eSUN's Kevin Yang: The Technical Pathway, Advantages, and Future Market of PLA Chemical Recycling

In 2006, with the open-sourcing of technology, 3D printing (additive manufacturing) began gaining momentum in Europe and America. At that time, however, 3D printing was still a very niche research field in China, just starting to find applications in industrial sectors like aircraft manufacturing.

Polylactic acid (PLA) is a type of polyester made from fermented plant starch derived from corn, cassava, sugarcane or sugar beets. The sugars in these renewable materials are fermented into lactic acid, which is then polymerized into polylactic acid (PLA).

eSUN was established in 2002, initially specializing in the research and development of products such as lactate esters, polylactic acid (PLA), and polycaprolactone (PCL). After five years of accumulation, eSUN decided to focus on 3D printing materials as one of its main development directions. In 2007, it became the first in the world to launch commercial polylactic acid 3D printing materials and subsequently established the "eSUN" brand, which has now grown into one of the globally renowned brands for 3D printing materials. In 2006, the company began research on the recycling and high-value reuse of polylactic acid.

On one hand, eSUN has expanded its product applications horizontally; on the other hand, it has also deepened its efforts vertically, striving to build a green closed-loop industrial chain for polylactic acid.

In 2013, eSUN established a self-developed "5,000-ton-per-year chemical recycling lactide production line" in Xiaogan, Hubei, initially forming a green closed-loop technical system—from material synthesis and modification to application, byproduct processing, and polymer chemical recycling.

In December 2023, eSUN completed the acquisition of a 51.265% equity stake in Hengtian Changjiang Biomaterials Co., Ltd. (hereinafter referred to as "Hengtian Changjiang"), marking another important milestone in eSUN's horizontal application development and vertical industrial chain expansion.

Now, Hengtian Changjiang Biomaterials Co., Ltd., which primarily focuses on the R&D and production of polylactic acid fibers and related products, has been officially renamed EsunFiber (Suzhou) Co., Ltd. (hereinafter referred to as "eSunfiber"). Through this acquisition, eSUN has completed its strategic layout across four major application fields—biomedical, 3D printing, eco-friendly fibers, and sustainable packaging—while further solidifying its green closed-loop industrial chain, from the chemical recycling of polylactic acid into lactide to the direct melt spinning of polylactic acid fibers.

"At the front end of the industrial chain, we have built a 5,000-ton/year lactide synthesis facility in Xiaogan, Hubei. In addition to using lactic acid as a raw material, we can also produce lactide from recycled polylactic acid. At the back end of the industrial chain, eSun New Materials utilizes lactide as a raw material to produce polylactic acid fibers. This way, we have established upstream and downstream linkages within the industrial chain while achieving complementary advantages at the technical level," said Kevin Yang.

According to European Plastics, in 2021, the global total production capacity of biodegradable materials was 1.553 million tons, while the global output of plastic products reached 390 million tons in the same period.

This vast gap signifies immense market potential.

Against the backdrop of steadily advancing global timelines for plastic restrictions and bans, polylactic acid (PLA), as one of the most promising biodegradable materials, has entered a global capacity expansion cycle in recent years. Since 2020, international players such as TotalEnergies Corbion and NatureWorks, as well as domestic companies like Fengyuan Group, Hisun Biomaterials, Jindan Technology, Kingfa Sci. & Tech., and Wanhua Chemical, have been actively expanding production capacities to seize growth opportunities in this emerging sector.

Yang Yihu believes that while raw material production capacity is expanding rapidly, downstream applications may not yet be fully prepared to absorb the new supply.

"Our assessment is that while upstream PLA production capacity is growing quickly, if downstream applications remain underdeveloped, the market may struggle to accommodate such a surge in raw material supply," said Yang Yihu. "In fact, as early as 2006, we began focusing on developing downstream PLA applications and exploring chemical recycling of post-consumer waste, aiming to complement weak links in the industry’s development. Beyond 3D printing, we have strategically expanded into biomedical, eco-friendly fibers, and biodegradable products, forming four major application segments."

"In recent years, with global plastic bans and restrictions, coupled with the increasing maturity of biomaterials—especially PLA technology—the market for environmentally friendly biodegradable materials has gradually expanded. We’ve devoted more effort to application development in this field. Today, our disposable biodegradable products and eco-fiber products have become the second-largest growth driver after 3D printing materials, and our lactate ester products, produced through chemical recycling, have also achieved rapid growth. Major domestic photoresist manufacturers are using our electronic-grade lactate esters. While volumes are still modest, the application prospects are promising," Kevin Yang explained.

Waste PLA can be recycled through chemical or mechanical processes. Although the waste may contain contaminants, PLA can undergo chemical recycling via thermal depolymerization or hydrolysis to produce monomers, which can then be used to manufacture new PLA. Additionally, PLA can be chemically recycled through transesterification to produce methyl lactate.

"Our proprietary X-configuration co-production innovation model enables diversified raw material sources and end products, thereby enhancing production line flexibility, improving system efficiency, and reducing energy consumption and costs," Kevin Yang added. "We can produce lactide from either lactic acid or recycled PLA, which can then be polymerized into various biomaterials. For example, when using recycled PLA as feedstock, high-purity lactide can be further polymerized into PLA, polycaprolactone (PCL), or polyols, while lower-purity byproducts can react with ethanol to produce chemically pure lactate esters. Alternatively, high-optical-purity lactide can directly serve as a raw material for high-purity lactate esters."

In 2012, after six years of dedicated R&D, eSUN officially filed a patent application for "A Method for Preparing Refined Lactide from Recycled Polylactic Acid", which was successfully granted in 2014. This groundbreaking technology—the first of its kind globally—enables the recovery of high-optical-purity lactide from recycled PLA, while byproducts can be repurposed to produce various lactate esters. It solved the worldwide challenge of recycling and reusing bio-based degradable materials, completing the industrial chain's closed loop and establishing a "green circular" economy.

Meanwhile, the issue of inadequate end-of-life disposal for degradable plastics has gained increasing recognition in recent years. According to a Research Report on Environmental Impact Assessment and Policy Support for Degradable Plastics jointly released by Tsinghua University and Sinopec, 96.77% of China’s biodegradable plastics end up incinerated or landfilled, 3.1% leak into the environment, and only 0.007% enter specialized biodegradation facilities for complete decomposition.

The European Commission’s 2021 Single-Use Plastics (SUP) Directive banned oxidatively degradable, biodegradable, and compostable plastics in single-use plastic products. The 2022 Packaging and Packaging Waste (PPW) Regulation mandates that all packaging must be recyclable or reusable by 2030. A 2023 proposal for End-of-Life Vehicles (ELV) regulations further requires that new vehicles contain at least 25% recycled plastics, emphasizing circularity in material use.

These policies indicate that the EU is advocating the concepts of plastic reduction, circularity, and recycling. However, the implementation of these regulations may also constrain the expansion plans of biodegradable plastic manufacturers, raising the question: Does biodegradable plastic still have a future?

Kevin Yang believes that, against the backdrop of carbon neutrality, PLA's bio-based origin remains meaningful and valuable. Therefore, the focus should now shift toward leveraging PLA's advantages in carbon sequestration and environmental friendliness.

On one hand, efforts should be made to develop and promote durable PLA products, such as long-lasting PLA stationery or high-gloss PLA ceramic-like cups. On the other hand, post-use recycling and reuse must be prioritized.

"From a technical perspective, PLA's chemical recycling holds advantages over other plastics like PET or TPU," Yang Yihu explained. "PLA has only one monomer—lactide—so after recycling, high-purity lactide can be obtained through a straightforward purification process. Economically, recycled PLA can partially replace starch- or sugar-based feedstocks, mitigating future competition between PLA raw materials and food resources."