Many types of paper can now be recycled, which is great, but textile waste is still mostly thrown away or incinerated. A new technology could change that by combining the two materials, using discarded cotton clothing to strengthen the wrapping paper.

From left: Researchers Alexander Weissensteiner, Alexander Wagner and Thomas Harter with paper pattern Lunghammer made from 30% recycled cotton fibers - University of Technology Graz

The process is being developed by a team led by Thomas Harter, a postdoctoral researcher at Austria's Graz University of Technology.

Discarded cotton clothing is first mechanically shredded into shreds and then mixed with a water-based solvent solution. The mixture is then milled to pull the intertwined cotton fibers apart without allowing them to clump together or form neps.

The resulting fibrous pulp is said to be much like the pulp used to make paper. In fact, this substance will be addedto recycled pulp used in the production of packaging paper such as cardboard, thereby increasing the strength of the finished product.

Shredded cotton is soaked in an aqueous solution before grinding

According to reports, laboratory tests show that even if the reinforced paper contains only 30% textile fibers, it is still significantly stronger than packaging paper made purely from recycled paper fibers. This is because the average length of textile fibers is 1.7 mm, which is much longer than comparable paper. The main component of both cotton fiber and wood fiber, traditionally used in papermaking, is cellulose.

Importantly, plasticized packaging paper can be processed like regular paper. It has a brown color mixed with colorful flecks of color-dyed fabric, but this property has no impact on its performance.

It is hoped that once the technology is further developed it could prevent textile waste from entering landfill, produce stronger packaging paper that lasts longer before needing to be recycled, and reduce the amount of waste paper required to produce packaging paper.

Harter and colleagues are currently exploring ways to expand the technology to industrial uses, including reducing the energy requirements of the milling process. This can be accomplished by pretreating the shredded fabric with enzymes, which allow the cotton fibers to unravel more easily.