Process for axial skinning apparatus

A process for operating an axial skinning apparatus for continuous manufacture of skinned ceramic honeycomb parts, the apparatus comprising:

• a skinning chamber that receives a source of flowable skin cement and receives a part to be skinned by the cement;
• and an annulus gap defined by the space between the skinning chamber and the part to be skinned;
• the process for operating the axial skinning apparatus comprising:
• determining physical process parameters of the apparatus including:
• a fluid rheology of the flowable skin cement;
• a geometry of the part to be skinned;
• and
• a geometry of the annulus gap;
• and
• calculating a plurality of dimensionless pressure values (Lambda (Λ)) according to the formula (1):
• Λ
• =
• (
• Δ
• ⁢
• ⁢
• P
• )
• ⁢
• R
• 2
• ⁢
• m
• ⁢
• ⁢
• L
• ⁢
• (
• R
• V
• )
• n
• (
• 1
• )
• where
• ΔP is the pressure drop in the initial applied manifold pressure (P) on the flowable skin cement,
• R is the radius of the skinning chamber,
• V is the velocity of a part traversing the skinning chamber,
• L is the axial length of the skinning chamber, and
• m and n characterize the fluid rheology of the flowable skin cement according to y equals m times Xn;
• plotting a plurality of manifold pressures versus a plurality of part velocities to produce a graph having a plurality of line plots;
• skinning a plurality of parts to produce a plurality of preliminarily skinned parts;
• and
• selecting at least one operating window based on the skin quality of the plurality of preliminarily skinned parts, wherein the plurality of dimensionless pressure values (Lambda (Λ)) have at least one critical pressure drop Lambda (Λcr), wherein the selected at least one operating window comprises the at least one point that corresponds to at least one critical pressure drop Lambda;
• and
• maintaining operation of the axial skinning apparatus at a pressure value less than the at least one critical pressure drop Lambda (Λcr).