differentroughness parametersat two cut-offwavelengths (2.5 and 0.8 mm) and
looked for correlationsbetween those parametersor combinationsof parameters
and the contaminations that remained aftercleaning of six flooringmaterials
inserted for four weeksin a cheese processingsite. Asperitiestaken into account
by parameterscalculatedwiththe cut-offwavelengthof 2.5 mmgavelower
correlations,suggestingthatthereis a thresholdvalue for the diameter of
asperitiesunderwhichthe soil is not removedby the mechanicalactionof the
hygiene procedure.Thiscorroborates the findingof Taylorand Holah(1996),
who observed that the gross topographic irregularities of floor were not
responsiblefor theircleanability performance.The Mettler and Carpentier study
showed thatRvk, the reducedvalleydepththat characterisesthe depth of the
inwardly directedportionof the surfaceprofile, was a betterparameterthanRa.
As slip resistance is supposed to be linkedwithotherroughness parameters,it
should be possible to select cleanablematerials withhighslip resistance.
Fig. 9.3 Stereomicroscopefor viewingtexturedefaults.176 Handbookof hygiene controlin the foodindustry