The discoverer of the polyactides is the French chemist Théophile-Jules Pelouze, who observed the formation of oligomers and polymers in 1845 during an experiment with lactic acid.
Polyactides belong to the polyesters and are composed of many lactic acid molecules bound to each other.
In the production of the material, lactic acid is fermented via a multi-stage synthesis of sugar. Today, lactic acid is obtained from glucose and molasses. These lactides, as the annular lactic acid molecules are called, can then be polymerized to PLA.
The PLA filaments used for 3D printing are also not pure PLA plastics, but so-called "PLA blends", i.e. mixtures in which special additives are inserted so that the material can withstand the special application conditions. In most cases, materials are developed and manufactured specifically for the respective conditions. This guarantees high efficiency and consistency. The PLA materials are particularly suitable for beginners due to their ease of use.
As a biomaterial, the PLA also has no unpleasant odor in the molten state. In addition, PLA absorbs little moisture during storage and is very UV resistant. The high flammability and good mechanical properties also open up a wide range of applications for this material.
Due to the mechanical properties, not everything is possible during the post-processing of the printed part. Especially drilling and milling should be avoided. It is also not possible to edit with acetone, as the PLA is resistant to acetone. Other machining methods such as gluing, painting or grinding can be carried out without any problems.
PLA is mainly used in the packaging industry. Particular emphasis is placed on biodegradability. For example, hygiene products or carrier bags are often made of PLA. Again, it is not the raw PLA that is used, but mixtures that have been specially developed for the application. Furthermore, packaging, foils, straws, fibers as suture material in the medical field or composite materials from PLA are also produced.