Method for uniformly distributing discrete particles on a moving porous web

Claim 2

1 . A method for substantially uniformly distributing a layer of discrete particles along a predetermined portion of the uppermost surface of a moving porous web traveling at a first velocity so that said particles occupy less than 100% of said predetermined portion of the uppermost surface of said moving web, said method comprising the steps of: (a) entraining said particles in a moving gaseous stream; (b) passing said gaseous stream through a conduit having a nozzle exit positioned adjacent the uppermost surface of and oriented so as to discharge said gaseous stream containing said entrained particles in a direction substantially parallel to the direction of travel of said moving porous web; (c) mixing said particles entrained in said gaseous stream inside said conduit to provide a substantially uniform distribution of said particles, as measured across the width of said nozzle exit of said conduit in a direction perpendicular to the direction of travel of said moving porous web; (d) discharging said gaseous stream containing said uniformly distributed entrained particles from said conduit adjacent said predetermined portion of the uppermost surface of said moving porous web at a second velocity; and (e) maintaining the fluid pressure adjacent the lowermost surface of said moving porous web at a level below the fluid pressure adjacent the uppermost surface of said moving porous web in an area coinciding in width to said predetermined portion of said web and located near the nozzle exit of said conduit, whereby the uniformly distributed particles entrained in said discharged gaseous stream are substantially uniformly deposited on said predetermined portion of the uppermost surface of said moving porous web as the bulk of the gas in said gaseous stream is drawn from the uppermost to the lowermost surface of said web.

Claim 3

A method according to claim 1 wherein said particles are substantially uniformly distributed onto the predetermined portion of said moving porous web so that they occupy less than 50% of said predetermined portion of the uppermost surface of said moving web.

Claim 4

A methoo according to either one of claims 1 and 2 wherein the width of said predetermined portion of said moving porous web comprises the entire width of said web.

Claim 6

A method according to claim 4 wherein said uniform stream is provided by means of a rotating auger.

Claim 11

A method according to claim 9 wherein said increased velocity results from a decrease in cross-sectional flow area, as measured in a direction substantially perpendicular to the direction of flow, said decrease in flow area occurring between the inlet of said conduit and the nozzle exit of said conduit.

Claim 12

ll. A method according to any one of claims 1-10 wherein the width of said nozzle exit corresponds to the width of said predetermined portion of the uppermost surface of said moving porous web onto which said particles are deposited and is in vertical alignment with said predetermined portion of said web.

Claim 21

A method according to claim 19, including the step of three-dimensionally embossing said first and second webs to secure them to one another and fix the position of said uniformly distributed particles therebetween.

Claim 22

21 . An apparatus for substantially uniformly distributing a layer of discrete particles along a predetermined portion of the uppermost surface of a moving porous web traveling at a first velocity so that said particles occupy less than 100% of said predetermined portion of the uppermost surface of said moving web, said apparatus comprising: (a) means for feeding said particles In a substantially uniform stream to the inlet of a gas eductor; (b) means for entraining said particles in a moving gaseous stream; (c) conduit means for passing said gaseous stream through a nozzle exit positioned adjacent the uppermost surface of and oriented so as to discharge said gaseous stream containing said entrained particles in a direction substantially parallel to the direction of travel of said moving porous web; (d) means for mixing said particles entrained in said gaseous stream inside said conduit to provide a substantially uniform distribution of said particles, as measured across the width of said nozzle exit of said conduit in a direction perpendicular to the direction of travel of said moving porous web; (e) nozzle exit means at the discharge end of said conduit means for discharging said gaseous stream containing said uniformly distributed entrained particles from said conduit adjacent said predetermined portion of the uppermost surface of said moving porous web at a second velocity which is greater than said first velocity; and (f) means for maintaining the fluid pressure adjacent the lowermost surface of said moving porous web at a level below the fluid pressure adjacent the uppermost surface of said moving porous web in an area coinciding in width to said predetermined portion of said web and located near the nozzle exit of said conduit, whereby the uniformly distributed particles entrained in said discharged gaseous stream are substantially uniformly deposited on said predetermined portion of the uppermost surface of said moving porous web as the bulk of the gas in said gaseous stream is drawn from the uppermost to the lowermost surface of said web.

Claim 23

21 . An apparatus for substantially uniformly distributing a layer of discrete particles along a predetermined portion of the uppermost surface of a moving porous web traveling at a first velocity so that said particles occupy less than 100% of said predetermined portion of the uppermost surface of said moving web, said apparatus comprising: (a) means for feeding said particles In a substantially uniform stream to the inlet of a gas eductor; (b) means for entraining said particles in a moving gaseous stream; (c) conduit means for passing said gaseous stream through a nozzle exit positioned adjacent the uppermost surface of and oriented so as to discharge said gaseous stream containing said entrained particles in a direction substantially parallel to the direction of travel of said moving porous web; (d) means for mixing said particles entrained in said gaseous stream inside said conduit to provide a substantially uniform distribution of said particles, as measured across the width of said nozzle exit of said conduit in a direction perpendicular to the direction of travel of said moving porous web; (e) nozzle exit means at the discharge end of said conduit means for discharging said gaseous stream containing said uniformly distributed entrained particles from said conduit adjacent said predetermined portion of the uppermost surface of said moving porous web at a second velocity which is greater than said first velocity; and (f) means for maintaining the fluid pressure adjacent the lowermost surface of said moving porous web at a level below the fluid pressure adjacent the uppermost surface of said moving porous web in an area coinciding in width to said predetermined portion of said web and located near the nozzle exit of said conduit, whereby the uniformly distributed particles entrained in said discharged gaseous stream are substantially uniformly deposited on said predetermined portion of the uppermost surface of said moving porous web as the bulk of the gas in said gaseous stream is drawn from the uppermost to the lowermost surface of said web.

Claim 24

An apparatus according to claim 21 wherein said conduit means causes said gaseous stream and said particles entrained therein to undergo a change of direction of approximately 90° as they pass through said conduit.