Nano compounding facilities opened up

Edited by the Engineeringtalk editorial team Feb 17, 2006

Nano compounding facilities and expertise available to companies seeking to optimise their own materials, processes and products.

Rapra Technology is making its nano compounding facilities and expertise available to companies seeking to optimise their own materials, processes and products.

All plastics materials and processes will be considered by Rapra for a nano-boost - and Rapra may be able to offer part-funding for some of the research and feasibility investigations.

Colin Chilles led the first part of Rapra's nano-compounding project - a 12 month research project into the effects of melt processing of montmorillonite type nanoclays when combined with selected polyamides and polypropylenes.

"Our initial work succeeded in mapping out the materials and processability terrain in several areas," he said.

"Truth to tell, there is much less mystery around nano materials than even 12 months ago".

"Practical development is the key and we at Rapra now feel ready to approach the market on that basis with our services, know-how and products".

"In commercial terms, nano-compounded polymers basically offer the user a much tidier and lighter package with improved structural performance than the alternative additives and fillers".

"True, the nano materials can be more expensive but they offer a combination of properties that can be hard to match, such as stiffness, heat distortion temperature, improved barrier and flame retardancy".

"In terms of overall additive loading, research shows that nanoclays can replace four to five times their weight of conventional additives for the same or better results - thus making the overall bill of material goods lighter and potentially cheaper".

Rapra is aiming to help companies with the formulation and development of nanoclay compounds for companies with ambitions in the nano materials area.

This will be backed with the testing and analysis facilities of Rapra.

"It will also be possible to look at the predictive processability of these polymers," said Chilles, "so that companies are confidently able to go forward to produce a better nano-based product on their own equipment - ideally at less cost".

The performance of a number of nylon and polypropylene materials in nano compounding has impressed the Rapra researchers to date, although Chilles said that many other polymers such as TPUs and polyesters have bright developmental futures.

Perhaps unsurprisingly engineering polymers and technical injection moulding have been leading the nano plastics future to date and automotive applications have seen the biggest take up of nano-polymer use.

Car trim and panels, for example, give greater tensile, impact and scratch resistance and engine parts give higher heat distortion temperatures.

"Generally," said Chilles, "the main uses for nanoclay polymer compounds are in high value applications where weight saving and specific properties are of importance".

"Our desk research has found estimates of the polymer nanocomposites market growing by 18.4% a year from 2003 to 2008, but I suspect that these figures are now higher".

At the heart of the project is Rapra's Rondol extruder machine.

The company chose the 21mm, 40 L/D screw Rondol compounder because its size and length was most appropriate for the project and because it can handle relatively low amounts of material (less than 1kg samples) with a fast turnaround.

The Rondol is also suited to producing sufficient quantities for customer evaluation trials and has up-scale potential in relation to larger compounding machines.

The 21mm clam shell barrel machine has a variable agitator configuration capability and side feeder and will soon include the touchscreen data acquisition option.

This provides flexibility for developing and making small production runs of new compounds of nanofilled or conventional compounds.

The machine can be configured for studying the effect of feeding and processing parameters on compound performance.

For example, Rapra researchers have configured it for the addition of carbon nanotubes, liquid plasticisers, super critical gases and nanoclays.