Which type of cutting action is best? Chop or slice?
This is possibly the most difficult selection concerning knife blades; whether the best cutting action should be chopping or slicing.
Chopping directly through the extrusion with a straight edged blade creates the least amount of product hold-up time. This means the least interruption to the extrudate as it is continuously pushed forward by the caterpillar infeeder belt. This will improve the squareness of the cut.
Slicing through the product with a curved blade tends to give a better-cut quality but can considerably increase product interruption time.
In reality, using a static cutter, such as the Servo-Torq®, with a continuously moving product, demands a compromise between slicing angle and blade hold-up time.
The type of blade you should use will obviously depend upon your application. However, in our experience, approximately 25% of products can be cut adequately with a straight edged ‘chopping' blade. These tend to be smaller, flexible extrusions, such as medical & automotive tubing. These types of product cut very well with our standard RAZOR or CHIP blades.
The remaining 75% of products are best served with a curved ‘slicing’ blade. Typical products would be larger, heavier wall, tubes, pipes or profiles which need a more resilient blade. Also profiles with an intricate shape where a chopping action might cause material distortion or collapse.
We can offer you a selection of straight or curved blades (see download section below), or produce a custom blade design especially for your product.
Additional advice is always available from GILLARD. Experienced staff would be pleased to share their knowledge, to help you achieve the best possible results from your Servo-Torq® cutter system.
Please email our Technical Team for more advice: firstname.lastname@example.org.