In a jointly-developed new production process, Voith Paper and Trützschler have successfully produced nonwovens that adhere to the latest INDA and Edana Flushability Guidelines and consequently have been certified as ‘flushable’.

For nonwovens manufacturers, such products that can be safely disposed of in toilets are currently a small but economically rewarding and growing market segment. Strong demands, however, are made on the structure of such materials – they have to be strong enough for cleaning while successfully dispersing in the sewage system or the environment after disposal.

The wet laid and hydroentangled nonwovens Voith and Trützschler have developed are characterised by a high level of wet strength, consisting only of fibres of natural origin that quickly disperse in water, and that are 100% biodegradable.

The raw material is exclusively cellulose, the main component being bleached long fibre pulp as used in paper manufacturing. A small percentage of viscose fibres spun from cellulose ensures the required strength. The newly developed production process uses neither binding agents nor melt fibres, guaranteeing that the wipes quickly disperse in water and the fibre material is completely biodegradable. Another advantage of the large quantity of long fibre pulp is that it significantly lowers production costs.

Flushability certification is an impressive example of the efficiency of the newly-developed production process with its core components of Voith’s HydroFormer for web formation and the Trützschler AquaJet for web bonding.

In August, the American and European Nonwovens Associations INDA und EDANA published the third edition of its flushability guidelines developed in cooperation with waste water authorities and the nonwovens industry. They specify seven material tests to establish standardised measurement methods. All must be passed for a product to be certified flushable.

The tests cover flushability and dispersement of the nonwoven product into single fibres, as well as degradation by means of aerobic and anaerobic bacteria. Just one negative test result makes ‘Do not Flush’ marking now mandatory.