Part 6:General calculation of the bonding pressure for hydraulic presses

For attaining the correct bonding pressure or different board sizes it is necessary to calculate the pressure exerted by the pistons and the corresponding pressure gauge pressure. Formula:

Formula:
(Required pressing pressure [bar] / Number of pistons [–]) × (sheet area [cm²] / piston area [cm²]) = gauge pressure [bar]

with piston area = r² × π [cm²]

Example:
A hydraulic press is given, 6 pistons with 12 cm diameter each (i. e. radius r = 6 cm), furthermore a board to be laminated 210 cm × 80 cm. The bonding
pressure is to be 3 bar.

( 3 [bar] / 6 [–] ) × ( (210 [cm] × 80 [cm]) / 6² [cm²] ) ≙ 74 bar gauge pressure

Notes:

• For workpieces with frame structures, only the load-bearing surface of the frame and the insert (e.g. honeycomb) is to be taken into account.
• 1 bar ≙ 0.1 N/mm² ≙ 100 kPa ≙ 1 kp/cm²