Adhesives Increase Productivity for Lightweight ‘Zbee’ Electric Vehicle

5th December 2013

The Zbee three-wheeler is an ultra-light, energy efficient electric vehicle. It was designed by Clean Motion AB, located in Lerum Sweden with its manufacturing site in Trollhättan. The Zbee’s final design and build specifications included the use of fibre reinforced plastic (FRP) body panels in combination with two Scott Bader structural adhesives: Crestabond® M1-05 and Crestomer® Advantage 30, which were selected as they provide a winning combination of light weight adhesive jointing, build quality and productivity.

The Zbee electric vehicle is very light and compact with dimensions of only 240cm long by 120cm wide and 150cm high. Its ultra-light curb weight of just 230kg has been achieved by the Clean Motion design team’s rigorous adoption of their “Lean Engineering” development philosophy, reinventing every part of the product through multifunctional design, simplification and a light weight approach to all aspects from materials selection to methods of assembly. The overall design makes it agile in traffic and easy to park; up to four Zbees can fit in a typical single parking space. Being powered by a 4KW electric motor, it has zero emissions and no engine noise. Clean Motion developed the Zbee as an ideal compact electric city vehicle for short distance urban transportation for up to three people. It has a maximum speed of 50km/h and a range of 45 km (~20 miles) on a single charge; the battery recharges in three hours.


The Zbee Electric Vehicle


On the build quality side, Crestabond M1-05 and Crestomer Advantage 30 have been specified by Clean Motion as they are proven structural adhesives with reliable long term bond strength performance combined with toughness and durability due to their high elongation and impact strength properties. The Clean Motion design team were so confident in the bond joint performance of both Scott Bader structural adhesives that only a bonded joint, with no mechanical fixings, was specified for joining the FRP body sections together to minimise weight. According to Scott Bader’s test data, the FRP substrate of a bonded Zbee body panel will always fail before the adhesive joint. All Zbee vehicles are assembled, tested and inspected in Trollhättan by Clean Motion AB.

From the start of the production phase in 2011, both Crestabond M1-05 and Crestomer Advantage 30 have been used for the Zbee fibreglass body panels by HJ Kompositmontering AB, the approved local FRP body parts subcontractor in Sweden for Clean Motion. Crestabond M1-05, which is a grey coloured adhesive, is used to bond FRP body sections together, and also for bonding aluminium profiles located in the boot of the car. High productivity is achieved on the shop floor due to Crestabond being a primer- less adhesive, thus needing little if any surface preparation, combined with its rapid cure and subsequent short fixture time of 12-18 minutes. Crestomer Advantage 30, which is coloured white, is used on all the visible FRP-FRP joints in order to provide a combination of a pleasing aesthetic finish to the Zbee’s GRP body with reliable build quality. Both manual and pneumatic handguns are used by HJ Kompositmontering AB during production of the FRP body parts, depending on the specific bonding application.

Looking forwards optimistically, to cost effectively ramp up production to keep pace with Clean Motion’s rapidly growing order book, HJ Kompositmontering AB is considering switching to using an automated 10:1 dispensing machine, using either 20 litre pails or 200 litre drums of Crestabond M1-05 and Crestomer Advantage 30 adhesives. Clean Motion is expecting to see a significant increase in orders in 2014, especially from Asia, with a forecast for over 350 Zbees, with continued growth in the coming years.