Method for control of ceiling tile process
AssigneeMeasurex Corporation
InventorsAl Al-Shaikh, Erik B. Dahlin
Life of this patent
Estimating the term…
Abstract
A process for controlling the dry density of ceiling tile where a delayed measurement of thickness or caliper is compared with an off-line oven dry basis weight measurement of a previously taken sample to provide dry density which is then compared to a dry density target to yield an error signal which updates an on-line wet density indication to provide control of stock flow.
Claims2
A method for the control of oven dry density of a moving sheet material where the on-line measurement of moisture before said sheet material is dried is not feasible due to the type of sheet material being manufactured said method comprising the following steps:
- measuring the total basis weight of said material;
- measuring the thickness of said material, the ratio of basis weight and thickness providing the wet density of said material;
- utilizing said wet density in a feedback control loop to control such density to a target;
- obtaining a sample of wet material;
- drying such sample in a manner equivalent to the oven drying of said sheet material, obtaining the oven dry density of said material by division with a thickness measurement taken substantially at the time said sample was obtained;
- compared said oven dry density of said sample with a predetermined dry density target to produce an error signal;
- and utilizing said error signal to update said wet density in a manner to achieve said dry density target.
Dependencies are inferred from the claim text.