The Family Factory Behind Your Parts

Weilin Plastic is a family-run injection molding factory in Ningbo, China. Before you trust us with your tooling money, here is what we actually own, who actually runs the machines, and how we prove the quality we promise.

30 yrs
Since our first mold in 1996
100+
Molds built in our own shop
13M+
Parts shipped to the US and Europe
ISO
9001:2015 certified
Home/About Us

Who We Are

A Small Factory That Keeps Big Customers

We are not the biggest molder you'll quote, and we don't pretend to be. Two long programs anchor this factory: dental consumables for a US brand since 1996, and gas equipment components for a European OEM since 2009. On that base we now mold for four industries: medical, dental, industrial, and gas equipment. The first mold we ever cut is still in production, which says more about how we work than any slogan could.

What working with a family factory means in practice:

  • The owner answers your email. Frank Lai runs the business and reviews your CAD files himself. No account manager layer between you and the person responsible.
  • References that go back decades. Our two oldest customers have reordered for 30 and 17 years. That track record anchors every new industry we take on, and when a part is outside our lane, we say so.
  • Molds treated as your asset. Built in-house, maintained between orders, still running after decades. You pay for the tool, you own the tool.
  • The name on the sign answers for the parts. Three generations of one family have stood behind this work. There is nobody to pass blame to, and we like it that way.
Inside the Weilin Plastic injection molding workshop in Xiangshan, Ningbo
Weilin Plastic workshop in Xiangshan, Ningbo

Our Facilities

The Hardware Behind Every Quote

Send us a fingertip-sized tip or a two-handed housing: the press for it is already running, and you're welcome to visit and count the machines yourself. Small precision parts run right beside the mold shop, so a tooling tweak never waits on a truck, while large housings run on high-tonnage machines. One team quotes, tools, molds, and inspects all of it.

  • Presses16 injection machines from 100T to 1,000T across two production sites
  • Mold shopDesign, cutting, and lifetime maintenance in-house, next to the presses
  • Secondary opsInsert molding, ultrasonic welding, hot stamping, printing, and assembly
  • TestingTensile, salt spray, flammability, spectroscopy, and drop impact on call
  • QualityISO 9001:2015 held by Weilin, recertified 2026; our large-tonnage partner site holds its own ISO 9001 and IATF 16949:2016
Injection molding machine in the Weilin Plastic production network
Presses matched to the part, from fingertip-sized tips to two-handed housings.

Equipment & Testing

What's Actually on the Floor

Buyers ask for the equipment list before the sales pitch, so here it is: what molds your parts, what builds the tools, and what checks the results.

16 Injection Presses to 1,000T

From fingertip-sized precision parts to large housings on 1,000T machines, the press is matched to the part, and one team runs the quality plan across all of them.

In-House Mold Shop

100+ production molds designed, cut, and maintained here in P20, H13, and 718H steels. A drifting dimension gets fixed at the tool in days, not quoted out to a subcontractor.

Secondary Operations

Insert molding with brass bushings and threads, ultrasonic welding, hot stamping, silk-screen printing, and assembly benches, so parts leave finished.

Measurement & Inspection

Calipers and gauges at every press, CMM checks on critical dimensions, color verification against retained standards, and FAI on every new tool.

Material Testing Access

Through the partner lab: tensile, salt spray, flammability, spectroscopy, and drop impact testing when your part needs proof beyond dimensions.

15+ Resins in Production

PP, ABS, PC, PA6/PA66, glass-filled nylon, POM, TPE, GPPS, PEI with carbon fiber, and more, all named grades from named suppliers, lot-traced per batch.

The Team

The People Who Answer for Your Parts

Three generations have worked these machines. When you email us, one of these people reads it, and one of them is accountable if something goes wrong.

Mr. Lai Minchun, founder and senior mold technician of Weilin Plastic

Lai Minchun

Founder · Senior Mold Advisor

Cut our first dental mold in December 1996; it still runs today. Now advises on every tricky tool, and still walks the floor checking molds the way he always has.

Frank Lai, second-generation owner of Weilin Plastic

Frank Lai

Second-Generation Owner

Spent 7 years managing international procurement before joining the family business, so he has sat on your side of the table. Opens your CAD file in SolidWorks himself and replies to every inquiry personally.

The Master Technicians

The Master Technicians

Molding & Toolroom Crew

The same hands have run the same customer programs for decades. They know each mold's habits by sound, which is why a 1996 tool can still hold its tolerances in 2026.

Certifications

Paperwork Your Auditor Can Verify

One Certificate, Backed by Records We Keep Daily

Our Ningbo production runs under ISO 9001:2015 certified quality management, recertified in 2026. Every program gets named resins, lot traceability, first article inspection, and batch records. Customers who need more assurance audit us on our own floor, and we welcome it. Several have re-audited for years and kept ordering.

ISO 9001:2015 — Weilin, Ningbo

Our own certificate, covering molding, assembly, and inspection at our workshop.

Material Documentation

Certificates of analysis per batch, plus resin producers' FDA, RoHS, and REACH statements on request.

Partner Facility Certificates

The Hefei partner holds its own ISO 9001 and IATF 16949:2016. Those are the partner's certificates, and we always say so.

Talk to Someone Who Actually Runs the Shop

Send a drawing or just describe the part. Frank reads every inquiry himself, and you'll get a quote, DFM feedback, and a straight answer within three business days.

Get in Touch → See How We Work →

Contact

FAQ

Are you a factory or a trading company?
A factory. Weilin Plastic is the brand of Ningbo Weilin Import and Export Co., Ltd., which is the same family business that owns the workshop, the machines, and the molds in Xiangshan, Ningbo. The export entity exists so we can ship to you directly. Visit us and you'll meet the people who actually mold your parts, not a middleman with a catalog.
Can we visit or audit the factory before ordering?
Yes, and we encourage it. Our workshop is in Xiangshan, Ningbo, about two hours from Ningbo airport. If you can't travel, we'll walk you through the floor on a live video call: machines, mold shop, inspection bench, your tooling if it's already here. An hour of looking beats a hundred pages of brochure.
Who will I actually be communicating with?
Frank Lai, the second-generation owner. He reads every inquiry, opens your CAD files in SolidWorks himself, and stays your contact from first quote to repeat orders. On tooling questions he brings in the founder, who has built molds here since 1996. There is no sales layer to translate through, so answers come back fast and unfiltered.
Where will my parts actually be made?
Small and mid-size precision parts run in our own Ningbo workshop on 100 to 150 ton presses. Larger parts run at a partner facility in Hefei with presses up to 1,000 tons, using our molds and our quality plan. Your quote states which location your part runs in, because you deserve to know before you commit, not after.
What certifications do you hold?
Weilin holds ISO 9001:2015, recertified in 2026, covering molding, assembly, and inspection at our Ningbo workshop. The Hefei partner facility holds its own ISO 9001 and IATF 16949:2016 certificates. At the material level we provide resin producers' FDA, RoHS, and REACH statements on request. If your project needs a certification we don't hold, we tell you in the first reply.
You're a small factory. How do I know you'll still be here in ten years?
Fair question to ask any supplier. Our answer: three generations have worked this business, our first customer from 1996 still orders every month, and the mold we cut for them that year is still in production. We grow by keeping customers for decades, and a company built that way doesn't disappear when the market dips.