Press Machines

The main difference between pneumatic and hydraulic press machines is in their power (or force, to be technical).  A hydraulic press can produce substantially more force than a pneumatic press, but the pneumatic variant makes up for this by being faster, cleaner, simpler, easier to work on and lower priced. In industrial manufacturing, pneumatic presses are preferred for component assembly and fabrication tasks where human safety is paramount, and hydraulic presses only where huge forces are required. 

Friction-fit assemblies are very popular in medical device manufacturing, for a few key reasons: When compared to other joining technologies, such as ultrasonic welding and adhesive bonding, press fitting shines where low cost, no added material and minimal structural integrity are called for. Of special note will be to make sure that the device does not need a hermetic, hygienic seal, which would call for a leak-free joint instead of a press-fit joint.

Press machines are categorized in a few different ways. When described by motive force, press machines are available in hydraulic, pneumatic, electric or hand-operated styles. When describing their level of automatic functionality, presses can be configured to be fully automated, semi-automated or manual. Lastly, when describing their overall design, most presses are made to be vertical presses (with the actuating cylinder pressing down onto a fixed work deck), but sometimes custom horizontal, angled, mobile or multi-axis presses are produced as well.   

The easiest answer is to contact a qualified press system manufacturer or engineer to get assistance. It is imperative that press machines are sized appropriately so as not to risk injury to operators or damage to components. Multiple technical factors all compile into a total force value, including material selection, surface friction, interference resistance, temperature, machining tolerances and even the speed of the press. In addition, part of a proper press force calculation relies on experience, such as with surface galling, thermal expansion and stress/strain impacts on the overall part.