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PSA Microfinishing Film for fine sanding operations

PSA Microfinishing Film for fine sanding operations

PSA Microfinishing Film is a product group where the microabrasive film backing is self-adhesive, as opposed to plain PET film.

The combination of the self-adhesive backing and microabrasive film, provides the user with a high-quality finishing solution on a wide variety of materials such as metals, composites, fiberglass, glass, paint, plastic and solid surfaces. PSA Microfinishing film is used both off-hand and in-conjunction with specialised machines in several markets where a consistent and fine finish is required.

PSA Microfinishing Film characteristics and features

PSA is the abbreviation for Pressure-Sensitive Adhesive and is also commonly known as “self-adhesive” or “self-stick”. PSA is a type of non-reactive adhesive, which forms a bond when pressure is applied. It allows PSA Microfinishing Film to be easily used with the following main benefits:

  • Consistent adhesion strength
  • High thickness stability
  • Can be used in wet or dry applications
  • The products can be remounted after being removed
  • Can be removed cleanly from the backing pad leaving an uncontaminated surface for the next sheet or disc


Focusing on the abrasive surface, microfinishing films are defined as electrostatic coated microabrasive films, where the abrasive grains are electrostatically oriented and fixed between 2 layers of resin (base coat and top coat) to the PET backing film. This process ensures a consistent and homogenous grain orientation, which provides a fast and precise cutting action. In addition to this process, the microabrasive powder is strictly controlled to ensure only the correct grain size is used in the production i.e. removal of any larger or smaller grain sizes.

Abrasive structure

PSA Microfinishing Film product range

Precison Polishing offers three product series as PSA Microfinishing Film. Variations depend on the mineral (aluminium oxide or silicon carbide), the grit range, and the thickness of the backing film required.

Microfinishing Film grit range

When to use Silicon Carbide or Aluminum Oxide?

  • Both minerals have advantages on certain workpiece materials.
  • Silicon Carbide is a sharp, friable material which gives a fast stock removal rate, but generally has a shorter tool life. Aluminium oxide has a “more rounded” grain structure. This durable grain generally gives a long tool life
  • Silicon Carbide is best suited for use on glass, plastics, and rubbers due to the sharp grain structure.
  • Aluminium Oxide is a tough durable grain that works on most workpiece materials, making it a popular choice; however, its “round” shape does not allow it to fracture easily and therefore the grain can become blunt during the application
  • Silicon Carbide usually achieves an improved surface finish compared with Aluminium Oxide


Below is an example of the grain structure:

Aluminium Oxide versus Silicon Carbide

FA35 PSA Microfinishing Film is a standard product available from stock. FA50 and FS50 are available on request i.e. special production.

Comparing FA35 and FA50. FA35 has a thinner film, thus producing a more flexible product, which is suitable for applications where the microabrasive film must be attached to an uneven surface. FA50 offers a wide grit range from 5 to 100 microns, where the coarser grits (50 to 100 microns) are suitable for aggressive grinding applications.

Application possibilities

PSA microfinishing Film is most commonly supplied in disc or sheet form to be used for flat sanding applications.
PSA microfinishing film is often compared to traditional coated abrasive papers and cloths, which use different grit size standards such as FEPA (Europe), ANSI (America) or JIS (Japan).

Below is a comparison table between the grits of PSA Microfinishing Film and the other grit measurement standards:

Abrasive Grit comparison

Discs are used on rotary machines in the metallurgy sector for surface preparation, or industrial flat lapping applications. Within the metallurgy sector, our products provide an excellent grinding consistency and can achieve a “pre-mirror” finish using our complete grit range.
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The standard disc diameters are: 200mm, 203mm, 230mm, 250mm, 254mm, 300mm and 305mm.

Other diameters are available on request, up to a maximum diameter of 350mm. Larger diameters may also be accommodated. 
A highly specialized niche market where this product is utilized is CD rom matrix stamper finishing applications. Precision Polishing provide its customers with PSA discs in roll form in their required diameters (i.e. 55mm or 30mm). These are supplied ready to be easily applied on the finishing machine, where the surface finish on the matrix is of paramount importance.

PSA microfinishing sheets are usually used off-hand. The PSA sheet is positioned on a flat rigid surface (holder), and the sanding operation is applied using a smooth and fluid movement over the abrasive surface. Main applications are found in precision mechanical industries such as the valve seat rings and the watch industries. They are also used in the jewelry market and in musical instrument manufacture and repair.
The standard sheet size is 230 x 280mm.

Other dimensions are available on request.
Maximum width of 350mm and maximum length of 1m (over 1m it must be supplied as a roll).
Larger widths can also be accommodated.

Valve seat rings finishing

Rolls are available on request. This product is suitable for users or converters that will carry-out a second step e.g. additional converting process.

PSA microfinishing film is also used in the textile industry. The PSA microfinishing film is wound onto the surface of the grinding cylinder which produces a very precise and consistent cut of the textile surface, far superior than coated abrasive options.