Abstract: A method and apparatus is disclosed for compensating for a reduction of die cavity pressure in a torsional rheometer caused by shrinkage of the test sample. In one embodiment, a compliant member is placed in series with load-bearing components of the rheometer. This compliant member deflects when pressure in the die cavity is reduced resulting in the die cavity becoming smaller to increase the pressure within the die cavity.

Abstract: A viscometer arrangement includes a detection system for detecting the proper placement of a rotor. An optical detection system may be used to detect the presence of an obstruction between the upper and lower dies while the upper and lower dies are in an open position.

Abstract: A method and apparatus is disclosed for compensating for a reduction of die cavity pressure in a torsional rheometer caused by shrinkage of the test sample. In one embodiment, a compliant member is placed in series with load-bearing components of the rheometer. This compliant member deflects when pressure in the die cavity is reduced resulting in the die cavity becoming smaller to increase the pressure within the die cavity.

Abstract: The present application relates generally to moving die rheometers, and more particularly to moving die rheometers that employ a variable eccentric cam. In one aspect, the eccentricity produced by the cam may be adjusted using shims of different thickness to alter the position of the post on the cam.

Abstract: A viscometer arrangement includes a detection system for detecting the proper placement of a rotor. An optical detection system may be used to detect the presence of an obstruction between the upper and lower dies while the upper and lower dies are in an open position.

Abstract: A method and apparatus is disclosed for compensating for a reduction of die cavity pressure in a torsional rheometer caused by shrinkage of the test sample. In one embodiment, a compliant member is placed in series with load-bearing components of the rheometer. This compliant member deflects when pressure in the die cavity is reduced resulting in the die cavity becoming smaller to increase the pressure within the die cavity.

Abstract: The present application relates generally rheometers. In one aspect, misalignment of the air cylinder with respect to the cross-head is accommodated using a flexible coupling between the air cylinder and the cross-head so as to prevent binding and stuttering of the machine due to misalignment.

Abstract: The present application relates generally rheometers. In one aspect, misalignment of the air cylinder with respect to the cross-head is accommodated using a flexible coupling between the air cylinder and the cross-head so as to prevent binding and stuttering of the machine due to misalignment.

Abstract: The present application relates generally to moving die rheometers, and more particularly to moving die rheometers that employ a variable eccentric cam. In one aspect, the eccentricity produced by the cam may be adjusted using shims of different thickness to alter the position of the post on the cam.

Abstract: A rheometer die with a groove configuration for reducing sample slippage in a rheometer chamber is provided. The rheometer die includes a surface and at least one radial groove extending into the surface. The groove defines at least a portion of a sample-holding chamber constructed to hold a sample. The groove may include a first zone and a second zone with a transition zone therebetween. The groove may also include a substantially wedge-shaped portion with sidewalls which taper generally towards the center of the rheometer die such that imaginary extensions of the sidewalls intersect before reaching the center of the die. A plurality of grooves may extend into the rheometer die. The rheometer die may be incorporated into a rheometer for testing process characteristics of a material.

Abstract: A rheometer die with a groove configuration for reducing sample slippage in a rheometer chamber is provided. The rheometer die includes a surface and at least one radial groove extending into the surface. The groove defines at least a portion of a sample-holding chamber constructed to hold a sample. The groove may include a first zone and a second zone with a transition zone therebetween. The groove may also include a substantially wedge-shaped portion with sidewalls which taper generally towards the center of the rheometer die such that imaginary extensions of the sidewalls intersect before reaching the center of the die. A plurality of grooves may extend into the rheometer die. The rheometer die may be incorporated into a rheometer for testing process characteristics of a material.