Plastic is a brittle material, so drilling holes in it might not be just as easy as you think. It is prone to crack and splinter if you are not being careful. So take your time to get to know the proper equipment and technique and you will save yourself a lot of trouble.
For drilling plastic prepare a ruler or measuring tape, a pencil, clamp, sandpaper, some kind of lubricant (for deeper holes), an electric drill with variable speed settings and a proper drill bit. Because the drill bit is very important here, let’s see which one would be most beneficial.
High-speed steel TAP PlasDrill Bits have sharper tips and cutting edges that are specifically ground to produce clean, chip-free holes in acrylic and many other sheet plastics. The most effective drill bits for plastics are spur-point bits, also known as dowel bits. They are specifically angled to make smooth cuts in the material.
A spur-point bit has a central point and spurs that keep the bit aligned, maintaining a clean, neat hole. Remember this: Never use twist bits when drilling plastics; they can splinter and ruin the material.
Mark the location where you want your hole to be. Use a ruler or a measuring tape and please be precise. The work piece should be held firmly, or, preferably, solidly clamped to the worktable. It is best to backup the piece being drilled with acrylic or plywood so the drill bit will continue on into solid material as it penetrates the bottom surface. This will prevent chipping of the bottom surface.
Put the chosen drill bit into the drill and start drilling slowly. According to the drill bit size you can determine which speed to use (slika plastic). Watch the area around the hole carefully as you drill. Stop drilling and let the plastic to cool if you start to see the plastic shavings around the hole gumming up. Complete your hole by putting the drill in reverse setting and slowly pull the drill bit out.
If you are drilling a hole three times deeper than the diameter of the drill, you should use a lubricant, or a coolant such as water. This will help in removing the chips, dissipate heat, and improve the finish of the hole. Gently sand the area around the hole, but be careful not to scuff the plastic in the process. Check for any cracks or splinters that might affect the integrity of the plastic before putting it to use.
Since plastics expand and contract with temperature changes, make sure you drill a slightly larger hole than necessary to allow room for screw movement without placing stress on the material.
Make sure that your holes are far from the edge as possible in order to avoid cracking.