In a Shoe Press Mullen increases with impulse but at some point insipient crushing significantly reduces the rate of increase. The lightly refined furnish does not exerience crushing. Burst and Tensile strength both increase with refining. Tear initially increases but then rapidly decreases because the fibres are becoming shorter. The compressive strength improves with density.
Short fibres have much less initial compressive strength than long fibres.
The dryness and finql sheet density are intimately related for a given furnish. It is not possible to change this relationship by pressing, except by a very small amount. The mechanical furnishes have a very steep slope because of the stiff fibre walls compared to the chemical pulp. The roll press and the shoe press data lie along the same dryness-density line for a given pressing temperature. Within a very small tolerance, there is no inherent difference between the two press types when it comes to achieving density and dryness.