Lightweight Self-Reinforced Plastics for Ultimate Recyclability
Submitting InstitutionQueen Mary, University of London
Unit of AssessmentElectrical and Electronic Engineering, Metallurgy and Materials
Summary Impact TypeTechnological
Research Subject Area(s)
Engineering: Aerospace Engineering, Civil Engineering, Materials Engineering
Summary of the impact
Research carried out by Prof. Ton Peijs and colleagues has led to
significant breakthroughs in engineering plastics: PURE®
and its licensed Tegris®
technology, which are lightweight self- reinforced alternatives to
traditional polypropylene (PP) composites such as glass-fibre or natural-
fibre-reinforced PP. Environmentally friendly and 100% recyclable, these
strong and ultra-light self- reinforced plastics have been successfully
used across a number of applications, from suitcases and sports gear to
protective armour and automotive panels, with impressive results. When
used for car, truck and van components, they have been shown to help lower
exhaust emission levels and increase fuel economy.
Research in self-reinforced polypropylene (SR-PP) commenced in 1999 when
Peijs joined QMUL from Eindhoven University of Technology. The `PURE'
research project was initiated by Peijs in the fall of 1998 and was
supported by the Dutch Government through their Economy, Ecology and
Technology (EET) programme. This collaborative project, led by Peijs ran
until 2004 and included 4 industrial partners including Lankhorst Indutech
(Sneek, The Netherlands). The QMUL research team led by Peijs and funded
through this EET programme drove the project from the start and involved
two PhD students (Norbert Cabrera and Ben Alcock), together with several
project students focusing on the process development and characterization
of high strength tapes and SR- PP (or all-PP) composites. The research
team was complimented by another PhD student and researcher at Eindhoven,
where Peijs maintained a part-time position to lead this team. From
2002-2004 the QMUL research team was complimented by two postdoc funded
through an EU FP5 project ORTHOFLEX (G5ST-CT-2002-50185) and a DTI project
ENVIROCOMP, focusing on developing thermoforming technologies for these
SR-PP materials. A patent was filed in 2001 on the concept of
self-reinforced polypropylene composites by Lankhorst Indutech with Peijs
as co- inventor (WO/2003/008190; Polyolefin Film, Tape or Yarn) and the
first results were published from 2003 onwards [1-6].
Polypropylene already has many advantages as it has the lowest
environmental impact of all petroleum-based polymers, but on its own it is
not strong enough for many engineering applications such as in automotive
parts. Normally PP has to be reinforced with glass- or natural fibres to
make it strong and stiff. However, the addition of these reinforcements
makes recycling more complicated, time-consuming and expensive, ruling out
the advantages of this useful plastic. Because of legislation such as the
End of Life Vehicle (ELV) directive, materials selection is now strongly
driven by recyclability and for this reason mono-materials are preferred.
However, if automotive panels are to be made from non-reinforced bulk PP
they simply have to be made thicker, or strengthened with extra ribbings,
which would make these parts heavier, defeating the industry's quest to
find lightweight alternatives to metals, as in transport applications the
environmental impact of materials is largely dominated by potential weight
savings through improved fuel efficiency and emission reductions.
PURE® `all-PP' composites are unique in that both the
reinforcement and matrix are made of the same material. They have specific
ecological advantages over traditional composites based on glass- or
natural fibres since they are entirely thermoplastic and can be re-melted
at the end of the product's life cycle without the need for a fibre
recovery process. Self-reinforced PP takes normal PP and by heating and
stretching treatments it aligns the molecules to make the end product 10
times stronger and stiffer, without any weight gain [1,6]. The technology
is based on highly engineered co-extruded tape which consists of a high
strength and high modulus PP core and a specially formulated thin PP
copolymer skin for welding the tapes together using heat and pressure
[1,2]. This process of co-extrusion and tape welding gives enormous
processing advantages over other `SR-PP' alternatives such as Curv®
as these co-extruded tapes exhibit a much larger processing window
(20-30°C to 1-2°C for Curv®). The tapes can be woven into
fabric and can be hot-pressed together into sheet. Parts can be produced
by thermoforming  or can be moulded directly from fabric using filament
winding, compression, autoclave or vacuumbag moulding, or can be combined
with PP foam or honeycomb into fully recyclable lightweight sandwich
In recent years, Peijs' research into all-polymer composites has moved
towards other polymer systems such as HDPE, PET, PLA, cellulose and aramid
. Many of these programmes were in collaboration with industrial
partners such as DSM Dyneema, Novameer, Dow Chemical, Teijin Monofilament,
Shell and GE Plastics. Peijs' team assisted in the development of
high-strength high-density polyethylene (HDPE) tapes and self-reinforced
HDPE composites (KAYPLATM)
This work on SR-HDPE, in collaboration with Novameer BV (The Netherlands)
was initially aimed at developing a cost-effective alternative for the
anti-ballistic market, but is currently also used in panels for caravans
and vans. After a buy-out by Japanese fibre giant Teijin for ~£10m in
2010, Novameer became part of Teijin Monofilament (became Nextrusion
GmbH). KAYPLATM tape is currently being produced by Compomeer
in Greece, with UD and cross-ply sheet production in The Netherlands. High
strength polyester (PET) tapes were developed for higher temperature
resistance products in collaboration with Dow, GE Plastics (became Sabic
Innovative Plastics) and later also Teijin Monofilament (became Nextrusion
GmbH). Fully biobased all-polymer composites are currently being developed
based on polylactic acid (PLA) in the framework of the EU FP7 Matera+
programme `HIGHBIOPOL'. Since 2003 our research in this area has been
published in over 30 papers in international peer reviewed journals
together with a large number of invited international conference and
key-note papers. One of the PhD students (Norbert Cabrera) received the
2005 Dow Energy Dissertation Award for his research in the area of
sustainable use of energy and sparing the environment. The award included
a prize of €2500 for his winning thesis entitled `Recyclable
all-polypropylene composites'. After his graduation, Dr. Cabrera was hired
by Pure Composites to lead their R&D in the area of composite
processing. As recognition for his work on self-reinforced plastics Peijs
received the Dutch Polymer Award of Polymer Technology Netherlands (PTN)
in 2008 and the Swinburne Medal & Prize of the Institute of Materials,
Minerals and Mining (IOM3) in 2010.
References to the research
1. Peijs T., Composites for recyclability, Materials Today, 6(4) 2003,
2. Alcock B.; Cabrera, N.O., Peijs T. et. al., The mechanical properties
of unidirectional all- polypropylene composites, Composites Part A: Appl.
Sci. Man., 37(5) 2006, 716-726
3. Alcock, B., Cabrera, N.O., Barkoula N.-M., Peijs, T., Low velocity
impact performance of recyclable all-polypropylene composites, Composite
Sci. & Techn., 66(11-12) 2006, 1724-1737.
4. Cabrera NO, Alcock B, Peijs T. Design and manufacture of all-PP
sandwich panels based on co-extruded polypropylene tapes. Composites Part
B: Engineering, 39(7-8) 2008, 1183-95.
5. Cabrera NO, Reynolds CT, Alcock B, Peijs T. Non-isothermal stamp
forming of continuous tape reinforced all-polypropylene composite sheet.
Composites Part A: Appl. Sci. Man., 39(9) 2008, 1455-66.
6. Alcock B, Peijs T, Technology and development of self-reinforced
polymer composites, Adv. Polymer Sci., 251, 2013, 1-76.
Research that led to the PURE® technology led to the following
• ORTHOFLEX: an EU FP5 collaborative project on `stiffened SR-PP vacuum
formings for orthoses to improve patients' comfort and mobility'. The
project included 8 companies from UK, Netherlands, Denmark, Sweden,
France, Belgium, and 2 R&D Institutes (Pera and QMUL), 2002-2004,
• SustComp: a DTI Sustainable Technology Initiative on `efficient and
environmentally friendly moulding of recyclable composites structures'
with 5 UK industrial partners, 2002-2004, £40k.
• INTELTEX: an EU FP6 collaborative project `intelligent textiles' using
our co-extrusion technology to create high strength electrically
conductive bicomponent tapes. The project included 12 industrial partners
including UK partner Peratech, 2006-2009, £230k.
• HIGHBIOPOL: an EU FP7 Matera+ project on `SR-PLA composites for
engineering applications', including 3 partners, 2010-2013, £250k.
• In addition it led to various industrially funded projects with GE
Plastics, Dow, Shell, Novomeer, Teijin Chelton Radomes, totalling £250k.
Details of the impact
In 2003 the PURE® technology, initiated through the `PURE'
project and co-developed by Peijs' and his team at QMUL was commercialized
through Lankhorst Pure Composites BV in The Netherlands, a division of the
Royal Lankhorst Group, one of the original partners in the `PURE' project.
The material is targeting application markets ranging from recyclable
lightweight automotive panels to suitcases, flight cases, helmets and
sports equipment. In 2006, the PURE® technology was licensed to
Milliken & Company in the U.S., the world's largest private textile
firm, who are now marketing this technology under the trade name Tegris®.
Pure Composites BV currently employs around 25 employees in The
Netherlands and Portugal for the production and marketing of the product,
with a similar number employed at Milliken to support Tegris®.
Automotive: SR-PP composites have opened the door to a vast
range of lightweight recyclable car, truck and van parts. Applications
include: under body shields, interior panels, load floors, scuff plates
and panelling for trucks and vans. The strong and ultra-light parts help
to save weight (30% compared to glass-fibre-reinforced PP has been
achieved) and lower exhaust emission levels and increase fuel economy.
Because these materials are 100% recyclable, the material is ideal for use
in automotive parts where the EU's End of Life Vehicle (ELV) Directive
dictates recycling rates up to 95% by the year 2015.
Tegra-Lite's premium luggage collection was introduced in 2012 and
is produced from Tegris® composite material from Milliken &
Company. Self-reinforced PP is ideal for hard shell luggage applications
where impact resistance, stiffness and weight are primary concerns. Tegra-
Lite combines an industrial aesthetic look, with a design that is 65%
lighter than glass fibre composites and provides up to 15x improvement in
impact resistance over typical thermoplastics, while it maintains this
performance level at low temperatures (-40°C), far exceeding other
comparable pieces of commercial hard-sided cases on the market today. PURE®
is also used for impact resistant flight cases, attaché and iPad cases.
TUMI is the world's second largest producer of hard shell luggage and
their Tegra-Lite series is available from large department stores like
Macy's or Selfridges as well as online retailers like Amazon.
Motor racing: The motor racing world has adopted SR-PP in a
number of ways. Powerstream's
Aero splitters based on Tegris® were introduced in 2011
and are now being used in NASCAR racing, as well as for door panels to
replace carbon fibre. Self-reinforced PP is not as light or as stiff as
carbon fibre composites; but it has about 70% of its strength at about 10%
of the cost. One of the most important reasons for its use in motor racing
besides its lightness, superior impact resistance and low cost, is the
fact that it does not splinter when it breaks, which prevents having sharp
pieces of splitter lying on the track after a crash, improving driver
safety. The material is also incorporated in the new DeltaWing racer,
developed by Chip Ganassi Racing for the American IndyCar series.
Protective armour: Tegris® is used in life
saving protective armour by the U.S. military in its vehicles, primarily
against improvised explosive devices (IEDs) or roadside bombs. Milliken
qualified Tegris® for a number of military armour applications
and in 2010 they have shipped 20,000 Tegris® armour kits for
vehicles deployed in Iraq and Afghanistan. Predominantly flat panel
systems for spall liners, these kits are used to retrofit vehicles for
enhanced protection. Norwegian company ROFI Industries AS have developed
De-mining Mask against humanitarian mine action (HMA). The mask,
which is made from PURE® is lighter, stronger and more
comfortable than existing de-mining masks and has proven to be effective
in demining operations. The mask won the Index Award 2007, an
international design award to promote design that improves life. Another
outfit that appreciates the lightness and toughness of the material is
Riddell, makers of body armour for American football players. Its Custom
Power® Lightspeed Shoulder PadsTM was
introduced in 2010 and are claimed to be the lightest in the business
without compromising protection. PURE® is also used for helmets
and other sports gear.
Blast Basket: Parcel bombs, either real or suspect are a
potential problem for security agencies, major corporations and targeted
groups. The PURE® Bomb or Blast Basket, is placed over the
suspected object and protects property and personnel from the blast and
fragmentation occurring when an IED is set off. It captures most of the
metal fragments and redirects the blast waves upwards, protecting
civilians. For example, a 35 kg blast basket, 400 mm high with a 500 mm
diameter, can handle a 1 kg TNT bare explosive charge.
Kayaks: The UltimateTM
12 Kayak from Legacy Paddlesports in the U.S., was introduced in
2007 and was one of the first commercial uses of PURE® or
Tegris® in a large 3D part, creating the strongest, lightest
kayak on the market. SR-PP is used because of it high stiffness and high
impact resistance, so it can shrug off hard landings and damage from rocky
bottoms. Other applications are in skis, snowboards, and surfboards.
Sources to corroborate the impact
- Director Lankhorst Indutech, and Managing Director Pure Composites BV
- Business Development Manager, Pure Composites BV, Sneek, The
- Business Development Director, Milliken & Company, Greenville,
South Carolina, U.S.A.
- Research Manager KAYPLATM, Novameer BV, and Compomeer BV,