Our supply: Special order material
Thickness: Available in 3mm, 4.5mm, 6mm
Sheet sizes: 2440×1220mm, 1200×1215mm, 1200×600mm, 600x400mm
Your supply: You can also supply your own polypropylene up to 6mm in thickness and any sheet size up to 2400×1200mm
Polypropylene Sheet, Copolymer – Propylex® is a flexible, tough material that is easy to fabricate with. When laser cutting polypropylene, the cut width (the amount the laser takes away when cutting) is generally slightly thicker than on acrylic which is worth bearing in mind if cutting very complicated artwork.
Polypropylene has a different texture on each face. One side is very slightly textured, the other side has a smooth flat finish. Polypropylene isn’t supplied with protective film on either side. It doesn’t tend to scratch very easily but it can get quite dirty particularly if light in colour. It can also get quite static meaning dust particles can stick to the exposed faces quite easily. This can easily be cleaned away with warm soapy water.
As a standard, we apply protective backing on both sides when just laser cutting is required to minimize heat marks. You will need to peel this off when you receive your job. Protective backing doesn’t always stick successfully to the slightly textured surface. It can sometimes peel off during the cutting process which can cause slight heat marks on the surrounding cut edge surface. As a standard all laser cutting is carried out with the textured surface facing up.
As a benchmark, we recommend that minimum cut widths be no smaller than the corresponding thickness of the material. For example, if cutting from 2mm polypropylene, it’s best not to allow anything less than 2mm in width. We can go smaller (see cut width image above) but this can make your components quite fragile which might not be suitable for the application. See more on cut widths and Kerf (how much the laser takes away.)
Polypropylene has a low melting point and has a tendency to heat up when being cut which can cause the sheet to warp during the cutting process. Make sure you leave lots of space between each component. 5mm is a safe distance.
Polypropylene laser cuts with a highly polished edge. We achieve this using a high laser frequency (ppi. pulses per inch ) that melts the edge as it cuts. If you look closely it is not entirely smooth and is made up of lots of tiny vertical lines. This is caused by the pulses of the laser.
The priority cutting bed for polypropylene are aluminium lamella slats. In some cases (artwork dependent) we will need to use the honeycomb laser bed which can cause minor flashback.
Polypropylene is not manufactured for ‘appearance’ engraving specifically but it can be achieved. Our standard setting is a light surface scratching. A small level of contrast will occur – engraved areas will turn slightly glossy. Raster engraving is not advised on thicknesses below 2mm due to the heat from the laser that can cause it to warp.
If you just require vector engraving / scoring and cutting, we apply paper backing to the top surface and engrave through the backing into the polypropylene surface. This helps to protect the top and bottom surface from heat and scratch marks when cutting also. Vector engraving is usually advised over raster engraving for component labelling and identification purposes.
When raster engraving is required alongside cutting we can’t apply protective backing to the top surface. The downside of this is that the material is more exposed when cutting. In this case, very slight heat marks can occur around the edge of the cuts. This is fairly minimal and can be cleaned off to some extent with a mild soap detergent and sponge if required.
Deeper engraving effects are not advised on polypropylene. The heat build-up can cause the material to warp making the engraving inconsistent.