A polylactic acid supplier explains the various applications of polylactic acid.

Polylactic acid suppliers explain that, since lactic acid can be produced through the biofermentation of starch or plant biomass such as straw, polylactic acid is fully degradable into water and carbon dioxide—though it is not necessarily biodegradable, it can still break down under natural conditions. Moreover, lactic acid is a naturally occurring compound in human tissues and can be used as a food additive. Consequently, polylactic acid can be regarded as an environmentally friendly, entirely bio-based material. In response to the increasingly severe issue of “white pollution” worldwide, China has issued and enforced its strictest-ever plastic‑ban regulations. As a result, driven by local governments and chemical research institutes, China’s polylactic acid industry has entered a period of rapid growth this year.

Turning to polylactic acid (PLA) polymerization technology, PLA suppliers report that in China there is no stable, large‑scale supply of film‑grade or fiber‑grade PLA resin. Some manufacturers claim to offer DTY or FDY filaments made from PLLA, but inquiries reveal that these filaments are not produced on dedicated production lines. The reasons lie, on the one hand, in the relatively low technical threshold for spinning, and on the other, in the limited spinnability of the raw material. The bottlenecks to consistently producing high‑molecular‑weight PLA essentially boil down to two factors: first, the stringent purity requirements for lactide; and second, the limitations imposed by the polymerization process itself. To begin with, lactide—used as the feedstock for high‑molecular‑weight PLA—must meet very strict purity standards, with additional specifications regarding acidity and water content. Due to proprietary technical considerations, this aspect will not be elaborated here. For industrial‑scale production, such high purity levels translate into significantly higher costs. Moreover, PLA polymerization differs markedly from conventional PET polyester synthesis; the equipment requirements are entirely different, not to mention the distinct process flows involved.

Polylactic acid suppliers point out that the polymerization equipment used for PBAT or PBS should only be taken as a reference. Consequently, breaking through these limitations under conditions of foreign technology blockades is extremely challenging. In the medical field, because production scales are relatively small and profitability is assured, it’s feasible to increase molecular weight. For instance, Chengdu Meiyida can achieve an annual output of one ton, with an intrinsic viscosity reaching 1.8, excellent spinnability, and approval from the National Medical Products Administration. Given this, most PLA currently available in the Chinese market has a low molecular weight, which can lead downstream processors to misconceptions—such as poor mechanical properties and excessive brittleness. Moreover, polylactic acid must be dried prior to processing; as a result, some manufacturers lacking a thorough understanding have wrongly concluded that PLA is easily degradable. In reality, PLA bone screws can remain intact in the human body for up to a year—this, of course, depends on molecular weight. I even know someone whose PLA‑based shirt, after being stored for several years, remains remarkably durable—though he never wore it once. Even some manufacturers who engage in modification originally used PLA to modify PBAT; however, to avoid hot spots and improve flow, they often simply label the resulting material as “PLA‑modified.” Of course, there are also producers who directly manufacture PLA‑modified materials. In fact, films made entirely from pure PLA exhibit excellent transparency and are already being exported—just search online.