Screen Printing - April/May 2017 - 28
ADVANCES IN FILM
Automotive interiors are a ready market for new molding
processes that combine decorative and functional prints.
Photo © Chesky / shutterstock.com
ilm insert molding (FIM) can be an excellent method for
integrating printed graphics into plastic parts. Such parts are
used in many applications, including automotive, consumer
electronics, industrial, white goods, and medical devices. The
greatest benefit of FIM, however, may lie in using it as a
platform for integrating printed electronics and decorative
printing into a single molded part that is both functional and
durable. Manufacturers are beginning to incorporate circuitry
created with conductive inks and encapsulate discrete
semiconductor chips within molded, decorated parts.
The automotive industry represents an excellent opportunity for this technology, as auto makers seek to differentiate
themselves with distinctive dashboard designs and displays that
include both decorative and functional features. Auto makers
are reaching out to companies in the FIM supply chain who can
help them incorporate advanced technologies into their vehicles.
FIM is compatible with a wide variety of coatings and inks. Designers have complete freedom in color and design for decoration,
since images are screen printed onto a flat film before the product
is formed into a 3D shape. It is possible to include special effects
such as metallic, mirror, or high-gloss black or white finishes.
In contrast, standard injection-molded 3D plastic parts are
formed from a single color of resin. They are typically pad
printed for decoration, or sometimes labeled using screen or
inkjet printing if the surface is sufficiently flat. But printed images on the surface of the part tend to wear off after repeated
3D printing may get the hype, but manufacturers looking to streamline decorative
and functional printing steps have another
option to consider that is much more
suited to high-volume production.
use. FIM creates a durable image that cannot be rubbed off.
The process can incorporate coatings with various desirable
properties, including hardness, chemical resistance, and light
reflection (or the lack thereof).
The automotive industry is especially demanding in its desire for coatings that are durable, scratch-resistant, and fingerprint-resistant with embedded graphics that will last the lifetime
of the vehicle. Different surfaces - center consoles, dashboards,
steering wheels, and interactive display screens - need different
types of coatings and finishes. FIM provides a solution that can
address all these needs, but it is important to optimize materials
and process parameters to get the best results.
PROCESSES AND MATERIALS FOR FIM
FIM is a multistep process that includes, at its core, screen
printing, forming, and molding steps. Additional optional steps
may be needed depending on product design and selected
materials. Figure 1 shows a possible process flow.
Films, inks, and resins need to be chosen carefully to meet
the demands of the end application. Such demands include
the geometry of the design, the environment in which it will be
used, and any relevant regulations. In the case of the automotive industry, materials and processes must meet stringent
specifications that may vary by auto manufacturer. Medical
devices come with their own set of regulations depending on
the setting in which they will be used.