For public transportation companies, they need to transport passengers to destinations in a comfortable and safe manner. At the same time, they want the operating costs associated with fuel consumption and maintenance to be as low as possible.
VDL Bus & Coach (hereinafter referred to as 'VDL') has extensive experience in manufacturing high-quality passenger cars with a modern look. Recently, the company launched a new Citea series bus, which uses multiple lightweight vehicles. Composite parts, these parts are made of a foamed resin formulation.
Büfa Composite Systems (hereafter referred to as 'Büfa') uses Aliancys resin to produce and provide this foamed resin formulation.
In addition to the unique shape and great aerodynamics, these low-density composite parts also reduce the weight of the bus body, reducing fuel consumption and emissions.
Applying composite materials to bus cars, VDL has a good experience. However, for its new Citea bus, the company wants to do its best to reduce weight and increase the production efficiency of this medium-production car.
The company has been actively looking for composite materials that combine design flexibility, mechanical strength and light weight.
The formulator OMB Composites (Psáry, Czech Republic) used Büfa's specially formulated resin compound to fabricate multiple composite parts for VDL in a vacuum expansion process (VEX technology).
First open the mold, cover the surface of the mold cavity with a layer of gel coat, then apply the reinforcing material and resin. After the mold is closed, the resin begins to foam and fill the cavity.
According to the design of the components and the performance requirements of the final application, this vacuum expansion process using foamed resin (VEX technology) allows the manufacture of large components of up to 2m x 6m.
Compared to parts made using conventional resin technology, the weight can be reduced by up to 45%.
By using this technology, the molding cycle time of each component is only 3 hours, compared with the production time using hand lay-up technology is much longer.
This new technology makes the surface of the component very smooth, so that the surface coating can be applied to obtain a perfect Class A surface effect.
When the Büfa-Firestop foamed resin system is used, it is also possible to increase the performance of fire protection and prevention of smoke propagation to the typical level required by the rail vehicle industry.
In developing this special foamed resin compound, Büfa worked closely with Aliancys to fine tune the resin composition and curing time.
Aliancys is experienced in developing new resins with unique chemical properties and other properties. Together, we have optimized the resin system to bring the correct performance to the final product. 'The commercial director of Büfa's Lothar Kempf said, 'We know that the very high quality consistency of Aliancys resin helps to ensure that our customers' processes are stable and predictable, so that their part production process is very reliable.'
For the special requirements of this application, Aliancys has ordered a special o-benzene resin for the production of this foam resin compound.