Acrylic sheet, such as clear red acrylic sheet, white transparent acrylic sheet, transparent orange acrylic sheet in the cutting process, due to tool wear, feed rate is not appropriate or thermal stress concentration, often formed tear type, jagged type or thermal deformation type burr.
Sandpaper sanding is the most basic treatment method, which should follow the progressive process of 'rough sanding - medium sanding - fine sanding'. Use 120 grit Silicon Carbide sandpaper with a wooden pad at a 45° angle in one direction, taking care to maintain a 15° angle between the plate and the sandpaper to avoid chipping the edges. Alcohol spraying during sanding reduces frictional heat and prevents the material from softening. This stage removes more than 80% of visible burrs. Intermediate sanding is carried out with 400 grit waterborne sandpaper and cerium oxide paste in a circular motion along the edges of the sheet. The focus is on stress concentrated areas in the corners, where increasing the amount of paste creates a lubricating film and reduces the amount of scratches. This stage reduces the surface roughness from Ra12.5μm to Ra3.2μm. 800 mesh non-woven sandpaper is used in the finishing stage with a wool polishing wheel applying 0.5kg/cm² pressure. The polishing was carried out at 200-300rpm in an '∞' motion along the edge of the plate. The result is a mirror finish of Ra0.8μm, restoring light transmission to over 92%.
For optical grade applications, flame polishing is a highly effective solution. Using a propane torch (flame temperature 1995°C) and keeping the nozzle at a distance of 2-3cm from the plate, the edge is swept at a constant speed of 10cm per second. The high temperature melts the surface material and re-flattens it to form a clear fused edge layer of 0.1-0.3mm. The flame height should be stabilised at 5-8cm, and the feed speed error of the sheet should be <±0.5cm/s. In order to avoid overheating and discolouration, a pulse heating mode can be used: heating for 3 seconds and cooling for 1 second, and the operation should be repeated. The light transmission rate of the treated edge can reach 95%, and the haze value is <0.5%.
Now, you have an understanding of the acrylic plate edge burr.