Method and apparatus for applying a material to a web

A method of manufacturing a web having an applied pattern of add-on material, said method comprising the steps of:

• moving a base web along a first path;
• preparing a slurry of add-on material;
• repetitively discharging said add-on slurry upon said moving sheet of base web by:
• establishing a reservoir of said add-on slurry across said first path:
• and
• continuously moving a belt having an orifice along an endless path, said belt moving step including the step of moving said belt along a first portion of said endless path where said orifice is communicated with said reservoir so as to discharge said add-on slurry from said reservoir through said orifice onto said base web as said orifice traverses said first path portion;
• and
• said slurry discharging step including the step of controlling variation of fluid pressure along said reservoir so as to achieve consistent discharge of said add-on slurry from said orifice as said orifice traverses said first path portion;
• wherein said step of controlling pressure along said reservoir includes the steps of:
• flowing said add-on slurry into said reservoir at spaced locations along said reservoir;
• monitoring fluid pressure at a plurality of regions along said reservoir so as to identify amongst said monitored regions a region of greatest variation of pressure;
• and
• adjacent said region of greatest variation of pressure, adjusting the flow of said add-on slurry into said reservoir counteractively to said greatest variation of pressure.

A method of manufacturing a web having an applied pattern of add-on material, said method comprising the steps of:

• moving a base web along a first path;
• preparing a slurry of add-on material;
• repetitively discharging said add-on slurry upon said moving sheet of base web by:
• establishing a reservoir of said add-on slurry across said first path;
• and
• continuously moving a belt having an orifice along an endless path, said belt moving step including the step of moving said belt along a first portion of said endless path where said orifice is communicated with said reservoir so as to discharge said add-on slurry from said reservoir through said orifice onto said base web as said orifice traverses said first path portion;
• and
• said slurry discharging step including the step of controlling variation of fluid pressure along said reservoir so as to achieve consistent discharge of said add-on slurry from said orifice as said orifice traverses said first path portion;
• wherein said reservoir establishing step includes the step of locating an elongate chamber box across said first path and introducing said add-on slurry into said chamber box through ports at spaced locations along said box, said step of moving said belt along said first endless path portion including the step of moving said belt through a lower portion of said chamber box, said reservoir establishing step including the step of filling said chamber box with add-on slurry under pressure and continuously supplying said add-on slurry to said filled box under pressure through said ports from individually adjustable metering pumps, said step of controlling pressure comprising the steps of:
• monitoring fluid pressure at spaced locations along said reservoir;
• resolving which monitored location contributes a fluid pressure of a highest variation from a norm;
• identifying a metering pump whose respective port is operatively adjacent said resolved location of highest pressure variation;
• adjusting output of said identified metering pump counteractively to said fluid pressure of the highest variation from the norm;
• and
• adjusting output of a remainder of said metering pumps in compensation to said output adjusting step of said identified metering pump so as to maintain said continuous supply of add-on slurry into said chamber box.

A method of manufacturing a web having an applied pattern of add-on material, said method comprising the steps of:

• moving a base web along a first path:
• preparing a slurry of add-on material;
• repetitively discharging said add-on slurry upon said moving sheet of base web by:
• establishing a reservoir of said add-on slurry across said first path;
• and
• continuously moving a belt having an orifice along an endless path, said belt moving step including the step of moving said belt along a first portion of said endless path where said orifice is communicated with said reservoir so as to discharge said add-on slurry from said reservoir through said orifice onto said base web as said orifice traverses said first path portion;
• and
• said slurry discharging step including the step of controlling variation of fluid pressure along said reservoir so as to achieve consistent discharge of said add-on slurry from said orifice as said orifice traverses said first path portion;
• wherein said step of controlling pressure along said reservoir includes the steps of supplying said add-on slurry to said reservoir by introduction of said add-on slurry into said reservoir at a plurality of spaced-apart, feed ports disposed along said reservoir and controlling said slurry introduction at each feed port by:
• (a) reading fluid pressure at spaced locations along said reservoir;
• (b) resolving whether variance among the pressure readings exceeds a predetermined value, and if said predetermined value is exceeded:
• (c) resolving which pressure reading singularly contributes the greatest variance from a norm;
• (d) identifying a feed port proximate to said pressure reading of greatest variance from the norm;
• and
• (e) adjusting the introduction of slurry at said identified feed port counteractively to said greatest variation.

An apparatus arranged to manufacture a web having an applied pattern of add-on material, said apparatus comprising:

• a first arrangement which establishes a sheet of base web from a first slurry and moves said established sheet along a first path;
• a second arrangement for preparing a add-on slurry;
• a moving orifice applicator at a location along said first arrangement, said moving orifice applicator in communication with said second arrangement, said moving orifice operative so as to repetitively discharge said add-on slurry upon said moving sheet of base web, said moving orifice applicator comprising:
• a chamber box arranged to establish a reservoir of said add-on slurry across said first path;
• an endless belt having an orifice, said endless belt received through said chamber box such that said orifice is communicated with said reservoir;
• a drive arrangement operative upon said endless belt to continuously move said orifice along an endless path and repetitively through said chamber box, said orifice when communicated with said reservoir being operative to discharge said second slurry from said reservoir through said orifice;
• a flow distribution system for introducing said second slurry into said chamber box at spaced-apart feed locations along said chamber box;
• a flow monitoring system for reading fluid pressure at spaced-apart locations along said chamber box;
• and
• a controller in communication with the output of said flow monitoring system, said controller arranged to identify which of said feed ports is operatively adjacent a monitored location of highest pressure variation, said controller selectively adjusting output of said flow distribution system at said identified feed location counteractively to said highest pressure variation, said controller adjusting output of a remainder of said feed locations counteractively to said output adjustment at said identified feed location;
• whereby fluid pressure along said reservoir is controlled so as to achieve consistent discharge of said second slurry from said orifice as said orifice traverses through said chamber box.