What advantages does injection moulding technology have over the laminating
process?
The major advantage of injection moulded smart cards, compared with
the traditional laminating process, is the cost per card. But how can
this price benefit be achieved?
The most noticeable difference is that, as opposed to normal production
methods, the basic bodies can be produced in a single-step operation.
The material needed is also kept to a minimum because there is no waste.
Compared with laminating, at a production speed of up to 1,000 card
bodies per hour, this technique reduces the consumption of plastic granules
by up to 70 percent.
Hot channel mould eliminates need for sprues
A recent innovation in production technology is the hot-channel mould.
As used in Arburg's SMARTLINER 800, the hot channel allows moulding
without the need for sprues. As a result, the downstream use of plastic
mills for sprue treatment is not necessary, which not only keeps the
material in better condition, but also saves time and expense. The modula-rity
of the mould remains unchanged, as does the inherent ability to change
card inserts quickly. The same is true of adapting the inserts for different
chip designs.
Reconfiguring the mould for other types of cards - made from a different
material or to produce basic bodies with space for a chip - can be achieved
in a matter of minutes by simply changing the mould insert. The basic
mould remains in place. There is no interruption to the moderation during
the change of card mould because the mould base and mould inserts are
supplied by two separate cooling circuits.
As the cards have to remain within very strict tolerances, and the
space for the chip is particularly difficult to achieve due to the wall
thickness of the remaining material, high reproducibility (DIN 7816)
is paramount for manufacturing such parts. Injection moulding ensures
this degree of quality thanks to absolute dimensional stability of the
card and the chip insert. Tolerances of plus/minus 0.12 millimeters
along the length, plus/minus 0.05 millimeters width and plus/minus 0.02
millimeters in thickness, as well as the parallelism of length and width
- set as plus/minus 0.05 millimeters - can be constantly maintained.
Fully automated production
Parallel moving actions ensure very short removal times. A conveyor
belt, which serves as both a cooling stretch and as a feeder for the
stacking magazines, picks up the smart cards in order. Placement occurs
within the guarding, and the belt carries the cards out through a gap
towards the magazine.
Six standard magazines, each with space for 500 cards, can be held
by the stacking device mounted at the end of the conveyor belt. This
actually extends the disposal periods, enabling fully automated manufacture.
Having been filled, the magazines are exchanged automatically in a rotating
movement and can be transported to a downstream processing lane. They
can also be removed, individually if necessary, for random sample checks
without stopping production.
Fully automated manufacturing of the cards is a further advantage,
allowing not only production with fewer staff on a 3-shift, 24 hour
rotation, but for further processing to be carried out automatically
from the stacking device - for example in a system for printing or adding
the chips. Since various different plastics can also be used in the
injection moulding process, e.g. ABS, PC/ABS, PCTG and PC, the material
that is best suited to individual production requirements can be used
in each case. This provides a further criterion for an economical treatment
process.
With an output of up to 1,000 card blanks per hour for a single cavity
mould, the production cell is suitable as a base specification for quick
and flexible series production of cards. After injection moulding, the
basic bodies only require printing and to have a chip inserted if needed,
before they are complete.
Central management of the machine cycle
Production cell and peripherals are programmed centrally using the
machine's SELOGICA operating display. The multitude of integrated functions
such as disk management, graphic display of different process parameters,
documentation possibilities or universal peripheral integration make
operation of the whole system trouble-free and safe. Even during the
injection process, all qualitative machine parameters can already be
monitored using clear graphs. Any changes in production can be detected
and corrected almost immediately.
Summary
Injection moulding of smart cards, already cheaper than the traditional
laminating process, becomes even more flexible with the introduction
of this new mould technology. Not only can the modular mould inserts
be changed within minutes for quick production changeover, hot-channel
technology now makes sprue-free, no-waste production possible. As a
result there is no need to regranulate sprues, saving a further production
stage, leading to simpler overall manufacture and a saving in time and
costs. Up to 1,000 basic smart card bodies in various designs can be
produced fully automatically and maintaining the same high quality levels.
Whereas the laminating process has to be carried out in several stages,
injection moulding makes do with just one.
For more information, contact Arburg GmbH, Lossburg, Germany, at tel:
+49 7446 33 0; fax: +49 7446 33 3365; email: contact@arburg.com; website:
www.arburg.com.