Method and apparatus for forming rigid paper products from wet paperboard stock

Claim 1

A METHOD OF FORMING A RIGID PAPER PRODUCT FROM PAPERBOARD STOCK HAVING A HIGH BULK AND A LOW DENSITY IN THE RANGE OF FROM ABOUT 8.8 TO ABOUT 9.6 POUNDS PER 0.001 IN. THICKNESS PER 3000 SQ. FT. AREA, A HIGH MOISTURE CONTENT IN THE RANGE OF FROM ABOUT 15% TO ABOUT 35% BY WEIGHT, BASED ON THE WEIGHT OF THE FINISHED PAPERBOARD STOCK, AND A THICKNESS IN THE RANGE OF FROM ABOUT 0.016 TO 0.040 IN., COMPRISING THE STEPS OF GRIPPING THE PAPERBOARD STOCK AROUND THE PERIPHERY OF A REGION TO BE FORMED, FORMING THE SAID REGION BETWEEN A PAIR OF FORMING DIES IN THE PRESENCE OF HEAT, SAID FORMING DIES INCREASING THE AREA OF THE REGION FORMED AND INVOLVING REORIENTATION OF THE FIBERS OF THE PAPERBOARD STOCK, AND WITHDRAWING THE VAPORS EVOLVED FROM THE PAPERBOARD STOCK FROM BETWEEN THE FORMING DIES DURING THE FORMING OPERATION, THE FORMING OPERATION BEING CARRIED OUT WITHOUT REDUCING THE THICKNESS OF THE STOCK MORE THAN 0.005 INCH SO AS TO AVOID COMPRESSING THE PAPERBOARD STOCK TO SUCH AN EXTENT THAT THE REMOVAL OF MOISTURE FROM THE PAPERBOARD STOCK IS IMPEDED.

Claim 2

A METHOD OF FORMING A RIGID PAPER PRODUCT FROM PAPERBOARD STOCK HAVING A HIGH BULK AND A LOW DENSITY IN THE RANGE OF FROM ABOUT 8.8 TO ABOUT 9.6 POUNDS PER 0.001 IN. THICKNESS PER 3000 SQ. FT. AREA, A HIGH MOISTURE CONTENT IN THE RANGE OF FROM ABOUT 15% TO ABOUT 35% BY WEIGHT, BASED ON THE WEIGHT OF THE FINISHED PAPERBOARD STOCK, AND A THICKNESS IN THE RANGE OF FROM ABOUT 0.016 TO 0.040 IN., COMPRISING THE STEPS OF GRIPPING THE PAPERBOARD STOCK AROUND THE PERIPHERY OF A REGION TO BE FORMED, FORMING THE SAID REGION BETWEEN A PAIR OF FORMING DIES IN THE PRESENCE OF HEAT, SAID FORMING DIES INCREASING THE AREA OF THE REGION FORMED AND INVOLVING REORIENTATION OF THE FIBERS OF THE PAPERBOARD STOCK, AND WITHDRAWING THE VAPORS EVOLVED FROM THE PAPERBOARD STOCK FROM BETWEEN THE FORMING DIES DURING THE FORMING OPERATION, THE FORMING OPERATION BEING CARRIED OUT WITHOUT REDUCING THE THICKNESS OF THE STOCK MORE THAN 0.005 INCH SO AS TO AVOID COMPRESSING THE PAPERBOARD STOCK TO SUCH AN EXTENT THAT THE REMOVAL OF MOISTURE FROM THE PAPERBOARD STOCK IS IMPEDED.

Claim 3

A METHOD FO FORMING A PAPER PLATE COMPRISING THE STEPS OF INTRODUCING PAPERBOARD STOCK BETWEEN TOW FORMING DIES, SAID PAPERBOARD STOCK BEING OF HIGH BULK AND HAVING A LOW DENSITY IN THE RANGE OF FROM ABOUT 8.8 TO ABOUT 9.6 LBS. PER 0.001 IN, THICKNESS PER 300 SQ. FT., A THICKNESS IN THE RANGE OF FROM ABOUT 0.016 TO ABOUT 0.040 INCH AND A HIGH MOISTURE CONTENT IN THE RANGE OF FROM ABOUT 15% TO ABOUT 35% BY WEIGHT, BASED ON THE WEIGHT OF FINISHED PAPERBOARD STOCK, GRIPPING THE PAPERBOARD STOCK BETWEEN A GRIPPING RING AND ONE OF THE FORMING DIES IN A NARROW BAND AROUND A REGION TO BE FORMED, BRINGING THE DIES TOGETHER IN THE PRESENCE OF HEAT TO FORM THE PAPERBOARD TO THE SHAPE OF A PLATE, SAID FORMING OPERATION SUBSTANTIALLY INCREASING THE AREA OF THE FORMED PAPERBOAD WITHOUT COMPRESSING THE STOCK MORE THAN ABOUT .005 INCH, AND REMOVING THE EVOLVED VAPOR FROM AT LEAST ONE SURFACE OF THE FORMED PAPERBOARD.

Claim 4

A METHOD FO FORMING A PAPER PLATE COMPRISING THE STEPS OF INTRODUCING PAPERBOARD STOCK BETWEEN TOW FORMING DIES, SAID PAPERBOARD STOCK BEING OF HIGH BULK AND HAVING A LOW DENSITY IN THE RANGE OF FROM ABOUT 8.8 TO ABOUT 9.6 LBS. PER 0.001 IN, THICKNESS PER 300 SQ. FT., A THICKNESS IN THE RANGE OF FROM ABOUT 0.016 TO ABOUT 0.040 INCH AND A HIGH MOISTURE CONTENT IN THE RANGE OF FROM ABOUT 15% TO ABOUT 35% BY WEIGHT, BASED ON THE WEIGHT OF FINISHED PAPERBOARD STOCK, GRIPPING THE PAPERBOARD STOCK BETWEEN A GRIPPING RING AND ONE OF THE FORMING DIES IN A NARROW BAND AROUND A REGION TO BE FORMED, BRINGING THE DIES TOGETHER IN THE PRESENCE OF HEAT TO FORM THE PAPERBOARD TO THE SHAPE OF A PLATE, SAID FORMING OPERATION SUBSTANTIALLY INCREASING THE AREA OF THE FORMED PAPERBOAD WITHOUT COMPRESSING THE STOCK MORE THAN ABOUT .005 INCH, AND REMOVING THE EVOLVED VAPOR FROM AT LEAST ONE SURFACE OF THE FORMED PAPERBOARD.