Case Overview

Longwang developed a custom industrial equipment cabinet and modular enclosure system for an automation equipment integrator. The project encompassed precision sheet metal fabrication, integrated welding and assembly, and industrial-grade surface treatment, delivering a comprehensive, one-stop solution ranging from structural design optimization to final product delivery.

The enclosure system is deployed in heavy industrial manufacturing workshops, serving as the protective housing for CNC control units, power distribution modules, and automated production line control systems. It requires high structural rigidity, excellent electromagnetic shielding performance, and reliable environmental adaptability to withstand long-term operation in dusty, vibrating, and temperature-varying industrial environments.

Case Details

Problems with Previous Supplier

Before partnering with Longwang, the customer suffered from persistent quality and delivery pain points caused by the former sheet metal suppliers, which severely restricted the stability of its complete enclosure product delivery:

Poor medium-thick plate forming accuracy & low modular interchangeability: The previous supplier lacked mature process control for 2.0–6.0mm medium-thick steel plates. Severe bending springback led to angle deviations over ±1.5° and linear dimensional errors exceeding ±0.5mm. Modular enclosure panels had poor universality, with mismatched mounting holes and uneven door gaps. On-site assembly required manual grinding, hole reaming and rework, with a rework rate staying above 18%, prolonging the assembly cycle by 30% and directly delaying complete equipment delivery.

Unstable surface treatment & insufficient corrosion resistance: With simple manual pretreatment and incomplete degreasing and phosphating processes, the former supplier delivered powder coatings with large thickness fluctuations (40–120μm) and poor adhesion. The coating easily peeled, bubbled and rusted in dusty, oily and humid industrial workshops. Its salt spray test performance was only 180–220 hours, far below industrial requirements. Enclosures showed corrosion within 6–8 months of use, triggering frequent after-sales maintenance and damaging the customer’s brand reputation.

Rough welding process & hidden structural safety risks: Random welding without tooling positioning caused large welding deformation. The flatness of the cabinet base exceeded 2.5mm/m², and side panel verticality was out of tolerance, leading to sealing failure and failure to reach even IP54 protection. Load-bearing positions had defects like incomplete penetration and porosity, with risk of cracking under long-term production line vibration. The protection level failed to meet contract requirements, and the structural strength could not support the 800kg static load target, exposing the customer to return and claim risks from heavy industry end users.

Slow customization response & unreliable delivery schedule: The customer’s product matrix covered multiple models with small-batch customization, requiring frequent mold and parameter adjustment. The previous supplier had low flexible manufacturing capability, long changeover time and unstable batch-to-batch consistency. Delivery was often delayed by 7–15 days, making the customer unable to respond quickly to end-user orders, facing inventory backlog and order loss risks, and bearing high multi-supplier management costs.

Incomplete quality control & lack of traceability: Only final inspection was performed without in-process quality control. Defects could not be traced to specific processes, and there was no formal dimensional test report or coating performance certificate. As a result, the customer failed to pass supplier audits of large end-users, and could not support projects with strict qualification requirements, restricting its business expansion in the high-end industrial market.

Longwang Solution

Precision forming system for medium-thick plates: Longwang deployed 3000W high-power fiber laser cutting machines and 4+1 axis electro-hydraulic servo bending machines with automatic deflection compensation, and built a dedicated process parameter database for 2.0–6.0mm thick plates of different materials. Through a springback compensation algorithm and mandatory first-article CMM verification for each batch, linear dimensional tolerance is controlled within ±0.2mm and bending angle accuracy reaches ±0.5°.

Outcome: Modular panels achieve 100% interchangeability without secondary grinding or reaming. The customer’s on-site assembly rework rate drops to less than 0.8%, and assembly efficiency increases by 35%.

Full-automatic industrial-grade surface treatment line: Longwang operates an 8-meter automatic spraying production line with a standard full-process pretreatment: degreasing → water washing → pickling → phosphating → passivation. TGIC polyester powder is applied by electrostatic spraying and cured at a constant temperature, with coating thickness precisely controlled at 60–80μm. Each batch undergoes cross-cut adhesion test and salt spray sampling.

Outcome: Coating adhesion reaches Grade 0 in the cross-cut test, and salt spray resistance stably exceeds 500 hours. The enclosure maintains intact appearance and anti-corrosion performance in harsh industrial environments for more than 5 years, completely eliminating after-sales complaints caused by coating problems.

Graded welding + stress relief process: Based on structural stress simulation, Longwang adopts a graded welding scheme: full CO2 gas shielded welding for load-bearing frames to ensure structural strength, and spot welding for appearance parts to reduce weld marks. All welding work is positioned by precision tooling, and shot blasting stress relief is performed after welding to suppress deformation.

Outcome: Cabinet base flatness ≤1.0mm/m², side panel verticality ≤1.0mm/m, and the protection grade stably reaches IP55 (IP65 optional). The static load capacity exceeds 800kg, and welds pass 100% appearance inspection and sampling flaw detection, fully adapting to long-term vibration scenarios of automated production lines.

Modular platform + flexible manufacturing: Based on the standardized modular enclosure platform, Longwang can quickly adjust opening sizes, internal beam layouts and installation hole positions, realizing rapid program change and production switching. With sufficient equipment capacity and scientific production scheduling, customized products can enter the production line rapidly.

Outcome: The customized sample delivery cycle is shortened by 40%, and mass production delivery is 20% faster than the previous supplier. Batch consistency is highly stable, supporting the customer’s rapid order response and multi-model parallel production needs.

Modular platform + flexible manufacturing: Based on the standardized modular enclosure platform, Longwang can quickly adjust opening sizes, internal beam layouts and installation hole positions, realizing rapid program change and production switching. With sufficient equipment capacity and scientific production scheduling, customized products can enter the production line rapidly.

Outcome: The customized sample delivery cycle is shortened by 40%, and mass production delivery is 20% faster than the previous supplier. Batch consistency is highly stable, supporting the customer’s rapid order response and multi-model parallel production needs.

Results Achieved

Following the full implementation of Longwang’s customized industrial enclosure solution, the client has achieved comprehensive and quantifiable operational improvements: the first-pass yield of mass-produced chassis stabilized at 99.2%, the on-site assembly rework rate plummeted to below 0.8%, the production and delivery cycle was shortened by 20% with a 12-month consecutive on-time delivery rate of 99.5%, comprehensive supply chain and after-sales maintenance costs decreased by more than 25%, and the client successfully passed supplier qualification audits of multiple heavy industry end-users to expand its high-end market business. Rooted in consistent quality concepts and reliable delivery performance, the bilateral relationship has been upgraded from ordinary transactional cooperation to a deep strategic partnership.