Plastics News Europe - November/December 2019 - 18

decoration & surface treatment

autonomous driving, advanced
interfaces and the circular economy
Stunning optical effects and advanced
human-machine interfaces with
decorated plastics were on show
at the K 2019 plastics industry fair.
David Vink looks at some of them,
and how decorated plastic parts can
contribute to the circular economy

t the K 2019 stand of decorative foil producer Leonhard
Kurz, the highlight was the
"world premiere" of an IMD PUR process for in-mould decoration with
preformed silk-screen decorative foil
printed on both sides, followed by
post-moulding flooding with polyurethane in thickness between 0.3mm
and 15mm over the foil-decorated
surface. The entire process took place
within the clamping unit in the production cell on the Kurz stand.
The PUR coating creates an optical
impression of depth, a high-gloss surface with high stone-impact resistance and self-healing after scratching, with no impairment to underlying
decoration.
According to Kurz, its IMD PUR
process differs significantly from other PU flooding processes. Describing
it as a "technological quantum leap",
the company noted that it is the first
time such a one-step process had
been shown with the use of the IMD
in-mould decoration process otherwise known as film insert moulding
(FIM). While the demonstration used
PMD (Print Mold Design) placement
of single sheets in the mould, Kurz
said roll-to-roll IMD technology can
also be used as a basis for IMD PUR.
ClearMelt technology is another
example of a PU flooding technique,
in this case developed by injection
moulding machinery producer Engel.
The technique was shown for the first
time at an Engel open house event in

Bird's eye view of the IMD PUR production cell
at K 2019

IMD PUR process layers, from top to bottom, polyurethane, film
décor, polycarbonate

Schwertberg, Austria in 2009. Hennecke, which supplied the PU equipment then as a ClearRIM wood and
plastics coating system was also involved with the IMD PUR demonstration on the Kurz K 2019 stand, but
with Streamline Mk 2 equipment this
time round.

Crystalline optics
There was also a difference in the material base selected for the IMD PUR
demonstration by Kurz at K 2019,
with clear Sabic polycarbonate used
as the base moulding material, instead of the opaque PC/ABS blend
used at the first ClearMelt demonstration back in 2009. Use of a transparent PC made a marked contribution to the "ground-breaking
crystalline-like design" optics of what
was being touted as a "futuristic
front panel for autonomous driving".
The production and PUR flooding
of injection moulded parts in a single
machine pass is a known process. The
novelty, however, is in combining this
with the IMD process, creating an optical effect that may be considered to
be the most innovative and impressive aspect of the Kurz demonstration. The specific effect on show was
developed by Burg Design, which has
been involved in ClearMelt projects
with Engel since 2009.
The panels were produced at K on
a 246-tonnes hydraulic Engel Duo
2460/900 injection moulding machine. "Creative moulding solutions"
mouldmaker Schöfer, located near
Engel in Schwertberg, supplied the
mould tool for both the Kurz K 2019
demonstration and the 2009 ClearMelt demonstration, among other
occasions. Its activities became integrated within Leonhard Kurz in 2018,

when Kurz became one of Schöfer's
shareholders.
Aside from the "futuristic" front
panel at the K fair, Kurz says it sees
potential for crystalline optics derived
from the IMD PUR process in autonomous driving front "grilles", as an
example of how the sophisticated
lighting design concepts common in
automotive interiors are now also
moving into exteriors.
Autonomous vehicles require materials permitting both light detection
and ranging (LiDAR) and radar beams
to pass through to sensors contained
within solid front panels. These can
also have visual appeal, such as a gradient from black to blue, or a "metallic-like" reflective colour alternating
with a saturated green, but which
becomes deep blue with changes in
incident light. Backlighting further
emphasizes these effects by making
the internal structure more visible
through the PU coating.

Recycling / sustainability
At Fakuma 2018 and again at K
2019, Engel demonstrated the Kurz
IMD Varioform process with its easy
change-over from one roll-fed foil to
another in order to apply different decors. As before, it partnered with
Isosport Verbundbauteile in this Engel
"FoilMelt" process, involving roll-toroll foil die-cutting & thermoforming
and back injection in the mould as a
single-step process. New, however,
was the use of Trexel's MuCell microcellular physical foaming process and
Riablend recycled PC/ABS from Ria
Polymers.
Engel also mechanically recycled
(ground) the parts for 10% use together with virgin plastic in the production of new ones. Kurz described

november/december 2019

Plastics News Europe - November/December 2019

Table of Contents for the Digital Edition of Plastics News Europe - November/December 2019