Paper
Trimmer Knives - Cutter Knife Cutting Tips
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| Tennessee Saw &
Knife's paper knives are used throughout the industry
to cut a wide variety of materials. Although our
knives are supplied with a standard bevel suitable
for most general cutting, further improvements in
cut quality and knife life may be obtained by slight
modification of the bevel angle to suit specific
materials. Below are listed various materials and
suggested bevels to assist you in obtaining maximum
benefit from our knives. |
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Tips for Cutting Soft "Fluffy"
Materials
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| Soft
Cutting Materials |
Soft materials, such
as flimsy, stencil duplicator paper tissue and blotting
paper have characteristics, which can be very troublesome
when cutting the material.
1. Bad sliding properties
2. High air volume in pile
3. The material softness itself |
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| Bad
Sliding Properties |
Owing to its bad sliding
properties the material is jammed in front of the
knife, blocking it and creating excessive cutting
pressure.
It should be observed that such materials should
always be placed on the left-hand side of the machine
table when the knife moves from left to right. Otherwise,
when placing the material on the right-hand side
gauge would impair the material flow even more. |
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| Air
Volume and Softness |
The high air volume
and material softness causes the knife to pull the
material from beneath the clamp during the cutting
cycle. This leads to an "over cut". |
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To prevent this a narrow cutting
angle and/or increased pressure time is required.
Further improvement can be achieved by giving
the knife bevel a particularly smooth surface
finish. As shown in the sketches above, a blunt
knife exerts a much stronger pulling force than
a sharp one.
The clamp as well as the clamping pressure also
play an important part -
Soft Material
- use high clamping pressure
Hard Material - use low
clamping pressure
If high pressure is exerted on
soft material the clamp rake will cause deformation
of the material cut. This disadvantage can be
overcome to a great extent by applying a false
clamp plate. In particularly difficult cases a
cardboard strip, 4 to 5 mm (.157" to .197") thick,
can be glued under the false clamp plate. This
strip should be smoothly tapered towards the rear.
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