Bio-materials are the future. Exciting new and old materials include wood pulp, plant cellulose, food waste, grass, algae, and mushrooms.

These materials can be made into trays, punnets, and clear, flexible films that look and behave like conventional plastic, but with two key differences: At the start of their lives, these materials can be sustainably sourced in full or in part. At the end of their lives, they can be composted into bio-mass to regenerate depleted farming soils.


PLA

Polylactic acid or polylactide is a compostable bioplastic derived from plant sugars. It can be made from any sugar, such as corn starch, cassava, sugar cane, or sugar beet. Industrial corn is the primary source crop at the moment, but manufacturers are working actively to diversify feedstocks, investigating other fibrous non-food crops, or even creating lactic acid from carbon dioxide or methane.

How PLA is made?
The raw materials are milled to extract the starch in the form of glucose. The glucose is then fermented to produce lactic acid, which is a monomer. Next up, a chemical process transforms the lactic acid into a polymer, which can be made into pellets, known in the industry as resin.

In what products is it used?
PLA is used in a variety of products, such as lining inside paper cups and soup containers, clear cold cups, containers, pots and lids, and clear windows in sandwich wedges, salad boxes, and bags.

The recycling process
PLA can be recycled back to its original monomer form which can be used for the manufacturing of virgin PLA with no loss of original properties (cradle-to-cradle recycling).

Currently, the SPI resin identification code 7 ("others") is applicable for PLA.


CPLA

PLA has a low melting point, so is therefore optimal for cold use up to 40ºC. A crystallised form (CPLA) is used where more heat resistance is needed such as in cutlery, lids for coffee, or soup containers. This involves adding chalk to the PLA to act as a catalyst and then rapidly heating and cooling the PLA resin during production. The result is a product which is heat stable to 90ºC.

The recycling process
CPLA products are still suitable for industrial composting, in either in-vessel or open windrow composting.


BAGASSE

Compostable bagasse is made from surplus natural material from sugar cane production: sugar cane stems.

The recycling process
Bagasse will readily biodegrade under controlled composting conditions. Once composted it turns into soil in just a few weeks.


other materials

Metal, paper, carton, and glass are also plastic free. Aluminium, tin, and glass can be recycled in an infinite loop. Paper, sustainably sourced through FSC™ or PEFC™ certification, can also be recycled and is one of the most versatile packaging materials. Steel and tin plate cans are of course free of plastic, but often have plastic linings. Similarly work is still needed to remove hidden plastic in products like Tetrapak.