It is known in the art to use a press to simulate a low strain activation operation such as the one discussed in published international application WO 99/56685. The press comprised a stationary first plate having first teeth, a second plate having second teeth, a movable ram to which the second plate was coupled, a rotary servo motor coupled to the ram, and a controller for controlling the operation of the rotary servo motor such that the second plate was moved toward the first plate so that a workpiece was engaged by the teeth of the first and second plates. The press did not include sensors of any sort for providing feedback information, such as position or force information concerning the ram, the plates or the motor, to the controller. Nor was the press used to simulate a fusion bonding operation.
U.S. Pat. Nos. 4,854,984 and 4,919,738, the disclosures of which are incorporated herein by reference, disclose a bonding apparatus for bonding portions of plural workpiece layers together, wherein at least one of the workpiece layers comprises a thermoplastic layer. The apparatus comprises a patterned cylinder 22, an anvil cylinder 24, and means 26 for adjustably biasing the cylinders 22 and 24 together. The patterned cylinder 22 is provided with a “saw-tooth shape pattern of protuberances 51 which extend circumferentially about each end of the cylinder,” see column 4, lines 65-67 of the '984 patent.
A simulation apparatus is currently unknown which would allow engineers/technicians to quickly and relatively inexpensively test workpieces/web materials to determine the effects of compression loading on a point site of such a workpiece/web material in a nip type process, such as a fusion bonding operation effected using first and second rolls, one of which is provided with a plurality of protuberances. Instead, an apparatus for effecting a nip type process must be constructed, such as an apparatus comprising first and second fusion bonding rolls, so as to allow workpieces to be passed through those rolls to effect a test operation.
Accordingly, there is a need for an apparatus for simulating compression loading of a point site on a workpiece in a nip type process, such as a fusion bonding operation.