Maintaining a Quality Stamp
by
David Mackey
F&S
Engraving, Inc.
In today’s economy, it is important to
maintain your equipment to achieve maximum performance and longevity. Downtime cuts
into profits and decreases customer satisfaction. You can take preventative
measures to increase the life of your stamps, thus maintaining your product
quality and customer satisfaction.
Once the characters of your stamp get
dirty, the quality and consistency of your product is greatly affected. The die can retain fluids, dirt, and scale
left behind during the manufacturing process.
It’s imperative that there is a procedure established to maintain the
dies and keep them clean. The best way
to clean them is with a light-duty, brass brush. The frequency of cleaning
should be determined by your shop manager, based on your output quantities and
the end product being produced.
The quality of the impression produced
by your stamps is affected when the tooling in which they are retained becomes
worn. A properly aligned die, when
rolled or impact stamped, will create a perfect
result. If it comes down at an angle or shifts sideways, it will cause quality
problems. Regular inspections of the
tooling are imperative to ensure that there is no movement. Likewise, the
positioning of the tooling and fixture that is being marked must also be inspected to ensure that there is no product movement.
Most shops do not store their stamps
properly. Stamp surfaces are very
delicate. It’s to the owner’s advantage
to contain the dies individually to avoid any damage. Keep stamps in a storage system that provides
individual isolation in a temperature-controlled environment.
Pressure plays a key role in the
longevity of your stamp. Dies must roll
and stamp at a constant and proper speed to ensure a consistent product. Hydraulic pressure can cause characters to
fail prematurely. In addition to a poor
impression and product results, stamps may fail rapidly if excessive pressure
or force is exerted upon the dies, resulting from foreign matter trapped in
characters. Equipment maintenance and
knowledge of correct pressure will prevent premature failure. Educating your staff on proper maintenance
protocol will go a long way in ensuring prolonged stamp life.
To learn the best course of action to
take with your production line or how to implement an effective maintenance
program, consult a stamp and marking die expert.
Creating a Quality
Stamp
by David Mackey
F&S Engraving, Inc.
There are many factors that
contribute to producing a quality, long-lasting stamp. Having your stamp
supplier select the
best materials and processes will produce a product that you can utilize
throughout your manufacturing process in a cost-effective and efficient manner.
Your
stamp supplier must be vigilant in the selection of the raw materials used for
the stamp, ensuring the properties meet the standards you require. Different
end-products and manufacturing processes require different materials to hold up
to the marking process and longevity you expect from your purchase. For instance, roll marking stamps will
require a different alloy composition and different character geometry than
impact marking stamps.
A
poor finish on your stamp is a recipe for disaster. This can result from the
methodology used by your stamp supplier and their performance during the
engraving process. This process must be
carefully monitored. It really comes
down to the skill of the technician. The
most common process used for producing stamps is Electrical Discharge Machining
(EDM). It’s important that the supplier
is vigilant in maintaining a high quality surface finish. If you’re not diligent with EDM, the stamp
surface is irregular resulting in strong points and weak points throughout the stamp, which
results in more stress and premature failure.
Additional engraving processes such as laser engraving and other high
speed machining can result in the same irregularities.
Stamp
life can be improved by having your supplier utilize a closely controlled
in-house heat treating process. Recent
studies have confirmed that the use of a cryogenic treatment following the heat
treating process can substantially increase the life of your marking dies.
During this process, the die is treated with liquid nitrogen after heating to
allow the alloys to normalize, correct surface imperfections, and rid the area
of residue left behind in manufacturing. This process produces an increase in
wear resistance and stamping performance.
The
geometry of the stamp is an engineered solution essential to the longevity of
your marking dies. For instance,
characters used for impact marking would have a different geometry than the
same characters used for rotary marking.
Geometry refers to the shape and depth of the characters. Up close, they look like pyramids and your
application determines the shape of the stamp.
Rolling dies have flatter characters while impact dies are shaped like
an Egyptian pyramid.
To
learn what the optimum materials, composition, finish, and geometry are for
your stamp to perform its best in your manufacturing process, consult a stamp
and marking die expert before making decisions that have long-term effects on
your business.