Biodegradability of Nonwoven Bags: Fact or Fiction?
With the global push to reduce plastic usage and implement plastic bans, manufacturers are seeking alternatives to plastic shopping bags, and nonwoven shopping bags have emerged as a popular choice. However, it is important to examine whether these nonwoven bags are truly biodegradable.
Composition and Manufacturing Process
Nonwoven bags differ from traditional woven or knitted fabrics as they do not require spinning and weaving processes. The main process involves consolidating a fiber mesh through methods such as spunbonding, spunlacing, impregnating, needle punching, and hot rolling. The raw materials used in the nonwoven fabric industry primarily consist of polypropylene (63%), polyester (23%), viscose (8%), acrylic (2%), polyamide (1.5%), and other fibers. Nonwoven fabrics find applications not only in shopping bags but also in wipes, food packaging, disposable surgical cloth, masks, tablecloths, as well as in various industrial and agricultural fields.
Biodegradability of Nonwoven Bags
The biodegradability of a fabric primarily depends on the type of fibers used. Natural fibers can biodegrade, but the majority of nonwoven shopping bags on the market are made from polypropylene, which is derived from petroleum and classified as a plastic, similar to polyethylene. While polypropylene is relatively fragile and decomposes more easily than other plastics, the resulting powder can persist in the soil, causing pollution to the environment, including the soil and groundwater, for hundreds of years.
Misconceptions about Nonwoven
There are misconceptions propagated online regarding the environmental friendliness of nonwoven fabrics. Claims such as “nonwoven fabrics can naturally decompose in 90 days outdoors” or “nonwoven fabrics are easy to decompose, non-toxic, and non-polluting” are baseless. In reality, like other polymer materials, plastic bags take decades to degrade in nature, and nonwoven fabrics made from polypropylene are no exception.
Advantages of Nonwoven Bags
While replacing one plastic with another may seem futile, nonwoven bags have certain advantages. The primary advantage is their reusability. After the implementation of plastic restrictions, the utilization rate of plastic bags in China’s supermarket retail industry decreased by an average of 66%, resulting in a significant reduction of nearly 40 billion plastic bags. Although nonwoven shopping bags have witnessed increased usage, the overall plastic consumption has significantly decreased due to their reusability.
Recycling of Nonwoven Bags
Efforts are underway in many countries to increase the recycling rate of nonwoven products and minimize their environmental impact. However, recycling nonwoven fabrics involves complex considerations. Certain nonwoven products used in sanitary items or containing harmful substances cannot be recycled. Additionally, the recycling of nonwoven fabrics in categories other than shopping bags and primary service products is challenging due to complexity and difficulty in distinguishing materials. Composite materials, resulting from processes like printing or lamination with materials like PE or PET, pose obstacles to effective recycling and reuse.
Research and Progress
Manufacturers are currently exploring the addition of functional additives to polypropylene materials in order to enhance the degradation performance of nonwoven. However, there are no nonwoven products available on the global market that ensure rapid and economically viable degradation.
The journey towards environmental protection is still ongoing, and there is a need for continued collaborative efforts. While nonwoven made from polypropylene are not biodegradable and can contribute to pollution, their reusability and potential for recycling present advantages over traditional plastic bags. Nonetheless, more research and innovation are required to develop truly biodegradable alternatives and improve the recycling capabilities of nonwoven products.