Fully biodegradable PE shrink film in terrestrial environment

Polyolefins come from natural gas or petroleum and are hydrocarbon compounds containing hydrogen [H] and carbon [C] atoms. They are polymer materials with a carbon-carbon [C-C] bond as the backbone. This molecular structure determines the highly stable chemical properties of polyolefins, making them resistant to rapid degradation by environmental microorganisms. The result is significant environmental pollution and ecological crises. With the increasing awareness of environmental protection in society, the development of fully biodegradable Polyolefin has become urgent.

Sunward Company, as a professional packaging material manufacturer, introduced advanced international technology, formulated a new recipe and meantime improved the manufacturing process. As a result, Sunward has successfully developed a PE shrink film that is fully biodegradable in natural environments. After testing and validation, the mechanical properties of the biodegradable PE shrink film from Sunward Company are essentially the same as traditional PE shrink films.

Extensive literature research, including domestic and international databases from 1985 to 2023, such as Chinese patents, Chinese scientific papers, Chinese theses, Chinese scientific journal papers, Chinese chemical abstracts, European Patent Office, Engineering Index, Science Abstracts, theses, Chemical Abstracts, and Scifinder database, concludes the following:

Innovativeness:

The biodegradable PE shrink film from Sunward Company is innovative, as there are reports of PE biodegradable shrink films in foreign and domestic literature, However, the preparation process, the composition and ratio of raw materials used by Sunward Company are different. Hence there are no literature reports of a product exactly the same as Sunward that is completely biodegradable in natural environments.

Advancement:

In terms of mechanical properties, the tensile strength of Sunward Company's biodegradable PE shrink film is superior to reported in foreign literature, but lower than reported in domestic literature. The elongation at break is lower than reported in both foreign and domestic literature, but the two values both meet standard requirements (refer to Table 1). In terms of biodegradability, testing by SGS-CSTC Standards Technical Services (Shanghai) Co., Ltd. confirms that the degradation performance of Sunward's fully biodegradable PE shrink film complies with the requirements of the UK PAS 9017 《Plastics - Polyolefins for biodegradation in terrestrial environments – Specification》 and the national standard GBT22047-2008/ISO17556-2003 《Determination of the ultimate aerobic biodegradability of plastic materials in soil by measuring the carbon dioxide evolved》 (refer to Table 2).

Table 1: Test Report for biodegradable PE shrink film (40 micron)

Table 2: SGS Test Report

In summary, Sunward Company's development of PE biodegradable shrink film have no identical literature reports both domestically and internationally. The tensile strength of the shrink film is superior to reported values in foreign literature, but lower than reported in domestic literature. The elongation at break is lower than reported values in both domestical and international literature, but two values both meet standard requirements. The degradation performance complies with the UK standard PAS 9017 and the national standard GBT22047-2008/ISO17556-2003. Therefore, the PE biodegradable shrink film developed by Sunward Company in Shanghai has fulfilled an international advanced standard.