This innovation makes paper bags stronger, reusable and cheaper
Even though state stores are phasing out the use of single-use plastics and offering customers alternatives like paper bags, these bags pose a problem when trying to transport wet items like packets of milk. , vegetables and fish. In addition, the paper-only bags are expensive due to the cost of production.
To overcome these problems, Dhananjay Hegde, co-director of District Industries Center, Karwar, has developed paper bags that are not only waterproof to a large extent, but also reusable (when dried at room temperature), recyclable and affordable.
He had developed a prototype (demonstration machine) last year and now, together with Dattatreya Bhat, a mechanical engineer from Kumta in the Uttara Kannada district, is working on the development of an improved manual machine that can be used on a level.
“Following the state’s single-use plastic ban in 2016, several stores / retailers have started looking for viable alternatives. And the most feasible option they found was non-woven bags. Although these bags look and feel like fabric bags and are widely considered to be “eco-friendly”, most of them used in the market contain polypropylene and polyester, which is nothing. other than plastic. So I wanted to find a better alternative, ”Hegde explains.
From paper to bags
To make these recyclable paper bags, Hegde uses newspaper waste. Two layers of paper are reinforced with a banana fiber liner or sewing thread using a resin derived from corn starch. As newspaper sheets are porous in nature, they absorb resin better, making the bag waterproof to a large extent. The corn starch resin can make the bag a little harder. Rain tree powder and other materials are added to give a smooth finish to the sheet of paper. Thread rolls have been built into the machine to help with the lining. Once the “waterproof” paper rolls are ready, they can be made to any shape and size.
“The bag can hold up to five kg, and our office staff have used and tested it. The carrying capacity of the bag can be further increased, ”explains Hegde.
He adds that these bags can be used as packing material and are more useful in coastal areas for transporting fish. Plastic bags are used in large quantities in fish markets.
While Hegde had developed the demo machine using PVC pipes, the user-friendly machine set up by Bhat has a steel structure made with a unique pressing technique to achieve precise dimensions and durability.
“The weaving machines available on the market cost around Rs 15 to 20 lakh, while our machine which produces the ready-to-use paper has been developed at around Rs 1.5 lakh. This includes research and development costs. On average, we expect 300 small paper bags to be produced on this machine per day. However, that would ultimately depend on the skill of the worker, ”Bhat explains.
He adds that he will start production shortly. While a normal medium sized paper bag would cost around Rs 15, these bags would cost around Rs 4-5. Once the bulk production started and the machine perfected, the cost per bag would decrease.
Hegde says that normal paper which is also fully biodegradable can be used to make these “waterproof” bags instead of newspaper, but that would cost more.
Plus, unlike single-use plastics, these bags can be sent for recycling and therefore can be checked from clogged drains or litter-strewn streets. The cost of installing and operating the machine is relatively low, so it can be set up as a cottage industry. It can help provide employment for several people as well.
Sandhya Narayanan, based in Bengaluru, an expert in solid waste management, said that although these newspaper bags cannot be considered completely biodegradable due to certain elements like ink in newspaper printing, they are better. than plastics because newspapers can be classified as recyclable materials.
Dhananjay Hegde can be contacted on +91 94813 72678.