Surface treatment / Functional micro-texturing
Micro dimple treatment
Micro dimple treatment is a surface treatment that forms a large number of micrometre-scale depressions (dimples) on a metal surface. The fine texture, created for example by blasting fine particles, prevents sticking, improves slip and reduces friction. It is used on food and pharmaceutical production equipment and on sliding parts.
How it works
"Why it works"When small depressions are distributed across a surface, the area in contact with mating parts or products shrinks. This is why sticky foods and powders are less likely to adhere.
On sliding parts, the depressions act as oil reservoirs that retain lubricant, preventing oil-film breakdown and reducing friction and wear.
When the dimples are formed by blasting fine particles, compressive residual stress is also introduced, so fatigue strength improves at the same time (the same principle as WPC treatment).
Because it is a physical process that uses no paints or chemicals, there is no film to peel off or components to leach out. This is the key difference from coatings.
Main effects
- Anti-stick (less adhesion of food, powders and viscous materials)
- Better slip and flowability
- Easier cleaning
- Less friction and wear (oil-reservoir effect)
- Reported antibacterial effect: a listed company reports an antibacterial activity value of 3 or higher in a JIS test conducted by the Kanagawa Institute of Industrial Science and Technology (KISTEC)
Definitions
- Micro dimple treatmentRegistered trademark
- A surface treatment that forms many micrometre-scale depressions on metal to prevent sticking, improve slip and reduce friction.
- Dimple
- A small depression formed on a surface, as on a golf ball.
- PFAS
- Per- and polyfluoroalkyl substances, used in some fluoropolymer coatings and increasingly regulated worldwide. Micro dimple treatment changes the surface shape and uses no fluoropolymers.
Applications
"Where it is used"| Field | Examples |
|---|---|
| Food production | Forming and conveying parts on spring roll, gyoza, noodle and bakery lines |
| Powders and packaging | Powder refining equipment, contact parts of filling and packaging machines |
| Pharmaceuticals and cosmetics | Equipment parts that touch the product |
| Machine parts | Sliding parts that need to retain lubricant |
Typical process conditions
"Under what conditions"These are general guides. Actual conditions are set by the supplier for each part, material and specification.
| Item | Typical |
|---|---|
| Dimple size | Micrometre order |
| Materials | Stainless steel and other metals |
| Dimensional change | Very small |
| Chemicals used | None (physical process) |
| Combined treatments | With DLC and other coatings |
FAQ
"Direct answers"Can it be used on parts that touch food?
Because it is a physical process with no paints or chemicals, it is offered for food production equipment. Confirm suitability for your application and the regulations that apply with the supplier.
How does it differ from PTFE (fluoropolymer) coating?
A fluoropolymer coating adds a resin film to the surface. Micro dimple treatment changes the shape of the surface and adds no film, so there is nothing to peel off and no fluoropolymer is used.
How is it related to WPC treatment?
Both are based on blasting fine particles to modify a surface. WPC treatment mainly targets fatigue strength and sliding properties, while micro dimple treatment designs the surface depressions mainly to prevent sticking and improve slip.
Which companies in Japan offer Micro dimple treatment?
Among the companies listed on FactoryMatch, Fuji WPC Co., Ltd., Surf Technology Co., Ltd. offer Micro dimple treatment (based on each company's published information). See the supplier comparison table for minimum lots and overseas support.
Suppliers
"Who to ask"Based on the listed companies' published information.
| Company | Location | Relevant technology | Minimum lot | Overseas support |
|---|---|---|---|---|
| Fuji WPC Co., Ltd. | Sagamihara, Kanagawa | Micro Dimple Treatment® | From 1 pc | English inquiry OK, 2005: established the US subsidiary WPC Treatment Co., Inc in Los Angeles |
| Surf Technology Co., Ltd. | Sagamihara, Kanagawa | Micro Dimple Treatment® (MD Treatment®) | — | English inquiry OK |