BW:
I believe what BW means by 'grab' in this instance is that the motion of the blade causes the plastic to ride up along the side of the blade and start chattering along the blade teeth at the top of the rotation resulting in a very uneven cut if not massive chip outs from the plastic). The other type of grab is when the motion of the blade forces the piece riding along the fence to shoot out and hit the person doing the cutting. This will occur if the piece is not supported in any way or supported only at the very back during the cut (learned this one the hard way in my reckless youth).
I find that an 80 tooth thin blade (I use a stiffener) is way less likely to chip any plastic but it will still grab even with a splitter in use since the plastic does not make it to the splitter before the blade grabs and forces the plastic up. Blade grab is prevalent when cutting narrow strips (no weight or mass to speak of).
To avoid blade grab you have to apply downward pressure along the length of the piece riding against the fence as it passes through the blade -
1. Set the blade so that the tooth gullet is just a little bit higher than the the thickness of the plastic you are cutting. This serves two purposes - first the blade will tend to cut through and not 'chop' down on the plastic and second there is little blade above the plastic for item 2 below.
2. I have shop built push sticks of different lengths (3/4 inch plywood or pine with a 1/8 thick stop on the bottom to grab the end of the piece I am cutting. The push sticks are designed so that the blade is buried inside of them giving support on both sides of the blade and saving my fingers. Inexpensive wood is used to make the push sticks since they get 'chewed' up fairly quickly by the blade due to the different widths of stock that need to be cut.
3. For short pieces or small pieces I have a 'small parts' tablesaw sled I use which makes cutting these easy and safe.
Cutting wide strips is easier since you can apply downward pressure with your hands (if enough room) or a finger board as the plastic passes by the blade. If I have ample room on the fence side I will use my hands. If I feel uncomfortable I will use a finger board.
Joe
