Processing 3M™ Protection Films with Laser Technology

3M™ Protection Film

Processing 3M™ Protection Films Using Digital Laser Material Processing (DLMP^®) Technology

As the name suggests, 3M™ Protection Films protect fragile displays against damage that can occur from everyday use. These products are based on polyester (i.e. PET) film and incorporate a low tack adhesive for easy application and removal. The base film is enhanced with additional layers and coatings to create specialized products for a variety of applications.

Anti-Reflection Matte Non-Conductive Protection Film (ARMR220 NC)
ARMR220 NC uses a non-conductive coating system with near neutral color anti-reflection surface treatment and an anti-glare coating to reduce glare and total reflected light.
Glossy LR Protection Film GLR320
GLR320 is a smooth, optically clear protection film with an anti-reflective coating. This provides up to 93% light transmission with no color distortion.
Glossy Protection Film GLS100
GLS100 Glossy Protection Film provides protection for smooth displays or can be used to transform matte display textures to a high gloss. It is optically clear and provides greater than 93% light transmission.

3M Protection Films are also available without an adhesive backing. Typical thickness for all films (adhesive layer included) is 0.006” (0.155 mm).

Related Names
Anti-Reflection Matte Non-Conductive Protection Film (ARMR220 NC), Glossy LR Protection Film GLR320, Glossy Protection Film GLS100

Chemical Names
N/A

Manufacturers
3M™

3M™ Protection Films and DLMP^® Technology

The thin thermoplastic film construction makes 3M Protection Films highly compatible with Digital Laser Material Processing (DLMP^®) technology. This material undergoes rapid degradation and vaporization, unlike thermoset materials that may oxidize and char. The influence that this property has on the results of DLMP technology is discussed in detail in the following sections.

The most useful effects of laser energy with 3M Protection films are material ablation and material modification. Each of these processes is discussed in its respective section below.

Laser Material Processing Whitepaper

3M™ Protection Film Laser Cut for Mobile Phone

3M™ Protection Film Laser Cut into Simple Shape

3M™ Protection Film Laser Marked with Part ID Number

3M™ Protection Film Laser Cut and Marked in Single Manufacturing Step

Ablation of Material

Organic polymers, such as those in various layers that make up 3M Protection Films, are excellent absorbers of CO₂ laser energy. When the polymer absorbs laser energy, it rapidly converts optical energy into molecular vibrations leading to rapid chemical degradation. Material directly in the laser path is ablated and carried away as vapor. The material just outside of the laser's spot or path will conduct some heat, but not enough for complete and thorough combustion and ablation. This area of thermal affect is often referred to as the heat affected zone or HAZ. The HAZ for 3M Protection Films is very small due to the low power required to process the thin material. The vapors generated by laser ablation may deposit on adjacent areas of the film. Several methods can be employed to combat this deposition.

CO₂ lasers are commonly available in two wavelengths, 10.6 μm and 9.3 μm. 10.6 μm CO₂ lasers are by far the most common, but PET processing is one instance where 9.3 μm lasers hold a clear advantage. PET has a higher absorptivity at 9.3 μm, meaning laser energy is more fully and efficiently converted into heat. The differences between these two laser wavelengths are explored further in the individual processing sections.

Laser Cutting

Laser cutting is the complete removal and separation of material from the top surface to the bottom surface along a designated path.

3M Protection Films are straightforward to cut using DLMP technology. The edges created by laser cutting will show no discoloration. Vapor deposition onto adjacent surfaces may occur; however, this can be mitigated using several methods.

As mentioned, 9.3 μm energy is more efficiently absorbed by PET, the base material in 3M Protection Films. This results in cleaner ablation, with less HAZ and melt-back. The example on the left shows shows a cut made with made with a 9.3 μm laser, and the example on the right shows a 10.6 μm laser magnified at 132x.

Finally, this example shows a simple shape cut from a sheet of 3M Glossy LR Protection Film GLR320. The basic capability shown can be extended to nearly any shape, even complex and closely-spaced cuts.

Material Modification

When using DLMP technology to cut material, enough energy is applied to vaporize all of the material directly in the laser path. The laser power can also be precisely controlled to only slightly melt the surface of the film, which quickly solidifies. This modifies the texture, giving the film a frosted appearance.

Laser Marking

Both CO₂ laser wavelengths are capable of marking and cutting polyester films, but the 9.3 μm laser will produce greater contrast when marking due to its higher absorptivity. This example shows the textural differences between 9.3 μm (left) and 10.6 μm (right) laser markings. Raster lines are crisp and well-defined with 9.3 μm markings, while 10.6 μm raster lines appear muddled.

When the laser energy is used to produce a human- and/or machine-readable identification or information on a material, such as a barcode, date/lot code, serial number or part number, the process is considered laser marking. Laser marking 3M Protection Films will yield a frosted texture. This image shows a part number marked onto 3M Glossy LR Protection Film GLR320.

Combined Processes

Multiple processes can be applied to 3M Protection Films without having to move or re-fixture the material. The example demonstrates how processes can be combined to cut square and round shapes and mark/engrave with 3M Glossy LR Protection Film GLR320 and DLMP technology.

Environmental, Health and Safety Considerations

Laser material interactions almost always create gaseous effluent and/or particles. Processing 3M Glossy LR Protection Film GLR320 with a CO₂ laser generates vapors primarily containing carbon monoxide, acetone, methyl isobutyrate, methyl acetate, benzene and dihydroxydimethylsilane. The effluent from processing 3M Protection Films should be routed to the exterior environment. Alternatively, it may be treated with a filtration system first and then routed to an exterior environment. Vapors from laser processing polyester-based products are flammable. Laser processing 3M Protection Films should always be supervised.