Busch have been manufacturing ram punches
for almost 40 years originally for the label sector. They
are now widely used right across the printing and packaging industries.
Busch ram punches work by pushing the material through the
die to create the desired shape whether it be for food
or drink labels, telephone cards, garment tags or promotional
products or more.
The Busch concept of punching has long been recognised for
its precision and productivity. There are very few outer contour
shapes which cannot be ram punched.
How it works
Square-cut stacks of printed material are placed in the feed
tray, between the die and the ram.
When the ram is activated it pushes the stack of material through
the die onto the delivery tray the size of the finished
article will determine the model of punch required up to
a maximum of 380x330mm.
The waste margin (23mm.) is removed with the aid of a
waste slitter blade, and falls down through the machine, to be
removed into a waste container by the accompanying Busch waste
conveyor.
The material can be zero-punched, where the whole stack is
punched, or alternatively a small quantity of material can be
left in front of the die after each stroke. A soft backing plate
on the ram protects the edge of the die when zero-punching. Those
models with light barriers work by the stroke being activated
automatically when the operator removes his/her hand from the
feeding tray. The operator determines the working speed of the
machine.
Make-ready
An aluminium die-positioning block is supplied as standard, enabling
the operator to set up each job off-line, safely and accurately.
The die is positioned on the block, with fine adjustments made
on the machine once the die has been fixed by the holding arms.
Materials
A Busch ram punch would be used to punch square-cut material,
whether it be paper, board, plastic or polypropylene. It can also
punch stitched, folded booklets on 3 sides
so that Busch punches are of increasing interest to print finishers.
Attractively-shaped promotional products, direct mail items
and Post-It type notes can also be produced on a ram punch.
Most types of materials can be made to work.
Tolerances and
counter-pressure
A counter-pressure device would be used where tight tolerances
were required or where the material to be punched was unstable
- especially for punching polypropylene for in-mould labels (IML).
The counter-pressure device can be retro-fitted and wheels
up to the punch in place of the delivery tray, which in turn is
wheeled away on a trolley. The die is manufactured especially
for counter-pressure punching, with a matrix of plastic/nylon
inside the die.
The counter-pressure system is connected to an air supply,
so that when the hydraulic pressure of the ram pushes the material
through the die, the material is held vertical by the matrix
thereby stabilising the pile and ensuring that no movement occurs.
When the ram reaches the end of its stroke and retracts, the material
is pushed back through the die by the counter-pressure system
(pneumatically) finishing back in the feed tray. This reduces
throughput of the punch by half, since the material is fed and
removed from the same place the delivery tray having been
removed to fit the counter-pressure unit.