Custom Injection Molding Manufacturer Plastic Components for Medical, Dental & Industrial Applications
We provide one-stop service from your idea to the finished product, with precision you can certify and parts you can rely on. Client partnerships that have lasted two decades are our proof.
Why Choose Weilin Plastic
Four reasons buyers in the USA and Europe keep working with us, some for nearly three decades.
Tooling our founder built in 1996, still running today
T1 samples, cut before any volume run
Nearly 30 Years of Injection Molding
Our founder cut his first dental mold in December 1996 and founded Weilin the following year. A few of the molds from those early years still run in production today.
OEM / ODM Manufacturing
Send a drawing or a sample part. We build the mold, mold the parts, and handle assembly and packing, so you receive finished goods rather than loose components.
Strict Quality Control
Every batch is measured against your drawing and gets a first-article inspection before it ships. Across our largest European program, returns average four to five parts a month.
Fast Sampling & Delivery
Quotes come back within three business days. After a mold is approved we cut T1 samples, usually within four to six weeks, before any volume runs.
Injection Molding Capabilities
You don't need to coordinate with mold makers, injection molding factories and packaging companies. We run all steps under one roof.
Mold Design
We review your 3D file for wall thickness, draft, and gating, then design tooling built to run for years.
- DFM feedback before tooling
- Single & multi-cavity molds
- Mold transfer from other suppliers
Injection Molding
50T to 1,000T machines run engineering resins and elastomers to tight, repeatable tolerances.
- Tolerances to ±0.02 mm
- 15+ engineering materials
- No MOQ, runs up to 1M+ a year
Assembly
We finish parts in-house so they arrive ready to use, not as a box of pieces to put together.
- Ultrasonic welding
- Hot stamping & silk-screen
- Sub-assembly & kitting
Quality Inspection
Parts are checked against your drawing at first article and through production, with records on file.
- CMM & dimensional reports
- Tensile, salt-spray, microscopy
- Batch traceability
| Machines | 50T to 1,000T injection molding machines across our Ningbo factory and partner facility in Hefei |
| Standard tolerance | ±0.05 mm, down to ±0.02 mm on critical features |
| Materials | PP, PC, ABS, ASA, PA6, PA66, PA66+30%GF, POM, PEI, TPE, LSR, medical silicone, and more |
| Color matching | European RAL standard and Pantone matching |
| Secondary work | Ultrasonic welding, hot stamping, silk-screen printing, assembly |
| Volume | No minimum order quantity, from prototype runs through to over one million units a year |
Industries We Serve
Medical Devices
Housings, fittings, and components for medical equipment, molded in medical-grade resins with material traceability.
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Dental Products
Impression trays, saliva ejectors, tongue scrapers, and suction tips. We have molded dental consumables for the same US brand since 1996.
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Industrial Equipment
Functional parts in PA6, PA66, POM, and PC for welding equipment and other industrial machinery.
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Gas Equipment
Flow-control handwheels, regulator and flowmeter parts, and color-coded fittings for medical and industrial gas systems.
Learn more →Custom Plastic Parts
A sample of our regular production. Most of our work is custom, so please send us a drawing or sample of the part you need.
Dental Impression Tray
Full size range (1# to 9#), in autoclavable PP.
Saliva Ejector & Suction Tip
Disposable dental evacuation parts in multiple colors.
Flow Tube
Transparent flowmeter tubes for medical gas equipment.
Rail Clamp
Glass-filled nylon clamps for equipment mounting.
Flow-Control Handwheel
φ26 to φ66 handwheels for gas regulators.
Custom Plastic Component
Built to your drawing in the resin your application needs.
Injection Molding Case Studies
Every program follows the same five steps, from your first file to parts on a pallet.
Requirement
You send a drawing, sample, or 3D file. We sign an NDA first if you need one.
Tooling
We give DFM feedback, then design and cut the mold.
Sampling
T1 samples go out for your approval before any production.
Production
We mold, assemble, and inspect each batch against your drawing.
Delivery
We pack, prepare export documents, and ship FOB, CIF, or DDP.
A US dental supply brand came to us for injection-molded consumables. What started with one impression tray grew into a 17-mold program covering eight tray sizes, saliva ejectors, tongue scrapers, and suction tips.
Several of the original molds are still in production, and to date the program has not had a returned batch.
Since 2008 we have supplied two European brands with shared Czech and Swedish roots: a welding equipment maker and a century-old gas equipment manufacturer. Together the work covers 81 dedicated molds for regulator parts, flowmeter housings, and color-coded fittings.
The program runs more than 15 engineering materials to European RAL color standards, with returns averaging four to five parts a month.
Injection Molding Factory Tour
A look at the machines, the mold shop, and the people behind every shipment.
Injection Molding Floor
Injection Molding Machine Running
Quality Inspection
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