Pressure distribution at the teat–liner and teat–calf interfaces

Different graph types of the pressure in time relative to the maximum pressure at the teat end. Type A=pressure built up and decreased rapidly; type B=pressure increased slowly and decreased quickly; and type C=pressure built up rapidly, immediately followed by a slow decrease. The tangents of the curves were determined between zero pressure and the moment when pressure exceeded 90% of its maximum. The threshold above 90% was chosen to determine the time when a high pressure was exerted to the teat. The graph types describe liner types in Table 2.

Projections of teat load as measured separately with the pressure sensor and later reconstructed in one image according to this matrix.

Pressure in time (s) measured at gauge point A7 (Figure 4); the 6 moments during the act of suckling and swallowing are indicated with dotted lines. During moments 1 and 5, no pressure was applied to the teat. From moment 1, the pressure increased to a maximum at moment 3. Thereafter, pressure decreased.

Example of the pressure distribution at the calf–teat interface at moment 3. The columns and rows correspond with the projections described in Figure 2.

Example of the pressure distribution at the artificial teat–liner interface of a round silicone liner at the moment of maximum compressive load. The columns and rows correspond to the projections described in Figure 2.

Pressure changes at gauge point C9 (Figure 5) applied to the artificial teat in time (s) and the corresponding vacuum level. The vacuum and the pressure during pulsation were not simultaneously sampled. The vacuum curve (gray curve) in this figure is provided as a visual aid for understanding the pressure–vacuum relationship.