Types of Stainless Steel Protective Films

1. Protective Film Made from White Polyethylene (PE)

A rubber adhesive layer and polyethylene (PE) make up the most suitable protective film for many applications. This film is automatically applied to protect surfaces unless otherwise specified.

The plastic sheet material has a nominal thickness of 80 micrometres. It is typically white, with two blue stripes running across its width, although the stripes hold no functional significance.

The adhesive can either be clear or black. Clear adhesive appears white on the film.

To prevent adhesive transfer, the clear adhesive film should not be exposed to sunlight for more than a few hours, as this may cause the adhesive to degrade and leave residue on stainless surfaces when removed. Dark adhesive films, however, tend to absorb heat and remain stable in sunlight for several months.

Since it doesn't release toxic or corrosive substances when burned, the protected surface can be laser or plasma cut. Laser cutting should be performed on the side without plastic. If oxygen is used as an assist gas, cut from this side.

2. Protective Film Made from Light Blue Polyvinyl Chloride

This film is ideal for deep-drawing applications, especially for multistage deep drawing. It is a polyvinyl chloride (PVC) film with a rubber adhesive.

The film has a nominal thickness of 70 micrometres and is light blue in color.

It should only be used in temperatures between 15°C and 40°C.

To prevent adhesive breakdown, the film should not be exposed to sunlight for more than a few minutes, as this could affect the deep-drawing process and leave residue on the stainless surface when removed.

Steel should not be plasma- or laser-cut with the film still in place, as the process will produce fumes containing hydrogen chloride, which are toxic and corrosive.

The steel should be pressed to remove the film prior to cutting.

3. Protective Film Black Polyvinyl Chloride

This PVC protective film is ideal for stainless steel in heavy roll-forming applications and other situations requiring robust surface protection. It is made from polyvinyl chloride (PVC) with an acrylic adhesive that offers strong adhesion.

The film has a nominal thickness of 120 micrometres and is black in color.

It should only be used in temperatures between 15°C and 40°C.

The film is weatherproof and can withstand exposure to sunlight for several months while maintaining protection.

Steel should not be plasma- or laser-cut with the film in place, as the process will generate fumes containing hydrogen chloride, which are toxic and corrosive.

4. Protective Films to Be Used for Laser Cutting

Special films are required when cutting with CO2 and fiber optic lasers. These films must meet specific requirements, including proper laser absorption, resistance to the pressures from cutting gases, and overall high film quality.

5. Protective Films

Some suppliers may use white PVC films for general surface protection, although this is less common due to the significantly higher cost of PVC films compared to PE films.

6. Stripping the Protective Foil & Cleaning the Stainless Surface

If the stainless steel protective film is left on for too long, it can become difficult to remove and may leave behind a gummy or fibrous residue from the degraded adhesive.

This residue is not always visible, making it challenging to achieve a smooth surface.

Even when the protective film is removed immediately, small amounts of adhesive residue may remain, though they might not be easily noticeable. It is advisable to clean the area after removing the film.

The adhesive residue can be removed using a solvent such as methyl ethyl ketone, eucalyptus oil, or a similar solvent.

To remove the residue, apply the solvent and use elbow grease to wipe it off the surface. The goal is to dissolve the adhesive in the solvent and then wipe away the mixture. It is important to choose a solvent that does not evaporate too quickly. Additionally, consider the solvent's flashpoint and toxicity when selecting a cleaning agent.