Forming a selectively decorated molded resin panel

A method for forming and selectively decorating a molded resin panel 10 begins with vacuum forming an applique 15 of decorative resin material and fitting applique 15 in an injection molding cavity. Base 11 is then injection molded to applique 15, and a mask 20 is formed to fit over applique 15. A decorative coating 18 is applied over the panel regions not covered by the mask. A resin undercoating 17 is applied under decorative coating 18 which is covered with a top coating 19 of clear resin material.

BACKGROUND 
The automotive industry demands selectively decorated resin panels having 
an applique in one region and a contrasting decor in another region. Such 
panels are used on dashboards and doors but can also be used elsewhere. A 
typical panel for automotive purposes has a bright metal border and a 
contrasting region formed as a wood grain, printed pattern, simulated 
suede, or other decoration. Variations on this can include stripes, 
beadings, several contrasting regions, raised and lowered regions, 
recesses or ridges between regions, and other alternatives. The invention 
can produce a wide variety of panels of this type and is not limited to 
any particular decoration or end use. 
Automotive panels have been made previously by molding resin to form the 
basic panel shape, undercoating the panel with a clear resin providing a 
smooth and receptive surface, vacuum metallizing this surface with a 
metallized layer, covering the metal layer with a clear resin top coat, 
and then adhering a contrasting applique over the top coat in another 
region of the panel. The adhesive is expensive; and the edges of the 
applique tend to work loose, marring the appearance. 
The invention provides more efficient methods for selectively decorating 
molded resin panels and also achieves a more attractive and durable 
result. It eliminates adhesive; protects the edges of the applique; and 
for most appliques, uses the top coat protecting the metallized layer to 
also protect the applique. 
SUMMARY OF THE INVENTION 
Preferred steps of our inventive method begin with vacuum forming an 
applique of decorative resin material and fitting the applique in an 
injection molding cavity. Then we injection mold a panel to the applique 
and form a mask that fits over the applique. We apply a decorative coating 
over regions of the panel not covered by the mask, and we precede the 
decorative coating with an undercoating of resin material under the 
decorative coating and follow the decorative coating with a top coating of 
clear resin material over the decorative coating.

DETAILED DESCRIPTION 
The preferred steps of our invention produce a panel 10 that is selectively 
decorated with an applique 15 in one region 12 and a contrasting coating 
in another region 14. The applique region 12 and one or more contrasting 
regions 14 can be arranged at different levels, given different contours, 
and used for many different decorative effects. A recess 13 around 
applique region 12 between applique 15 and contrasting region 14 is useful 
as explained below, but is not required. The resulting panels can have 
many different shapes, decorations, and end uses. 
We combine applique 15 with base or support 11 in a secure fusion bond 
accomplished by molding base 11 directly to applique 15. The preferred way 
of accomplishing this is by vacuum forming an applique of decorative resin 
material and die cutting the vacuum formed applique to the desired shape 
to fit the applique in an injection molding cavity where it is held 
securely in place during injection molding. We then injection mold panel 
11 directly to the formed applique within the injection molding cavity 
that shapes base 11. Applique 15 can have many different configurations 
that cooperate with an injection molding cavity to hold applique 15 
securely in a desired position within the mold cavity during injection 
molding. 
An undercoating 17 must be applied to the panel surfaces to form a smooth 
and receptive surface for a decorative coat 18 providing a contrasting 
decoration. The decorative coat 18 is preferably sprayed or vacuum 
deposited in place and is usually formed as a metallic layer; and to 
prevent the decorative coating from encroaching on applique 15, we form a 
mask 20 and fit the mask over applique 15 before applying the decorative 
coating. 
If the material of applique 15 permits, we form undercoat 17 of clear resin 
material and apply it over the applique and over the entire front surface 
of panel 10 to help protect and secure the applique in place. This also 
eliminates the need for any mask as the undercoat is applied, and 
undercoat 17 can be spray or flow coated. 
The mask is required to prevent the spray or vacuum deposited decorative 
coat 18 from encroaching on applique 15; but if materials permit, we 
remove mask 20 after completing the decorative coating and extend the 
protective top coat 19 of clear resin over applique 15 as well as over 
decorative coat 18. If this is not possible because of incompatible 
materials, we leave the mask in place as we apply top coat 19, preferably 
by spray or flow coating. 
Mask 20 fits over and around decorative applique 15 and can have its edges 
21 conveniently disposed in recess 13 between applique 15 and contrasting 
region 14. Mask 20 protects decorative applique 15 during application of 
decorative coating 18 and can also protect applique 15 from undercoating 
17 and top coating 19 if necessary. We prefer whenever possible to form 
both undercoat 17 and top coat 19 of clear resin material and extend these 
coats over applique 15 for better protection. Although recess 13 is not 
essential to masking applique 15, it is preferred for helping to retain 
mask 20 in place and for concealing the mask line. 
Our process eliminates adhesives; provides edge security for the applique; 
and for many applique materials, allows at least one protective clear 
resin coating providing a good-looking appearance and a long and durable 
wear life.