Method of and apparatus for shielding inert-zone electron irradiation of moving web materials

Claim 2

Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated; means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone; means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap including angulated walls defining a box for stopping the electron beam at the intermediate zone, said box having within it a low atomic number plate upon which the electron beam radiation impinges and provided with cooling means; each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone; shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone; means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom; and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.

Claim 3

Apparatus as claimed in claim 1 and in which said electron beam extends transversely across said web.

Claim 4

Apparatus as claimed in claim 2 and in which the shielding of said traps and wall surfaces comprises lead faced with a low atomic number surface such as aluminum.

Claim 5

Apparatus as claimed in claim 2 and in which at least one of said cavity trap means is disposed spaced from the end of its adjacent collimating slot.

Claim 6

Apparatus as claimed in claim 2 and in which said electron beam directing means is contained within a transversely extending shielding housing mounted upon said enclosure on each side of said irradiation zone.

Claim 7

Apparatus as claimed in claim 1 and in which said cooling means comprises water-cooled means covered by said plate and disposed at the base of said box trap.

Claim 8

Apparatus as claimed in claim 1 and in which the longitudinally extending slots have successive angle changes.

Claim 9

Apparatus as claimed in claim 1 and in which the longitudinally extending slots are arcuate.

Claim 10

Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated; means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone; means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means; each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone; shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone; means for feeding a web to the inlet intermediate zone; means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, said cavity trap means being disposed within terminal shielded sections containing inclined guides for directing the web at acute angles into and out of said enclosure; and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.

Claim 11

Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated; means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone; means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means; each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone; shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone; means for feeding a web to the inlet intermediate zone; means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, said cavity trap means being disposed within terminal shielded sections containing inclined guides for directing the web at acute angles into and out of said enclosure; and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.

Claim 12

Apparatus as claimed in claim 9 and in which one of the said sections contains means for diffusing an inert medium into said channel.

Claim 13

Apparatus as claimed in claim 9 and in which air-knife means is directed upon the web entering the guide of the inlet terminal section.

Claim 14

Apparatus as claimed in claim 11 and in which the mounting comprises a housing the free edges of which are received within a transversely extending U-shaped radiation trap carried externally by the enclosure to the sides of said irradiation zone.

Claim 15

Apparatus as claimed in claim 6 and in which the said terminal section guides and web-feeding means and the shielded box trap are disposed as a unit forming one wall of the shielded enclosure and movable into juxtaposition with the opposing wall carrying the electron generating means and with a peripheral radiation trapping flange closing the same.

Claim 18

A method as claimed in claim 14 and in which a gas is blown upon the web as it passes between inlet and processing zone.

Claim 19

A method as claimed in claim 14 and in which the introducing and exiting steps each comprise successive angular changes.

Claim 20

A method as claimed in claim 16 and in which a gas blanket is provided upon the web following the angular changes.

Claim 21

A method as claimed in claim 16 and in which the introducing and exiting steps are along substantially arcuate paths.

Claim 22

Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated; means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone; means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means; each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone; shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone, the shielding of said traps and wall surfaces comprising lead faced with a low atomic number surface such as aluminum, said cavity trap means being bounded by said shielding and comprising a labyrinth faced with an electron-permeable window to close off the same but into which radiation scattered outward along the collimating slots may enter the cavity labyrinth; means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, said electron beam extending transversely across said web; and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.

Claim 23

Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated; means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone; means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means; each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone; shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone, the shielding of said traps and wall surfaces comprising lead faced with a low atomic number surface such as aluminum, said cavity trap means being bounded by said shielding and comprising a labyrinth faced with an electron-permeable window to close off the same but into which radiation scattered outward along the collimating slots may enter the cavity labyrinth; means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, said electron beam extending transversely across said web; and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.

Claim 24

Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated; means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone; means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means; each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone; shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone; means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, at least one of said cavity trap means being disposed within a terminal shielded section containing a guide for directing the web-substantially horizontally, with the web passing inclinedly through said zone; and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.

Claim 25

Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated; means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone; means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means; each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone; shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone; means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, at least one of said cavity trap means being disposed within a terminal shielded section containing a guide for directing the web-substantially horizontally, with the web passing inclinedly through said zone; and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.