Managing Anisotropic Shrinkage and Restraint Fixturing in Polymer Metrology
Polymer metrology requires force-controlled restraint fixturing and thermal conditioning to isolate mold geometry from anisotropic shrinkage and sag.
Pneumatic Clamping Force
Meaning
Pressure exerted by air-powered actuators to hold a workpiece securely in place during machining or assembly. Pneumatic clamping force must be calculated to prevent part movement while avoiding structural deformation of the material. It relies on the regulated air pressure supplied to the fixture.
Mechanical Grip
Consistent holding power is required to maintain the alignment of a part as it undergoes high-speed cutting or drilling. In pneumatic clamping force, the air cylinders convert line pressure into a linear or rotational load that keeps the workpiece static. This force is easily adjusted by changing the input pressure at the manifold.
Higher forces are necessary for heavy milling where tool loads are extreme.
Pressure Regulation
Regulators maintain a constant supply to the clamping cylinders regardless of fluctuations in the main plant air line. In pneumatic clamping force, any drop in pressure could lead to the tool grabbing the part and pulling it from the fixture.
Safety Margin
Sudden loss of air pressure can lead to part ejection and operator injury. Pneumatic clamping force often incorporates check valves or mechanical locks to maintain the grip during a power failure. The design must ensure that the part is held safely even if the compressor stops running.