For maximum protection and grade change prevention, it is best practice to change milk filters after every milking.
By changing the filter each milking, sediment build-up is kept minimal, thereby preventing potential grading. It is not only best practice, but also more cost effective than cleaning and reusing filters, as it takes less man hours to change out a new filter that it does to clean and dry old ones*. Old filters let sediment build up in the stretched fibres, which in turn allows more containments through into the milk flow and the filter can split completely.
* A new filter costs approx 50c, whereas it takes at least $1 of labour to wash the filter (working on an average of 5 minutes per filter at an hourly rate of $12.)
All Skellerup Dairy Products that come into contact with milk are Food Grade Compliant. NZFSA Milk Filter Regulations - 6cm² of filtration per cow milked.
To check filtration; 2 x width of filter paper x length x 80%
e.g. 300 cows require 1800cm² of filtration (minimum)
A 150 x 760mm filter element = 2 x 150 x 760 x 80% = 1824cm² (the 80% allows for folding ends).