Weight reduction to save
energy and costs has been and will continue to be a constant topic of interest in
the aircraft and automotive industries. In this regard, much has been done
toward replacement of metals especially the heaviest ones by lighter materials
still able to fulfill application demands. Nevertheless, there are other industries
where metal replacement and consequent weight reduction can also make life
easier especially when you have children. I am talking about children buggies. Most
buggies have between 8.5 kg and 10 kg. Heaviest ones may range from 12 kg to 17
kg in total weight (frame plus seat). The weight is a result of using aluminum,
which is already among the lightest metal materials (2700 kg/m3).
Furthermore, it is naturally resistant to corrosion. Is it still possible to
make buggies lighter while keeping their current application suitability? Yes,
by using high performance polymers.
Following, I will
present you a commercial example of the company Quinny that won the 2014 Red
Dot ‘Best of the Best’ Award for their 5 kg Yezz buggy [1,2]. |
| 5 kg Yezz buggy using PARA frames [1,2] |
Why is it only 5 kg heavy and still a high-end performer?
The frame of the buggy is
made of several frame parts using the high performance polymer, polyarylamide, commonly
known as PARA (or MXD6), reinforced with glass fibers (50 wt%) [3]. The weight reduction
is achieved by the reduced density of PARA, 1600 kg/m3. The high-end
performance comparable to metal is achieved by the aromatic amide macromolecular
structure of PARA, which provides this polymer with inherent high stiffness and
strength. For instances, the tensile modulus of PARA can reach values up to 23
GPa at 20°C.
In terms of processing, a
major added value of PARA is that it can be loaded up to 60%wt with glass fibers
for reinforcement purposes [4] without this to be noticed in the moulded part.
The latter will still exhibit a smooth surface with no evidence of contained glass
fibers. Such surface allows excellent painting and/or metallization. Additionally,
PARA has good flow properties at melting temperatures, which allow the moulding
of parts as thin as 0.5 mm. For these reasons, PARA can be a suitable material
when complex parts requiring high stiffness in combination with superior
surface quality are needed. Accordingly, premium automotive interiors could be
of interest.
Next time when you’re are looking for a buggy keep in mind that
there are lightweight solutions to make travelling activities with your
children easier.
Thanks for reading!
Greetings,
Herwig Juster
New to my Find Out About Plastics Blog – check out the start here section.
Literature:
[1] http://www.juniormagazine.co.uk/interiors-and-lifestyle-awards/quinny-yezz-best-lightweight-buggy-design-junior-design-awards-2014-highly-commended/18838.html
[2] http://www.quinny.com/stroller-buggy/reviews/quinny-yezz-red-dot-award/
[3] http://www.quinny.de/de-de/kinderwagen-buggy/yezz-air/
[4] https://www.solvay.com/en/markets-and-products/featured-products/ixef.html
