Abstract
Keywords - instrument panel, mass-reduction, low-cost, CO2emissions, all-olefin
The reduction of CO2 emissions is an important issue in automobile development. In order to reduce CO2 emissions, we have developed new manufacturing methods and materials for a soft instrument panel. The following is a report on our achievement of the reduction of CO2 emissions in driving by reducing the mass of the part and in manufacturing.
The developed part is formed with the PP base and the laminated sheet composed of the TPO skin, PP foam and Olefinic adhesive.
The reduction in mass is achieved by developing a low-density all-olefin laminated sheet. This material still gives the instrument panel a soft feel and can be formed into various shapes and designs.
By reducing the number of manufacturing processes, the reduction of CO2 emissions in manufacturing has been realized.
In order to reduce the number of manufacturing processes we have developed the following three items:
First, we developed a pre-coating adhesive for the laminated sheet to apply on its backside. This material is applied prior to the laminated sheet manufacturing and turns adhesive with the application of heat in the laminated sheet forming process. In addition, it does not require pre-treatment of PP base in advance of adhering the laminated sheet as it is made of the Olefinic material which is the same as in the PP base.
Second, we developed the manufacturing method which combines the vacuum forming and pressing for the laminated sheet. By heating the laminated sheet and combining these two processes, it is possible to form the laminated sheet and adhere it onto the PP base at the same time in one process, which simplifies the laminated sheet forming.
Third, we have developed the material that enables us to eliminate the process of tear-line application on the skin in the air bag area. This newly developed material is designed that the stress concentrates at the skin in the tear area of the PP base. The air bag expansion performance is ensured without the tear-line on the backside of the skin.
By adopting these manufacturing method and materials above for the soft instrument panel, we have succeeded in reducing the mass of the instrument panel by 30% and CO2 emissions during production by 70%, compared with the conventional products. Also, by reducing the number of manufacturing processes, the reduction of the costs is realized by 20%.