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Product Assembly · 5 Assembly Lines · Packing and Shipping
Contract Assembly for Plastic Products: 5 Assembly Lines, from Heat-Staked Inserts to Packed Goods
After molding and finishing, Hongqing runs 5 assembly lines for heat-staked inserts, insert installation, sub-assembly, final assembly, functional checks, packing and shipping. The assembly workshop is enclosed, and staff enter through an air shower to keep out dust and debris. You work with one factory and receive finished goods ready to sell.
We'll sign an NDA before you send drawings · Or email info@dghongqing.com
Last updated: October 2026
5 assembly lines
Enclosed workshop · Air shower
Heat-staked inserts · Insert assembly
Packing and shipping in one place
Assembly capabilities
Assembly capabilities at a glance
These figures match our factory page, and you can check each one during a factory visit or video audit.
Assembly lines
5 lines in an enclosed workshop; staff enter through an air shower
Secondary operations
Heat-staked threaded inserts and insert installation
Assembly scope
Component assembly, sub-assembly and final assembly
Parts we assemble
Molded parts, metal parts, electronic components, seals, buttons, panels and trim
Inspection
Assembly and functional checks to your test requirements
Packing
Cleaning, labeling, bagging, sealing, boxing and cartoning to your packaging spec
Shipping
FOB or EXW; we can arrange sea, air or express freight
What we need from you
Sample, BOM, assembly drawing, functional test requirements and packaging requirements
Hongqing assembly line, photographed at our Qiaotou, Dongguan plant
Assembly process
From parts to retail-ready products
Molding, finishing and assembly connect on one site, so parts never travel between factories.
Heat-staking machine: threaded inserts are heat-staked into plastic parts before assembly
1
Confirm the documents
You provide a sample, BOM, assembly drawing, functional test requirements and packaging requirements, and we plan operations and inspections from them.
2
Kit the materials
Molded and finished parts are made in-house; purchased metal parts and electronic components are kitted after incoming inspection.
3
Heat staking and pre-assembly
Heat-staked inserts, insert installation and sub-assembly prepare parts for final assembly.
4
Final assembly
Final assembly follows the assembly drawing on the line, with in-line checks at critical points.
5
Functional and cosmetic checks
Functional checks to your test requirements, plus appearance, assembly gaps and markings.
6
Packing and shipping
Cleaning, labeling, bagging, sealing, boxing and cartoning, with sampling inspection per GB/T 2828.1 (ISO 2859-1) AQL or your standard before shipment.
Assembly capability
4 key numbers for assembly and shipping
You can see the equipment and records behind every number during a factory visit or video audit.
5 lines
Assembly lines in an enclosed workshop with an air shower
From 100 pieces
Pilot run
From 2,000 pieces
Production MOQ
FOB · EXW
Shipping terms; we can arrange freight
Typical products
Multi-part plastic products that need assembly
Hongqing has developed and produced electric toothbrushes, water flossers, timer switches, LED lights, smart thermostats and self-cleaning litter boxes. Products like these combine molded parts, electronics, metal parts and seals, and assembling them on one site removes a round of shipping and handover.
01
Personal Care
Electric toothbrushes and water flossers
Assembly and testing of two-shot handles, waterproof seals and motor units.
02
Electrical and lighting
Timer switches and LED lights
Assembly of panels, buttons, terminals and circuit boards, with markings screen printed or laser marked.
03
Smart Home & IoT
Smart thermostats
Assembly of housings, display windows, buttons and circuit boards, packed after functional checks.
04
Pet Products
Self-cleaning litter boxes
Final assembly of large molded housings with motors, sensors and other components.
Factory photos
Inside our assembly workshop
These photos were taken at Hongqing's factory in Qiaotou, Dongguan; you will see the same assembly lines and warehouse during a factory visit or video audit.
Assembly lines
Components and complete units are assembled and checked on the line.
Air shower
Staff enter through an air shower to keep out dust and debris.
Outbound staging area
Packed goods wait here for inspection and container loading.
Before and after assembly
From tooling to assembly in one factory
Tooling, molding, finishing and assembly share one site, so any quality issue can be traced to the responsible step.
Injection Molding
90+ presses from 80T to 1300T; mold trials and production both run in our own factory.
Explore injection molding →
Surface Finishing & Secondary Operations
6 robotic painting lines, 30+ pad printers and 7+ automatic screen printers, plus UV printing, laser marking and conductive coating.
Explore finishing →
Quality Control
A 20-person QC team inspecting at four gates: incoming, first article, in-process and outgoing.
Explore quality control →
OEM manufacturing
Have drawings or a sample? After a DFM review we build the mold in-house, then mold, finish, assemble and ship.
See OEM manufacturing →
What documents do I need to outsource assembly to Hongqing?
To outsource assembly to Hongqing, prepare 5 items: a sample or approved prototype, a BOM listing each part's specification and source, an assembly drawing or instructions, functional test requirements, and packaging requirements covering labels, retail boxes, cartons and shipping marks. We use them to plan heat staking, pre-assembly, final assembly, inspection and packing, and write the checks into the inspection standard. If something is missing, contact us anyway: our sales manager, Coya Xiang, will tell you what else is needed within 1 business day, and we can sign an NDA before you send files.
What checks does Hongqing run after assembly?
Hongqing checks assembled products at 3 levels. On the line, critical points such as screws, snap fits, seals and assembly gaps are checked in-line. Each finished unit gets functional checks to your test requirements, plus appearance and marking checks. Around packing, we sample per GB/T 2828.1 (ISO 2859-1) AQL or your standard. Functional test items and methods are agreed with you in writing before the order; certification tests such as CE and UL are done by accredited third-party labs. You or a third party are welcome to inspect at our factory before shipment.
Can packaging follow our exact requirements?
Yes. Packing is the final stage of Hongqing's 5 assembly lines, covering cleaning, labeling, bagging, sealing, boxing and cartoning to your requirements, with label content, retail boxes, manuals and carton marks taken from the files you provide. Packing method and carton quantity are confirmed during sampling or the pilot run, so nothing changes in mass production, and the quote states who supplies the packaging materials. If your packaging must pass drop or transit tests, tell us before ordering and we will agree the packaging plan together.
How are assembled products shipped?
Hongqing ships finished goods on 2 terms, FOB or EXW, and can arrange sea, air or express freight. After packing, goods wait in the outbound staging area for inspection: you or a third party you appoint can inspect at our factory before shipment, or book a video inspection. Payment is a 50% deposit with the balance due before shipment. Carton marks are prepared to your requirements, and the freight method and timing are confirmed with the quote and order.
Send us what you have. We'll map out the route to mass production.
Wherever you are in development, we'll propose the right manufacturing plan, from early design review through tooling and molding to finishing, assembly and shipping, and move your project step by step to mass production.
Helpful to include: sketches, drawings or 3D files, annual volume and target market.
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