Compostable plastics applications

In Europe, compostable plastics are being used in several applications. Compostable plastics must comply with the International Norm... 

The compostability is independent of the resources used as raw materials. Therefore, the market should decide which raw material is best for the respective biodegradable plastics application. 

Plastic Suppliers Inc., a US extruder of blown film for labels and envelopes, has produced the world s first blown film from NatureWorks PLA. It was hitherto thought that PLA was unsuitable for blown film extrusion. Plastic Supplies claims that its EarthFirst film is 100% compostable, has high gloss, optimum clarity and transparency, high moisture vapour transmission rate, flavour retention, odour barrier, is breathable and is US Food and Drug Administration (FDA) compliant. Areas of application for EarthFirst include window carton film for food packaging, label film, floral wrap film, shrink film and envelope film. 

Applications currently promoted for oxidatively biodegradable plastics include, landfill covers and bags for landfill disposal, agricultural film and a route to alleviate litter. They do not currently meet compost bag use. 

Thermoplastic starch can be processed as a plastic material, but it is sensitivity to humidity, what makes it unsuitable for most applications. Thus, its principal use is in compostable foams to replace EPS. 

The correct balance has to be found between the durability of the packaging needed for the preservation of packed food during its shelf-life, and the expected biodegradability at the end of the life cycle. Addition of nanocomposites in PLA can improve barrier properties for food applications and increase degradation in compost conditions [217]. On the other hand, plasticizers are commonly added to promote flexibility of PLA but degradation increases, and food shelf life is often negatively affected by increasing plasticizer content [89]. 

---