Published: 2026-10-16 · Category: Case note
We manufacture air, oil and fuel filter paper, flame-retardant paper and oil-water separation filter paper. In a filter plant that paper is assembled with other components: end caps, centre tubes, skeletons, guards, plus the non-standard tooling and forming dies used on the production line. We do not make those metal parts ourselves - we buy them from specialist partners.
For metal parts we work with Balford (Zhejiang Balford Mechatronics Co., Ltd.), covering three process families: stamping, sheet metal fabrication and turning.
What each process covers
Stamping
Thin flat parts such as end caps, skeletons, shims and brackets are formed in one press stroke, which beats machining them one by one on both rate and consistency. Where the cut edge and flatness are functional rather than cosmetic, fine blanking is used; for deeper cup-shaped parts, deep drawing reaches the wall and depth in fewer operations. Their stamping capacity runs on own presses from 25 to 350 t, with deep drawing up to 250 mm diameter.
Sheet metal fabrication
Machine guards, frames, hoppers and tooling benches are classic sheet metal work: cutting, bending, welding, assembly. These are usually one-off or low-volume, large and frequently revised, so sheet metal fabrication is a better route than a die. Some of our line modifications are supplied this way.
Turning
Centre tubes, bushes, flanges and threaded fittings are turned parts, where concentricity and fit matter more than volume. They are produced by turning and machining, sometimes as a second operation on a stamped blank.
Three things we watch in this supply
- Dimensional consistency: metal parts and paper are assembled together, so lot-to-lot variation in cap bore or tube diameter shows up directly in assembly cycle time and sealing.
- Drawing control: filter ranges change often. Without clear drawing revision control, the part that arrives is not the part that was intended.
- Lead time and lot stability: paper and metal parts have to arrive as a set; a slip on either side ties up work in progress.
About Balford
Balford operates a 12,000 m² plant in Zhuji, Zhejiang, with fine blanking and thinning/ironing deep drawing as its two focus processes, alongside sheet metal fabrication and machining. It holds ISO 9001:2015 quality management certification. That focus on fine blanking and thinning matches what thin-wall caps and similar parts need. See Balford's manufacturing capabilities.