PLA BIOPOLYMER BOTTLES

SMILAB recently developed a project in the packaging sector with the feasibility study and the prototyping of a 1.5 L bottle in PLA, a vegetable biopolymer replacing thermoplastic polymers like PET.

PLA (polylactic acid) has been the second biopolymer to be commercialized and sold on a large scale (2002). This material is characterized by excellent physical and mechanical features which let it be the best alternative to thermoplastic polymers.

PLA and PET share features like hardness, stiffness, shock resistance and elasticity.
These features, together with flexibility and high transparency, make the PLA film a material to be used like cellophane.

About the 70% of PLA is produced and used in the packaging field for the following products:

- Bread and food in general: it is suitable thanks to its transparency, the mechanical features and  better moisture resistance compared to polymeric amides.

- Juices and milk: it is not suitable due to its low moisture barrier, even though it may be enhanced thanks to the aluminium-oxide deposition process (with the resulting increase in costs).

- Water: it is suitable for still water containers.

- Fats and oils: it is suitable for its chemical resistance to these types of products.

- Non-food: Panasonic exploited this material for the rigid packaging of batteries.

- Perfumes: this type of application may be developed thanks to PLA alcohol resistance.

- Detergents: the application on this kind of products requires a solution to the low stress cracking through the use of PLA modified with anti-shock agents.