Automatic PE Powder Dip-Coating Line for Wire Racks, 3,500 pcs/shift – Thanglong Metal Wares Joint Stock Company

KIEUAN designed, fabricated, installed and commissioned an automatic PE powder dip-coating line for Thanglong Metal Wares Joint Stock Company (Công ty CP Kim khí Thăng Long) in Sai Dong, Long Bien, Hanoi. The line coats steel wire racks at a design capacity of 3,500 pieces per shift. Installation was completed on 4 February 2024, and the line was fine-tuned and finalised through June 2024.

Project information

Client	Thanglong Metal Wares Joint Stock Company
Location	Sai Dong, Long Bien, Hanoi, Vietnam
Product	PE-coated steel wire racks
KIEUAN scope	Survey, design, fabrication, installation, commissioning, technology transfer
Design capacity	3,500 pieces per shift
Timeline	October 2023 – June 2024

Requirements and design approach

Thanglong Metal Wares wanted to automate wire-rack coating within the footprint of an old paint line, reusing part of its equipment. After a site survey in October 2023, KIEUAN proposed:

A 66 m continuous overhead conveyor with 21 hangers at 3.15 m pitch (100 kg each), running on a run / stop cycle adjustable from 1 s to 10 min at 1 – 5 m/min.
A 2,000-litre fluidised powder bath on a 3-tonne automatic lift that rises around the parts for the time set on the PLC.
Two electrically heated ovens: a 12.85 m pre-heating oven (200 – 400°C) and a 9.5 m post-curing oven (180 – 220°C), with automatic doors and SCR power control.

Layout of the automatic dip-coating line
Line layout: 21 hangers, 66 m conveyor, 31.4 m system length

Fabrication and installation

All mechanical systems, ovens and control panels were built at KIEUAN's own factory in January 2024, then pre-assembled and test-run before leaving the fabrication shop. The equipment was dismantled, shipped and fully installed at Thanglong Metal Wares' factory on 4 February 2024.

Conveyor and ovens pre-assembled at the KIEUAN workshop

Fluidised powder bath with automatic lift
2,000-litre fluidised bath and 3-tonne lifting frame

PLC + HMI control cabinet of the dip-coating line
Central PLC + HMI control cabinet

Dipping area and fume extraction at Thanglong Metal Wares
Installed at Thanglong Metal Wares, completed 4 February 2024

Full-line trial run

From November 2023 to March 2024, KIEUAN dip-tested several powders and heat settings on samples supplied by Thanglong Metal Wares. The process runs: loading → pre-heating → fluidised-bed dipping → post-curing → cooling → unloading. In the test of 9 March 2024, the coating reached 350 – 400 µm thickness and 50 – 60 gloss with an even surface.

PE powder fluidising in the bath
Powder fluidising evenly in the dipping bath

PE-coated steel wire racks
Wire racks after PE coating, 350 – 400 µm

Dip-coated test samples with labelled settings
Test samples with settings written on the labels

Handover and production

After fine-tuning through June 2024, KIEUAN trained Thanglong Metal Wares' team and transferred the process so they can run the line and produce parts to specification.

Results

Design capacity of 3,500 pieces per shift, continuous and automatic.
Even PE coating, 350 – 400 µm thick, gloss 50 – 60.
Conveyor chain, guide rails and wall panels from the old line reused, lowering investment cost.