Finnish team develops new cardboard recycling process

Hygiene and home care products are among the items that can be manufactured from the biodegradable non-wovens.

The manufacturing costs of cardboard-based non-wovens are said to be around 20 per cent lower than for non-wovens produced from wood raw materials.

Non-wovens are essentially consumer goods that, once used, end up in a landfill site. In metropolitan areas alone, an estimated 10,000 tonnes of nappies and sanitary towels are disposed of each year. The principle raw material in non-wovens manufacture is biologically non-degradable polyester. Up until to now, market entry for bio-based non-wovens derived from wood has stalled because of prohibitive production costs.

‘Now for the first time we can make use of recycled paper and cardboard as a non-wovens raw material,’ said Ali Harlin, a Research Professor at VTT. ‘The new process means that bio-based non-wovens are now more competitive on price in comparison with plastic-based products.

‘The manufacturing costs of cardboard-based non-wovens are around 20 per cent lower than for non-wovens produced from wood raw materials. New business opportunities should open up fairly rapidly, since the technology required for manufacturing non-wovens from recycled materials is already in place.’

According to VTT, Europe generates around 60 million tonnes of recycled paper annually, of which cardboard makes up around 40 per cent. The demand exists for new applications and technology for exploiting recycled paper due to the EU’s objective of raising the proportion of recycled paper to 70 per cent.

The method developed by VTT could extend future possibilities for re-use, particularly in the case of cardboard, which is more cost-effective as a raw material than fine paper.

Cleansing the cardboard of filler material, lignin and hemicellulose is a key part of non-wovens manufacture.

VTT has matched several fibre-processing methods in the preparation of dissolving pulp to assist in obtaining pure cellulose from the recycled cardboard.

The dissolving pulp produced in the research project was regenerated using VTT’s patented carbamate technology, which is claimed to be safer and more environmentally friendly than the traditional viscose process. The non-wovens were manufactured with foam forming technology that uses little water.

Around 1.9 million tonnes of various types of non-wovens were manufactured in Europe in 2011. Strong growth in the global market for non-wovens is forecast to continue for the foreseeable future. Apart from hygiene, health and cleaning products, the non-wovens have further applications in, among others, the construction industry.