Abstract A thin-walled honeycombed structure is made by extruding a plastically deformable batch, including ceramic materials mixed with water and a methyl cellulose extrusion aid, through a die apparatus comprising an extrusion barrel, an extrusion die extending transversely across the barrel and a mask located around the periphery of the outlet face of the die for inwardly moving peripheral portions of the extruded structure to form an integral skin of material. The temperature of the batch as it is placed into the barrel is 2*-25*F. (preferably 5*-15*F.) above the gel point of such batch. The extrusion barrel is maintained at a temperature 0*-15*F. (preferably 5*-12*F.) less than the temperature of the ceramic batch placed in the barrel (and preferably not less than 5*F. below the gel point of the batch) to form a uniform skin of desired thickness on the honeycombed structure.
A METHOD OF MAKING A HONEYCOMBED STRUCTURE BY EXTRUDING A PLASTICALLY DDEFORMABLE BATCH THROUGH A DIE APPARATUS COMPRISING AN EXTRUSION DIE HAVING AN INLETT FACE AND AN OUTLET FACE, AN EXTRUSION BARREL IN COMMUNICATION WITH THE INLET FACE AND AN EXTRUSION MASK IN COMMUNICATION WITH THE OUTLET FACE, THE METHOD COMPRISING THE STEPS OF PLACING A PLASTICALLY DEFORMABLE BATCH IN THE EXTRUSION BARREL PRIOR TO EXTRUSION, FORMING THE EXTRUSION BATCH THROUGH THE EXTRUSION DIE TO FORM AN EXTRUDED HONEYCOMBED STRUCTURE AND FORCING THE EXTRUDED HONEYCOMBED STRUCTURE THROUGH AN ORIFICE IN THE MASK SO AAS TO MOVE PERIPHERAL PORTIONS OF THE EXTRUDEDD STRUCTURE INWARDLY TOWARD THE EXTRUSION AXIS AND COLLAPSE PERIPHERAL CELLS TO FORM AN INTEGRAL SKIN OF MATERIAL AT THE PERIPHERY OF THE STRUCTURE, THE IMPROVEMENT COMPRISING THE STEPS OF PROVIDING THE BATCH AS A BLENDED MIXTURE OF PARTICULATE MATERIAL CONTAINING WATER AND METHYL CELLULOSE AND HAVING A GEL POINT, PROVIDING THE BATCH AT THE TIME OF PLACING IT IN THE BARREL WITH A TEMPERATURE OF ABOUT 20*-25*F. ABOVVE THE GEL POINT OF THE BATCH, AND MAINTAINING THE TEMPERATURE OF THE EXTRUSION BARREL ABOUT 0*-15*F. LESS THAN THE TEMPERATURE OF THE BATCH PLACED IN THE BARREL SO AS TO FORM A SUBSTANTIALLY UNIFORM SKIN AT THE PERIPHERY OF THE STRUCTURE.
Claim 2
Independent Claim
210 words
A METHOD OF MAKING A HONEYCOMBED STRUCTURE BY EXTRUDING A PLASTICALLY DDEFORMABLE BATCH THROUGH A DIE APPARATUS COMPRISING AN EXTRUSION DIE HAVING AN INLETT FACE AND AN OUTLET FACE, AN EXTRUSION BARREL IN COMMUNICATION WITH THE INLET FACE AND AN EXTRUSION MASK IN COMMUNICATION WITH THE OUTLET FACE, THE METHOD COMPRISING THE STEPS OF PLACING A PLASTICALLY DEFORMABLE BATCH IN THE EXTRUSION BARREL PRIOR TO EXTRUSION, FORMING THE EXTRUSION BATCH THROUGH THE EXTRUSION DIE TO FORM AN EXTRUDED HONEYCOMBED STRUCTURE AND FORCING THE EXTRUDED HONEYCOMBED STRUCTURE THROUGH AN ORIFICE IN THE MASK SO AAS TO MOVE PERIPHERAL PORTIONS OF THE EXTRUDEDD STRUCTURE INWARDLY TOWARD THE EXTRUSION AXIS AND COLLAPSE PERIPHERAL CELLS TO FORM AN INTEGRAL SKIN OF MATERIAL AT THE PERIPHERY OF THE STRUCTURE, THE IMPROVEMENT COMPRISING THE STEPS OF PROVIDING THE BATCH AS A BLENDED MIXTURE OF PARTICULATE MATERIAL CONTAINING WATER AND METHYL CELLULOSE AND HAVING A GEL POINT, PROVIDING THE BATCH AT THE TIME OF PLACING IT IN THE BARREL WITH A TEMPERATURE OF ABOUT 20*-25*F. ABOVVE THE GEL POINT OF THE BATCH, AND MAINTAINING THE TEMPERATURE OF THE EXTRUSION BARREL ABOUT 0*-15*F. LESS THAN THE TEMPERATURE OF THE BATCH PLACED IN THE BARREL SO AS TO FORM A SUBSTANTIALLY UNIFORM SKIN AT THE PERIPHERY OF THE STRUCTURE.
Claim 3
Dependent Claim
44 words
The method of claim 1 wherein the temperature of the batch placed in the barrel is about 5*-15*F. above the gel point of the batch and the temperature of the barrel is about 5*-12*F. below the temperature of the batch placed in the barrel.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein the temperature of the barrel is not less than 5*F. below the gel point of the batch.
Claim 5
Dependent Claim
16 words
The method of claim 3 wherein the particulate material is a mixture of refractory metal oxides.
Claim 6
Dependent Claim
16 words
The method of claim 4 wherein the refractory metal oxides comprise silica, alumina and magnesium oxide.
Claim 7
Dependent Claim
29 words
The method of claim 5 wherein the methyl cellulose is 1-7% by weight of the oxides and the water is 25-40% by weight of The oxides plus methyl cellulose.