Leeds University, UK has developed a composite
material entirely of compressed PP fabric that has greater toughness
than glass reinforced composites.
BP, a well-known petrochemical company has acquired the patent rights
from the University and has initiated development work. It has trademarked
the new products as Curv. These products can be produced either
from fibers or stretched tapes from several polymers including PP.
BP currently makes it from PP.
The process for making Curv products is:
Tapes are extruded and drawn to a high stretch ratio of almost 18:1
to obtain higher mechanical properties. The tapes are woven into
a fabric. The fabric is heated and compressed while the tape surface
gets metled but the core remains soild due to higher melting points.
The orientation in the core is therefore retained. The resulting
compressed blocks are then moulded into finished products using
compression moulding. The Curv products have excellent toughness.
BP has evaluated the new products and compared them with other products.
Material |
Density gm/cm3 |
Tensile Strength |
IZOD Impact V/M
|
|
|
MPa |
20° C |
-40° C |
Curv |
0.92 |
180 |
4750 |
7500 |
Isotropic PP homopolymer |
0.90 |
27 |
200 |
Brittle |
40% glass mat random PP |
1.19 |
99 |
672 |
Brittle |
60% glass reinforced
PP |
1.49 |
340 |
1600 |
-
|
Curv based laminates could have excellent potential
in automobiles for energy absorbing interior components. More information
could be obtained on www.curvonline.com.
|