1. Shearing
A “Guillotine” power shear can be used for straight-line cuts. Easy, reasonably clean cuts can be obtained for thicknesses of up to 3 mm (1/8 in.). Beyond this, the material tends to draw, leaving uneven, stretched edge finish.
We recommend cutting only one single sheet at a time.
The shearing blade should be very sharp, with a single bevel of a 45o angle or less, or a hollow ground one of approximately 30°. Recommended clearance between blade and anvil (bed) should be kept to very close tolerances as appear in the table below:

Table 13: Recommended gap between blade and anvil (bed) (5% of the sheet thickness)

The cut appearance may be adequate and suitable for many applications, but will not be similar in quality to the cut with a circular saw. Rough-finished cut edges can be improved by sanding, same as recommended for the other types of sawing.
As there are many power shears manufacturers it is recommended that before making a purchase, one should investigate the intended instrument capability, and confer with the manufacturer in reference to plastic sheets cutting.
For accurate cutting it is recommended to cut only single sheets. Cutting more than one sheet at a time may cause a break in one of the sheets, and / or yielding inaccurately sized parts. Blade maintenance is an important factor in achieving a quality cut.

Nevertheless, if you decide to cut a few sheets together and breakage occurs, please check the following
items:
1. Try cutting fewer sheets at a time.
2. Check blade condition: sharpness, uniformity and alignment.
3. Change the gap between the blade and the bed to a more suitable one.
Our experience shows that cutting quality can be checked in advance by a simple trial cutting of an 80g-paper sheet:
Acceptable – if the paper is cut cleanly, without tearing or crumpling.
Unacceptable – if cut results in the paper torn and crumpled.

2. Punching
A technique usually used for cutting multiple holes and apertures (circular shaped or rounded) in thin or medium thickness PALSUN sheets quickly and uniformly. It uses a mechanical press with a quick moving, limited depth cutting male punch and static female anvil (base). Recommended for a maximal thickness up to 3mm (1/8 in.).

Punch cutting edges should be hollow-ground and very sharp for good quality cuts. Due to the tendency of edge drawing when punching, resulting in “blown-in” aperture edges, this “hole shrinkage” should be taken into consideration and provided for in cases of critically close tolerances. Exemplary values are about 0.2 mm (0.008 in.) shrinkage for a 12 mm (0.47 in.) hole, or 0.1 mm (0.004 in.) for a 6 mm (0.24 in.) hole, for a 3 mm (0.12 in.) thick sheet.

3. Die Cutting
A technique stemming from punching, it is generally used for cutting out apertures or blanks in the sheet, in almost any size or shape. The technique uses thin gauge rule type blades. For non-straight cuts asymmetric double beveled blades of 1mm (0.04 in.) thickness, are used, suitable for thicknesses of up to 1.5 mm (0.06 in.).
For thicknesses above that, a 2mm (0.08 in.) thick, double beveled, double-angled symmetric blades are recommended. For straight edged cutting, a 1 mm (0.04 in.) thick, single bevel blade of 30° angle or less is recommended.
The backing for these blades is a pad made of nylon or high-density polyethylene. Precise alignment of blades and pad is a must for obtaining satisfactory cuts.
The blades are steel rules - thin steel ribbons with one sharpened edge, 0.8 to 2.5 mm (0.03 to 0.1 in.) thick, 12-15 mm (0.5 in.) wide. They are generally mounted in slots cut into wood blocks and are relatively inexpensive. The steel rule must be sharpened or replaced fairly often.
Figure 11 depicts two steel rule designs that work equally well in sheet gauges up to 2.5 mm (0.1 in.). Hardness may vary from 45 to 55 Rockwell C and depends on the degree of bending required in fabrication.

Die cutting presses are to be adjusted to cut completely through the sheet with a stroke stopping just before damaging the cutting rule.
A make-ready procedure is used to shim the die areas that must be shimmed, to ensure that it cuts through the sheet uniformly. The press should have a softer steel cutting plate (30-35 Rockwell C) to prevent contact with the press bed.
The cutting surface is normally a 0.5 mm to 3.2 mm (0.02-0.13 in.) thick steel plate. Test the die to ensure full, uniform cut through the sheet, by alternating with shimming of rule areas until a satisfactory cut is obtained.
Cut in the same place each time and keep the cutting dies as sharp as possible.

    

A A die press must have adequate power to achieve the desired cut.

4. Shearing & Punching Tips
a. Best results from these techniques are obtained by cutting a single sheet at a time. We recommend this. Cutting a batch of sheets may result in breakage and/or imprecise dimensions. Nevertheless, if one is committed to such a procedure, We recommend a few trial runs with small samples, and consultation with the shearing machine manufacturer.
b. A good indication for a quality cut is a trial cut of a regular 80 g paper page: If the outcome is a clean, straight cut, the actual result will be acceptable. If the cut paper is jagged, torn or crumpled- sharpen the blade and/or adjus the clearance and alignment.
c. We recommend that sanding and polishing of the cut edges should be used as a regular practice. Never leave on rough or jagged edged apertures as that may lead on to crazing and imminent failure.