Friday, 26 September 2014

Certification of Biopolymers

More from AIMPLAS Valencia...
Miriam Lübbecke of DIN Certco (Germany) specialises in biopolymer certification using a scheme which is totally transparent with all details publically available on their website.  When a manufacturer applies for a certificate, DIN Certco assesses the relevant literature and decides how to test the product.  It uses appropriate independent test laboratories chosen from its list of 130 accredited and contracted testing partners, issues a report on the results,  and if appropriate, the certificate of conformance and permission to use the logo.  “Biobased” certificates cover three levels, 20-50%, 50-85% and >85% biobased according to ASTM D 6866 methods which requires a total organic carbon of >50% and a C14 content above 20%.  Testing is required every second year.

“Compostable” certificates can include 4 logos, “the seedling” for industrial compostability, and 3 “DIN-Gepruft” logos covering industrial, home composting and additive content. ASTM D6400 is among the approved tests, but only the Australian standard AS 5810 is used for home composting certification.  The tests include ultimate biodegradability, disintegration, plant toxicity, EN 13432 chemical analysis and, for home composting the ASTM E 1676 earthworm toxicity test.

“Recycled Content” is determined by DIN EN ISO 14021 and audits of the manufacturing site to determine traceability under DIN EN 15343.  A new “All-in-one” DIN Certco logo covering all 4 properties is now available.

Sunday, 21 September 2014

Biocomposites from Starch, Natural Fibres and Polymers

More from AIMPLAS, Valencia...
Leon Mentik of Roquette (France) explained how they bought maize, potatoes, wheat, tapioca and peas for processing and used the extracted starches to make bioplastics.  After cellulose, starch was the second most abundant polymer on the planet with 1.3 billion tonnes being produced annually in plants.  6% of this (80 million tonnes/year) is extracted very easily, the by-products being proteins and fibre for use as food.  Starch is highly reactive and easily grafted or alloyed with other materials to add desirable functionalities.  It can be used directly to make starch-based plastics, either as blends with other polymers or in the form of durable thermoplastic starch.  It can also be easily hydrolysed to glucose to provide the starting point for the whole range of bio-based or bacterially produced polymers.

Gaialene® is Roquette’s durable, i.e non-compostable, starch-based plastic which has been certified against ISO 14040/44 by Price Waterhouse Coopers with a carbon footprint of 0.74 kg CO2 eq./kg resin or ~1/3rd that of PP.  It has applications in replacing polyolefins in  films, injection moulding and foams, to produce  shopping bags (for recycling or incineration), multilayer shrink wrap, moulded paint containers, fabric coatings, mud-guards, sound insulation and packaging foams.  It is fully recyclable, GMO-free and does not compete with food crops.

Sergio Fita of Aimplas provided another comprehensive overview of the Technological Institute and its work on composites for those who joined the conference late.  He reiterated the variability issue which arises because natural fibres are inherently variable and moisture sensitive and said AIMPLAS was working to overcome this deficiency.  Examples of successes were the woven Flax/Jute battery case which used an epoxidised acrylate soybean-oil resin (ASEO); the Roadside Grit Box using wet compression moulded Flax/biobased unsaturated PET resin (thermoset); the woven flax/PLA tractor door, the Cayley project honeycombs based on FR-treated bio-resins and natural fibres and the Ecoplast project for automotive parts made by extruding PHB polymer onto flax fabrics, calendaring to impregnate and then moulding to shape.

Wednesday, 3 September 2014

Biopolymer Waste in Spain

More from AIMPLAS Valencia...
Francesc Giró of the Catalonia Waste Agency was concerned that the desertification now occurring in southern Europe needed to be corrected by adding massive amounts of organic matter to the soil, and this required more composting infrastructure.  In reality 70% of waste organic matter in the region is still land-filled or incinerated and action was needed to allow this to be collected separately and composted.  The target is to compost 50% of organic matter by 2020 and in Catalonia a tax on landfill and incineration is encouraging movement in this direction.

  • ·         Door to door collection of food waste is required.
  • ·         Compostable bags need to be used for this collection.
  • ·         Disposable nappies were a huge problem, accounting for 2.5% of all waste.
  • ·         Compostable diapers could make a large contribution to compost production, but they were currently twice the price of the petro-diapers.
Judit Janasa of TOMRA Sorting and Recycling commented on the difficulties of separating mixtures of plastics containing biopolymers but concluded that their sorting machines would soon be able to remove compostable bioplastics from the recycling stream.  They have installed 3470 sorting machines worldwide, mostly in the Iberian peninsula.  These machines use electromagnets, high intensity visible light, infra-red both transmitted and reflected, X-ray, atomic density, and laser fluorescence sensors to identify different materials.

The machines are tuned to the key wavelengths reflected or transmitted by each polymer and digital images taken at these wavelegths are analysed pixel-by-pixel so that for a bottle for example, the cap, label and body polymers are identified and recorded.  Problems arise with black polymers (no reflection), and labels made of paper prevent the underlying polymer being seen.  PLA and PET bottles which look identical can be separated easily.  The software in use can be updated for every new polymer once samples have been tested.

Asked how multilayer bottles or films would be treated, Ms Janasa said the majority polymer would take precedence.