Biodegradable products and how to make them?
Updated: Mar 31, 2022
Biodegradable products can be defined as products that can be decomposed by the naturally occurring living micro-organisms and converted into water, carbon dioxide and biomass. The raw materials of biodegradable products can be micro-organisms, renewable feedstock, petrochemical or all of these.
The biggest market of biodegradable products is single-use plastic products like food packaging, various bags like carry bags, courier bags, garbage bags, medical waste bags, grocery bags, etc., spoons, forks, straws, glass, cups, containers, plates, bowls, food box, etc. Depending on processing techniques, more details on the manufacturing process are given below.
Blown film extrusion products:
It includes carry bags, D-cut bags, courier bags, product covers, grocery bags, food packets, garbage bags, medical waste bags, agricultural mulch film, etc. The certified compostable raw material is used to make these items. Pure biopolymers like PLA, PBAT and PBS can not be used directly to make these products due to the high cost of end products, difficulties in achieving desired properties in end product and absence of required additives for proper processing. Hence, compounding needs to be done with materials like biopolymers, fillers and additives (stabilizer, antioxidant, plasticizer, impact modifier, nucleating agent, etc.).
This compound can be used to process in existing mono-layer or multi-layer blown film machines to make the desired film. As per the requirement of film, various additives and biopolymer content need to be tuned. The compound is also easily available in the market for processors.
Injection-molded & extrusion products:
Biodegradable injection molded products are mostly spoons, forks, knives, stirrers, food containers, cups, glass, straws, etc. Similarly, compounded material is required to manufacture these products and the content of it needs to be adjusted as per the requirements. Existing injection molding machines and existing mold can be used to manufacture biodegradable products. Likewise, the existing extrusion line can be used to make biodegradable straws. Only machine process parameters need to be adjusted.
Glass, cups, lids, trays, containers, etc. are thermoformed single-use products, that can be made from biodegradable materials with existing machinery. Some grades of pure PLA (for example Luminy LX175) can also be used directly to make thermoforming products. However, to achieve better properties of the final product and processing stability, compounded material with major content of PLA is preferable. Here, a minor change in the existing machinery is required and pre-drying of material by dehumidifier is advisable.
Bagasse tableware products:
Here, the products like plates, compartment plates, trays, dishes, bowls, cups, food boxes, containers, etc. are made from sugarcane bagasse. The main raw material is sugarcane bagasse sheets, that is readily available in the market. These sheets are mixed with water and additives. The wet pulp is forwarded to the press to mold into a product. Afterward, it goes for trimming and finishing.
Currently. These products are more in demand because special certifications like compostable plastic are not required to manufacture these products. Moreover, it is comparatively less costly. Users also like its look and feel.
The biodegradable products market is being developed rapidly and it has the potential to replace the whole single-use plastic products market. Government policy, cost competitiveness and public awareness are key drivers of the market.