Saving the planet… with plastic!?

The plastics industry is trying to change the view that it is bad for the environment. Justin Cunningham investigates

Environmental benefit and plastic do not normally appear in the same sentence, but the plastics community is making a big effort to change this mindset.

And one of the tools being used to change this thinking is the lifecycle assessment. Although the approach is being widely used and is certainly not unique to the plastics industry, it has thrown up some interesting results for the sector. One company that recently undertook the independent ISO14040 approved standard was JSP.

The company, which manufactures Arpro expanded polypropylene predominantly for the automotive sector, claims it can save millions of tonnes of CO2 per year just from producing a seat core made from the substance over a conventional steel equivalent.

"The saving comes over the life of a car being a lower weight," says Paul Compton, JSP's executive vice president and chief operating officer in Europe. "And that doesn't even take into account that steel is hugely energy intensive to produce."

Vehicles have got heavier in the last 20 years with the addition of safety systems and electronics, and more recently because of electric motors used for hybrid vehicles. As a result car manufactures have increasingly been looking at alternatives that offer the same, if not better, safety protection but are lighter weight and, where possible, cheaper to produce.

This is where Arpro found its niche. The company makes and moulds expanded polypropylene, which it can tailor for use by adding colour or special additives to make the material antistatic or dispersive, depending on the requirement. It has found a big increase in the amount of its product used in vehicles in the last 10 years as manufacturers strive to keep weight down.

The most recent example is the seat core of a Volvo XC60. Although the use of Arpro takes just 2.5kg out of the body in white floorpan, if this saving is applied to the number of cars sold annually, based on a 100,000km vehicle life, the saving adds up to some 16million tonnes of CO2.
The ISO-compliant study has to be peer reviewed by a second, independent life cycle assessment expert. It found that from raw-material production to disposal, considerable CO2 savings could be expected from a vehicle using the materials over its lifetime.

"This was important to JSP as it enables our customers to have confidence in the data and findings delivered," says Compton. "JSP developed Arpro seating solutions for three of 2008's major European car launches, including the Volvo XC60, and more innovative solutions are in the pipeline. Arpro delivers seating structures that preserve safety, enable flat floors and cost-effective H-Point variation for multiple platforms, save weight and provide a positive environmental impact."

And, it is saving the manufacturer money on production by offering the potential to get rid of the pressing operation normally used on the steel equivalent. It also allows for a completely flat floor.

The material is 100% recyclable making it increasingly ideal for automotive components as car makers strive to meet the 2005 ELV Regulations which stipulate a reuse and recycling target of 85% of the weight of the vehicle.

"It is scientific proof that the environmental impact of Arpro is less than conventional materials," says Compton. "We think that should encourage vehicle makers looking to dramatically reduce carbon emissions. We have also identified other parts and components that could be replaced and these are already being acted upon."

SABIC Innovative Plastics have also been making similar moves and has recently been awarded a cradle to cradle compliance for its Valox iQ resin system. Rather than a lifecycle assessment, the compliance recognises that the material is largely suitable for reuse.

The resin is created by using up to 85% of post-consumer plastic waste, giving it a carbon footprint 50 to 85% lower than other engineered thermoplastics. The approach, replaces the less environmentally compatible "cradle-to-grave" model, and it aims to eliminate waste entirely by circulating safe materials within closed-loop systems of continuous reuse and the resin has an important contribution to sustainability and reduction of landfill waste.

"There are so many eco claims for today's products and materials that it's easy to become sceptical," said William McDonough, co-founder, McDonough Braungart Design Chemistry. The firm independently certifies firms design processes, or materials to meet the internationally recognised standard."Cradle to Cradle Certification provides a means to tangibly measure achievement in environmentally intelligent design."

Valox iQ resin is made with polybutylene terephthalate based polymers using a proprietary process. The material consumes less energy and yields less CO2 than traditional resins through its entire manufacturing process from cradle - discarded PET bottle - to gate Valox iQ resin pellet.

When the plastic is recycled, the chemical properties of the post-consumer plastic resin have the same quality as the original resin. Applications for Valox iQ resin include furniture, computers and consumer electronics, transportation and automotive components.

The company is also introducing a bio-based composite material. The company is developing the use of natural, sustainable fibres made from the Curaua plant and wood shavings to be used as reinforcement inside its resins. The strong but lightweight fibres can actually reduce overall composite weight compared with glass fibres while improving recyclability.

And UK based Smithers Rapra, which used to be the Rubber and Plastics Research Association, are unsurprising leading the way for research in the field.
It has a number of research projects and studies on this area, just what the industry can do to become more sustainable and environmental beneficial and reduce its carbon footprint.

These include developing new materials such as, bio-composite, which will be made of completely natural resources. To date, the materials are used for low grade applications, but the research project aims to change this by targeting innovations in engineering thermoplastic and thermosetting materials.

"A lot of people are looking at using and developing biodegradable polymers," says Dr Chris O'Connor, a director at Smithers Rapra. "But we have spent the last 60 years trying to get plastics to last a long time so those sorts of materials are unlikely to find much use in engineering design."

It has also been developing biodegradable polymers, which it is targeting for medical applications. The project called, Protec, aims to develop a super critical fluid processing technology to enable processing of biodegradable and bioabsorbable polymers. Amongst the goals is to have consistent and well-defined mechanical properties.

The project is collaboration between industry and academic research and is designed to be compatible with existing extrusion and injection moulding machines. "There is a lot of interest from the outcome of this study," says O'Connor.

Advice from an expert: Plastics

It is amazing, but around 70% of plastics fail prematurely. For most, knowledge of metals is better known, and the material is much easier to predict.
"But for plastics it is a minefield," says Dr Chris O'Connor, a director at Smithers Rapra. "Where do you start when selecting a plastic for an application, because there are over 1000 generic and sub generic types.

"The problem is a lack of understanding in plastic materials and applications. The major problem is a lot of designers get a materials data sheet and use that information. Rip it up and throw it away. That is purely a quality document to compare different generic types, but it is all short-term data under ideal conditions."

O'Connor says 65% of premature failures happen in the design phase and are due to either material mis-selection or just poor design. He says that a better knowledge of the materials fundamental behaviour, failure modes is necessary to minimise early failures. Seemingly small differences can have a big effect of the overall product performance.

Justin Cunningham

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