Suspension components — pretreatment and cathodic e-coat line with programmed hoists
A dipping line for automotive suspension parts on 3,600 × 900 × 1,200 mm hangers, up to 38 m² of surface and 500 kg per load, at a 6 min line cycle with 3 min of current: spray and dip degrease, zinc phosphating at 46–54 °C, cathodic e-coat at 30–34 °C for 180 s, ultrafiltration and a 160–180 °C oven. Two contracts concluded.
The problem the customer brought
Not enough skilled operators, a manual process that was hard to manage, and finish quality that was hard to control.
Workpiece
Automotive suspension components; hanger envelope 3,600 × 900 × 1,200 mm, maximum surface area about 38 m² per transfer load, 500 kg; line cycle 6 min with 3 min of applied current.
Robots
No robots — a programmed-hoist dipping line with four programmed hoists of 1,000 kg lifting capacity.
Process and equipment
Spray degrease → dip degrease → rinse ×2 → DI rinse → surface conditioning → zinc phosphating at 46–54 °C for 180 s → DI rinse ×3 → e-coat at 30–34 °C for 180 s → UF1/UF2 → DI rinse → drain → blow-off, then an oven at 160–180 °C in six zones of six minutes and 30 min of forced cooling. Main equipment: e-coat tank in 4 mm carbon steel with GRP lining rated ≥20 kV; 44 tubular anodes (316L, 1,450 mm effective, each with a flow meter and ammeter) with a conductivity meter compensating DI water automatically at ±100 µs/cm; 500 L/h ultrafiltration (UF80 housings, 25 µm bag filters, 1,000 L permeate tank); rectifier set 380 V / 450 A; 5 t/h RO water; a 15 m² plate heat exchanger with 30 hp and 50 hp chiller-heater units; ultrasonic degreasing (12 transducer boxes, 600 transducers at 60 W, 25 kHz, SUS304 tank with hard-chromed base); and an ECOCO BLG-12 pyrolysis furnace with primary and secondary combustion chambers, internal and external trolleys, water scrubbing and a Russian-language PLC.
Commercial terms
Ultrasonic cleaning machine 15–20 calendar days, FCA; pyrolysis furnace 30 working days, EXW.
Shipping terms on current projects: EXW, FOB, CIF or DAP. Customer names, plant locations and prices are not published.
Result
Both contracts concluded. The ultrasonic cleaning contract was fixed in total value and unalterable, with a 12-month warranty from acceptance and no later than six months after receipt. The pyrolysis furnace contract collected its 40 % advance; the customer then added stainless steel chimney spares, raising the quantity from three to four at a revised unit price.
What we do differently because of this project
The country of origin of one key component appeared as two different statements — "IR, USA" and "imported from Korea" — across the Chinese, English and Russian versions. A single version is now fixed as the contract annex before signature, or it becomes a ready-made dispute at acceptance. E-coat quotations from different suppliers also differed by a factor of about 2.3, so the process boundary (oven, forced cooling, RO, installation — in or out) is unified before any comparison.
Photographs from this project
Customer names, plant identification and location watermarks are removed. Captions state where an image is a general illustration rather than this customer's plant.
