0.53mm! Japan’s Sanyi Lacquerware launches the world’s thinnest PLA injection container

Recently, Japan’s Sanyoshi Lacquerware (Sanyoshi) launched a 0.53mm thick transparent cup made of polylactic acid (PLA). According to the company, it is the world’s thinnest PLA
Injection molded plastic cup. The Sanyi lacquerware store has named the thin-walled PLA cup the “IZ EARTH” brand. Sales are expected to begin after spring 2024.

PLA is increasingly used in food packaging and tableware, but its fluidity when melted is poor. So far, it has been difficult to form thin-walled products with a wall thickness of 1 mm or less using injection molding. In addition, raw material costs are higher compared to petroleum-derived polystyrene and polyolefins, and if the product is made thicker to improve flowability, the cost of the molded product will increase beyond the retail price range, so polylactic acid injection Molded products are not widely sold worldwide.

In order to solve this problem, Sanyi Lacquerware Co., Ltd. signed a patent license agreement with Mr. Michio Komatsu (director of Komatsu Engineering Office), who holds a patent for the manufacturing process and can injection mold many thin-walled containers with polylactic acid. In order to develop the thinnest polylactic acid, the company established a research base and production plant at its head office in Aizuwakamatsu, Fukushima Prefecture.

In addition to Japan, the patent license agreement also covers the United States, the United Kingdom, Germany, France, the Netherlands and Switzerland.

Three methods were used to develop the world’s thinnest PLA (0.53mm) transparent container:

① Instantly dissolve a large amount of supercritical CO2 into polylactic acid to improve the fluidity of polylactic acid.

② By filling the cavity directly using the valve gate, it is possible to fill to the flow end of the thin-walled container.

③ By rapidly cooling the mold (8 cavities), the foaming of CO2 is suppressed, enabling continuous production of 8 transparent containers.

In addition, a dedicated injection molding system, supercritical fluid generation device, particle pre-treatment device, mold temperature control system and valve gate system are integrated and coordinated to enable the world’s top polylactic acid thin-walled container injection molding line to be completed this fall .

The newly developed polylactic acid thin-walled containers are thin and light and can be used for products that come into direct contact with food, such as beverage cups and candy containers. In addition, unlike vacuum-formed products, this product can be cleaned and used multiple times, and can also be used to make beverage cups with company or local government logos, transparent containers for Western and Japanese desserts, etc. If you want to throw it away, you can put it in a “compost” where it will break down into carbon dioxide and water.