Kitchen or bathroom cleaning creams are made up of fine particles dispersed in a carrier fluid. They are usually applied using a cloth. In order to provide effective cleaning an abrasive cleaning product should give maximum soil removal with minimum substrate damage. To understand how the cleaning product works to remove soil it is necessary to understand how the cloth, particles and carrier fluid interact in the cleaning contact.
The aims of this work were threefold; to visualise particles entering into and passing through abrasive cleaning contacts; to investigate the role of the carrier fluid, the abrasive particle and the cloth applicator; and to study how particles cause abrasion of soil layers on a substrate, and abrasive damage to the substrate.
Results from experiments carried out on a friction tester have indicated that particle settling/reorientation occurs in a sliding cloth pad leading to reduced friction and hence scratching. This leads to the concept of a critical distance of cleaning effectiveness. Particle penetration into a cloth has been shown to be dependent on particle size and cloth weave configuration. The effective modulus of a cloth has a large influence on the material removal process.
We are grateful to the Household Care Department at Unilever Research for sponsorship of this work.