| The major components of the instrument panel in the Chevrolet Colorado and GMC Canyon compact pick-up trucks are moulded of Sequel 2380 thermoplastic polyolefin (TPO). This new material has been developed by Solvay Engineered Polymers specifically for this type of application, and it is approved to the pertinent specifications at each of the North American Big Three carmakers.
The instrument panel (IP) cover, which is the major visible surface of the IP, is moulded by Intier Automotive. The glovebox door assembly and the driver’s knee bolster are moulded for Intier by NYX. Intier assembles and sequences the instrument panel for just-in-time shipment to the General Motors assembly plant that builds the two trucks in Shreveport , Louisiana .
The instrument panel in the Chevrolet Colorado and GMC Canyon compact pick-up trucks is the first all-TPO design by Intier Automotive Interiors. It is also the first such application by General Motors in a North American vehicle. |
|
 |
This all-TPO panel in the Colorado/Canyon is the first of its kind for GM in North America although it has similar applications in production in Europe. Traditionally, GM instrument panels have been built using painted PC/ABS parts or vinyl skin-and-foam construction. The unpainted TPO panel is a lower cost alternative to both of these techniques, since it is moulded with a grained Class A finish, eliminating the cost of secondary finishing operations.
For the IP cover, glovebox door, and knee bolster, Sequel 2380 TPO is delivered as a natural, and the parts are integrally coloured at the press using a colour concentrate supplied by PolyOne Corporation of Avon Lake , Ohio . The two colours in the programme − medium dark pewter and very dark pewter − are achieved at concentrate letdown ratios of 50:1, a significant saving over typical ratios of 25:1.
The gloss level of the unpainted Colorado/Canyon instrument panel is measured at a level of four by industry standards, and this level can be maintained in high-volume production.
“You can really see the grain on the surface because you’re not filling it full of paint,” points out Gary Kulhanek, the senior account manager for this application at Solvay Engineered Polymers. “The result is a more leather-like appearance and a look that has been described as ‘frugally elegant’ in an entry-level vehicle.” He adds that the low-gloss surface also helps to eliminate reflections that can be a distraction to a driver.
Sequel 2380 engineered polyolefin was selected for use in these parts based on several of its performance properties. Perhaps most important for such an application, the material meets the impact requirements of FMVSS (Federal Motor Vehicle Safety Standard) 201 and 208.
The new TPO demonstrates excellent heat resistance at 110°C, the benchmark temperature for automotive interior applications. Dimensional stability across a broad temperature range is critical in a large part that is intended for snap-fit assembly. The Colorado/Canyon instrument panel is designed to achieve very tight gaps of 1 mm between the cover and adjacent trim parts such as the knee bolster.
Sequel 2380 polyolefin also exhibits extraordinary scratch resistance for a TPO. The new material meets a minimum requirement of 15 newtons in a re-engineered scratch test that is becoming a standard among automotive OEMs. Application of this level of force causes no visible whitening in the Sequel 2380 surface.
For all its structural stiffness and scratch resistance, this instrument panel has a softer feel than one moulded in PC/ABS. The Sequel 2380 material is inherently resistant to the buzz, squeak, and rattle that can be produced by traditional interior materials. The elimination of acoustic materials or stand-off bumpers results in significant cost saving.
The use of Sequel 2380 in an all-TPO instrument panel system simplifies processing. The moulder is able to use gravimetric blenders for colour mixing at the press, achieving uniformly consistent appearance without streaking. The effects of in-plant damage are minimised by using a scratch-resistant TPO. While a tear in a foam-and-skin instrument panel would mean a fully scrapped part, Sequel 2380 is completely recyclable.
|
|
|
