Apparatus for producing reticulate sheet material

Claim 2

APPARATUS FOR FORMING A RETICULATE SHEET MATERIAL OF A POLYMER SELECTED FROM THE CLASS CONSISTING OF HIGH-DENSITY POLYETHYLENE AND PREDOMINANTLY ISOTACTIC POLYPROPYLENE WHICH COMPRISES; SPACED MEANS FOR SUPPORTING AND ADVANCING A THIN SHEET OF POLYMER, SAID SUPPORTING MEANS INCLUDING MEANS FOR HEATING SAID POLYMER TO A FORMABLE STATE, FORMING MEANS ADJACENT SAID SUPPORTING AND HEATING MEANS AND IN CLOSE PROXIMITY THERETO FOR REMOVING SAID POLYMER WHILE IN A FORMABLE STATE FROM SAID SUPPORTING AND HEATING MEANS WHILE SIMULTANEOUSLY APPLYING COMPRESSIVE AND SHEARING FORCES CAPABLE OF PENETRATING THROUGH SAID POLYMER TO FORM SAID POLYMER INTO A SUBSTANTIALLY OPEN RETICULATE STRUCTURE COMPRISING FILAMENTS, SAID FILAMENTS BEING INTEGRAL AT THEIR INTERSECTIONS AND MEANS INCLUDING SAID FORMING MEANS FOR COOLING SAID SUBSTANTIALLY OPEN RETICULATE STRUCTURE TO BELOW THE SOLIDIFICATION TEMPERATURE OF THE POLYMER AND MEANS FOR REMOVING SAID RETICULATE SHEET MATERIAL FROM SAID FORMING MEANS WHEREBY A STRETCHABLE RETICULATE SHEET MATERIAL OF SAID POLYMER IS PRODUCED.

Claim 3

Apparatus according to claim 1 wherein the means for heating a thin sheet of said polymer is a continuously moving uniform surface heated to a temperature of at least 280*F., said thin sheet being placed on said surface and being heated to 280*F. while moving with said surface.

Claim 4

Apparatus according to claim 1 wherein the forming means includes a continuously moving resilient surface having a pattern of continuously arranged recessed areas and discontinuously arranged raised areas disposed uniformly over said surface.

Claim 5

Apparatus according to claim 1 wherein the forming means includes pressure applying means for applying from 18 to 125 pounds per linear inch pressure to said polymer while it is being formed.

Claim 6

Apparatus according to claim 1 wherein the forming means includes a continuously moving resilient surface having a pattern of recessed areas disposed in the direction of the length and width of said surface to define a pattern of raised areas.

Claim 7

Apparatus according to claim 1 wherein the forming means includes a continuously moving resilient surface having an overall heat transfer coefficient of about 10 and having a pattern of continuously arranged recessed areas and discontinuously arranged raised areas disposed uniformly over said surface.

Claim 8

Apparatus according to claim 1 wherein the forming means comprises a continuously moving resilient surface having a pattern of continuously arranged recessed areas and discontinuously arranged raised areas disposed uniformly oVer said surface and pressure applying means for applying from 18 to 125 pounds per linear inch pressure to said polymer while it is being formed.

Claim 9

Apparatus according to claim 1 wherein the forming means comprises a continuously moving resilient surface having an overall heat transfer coefficient of about 10 and having a pattern of recessed areas disposed in the direction of the length and width of said surface to define a pattern of raised areas and pressure applying means for applying from 18 to 125 pounds per linear inch pressure to said polymer while it is being formed.

Claim 10

Apparatus according to claim 1 wherein the means for heating a thin sheet of said polymer is a continuously moving uniform surface heated to a temperature of at least 280*F., said thin sheet being placed on said surface and being heated to 280*F. while moving with said surface and said forming means comprising a continuously moving resilient surface having an overall heat transfer coefficient of about 10 and having a pattern of continuously arranged recessed areas and discontinuously arranged raised areas disposed uniformly over said surface and pressure applying means for applying from 10 to 125 pounds for linear inch pressure to said polymer while it is being formed.

Claim 11

Apparatus for forming a reticulate sheet material of a polymer selected from the class consisting of high-density polyethylene and predominantly isotactic polypropylene which comprises; spaced means for supporting and advancing a thin sheet of polymer, said supporting means including means for heating said polymer to a formable state, forming means adjacent said supporting and heating means and in close proximity thereto for removing said polymer while in the formable state from said supporting and heating means while simultaneously applying compressive and shearing forces capable of penetrating through said polymer to form said polymer into a substantially open reticulate structure comprising intersecting filaments, said filaments being integral at their intersections and means including said forming means for cooling said reticulate structure to below the solidification temperature of the polymer, means for removing said cooled reticulate structure from said cooling and forming means and means for stretching said reticulate structure in the direction along the axis of the filaments whereby an original open, net-like structure of said polymer is produced.

Claim 12

Apparatus for forming a reticulate sheet material of a polymer selected from the class consisting of high-density polyethylene and predominantly isotactic polypropylene which comprises; spaced means for supporting and advancing a thin sheet of polymer, said supporting means including means for heating said polymer to a formable state, forming means adjacent said supporting and heating means and in close proximity thereto for removing said polymer while in the formable state from said supporting and heating means while simultaneously applying compressive and shearing forces capable of penetrating through said polymer to form said polymer into a substantially open reticulate structure comprising intersecting filaments, said filaments being integral at their intersections and means including said forming means for cooling said reticulate structure to below the solidification temperature of the polymer, means for removing said cooled reticulate structure from said cooling and forming means and means for stretching said reticulate structure in the direction along the axis of the filaments whereby an original open, net-like structure of said polymer is produced.

Claim 13

Apparatus according to claim 10 wherein the means for heating a thin sheet of said polymer is a continuously moving uniform surface heated to a temperature of at least 280*F., said thin sheet being placed on said surface and being heated to 280*F. while moving with said surface.

Claim 14

Apparatus according to claim 10 wherein the forming means includes a continuously moving resilient surface having a pattern of continuously arranged recessed areas and discontinuously arranged raised areas disposed uniformly over said surface.

Claim 15

Apparatus according to claim 10 wherein the forming means includes pressure applying means for applying from 18 to 125 pounds per linear inch pressure to said polymer while it is being formed.

Claim 16

Apparatus according to claim 10 wherein the forming means includes a continuously moving resilient surface having a pattern of recessed areas disposed in the direction of the length and width of said surface to define a pattern of raised areas whereby intersecting filaments running the length and width of said sheet material are formed and the means for stretching the reticulate structure comprises means for stretching in both the directions of the length and width of said structure to orient the filaments.

Claim 17

Apparatus according to claim 10 wherein the forming means includes a continuously moving resilient surface having an overall heat transfer coefficient of about 10 and having a pattern of continuously arrangEd recessed areas and discontinuously arranged raised areas disposed uniformly over said surface and the means for stretching said reticulate structure comprises means for stretching in both the lengthwise directions of saiid structure to orient the filaments.

Claim 18

Apparatus according to claim 10 wherein the forming means comprises a continuously moving resilient surface having a pattern of continuously arranged recessed areas and discontinuously arranged areas disposed uniformly over said surface and pressure applying means for applying from 20 to 100 pounds per linear inch pressure to said polymer while it is being formed and the means for stretching said reticulate structure comprises means for stretching said structure in both the lengthwise and widthwise directions of said structure to orient the filaments.

Claim 19

Apparatus according to claim 10 wherein the forming means comprises a continuously moving resilient surface having an overall heat transfer coefficient of about 10 and having a pattern of recessed areas disposed in the direction of the length and width of said surface to define a pattern of raised areas and pressure applying means for applying from 24 to 100 pounds per linear inch pressure to said polymer while it is being formed whereby intersecting filaments running the length and width of said sheet material are formed and the means for stretching the reticulate structure comprises means for stretching in both the directions of the length and width of said structure to orient the filaments.

Claim 20

Apparatus according to claim 10 wherein the means for heating a thin sheet of said polymer is a continuously moving uniform surface heated to a temperature of at least 280*F., said thin sheet being placed on said surface and being heated to 280*F. while moving with said surface and said forming means comprises a continuously moving resilient surface having an overall heat transfer coefficient of about 10 and having a pattern of continuously arranged recessed areas and discontinuously arranged raised areas disposed uniformly over said surface and pressure applying means for applying from 24 to 100 pounds per linear inch pressure to said polymer while it is being formed and the means for stretching said reticulate structure comprises means for stretching said structure in both the lengthwise and widthwise directions of said structure to orient the filaments.

Claim 21

Apparatus for forming a reticulate sheet material of a polymer selected from the class consisting of high-density polyethylene and predominantly isotactic polypropylene which comprises a smooth surfaced heated roll, means for rotating said heated roll in a first direction at a first peripheral linear speed, means for continuously feeding a thin sheet of said polymer to the surface of said heated roll at a first position on said surface, a forming roll positioned with its axis parallel to the axis of said heated roll, the surface of said heated roll and said forming roll being in contact with each other to form a nip at a second position disposed from said first position whereby said polymer sheet is heated to a formable state as it passes from said first position to said second position, means for rotating said forming roll in the opposite direction to said heated roll and at a second peripheral linear speed, said forming roll having a pattern of continuous recessed areas and discontinuous raised areas disposed over its surface, means for applying pressure to the nip formed by the heated roll and the forming roll said pressure being capable of penetrating through said polymer to form said thin sheet of polymer into a substantially open reticulate structure of intersecting filaments as it passes said second position and onto said forming roll, said filaments being integral at the intersections, means including said forming roll for cooling said reticulate structure to below the solidification temperature of said polymer while saId reticulate structure is on the surface of said forming roll and means spaced from said forming roll for continually removing said cooled reticulate structure from said forming roll to produce a stretchable reticulate sheet material.

Claim 22

Apparatus for forming a reticulate sheet material of a polymer selected from the class consisting of high-density polyethylene and predominantly isotactic polypropylene which comprises a smooth surfaced heated roll, means for rotating said heated roll in a first direction at a first peripheral linear speed, means for continuously feeding a thin sheet of said polymer to the surface of said heated roll at a first position on said surface, a forming roll positioned with its axis parallel to the axis of said heated roll, the surface of said heated roll and said forming roll being in contact with each other to form a nip at a second position disposed from said first position whereby said polymer sheet is heated to a formable state as it passes from said first position to said second position, means for rotating said forming roll in the opposite direction to said heated roll and at a second peripheral linear speed, said forming roll having a pattern of continuous recessed areas and discontinuous raised areas disposed over its surface, means for applying pressure to the nip formed by the heated roll and the forming roll said pressure being capable of penetrating through said polymer to form said thin sheet of polymer into a substantially open reticulate structure of intersecting filaments as it passes said second position and onto said forming roll, said filaments being integral at the intersections, means including said forming roll for cooling said reticulate structure to below the solidification temperature of said polymer while saId reticulate structure is on the surface of said forming roll and means spaced from said forming roll for continually removing said cooled reticulate structure from said forming roll to produce a stretchable reticulate sheet material.

Claim 23

Apparatus according to claim 18 wherein the heated roll is a metal roll heated to a temperature of at least 280*F.

Claim 24

Apparatus according to claim 19 wherein the forming roll has a resilient surface and a Durometer hardness of about 60.

Claim 25

Apparatus according to claim 19 wherein the forming roll has a rubber surface.

Claim 26

Apparatus according to claim 19 wherein the forming roll has an overall heat transfer coefficient of about 10.

Claim 27

Apparatus according to claim 19 wherein the recessed areas in the forming roll are disposed in parallel circular stripes around the roll and in parallel stripes across the roll to produce intersecting filaments running the length and width of the reticulate structure.

Claim 28

Apparatus according to claim 19 wherein the peripheral linear speed of the forming roll is from 10 to 20 percent greater than the peripheral linear speed of the heated roll.

Claim 29

Apparatus according to claim 19 wherein the means for cooling the reticulate structure includes means for controlling the temperature of the forming roll at a temperature of less than 240*F.

Claim 30

Apparatus according to claim 19 wherein the means for applying pressure to the nip comprises a rotatable roll in pressing contact with the surface of said forming roll at a position disposed opposite the nip formed by the heated roll and the forming roll to apply from 18 to 125 pounds per linear inch pressure at the nip of the heated roll and forming roll.

Claim 31

Apparatus according to claim 19 wherein the forming roll comprises a rubber roll having a Durometer hardness of about 60 and an overall heat transfer coefficient of about 10.

Claim 32

Apparatus according to claim 19 wherein the heated roll is a metal roll maintained at a temperature of at least 280*F., the forming roll has a resilient surface and the recessed areas in the forming roll are disposed in parallel circular stripes around the roll and in parallel stripes across the roll to produce intersecting filaments running the length and width of the reticulate structure, the means for applying pressure to the nip of the heated roll and forming roll comprises a rotatable roll in pressing contact with the surface of the forming roll at a position disposed opposite the heated roll to apply from 18 to 125 pounds per linear inch pressure at the nip of the heated roll and forming roll and the means for cooling the reticulate structure includes means for controlling the temperature of the forming roll at a temperature of less than 240*F.

Claim 33

Apparatus according to claim 19 wherein the heated roll is a metal roll maintained at a temperature of at least 280*F., the forming roll is a rubber roll having a Durometer hardness of about 60 and an overall heat transfer coefficient of about 10 and the recessed areas in the forming roll are disposed in parallel circular stripes around the roll and in parallel stripes across the roll to produce intersecting filaments running the length and width of the reticulate structure, the peripheral linear speed of the forming roll is 10 to 20 percent greater than the peripheral linear speed of the heated roll, the means for applying pressure to the nip of the heated roll and the forming roll comprises a rotatable roll in pressing contact with the surface of the forming roll at a position disposed opposite the heated roll to apply from 24 to 100 pounds per linear inch pressure at the nip of the heated roll and forming roll and the means for cooling the reticulate structure includes means for controlling the temperature of the forming roll at a temperature of less than 240*F.

Claim 34

Apparatus for forminG a reticulate sheet material of a polymer selected from the class consisting of high-density polyethylene and predominantly isotactic polypropylene which comprises a smooth surfaced heated roll, means for rotating said heated roll in a first direction at a first peripheral linear speed, means for continuously feeding a thin sheet of said polymer to the surface of said heated roll at a first position on said surface, a forming roll positioned with its axis parallel to the axis of said heated roll, the surface of said heated roll and said forming roll being in contact with each other to form a nip at a second position disposed from said first position whereby said polymer sheet is heated to a formable state as it passes from said first position to said second position, means for rotating said forming roll in the opposite direction to said heated roll and at a second peripheral linear speed, said forming roll having a pattern of continuous recessed areas and discontinuous raised areas disposed over its surface, means for applying pressure to the nip formed by the heated roll and the forming roll said pressure capable of penetrating through said polymer to form said thin sheet of polymer into a substantially open reticulate structure of intersecting filaments as it passes said second position and onto said forming roll, said filaments being integral at the intersections, means including said forming roll for cooling said reticulate structure to below the solidification temperature of said polymer while said reticulate structure is on the surface of said forming roll, means spaced from said forming roll for continually removing said cooled reticulate structure from said forming roll to produce a stretchable reticulate sheet material, means for heating said stretchable reticulate sheet material, and means for stretching said heated sheet material in the direction along the axis of the filaments to produce an original open net-like material.

Claim 35

Apparatus for forminG a reticulate sheet material of a polymer selected from the class consisting of high-density polyethylene and predominantly isotactic polypropylene which comprises a smooth surfaced heated roll, means for rotating said heated roll in a first direction at a first peripheral linear speed, means for continuously feeding a thin sheet of said polymer to the surface of said heated roll at a first position on said surface, a forming roll positioned with its axis parallel to the axis of said heated roll, the surface of said heated roll and said forming roll being in contact with each other to form a nip at a second position disposed from said first position whereby said polymer sheet is heated to a formable state as it passes from said first position to said second position, means for rotating said forming roll in the opposite direction to said heated roll and at a second peripheral linear speed, said forming roll having a pattern of continuous recessed areas and discontinuous raised areas disposed over its surface, means for applying pressure to the nip formed by the heated roll and the forming roll said pressure capable of penetrating through said polymer to form said thin sheet of polymer into a substantially open reticulate structure of intersecting filaments as it passes said second position and onto said forming roll, said filaments being integral at the intersections, means including said forming roll for cooling said reticulate structure to below the solidification temperature of said polymer while said reticulate structure is on the surface of said forming roll, means spaced from said forming roll for continually removing said cooled reticulate structure from said forming roll to produce a stretchable reticulate sheet material, means for heating said stretchable reticulate sheet material, and means for stretching said heated sheet material in the direction along the axis of the filaments to produce an original open net-like material.

Claim 36

Apparatus according to claim 31 wherein the heated roll is a metal roll heated to a temperature of at least 280*F.

Claim 37

Apparatus according to claim 31 wherein the forming roll has a resilient surface and a Durometer hardness of about 60.

Claim 38

Apparatus according to claim 31 wherein the forming roll has a rubber surface.

Claim 39

Apparatus according to claim 31 wherein the forming roll has an overall heat transfer coefficient of about 10.

Claim 40

Apparatus according to claim 31 wherein the recessed areas in the forming roll are disposed in parallel circular stripes around the roll and in parallel stripes across the roll to produce intersecting filaments running the length and width of the reticulate structure and the means for stretching the reticulate sheet material comprises means for stretching said material in both the direction of its length and width.

Claim 41

Apparatus according to claim 31 wherein the peripheral linear speed of the forming roll is from 10 to 20 percent greater than the peripheral linear speed of the heated roll.

Claim 42

Apparatus according to claim 31 wherein the means for cooling the reticulate structure includes means for controlling the temperature of the forming roll at a temperature of less than 240*F.

Claim 43

Apparatus according to claim 31 wherein the means for applying pressure to the nip comprises a rotatable roll in pressing contact with the surface of said forming roll at a position disposed opposite the nip formed by the heated roll and the forming roll to apply from 18 to 125 pounds per linear inch pressure at the nip of the heated roll and forming roll.

Claim 44

Apparatus according to claim 31 wherein the forming roll is a rubber roll having a Durometer hardness of about 60 and an overall heat transfer coefficient of about 10.

Claim 45

Apparatus according to claim 31 wherein the heated roll is a metal roll maintained at a temperature of at least 280*F., the forming roll has a resilient surface and the recessed areas in the formIng roll are diisposed in parallel circular stripes around the roll and in parallel stripes across the roll to produce intersecting filaments running the length and width of the reticulate structure, the means for applying pressure to the nip of the heated roll and forming roll comprises a rotatable roll in pressing contact with the surface of the forming roll at a position disposed opposite the heated roll to apply from 24 to 100 pounds per linear inch pressre at the nip of the heated roll and forming roll, the means for cooling the reticulate structure includes means for controlling the temperature of the forming roll at less than 240*F., and the means for stretching the reticulate sheet material comprises means for stretching said material in both the direction of its length and width.

Claim 46

Apparatus according to claim 3 wherein the heated roll is a metal roll maintained at a temperature of at least 280*F., the forming roll is a rubber roll having a Durometer hardness of about 60 and an overall heat transfer coefficient of about 10 and the recessed areas in the forming roll are disposed in parallel circular stripes around the roll and in parallell stripes across the roll to produce intersecting filaments running the length and width of the reticulate structure, the peripheral linear speed of the forming roll is 10 to 20 percent greater than the peripheral linear speed of the heated roll, the means for applying pressure to the nip of the heated roll and the forming roll comprises a rotatable roll in pressing contact with the surface of the forming roll at a position disposed opposite the heated roll to apply from 24 to 100 pounds per linear inch pressure at the nip of the heated roll and forming roll, the means for cooling the reticulate structure includes means for controlling the temperature of the forming roll at less than 240*F., and the means for stretching the reticulate sheet material comprises means for stretching said material in both the directions of its length and width.