomotive, electronics, structural parts
High-PerformancePEEK, PEI (Ultem), LCP, PTFEAerospace, medical implants, high-temp
ElastomersTPU, TPE, Silicone (LSR)Gaskets, seals, soft-touch surfaces
Filled / ReinforcedGlass-filled Nylon, Carbon-filled PCHigh-strength brackets, structural components

Industries & Applications

🚗 Automotive

Interior trims, dashboard components, connectors, under-hood parts.

⚕️ Medical

Syringes, IV components, diagnostic cassettes, surgical handles.

📱 Electronics

Phone cases, connectors, switches, LED lenses, battery housings.

🏠 Consumer Goods

Kitchen appliances, power tool housings, furniture parts, sport equipment.

🏭 Industrial

Gears, pulleys, valves, pipe fittings, pump housings.

🧸 Packaging

Thin-wall containers, caps & closures, preforms for blow molding.

Advantages & Limitations

✅ Advantages⚠️ Limitations
Lowest per-unit cost at scaleHigh initial mold tooling investment
Excellent repeatability across millions of partsNot economical for very low volumes (under 500 pcs)
Complex geometries possible (threads, undercuts, inserts)Design changes after tooling = expensive mold modifications
Wide range of materials with tailored propertiesLead time for mold fabrication: 3–8 weeks minimum
Minimal post-processing requiredDraft angles required for ejection

Frequently Asked Questions

How much does injection molding cost?

Cost has two parts: mold tooling ($2,000–$50,000+ depending on complexity) and per-part price ($0.05–$5.00 depending on material and volume). Use AI Quote for an estimate or post an RFQ.

What is the minimum order quantity (MOQ)?

Typical MOQ is 500–5,000 pcs for production molds. Prototype molds can go as low as 100–200 pcs.

How long does mold making take?

Standard mold fabrication: 25–40 business days. Prototype molds (aluminum): 15–20 days. Expedited: 10–15 days.

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