One tool, multiple surface finishes

To achieve this, careful coordination is required in the project phase as well as adjustments in the tool design phase in order to satisfy the requirements for a variety of surface finishes on a single component. This additional effort brings added value, because with careful advanced planning, the range of surfaces can be expanded considerably with a simple investment in moulding tools.

The Solingen-based automotive supplier BIA makes use of this principle in order to be able to offer its customers as varied a spectrum of surfaces as possible. Thus for example, plateable raw parts, which are usually made of ABS or a PC / ABS blend, can also be painted as an alternative to chrome plating. A three-layer chrome-effect paint system is a variant that BIA can offer from its in-house production. Further optical options are also conceivable and feasible. For example, BIA can also paint components in both matt and high-gloss black. Given the broad colour spectrum in the paint sector, the variety of colours here is almost limitless. As with the BIA Night Design technology, combinations with lasered structures and symbols are also achievable for paint e.g., for translucent areas.

Depending on the requirement profile, the same moulding tool can also be used to inject components with coloured granules. This process, known as mould-in-colour, is one of the most tried and tested and simplest methods of manufacturing monochrome through-pigmented raw parts. Although this technology, or components produced on this basis find limited use in the automotive sector as the design creativity is limited, in cases where it can be used, this alternative can offer an attractive solution, since no further processing steps are necessary.

In addition to all this, chrome plated surfaces, a proven technology, also offer a wide range of design options, not only by changing the degree of gloss and tonality. In particular, the development and optimization of Chrome(III) surface finishes in recent years has also opened up perspectives for colour variations. Chrome(III)-based surface finishes can be used to create both the familiar cold-bluish surfaces and warmer, yellowish tones. In addition, at the beginning of 2021, a new electrolyte which produces very dark, anthracite colours, was put into operation at the main plant in Solingen. The first production orders have already been received.

Finally, the subject of back injection moulding should be mentioned. In addition to the well-known decorative foils which are back-injected with ABS / PC or PC, BIA has also co-developed a foil for decoration that is insensitive and chemically resistant to the electroplating process, can be back-moulded with an electroplatable plastic substrate and at the same time meets the test and field requirements of the automotive industry. In this way, a highly selective combination of individual foil decorations and chrome-plating can be achieved on a single component without additional assembly work.

BIA also has a plateable foil in its range. A special feature of the “galvano-foil” co-developed by BIA is its high transmission capacity, which enables improved transmission values and improved day / night contrasts to be achieved than with conventional Night Design materials. This foil variant is best suited for ambient light applications and functional integration.

Thanks to all these manufacturing options, BIA now offers an extensive portfolio of surface designs to automobile manufacturers. All design options for the components can be based on the same tool shape. Not every component geometry is equally suitable for all processes so that production flexibility should be considered prior to tool design. However, if these aspects are evaluated in advance and included in the design planning, BIA customers have a high degree of design freedom with a simple tool investment.