Phill if you put a crb alongside a rotary you will see the differemce, A single brush rotating in one direcention is flattening the pile, Crb s lift and open the pile. You only need to see the crud and the sand that is brought up with a crb to realise the effectiveness. The single direction on a rotary will flatten the pile a lot more.
The black brushes for the von schader are as stiff as the holloway, the white brushes are very gentle. Again the cotra rotating brush head is getting to different sides of the fibres and does not leave swirls that you will get with a single brushas.
Foam as a media has the greatest penetration the thicker bristles will not determine the amount of foam produced. As said before foam with it neutral ph has it limitations but this can be altered by using additives. Oxidisers are enhanced with the penetrating abilities of the foam.
I think it takes along time mastering foam cleaning because of it limitations and it is just a lot quisker and easier to fire up the truckmount, but for quite some time my marketing was based around the low moisture advantages of upholstery cleaning with dry foam.
Every system has its uses but some of these systems take time to perfect.
Peter
www.carpetcleanercardiff.comhttp://