MXPA97006210A - Method for applying a photosensible resin to a substrate for use in pa manufacturing - Google Patents

Abstract

The present invention relates to a method for applying a photosensitive resin to a substrate to form an apparatus for use in papermaking, the method characterized in that it comprises the steps of: providing a substrate having a first surface, a second surface, and a thickness, the substrate having intermediate voids to the first and second surfaces, providing a liquid photosensitive resin, providing a second material different from photosensitive liquid resin, providing a source of actinic radiation, applying the second material to the substrate to occupy minus some of the gaps in the intermediate substrate to the first and second surfaces of the substrate, remove at least some, but not all, of the second substrate material before applying the photosensitive liquid resin to the substrate, apply the liquid photosensitive resin to the substrate for occupy at least some of the holes in the substrate, expose at least some of the liquid resin photosensitive to actinic radiation, and cure at least some of the photosensitive resin to provide a patterned resin layer on the first substratum surface

Description

METHOD FOR APPLYING A PHOTOSENSIBLE RESIN TO UISI SUBSTRATE FOR USE IN PAPER MANUFACTURE FIELD OF THE INVENTION The present invention provides a method for applying a curable resin to a substrate, and more particularly, to a method for applying a photosensitive resin to a substrate to form a pattern modeling apparatus for use in papermaking.

BACKGROUND OF THE INVENTION The application of coatings, such as resin coatings and foam coatings to substrates is known in the papermaking art. For example, it is known to apply a photosensitive resin to a foraminous member in a preselected pattern for use in the papermaking operation. It is also known to provide compression fabrics for papermaking with a coating, such as a foam coating, to obtain a controlled void volume and permeability. The following documents describe the use of resin, fillers, foams, layered constructions, or other coatings to make equipment for the manufacture of paper: patent of E.U.A. 3,549,742 issued December 22, 1970 to Benz; patent of E.U.A. 4,446,187 to Eklund; patent of E.U.A. 4,514,345 issued April 30, 1985 to Johnson and others; patent of E.U.A. 4,637,859 issued on January 20, 1987 to Trokhan; patent of E.U.A. 4,795,480 issued on January 3, 1989 to Boyer et al .; patent of E.U.A. 5,098,522 issued March 24, 1992 to Smurkoski et al .; patent of E.U.A. 5,346,567 issued September 13, 1994 to Barnewail; patent of E.U.A. 5,334,289 issued August 2, 1994 to Trokhan et al .; and PCT Publication Number WO 91/14558 published October 3, 1991, in the name of Sayers et al. and assigned to SCAPA Group. It is also known to impregnate textile fabrics, such as needled fiber mats and felt material, with resins and filler materials. The following documents describe the use of resins and / or fillers in fabrics: patent of E.U.A. 4,250,172 to Mutzenberg et al .; patent of E.U.A. 4,390,574 to Wood; patent of E.U.A. 4,464,432 to Dost et al .; patent of E.U.A. 5,217,799 to Sumii et al .; patent of E.U.A. 5,236,778 to Landis and others; and Reissue Patent 32,713 reissued on July 12, 1988 to Woo. After curing a portion of the resin on a substrate to form a papermaking apparatus, it is desirable to remove the uncured resin from the substrate.

The removal of the uncured resin from the substrate is important, so that the papermaking apparatus has the desired characteristics for its application in the manufacture of particular paper. Such features may include, but are not limited to, flexibility of the apparatus, compressibility of the apparatus, air permeability through the apparatus, and water permeability through the apparatus. The removal of the uncured resin is especially important in a papermaking apparatus having a patterned resin surface with openings, through which air and / or water is transported during the formation or drying of the weft. paper. The uncured resin remaining in the substrate can reduce the permeability of the substrate, and thus reduce flow through the openings in the patterned resin surface. A method for removing the uncured resin includes washing the uncured resin from the substrate. For example, the patent of E.U.A. 4,514,345, mentioned above, describes washing the uncured resin from a foraminous member of woven filaments, followed by the vacuum of the residual wash liquid and uncured liquid from the foraminous member. However, washing and vacuum, alone, can be effective in removing all uncured resin.

A felt or open cell substrate can have a large number of relatively small internal hollow cavities which can trap uncured resin. Said uncured trapped resin can degrade the performance of the papermaking apparatus, as described above. In addition, said trapped resin is essentially wasted, increasing the cost of the resin casting process.

Removing the trapped resin by increasing the number of wash cycles and vacuum also increases the cost of the procedure. In addition, in some applications, it may be desirable to control the depth of penetration of the resin to the substrate. For example, it may be desirable for the cured resin to penetrate a predetermined portion of the thickness of the substrate, in order to provide an acceptable bond of the resin to the substrate, while maintaining the flexibility of the substrate and the permeability of the substrate to air and water. The patent of E.U.A. 3,549,742 issued December 22, 1970 to Benz discloses inserting a filler material into the openings in a drainage member, which will eventually be opened for drainage, after which a settleable material is inserted into the remaining openings of the drainage member in the predetermined areas, in which the flow of liquid through the drainage member is to be prevented. The settling material is fixed or cured, after which the filler material is removed from the drainage member. Benz has the advantage that the filler material is disposed in a predetermined pattern before application to the drainage member, and the filler material must be compressed to the drainage member, so that the predetermined areas of the drainage member are left free from the drainage member. filler material. Accordingly, the pattern in which the settling material can be fixed to the drainage member is limited by the predetermined areas of the drainage member that are free of the filler material.

Also, Benz uses pressure to mechanically force the filler material into the drain member. Compression of a filler material to a substrate can have the disadvantage that, if the substrate has very small internal voids, and is relatively compressible, the application of pressure to the substrate can crush the substrate or close some of the voids in the substrate, making penetration of the substrate difficult by the filler material. In addition, compression of a filler material into a felt layer can result in the filler material flowing laterally into areas of the felt, which are intended to remain open for the settling material. Therefore, the method described by Benz is undesirable for use in the application of a curable resin to a felt layer. Accordingly, an object of the present invention is to provide a method for applying a curable resin to a substrate to form a papermaking apparatus. Another object of the invention is to provide a method for reducing the amount of uncured photosensitive resin that is required to be removed from a paper-weave modeling apparatus suitable for making paper having visually discernible patterns. Another object is to provide a method for forming a weft modeling apparatus having a layer of felt drainage and a patterned photosensitive resin layer, which penetrates a surface of the felt layer and extends from the surface of the layer. felt.

BRIEF DESCRIPTION OF THE INVENTION The present invention comprises a method for applying a curable resin to a substrate. In particular, the method can be used to form a papermaking apparatus, such as a paper weave forming fabric or a paper weave drying fabric. In one embodiment, the method of the present invention can be used to apply a photosensitive resin to a layer of drainage felt to provide an apparatus for making paper that can be used to model and dewater a paper web. The resulting papermaking apparatus may comprise a drainage felt layer having a first felt surface facing the weft at a first elevation and a second felt surface facing away from the weft, and a patterned overlay layer. plot comprising the photosensitive resin. The modeling layer penetrates the first felt surface, and extends from the first felt surface to form a weft that is in contact with the upper surface at a second elevation different from the elevation of the first felt surface. The method according to the present invention provides a barrier in the substrate to restrict the depth at which the curable liquid resin can penetrate through the thickness of the substrate. The method comprises the steps of: providing a substrate having a first surface, a second surface and a thickness, the substrate having intermediate voids to the first and second surfaces; provide a curable liquid resin; provide a second material different from the curable liquid resin; applying the second material to the substrate to occupy at least some of the voids in the intermediate substrate to the first and second surfaces of the substrate; apply the curable resin to the substrate; curing at least some of the resin to provide a layer of resin on the substrate; and removing at least some of the second material from the substrate, wherein at least some of the second material is removed from the substrate after applying the curable resin to the substrate. The step of removing at least some of the second material preferably comprises removing at least about 50% of the second material applied to the substrate, and most preferably, removing substantially all of the second material applied to the substrate. In one embodiment, the substrate comprises a drainage felt for making paper, and the resin comprises a photosensitive resin. In one embodiment, the method includes the steps of reducing the mobility of the second material applied to the substrate before applying the resin to the substrate. The method may also include the step of increasing the mobility of the second material after curing at least some of the resin, to thereby facilitate the removal of the second material from the substrate. In one embodiment, the method may include the step of changing the phase of the second material applied to the substrate before applying the liquid photosensitive resin. In one embodiment, the second material is applied across the entire thickness of the substrate as a liquid mixture of water and a soap gelling agent. The second material is cooled to harden the second material to a gel phase. A thin layer of the second gelled material adjacent to the first surface of the substrate is liquefied or solubilized for water jet removal to provide a portion of the thickness of the substrate adjacent to the first surface, which is substantially free of the second material. The liquid photosensitive resin can then be applied to the first surface of the substrate to penetrate the substrate from the first surface, and extend out of the substrate at a predetermined distance from the first surface.

A source of actinic radiation and a mask having opaque and transparent regions are provided. The liquid photosensitive resin is cured in a predetermined pattern by exposing the resin to the actinic radiation through the mask. The uncured liquid resin can then be removed by washing the first surface of the substrate with a water jet. The second gelled material remaining in the substrate is then liquefied and removed from the substrate through heating, hot water jet or vacuum formation.

DESCRIPTION OF THE DRAWINGS Since the specification concludes with the claims that particularly indicate and claim in a different way the present invention, the invention will be better understood from the following description taken together with the attached drawings, in which similar elements are designated with the same numbers of reference, and: Figure 1 is an illustration of a silver view of an apparatus made in accordance with the method of the present invention, the apparatus includes a layer of drainage felt and a patterned layer of photosensitive resin, cured, attached to the drainage felt layer and having a continuous network weft in contact with the upper surface. Figure 2 is a cross-sectional view of the apparatus of Figure 1. Figure 3 is an illustration of a process for making paper with a weft modeling apparatus made in accordance with the method of the present invention. Figures 4A-4H are schematic illustrations of the steps for making a pattern modeling apparatus according to the method of the present invention. Figure 5 is a schematic illustration of a method according to the present invention for making a weft modeling apparatus having a drainage felt layer and a weft modeling layer formed of photosensitive resin. Figure 6 is a photomicrograph of an apparatus made in accordance with the method of the present invention. Figure 7 is a photomicrograph of a cross section of the apparatus of Figure 6.

DETAILED DESCRIPTION OF THE INVENTION Figures 1 and 2 are illustrations of a weft support apparatus for papermaking 200, which can be made using the method of the present invention. The apparatus 200 may comprise a substrate, such as a drape felt layer 220, and a cured resin patterning layer 250 bonded to a surface of the felt layer 220. Figure 3 illustrates a method for making a weft. of paper using the apparatus 200 shown in Figures 1 and 2. Figures 4A-4H illustrate the steps according to the present invention, to make a screen modeling apparatus 200 by curing a photosensitive resin on a surface of a substrate. Figure 5 is a schematic illustration of one embodiment of the method of the present invention. Figures 6 and 7 are photomicrographs of an apparatus 200 made using the method of the present invention.

The Raster Support Apparatus Figures 1, 2 and 4H show a weft support apparatus 200, which may comprise a continuous drying band for drying and imparting a pattern to a paper web. The frame support apparatus 200 has a first side 202 facing the weft and a second side 204 facing the opposite. The weft support apparatus 200 is seen with the first side 202 facing the weft, towards the visor in Figure 1. The weft support apparatus 200 includes a substrate having first and second intermediate hollow surfaces of the substrate. At least some of the recesses are preferably in fluid communication with at least one of the surfaces of the substrate. For example, the substrate may comprise a drainage felt layer 220 having a first felt surface 230 facing the weft disposed at a first elevation 231 (Figure 2), and a second felt surface 232 facing the opposite way . The felt layer 220 has a plurality of intermediate recesses in the first surface 230 and the second surface 232. The weft support apparatus 200 also comprises a weft modeling layer 250 attached to the first surface 230 facing the weft. The pattern modeling layer 250 extends from the first felt surface 230, as shown in Figure 2, for a frame to be in contact with the upper surface 260 at the second elevation 261 different from the first elevation 231.

The difference 262 (Figure 4H) between the first elevation 231 and the second elevation 261 may be at least about 0.05 millimeters, and in one embodiment, is between about 0.1 and about 2.0 millimeters. The drainage felt layer 220 is permeable to water and is capable of receiving and containing compressed water from a wet weft of papermaking fibers. The screen modeling layer 250 is impermeable to water, and does not receive or contain compressed water from a web of fibers to make paper. The pattern modeling layer 250 has a plurality of discrete apertures 270 therethrough, and forms a continuous network on the first felt surface 230, as shown in Figure 1. Alternatively, the pattern modeling layer may be discontinuous or semicontinuous.

The screen modeling layer 250 comprises a curable resin, which can be deposited on a surface of a substrate as a liquid, and subsequently cured, so that a portion of the screen modeling layer penetrates a surface of the substrate. In particular, the screen modeling layer 250 may comprise a photosensitive resin, which may be deposited on the first surface 230 as a liquid and subsequently cured by radiation, such that a portion of the pattern modeling layer 250 it penetrates, and, thus, securely attaches to the first felt surface 230. The screen modeling layer 250 preferably does not extend through the entire thickness of the felt layer 220, but rather extends through less than half the thickness of the felt layer 220 to maintain the flexibility and compressibility of the weft support apparatus 200, and particularly the flexibility and compressibility of the felt layer 220. A felt layer suitable drainage 220 comprises a mattress 240 of bound natural or synthetic fibers, such as by needling, for a support structure formed of woven filaments 244, as shown in Figure 4A. Suitable materials, from which the mattress 240 is formed, include, but are not limited to, natural fibers such as wool and synthetic fibers, such as polyester and nylon. The fibers from which the mattress 240 is formed can have a denier of between about 1 and 20 grams per 9000 meters of filament length. The felt layer 220 may have a layered construction, and may comprise a mixture of fiber types and sizes. The felt layer 220 may have very fine fibers, packed relatively dense, adjacent to the first felt surface 230. In one embodiment, the felt layer 220 may have a relatively high density and a relatively small pore size adjacent to the felt. the first felt surface 230, compared to the density and pore size of the felt layer 220 adjacent the second felt surface 232. The waste felt layer 220 can have a thickness of between about 2 millimeters and about 5 millimeters. millimeters, a basis weight of about 800 and about 2000 grams per square meter, an average density (basis weight divided by thickness) of between about 0.16 grams per cubic centimeter and about 1.0 grams per cubic centimeter, and an air permeability of between approximately 2.3595 and approximately 141.57 liters per second, where air permeability in liters per second is a measure of the number of liters of air per second that passes through a square meter area of the felt layer 220 to a pressure drop across the thickness of the felt layer 220 equal to about 1.27 cm of water. Air permeability is measured using a Valmet permeability measuring device (Model Wigo Taifun Type 1000) available from Valmet Corp. of Pansio, Finland. The permeability of the weft support apparatus 200 is less than or equal to the permeability of the felt layer 220 and is approximately equal to the permeability of the felt layer 220 multiplied by the fraction of the projected area of the apparatus 200 not covered by the plot modeling layer 250. A suitable felt layer 220 is an Amflex Felt 2 Press Felt, manufactured by Appleton Mills Company of Appleton, Wisconsin. Said felt layer 220 may have a thickness of about 3 mm, a basis weight of about 1400 g / m2, an air permeability of about 9,438 to 14,157 liters per second, and has a double layer support structure having a sheath upper and lower of multiple filaments of 3 folds and a sheath in the transverse direction of the monofilament machine of 4 folds. The mattress 240 may comprise nylon fibers having a denier of about 3 on the first surface 230, and a denier of between about 10-15 on the mattress substrate underlying the first surface 230.

Suitable photosensitive resins are described in the U.S.A. 4,514,345 issued April 30, 1985 to Johnson et al., And the US patent. 5,334,289 issued August 2, 1994 to Trokhan et al., Which are incorporated herein by reference. The resin, when cured, may have a thickness less than or equal to 60 Shore D. The hardness is the average of the five measurements in a non-patterned photopolymer resin coupon measuring approximately 2.54 cm by 5.08 cm by 0.0635 cm thick cured under the same conditions as the screen modeling layer 250. The hardness measurements are made at 25 ° C and read 10 seconds after the initial coupling of the Shore D durometer probe with the resin. A resin having said hardness after curing is desirable, so that the screen modeling layer 250 is somewhat flexible and deformable. The cured resin preferably resists oxidation. The uncured resin may have a viscosity of between about 5000 and about 25,000 centipoise at 21.1 ° C to facilitate the penetration of the felt layer 220 by the resin prior to curing. Suitable liquid photosensitive resins are those included in the Merigraph series of resins made by Hercules Inc. of Wilmington, Delaware, which incorporate an antioxidant, as described in the U.S. patent. 5,334,289, previously cited. A suitable liquid photosensitive resin is an MEH-1000 resin available from Hercules, Inc.

Use of the Raster Support Device to Make Paper Figure 3 illustrates the use of the apparatus 200 for making a paper web 20. A slurry of paper fibers, such as cellulosic wood pulp fibers, is deposited from a head box 500 on a foraminous web, formation, permeable to liquid 542, to form an embryonic fiber web to make paper 543 supported by forming web 542. Formation web 542 can comprise a continuous Fourdrinier wire, or alternatively, it can be in the form of any of the several twin wire formers known in the art. The web 543 is then transferred from the forming web 542 to the web support apparatus 200, with the embryonic web 543 placed on the first side 202 of the web support apparatus 200. The step of transferring the embryonic web 543 to the weft support apparatus 200 may simultaneously include the step of folding a portion of the web 543 into the openings 270 in the weft modeling layer 250 to form a non-monoplane weft 545. Steps for transferring the embryonic web 543 to the weft support apparatus 200 and folding a portion of the embryonic web 543 may be provided, at least in part, by applying a differential fluid pressure to the embryonic web 543 through a source of vacuum 600. One or more additional vacuum sources 620 may also be provided downstream of the embryonic screen transfer point. After transferring and folding the embryonic web 543 to form the non-monoplane web 545, the web 545 is carried over the support apparatus 200 through a contact line 800 provided between the Yankee drying drum 880 and a roller 900. The web is transferred to and dried on the surface 875 of the drum 880, and then pleated from the surface 880 through a scraping blade 1000 to form a pleated paper web 20. Before transferring the web 545 to the drying drum 880, the The weft can be dewatered, such as through compression or through air drying. For example, the weft may be compressed in a press contact line 700 between the weft support apparatus 200 and a drain felt 712 separately, as described in U.S. Patent Application. Series No. 08 / 358,661, "Wet Pressed Paper Web and Method of making the Same" (Wet Compressed Paper Screen and Method to Do the Same), presented on December 19, 1994 in the name of Ampulski et al. The following patent documents are hereby incorporated by reference in their entirety for the purpose of describing how to make a patterned plot 20: US patent. 4,529,480 issued July 16, 1985 to Trokhan; patent application of E.U.A. Series No. 08 / 268,154, "Web Patterning Apparatus Comprising a Felt Layer and a Photosensitive Resin Layer "(Screen Modeling Apparatus comprising a layer of Felt and a Photosensitive Resin Layer), filed on June 29, 1994 in the name of Trokhan et al .; US Patent Application Series No. 08 / 268,213" Paper Structures Having at Least Three Regions Including a Transition Region Interconnecting Relatively Thinner Regions disposed at Different Elevations, and Apparatus and Process for Making the Same " Role of at least Three Regions Including a Transition Region Interconnecting Relatively Thin Regions Arranged at Different Elevations, and Apparatus and Procedure to Do The Same), presented on June 29, 1994, in the name of Trokhan et al .; and the patent application of E.U.A. Series No. 08 / 358,661, "Wet Pressed Paper Web and Method of Making the Same" (Wet Compressed Paper Plot and Method to Make Same), filed on December 19, 1994, in the name of Amulski et al.

Fabrication of a Raster Support Device with Photosensitive Resin Cured on a Felt Layer The weft support apparatus 200 may be made in accordance with the present invention using the steps illustrated in Figures 4A-4H. A substrate having a first surface, a second surface, and a thickness is provided, the substrate having intermediate recesses to the first and second surfaces. In Figure 4A, the substrate provided is a layer of drain felt 220. A liquid photosensitive resin and a second material different from the photosensitive resin are also provided. Referring to Figure 4B, the present invention includes the step of applying the second material, designated with the number 2000, to the felt layer 220. The felt layer 220 is transported in the direction shown by the arrow in Figure 4B. . In one embodiment, the felt layer 220 can be transported adjacent to an infrared heating lamp 2310 positioned adjacent the first felt surface 230 of the felt layer 220 before applying the second material to the felt layer 220. The lamp 2310 can be used to heat the felt layer 220. The use of the heating lamp 2310 is optional, and is not required. The felt layer 220 can then be transported adjacent to a collection pipe 2410, positioned adjacent the second surface 232 of the felt layer 220. The collection pipe 2410 has an opening through which the second material 2000 is directed over the second surface 232 of felt layer 220. The second material is applied as a liquid to felt layer 220 to occupy at least some of the voids in the felt layer intermediate surfaces 230 and 232. In Figure 4B , the second material is applied to the felt layer 200 to penetrate the entire thickness of the felt layer between the surfaces 230 and 232. The felt layer 220, on which the second material 200 has been deposited, is directed through of a 2470 contact line between the rollers 2472 to ensure that the second material is distributed through the entire thickness of the felt layer 220, between the surfaces 230 and 232. Alternatively, the second The material 2000 can be applied to the first surface 230 of the felt layer 220. The second material 200 fills the voids in the felt layer 220, and thus provides a barrier to the penetration of the liquid photosensitive resin through the layer. of felt 220. The second material 2000 serves to prevent the curable resin from entering certain target portions of the felt layer 220 that contains voids. The second material of preference is easily applied to the substrate, and preferably is not displaced from the felt layer 220 by the curable resin. The second material is also preferably easily removed from the felt layer 220, after the curing of the resin applied to the felt layer 220. In one embodiment, the second material 2000, (1) can be applied to the felt 220 in a relatively mobile state to provide a penetration of the second material 2000 through the felt layer 220; (2) it can be altered after it has been applied to the felt layer and before the application of the photosensitive resin to the felt layer 220 to have a reduced mobility to resist the displacement of the second material by the photosensitive resin; and (3) it can be altered to have increased mobility after at least partially healing the resin to facilitate the second material from the gaps in the felt layer 220. In one embodiment, the second material is relatively mobile when applied first. to the substrate. For example, the second material may comprise a liquid, a solute dissolved in a liquid solvent, solid particles dispersed in a liquid component of the second material, or a mixture of liquid reaction components when first applied to the substrate. After the second material has been applied to the substrate, and before the application of the curable resin to the substrate, the second material is altered to be relatively less mobile than when it was first applied to the substrate, in order to provide a barrier to the substrate. the penetration of the curable resin to the predetermined portions of the substrate. Prior to the application of the curable resin to the substrate, the second material applied to the substrate is preferably transformable to be relatively immobile, for example: increasing the viscosity of the second material; changing the phase of at least a portion of the second material from a liquid to a solid; evaporating a fluid component of the second material to provide an occlusive film or closed cell foam barrier in the substrate; or by providing a chemical reaction that transforms the liquid reaction components of the second material into highly viscous or solid reaction products. Since Figures 4B to 4H will be discussed with reference to a second material that will form a gel, other examples of suitable secondary materials are provided below. In one embodiment, the present invention includes the step of changing the phase of the secondary material 2000 applied to the felt layer 220. The phrase "changing the phase of the second material" refers to a discontinuous change in certain properties of the second material to a temperature and pressure determined. The change in phase of the second material includes changing a gas phase from the second material to a liquid or solid phase, changing a liquid phase from the second material to a gas phase or solid phase, and changing a solid phase from the second material to a gas phase or liquid phase. Examples of phase changes of the second material include, but are not limited to, liquefying the second material, sublimating the second material, and solidifying the second material by freezing or gelling the second material. In one embodiment, the second material undergoes a phase change from a solid phase to a liquid phase at a temperature below the temperature at which the cured resin degrades (i.e., less than the melting temperature or the decomposition of the cured resin), and most preferably at a temperature between about 10 ° C and about 65.5 ° C. Referring to Figure 4B, in one embodiment, the second material can be applied to the felt layer 220 as a liquid mixture of water and a gelling agent at an elevated temperature. The reaction mixture of the water and the gelling agent can then be allowed to cool on the felt layer 220 to form a solid gel phase of the second material, which fills the voids in the felt layer 220. Before applying the photosensitive resin to the felt resin 220, it may be desirable to remove some, but not all, of the second material from the felt layer 220 before applying the photosensitive resin to the felt layer 220. Referring to Figure 4C, the present invention may be including the step of removing the second material from the first adjacent surface 230 of the felt layer 220, thereby providing a portion of the thickness of the felt layer 220, which is substantially free of the second material. When the second material comprises a gel, a layer of the second material adjacent to the first surface 230 of the felt layer 220 can be removed with a water sprinkler 2510.

Alternatively, the layer of the second material can be removed from the felt layer 220 by mechanical brushing. The removal of a layer of the second material adjacent to the first surface 230 provides a predetermined portion of the thickness of the felt layer 220 to which the photosensitive resin can be applied and finally secured. Referring to Figure 4D, the present invention includes the step of applying the curable resin to the substrate. In the embodiment shown, a layer 2010 of the liquid photosensitive resin is applied to the first exposed surface 23 'of the felt layer 220 after some of the second material is removed from the surface 230. A mask 3010 is placed adjacent to the 2010 layer of liquid resin. The mask 3010 has opaque regions 3012 and transparent regions 3014. A pressure roller 3100 controls the depth d of the layer 2010 deposited on the felt layer 220. The depth d is selected to be approximately equal to the desired difference in elevation 262 between the surface 260 of the cured resin layer 250 and the felt surface 230 (Figure 4G) plus the thickness of the layer of the second material 2000 removed from the felt layer in Figure 4C.

Referring to Figure 4E, the present invention includes the step of curing at least some of the resin applied to the substrate. In one embodiment of the present invention, the resin is selectively cured to provide a patterned resin layer on the substrate. In Figure 4E, the resin curing lamps 3150 provide a source of actinic radiation in a first curing step to at least partially cure the 2010 layer of the liquid photosensitive resin deposited on the felt layer 220. The mask 3010 is placed intermediate to the 3150 lamps and to the 2010 layer of the liquid photosensitive resin. The liquid photosensitive resin is selectively exposed to actinic radiation through the mask 3010 to induce healing of the photosensitive resin relative to the transparent regions 3014 in the mask 3010. The first cure step provides a patterned resin layer 250, which is at least partially cured on the first surface 230 of the felt layer 220. Referring to Figure 4F, the present invention may include the step of removing the uncured resin from the substrate after the first healing step shown in FIG. Figure 4E. In Figure 4F, the uncured resin is indicated with the reference number 2010A. Mask 3010 can be removed from patterned resin layer 250, Uncured resin 2010A can then be removed with water sprinklers 2530. Water sprinklers can be angled to remove uncured resin 2010A from openings 270 in the layer of patterned resin 250. The second solidified material 2000 prevents the uncured resin from penetrating through the total thickness of the felt layer 220, and keeps the uncured resin adjacent to the first surface 230 of the felt layer 220. Accordingly , the uncured resin 2010A is relatively easy to remove from the openings 270 in the resin layer 250 with a water sprinkler 2530. Referring to Figure 4G, the present invention includes the step of removing at least some of the second material 2000 of the substrate after the resin is applied to the substrate. In embodiments wherein the second material 2000 is solidified, such as by gelation, the second material 2000 can be removed by heating the second material at a temperature above its gelation temperature, thereby liquefying the second gelled material. In Figure 4G, the felt layer 220 is transported adjacent to the infrared heating lamp 3170 positioned adjacent the first surface 230 of the felt layer 220. The second material 2000 can be heated with infrared heating lamps 3170 to liquefy the second material. The felt layer 220 can then be washed with a 2550 hot water shower, and directed over a vacuum box 2570 to remove the second liquefied material, as well as any uncured photosensitive resin. In Figure 4G, the hot water shower 2550 directs a spray against the first surface 230 of the felt layer 220. The vacuum box 2570 provides a vacuum in the second surface 232 of the felt layer 220 to remove the second material Liquid from the second surface 232. The jet and vacuum application may be repeated, as necessary, to remove the second liquefied material from the felt layer 220. Preferably, at least the second material 2000 applied to the substrate is removed, and most preferably all of the second material 2000 applied to the substrate is removed from the substrate. As shown in Figures 4C and 4G, the second material can be removed from the substrate both before and after the liquid resin is applied to the substrate. In one embodiment shown, more than the second material is removed after the application of the liquid resin to the substrate that is removed before the resin is applied to the substrate. In Figures 4F and 4G, the uncured liquid resin is washed before the removal of the second material remaining on the felt layer 220. Alternatively, the entire second material 220 can be removed from the felt layer 220, followed by the washing the uncured liquid resin from the felt layer 220. Referring to Figure 4H, the method according to the present invention may include a post-cure step carried out after substantially all the liquid resin not cured 201 OA and substantially all of the second material 2000 has been removed from the felt layer 220. A source of actinic radiation, such as post-cure lamps 3180, is placed above the resin layer 250 to complete the healing of the layer of resin 250. The removal of all the second material and all the uncured liquid resin from the substrate before the final cure of the resin layer 250 by the lamps 3180, it is desirable to avoid the Inadvertent cure of the resin in portions of the felt layer 220, where air and water permeability is desired. The post-cure step can be performed with the resin layer 250 immersed in a water bath 1620 to promote the complete reaction of the photosensitive resin, as described below. The resulting weft support apparatus 200 has a resin layer 250, which penetrates the first surface 230 of the felt layer 220 to extend, intermediate, the first and second surfaces 230 and 232. The cured resin layer 250 it also extends from the first surface 230 to have a web in contact with an upper surface 260 at a second elevation different from the elevation of the first surface 230.

Examples of Secondary Materials to Fill Gaps in the Substrate A number of materials are suitable for use as the second material 2000 for filling gaps in the substrate to prevent penetration of the liquid resin through the thickness of the substrate. Preferably, the second material is added to the substrate before the application of the liquid resin to the substrate. However, in alternative embodiments, the second material may be applied to a substrate to displace the liquid resin that has previously been applied to the substrate. The following examples are intended to be illustrative but not limiting. In one embodiment, the second material may comprise water. When water is used as the second material 2000, it is preferred to use distilled water to avoid hard water deposits on the substrate. For example, water can be added to the felt layer 220 as a liquid, and maintained as a liquid through the addition and cure steps of the photosensitive liquid. Maintaining the water as a liquid while adding the liquid curable resin to the substrate has the disadvantage that something, if not most, of the water can be displaced by the liquid resin before the resin is cured. In another embodiment, the water can be added to the felt layer 220 as a liquid, and then frozen prior to the addition of the liquid photosensitive resin. The change of the water phase by freezing the water can provide an ice layer in the felt layer which prevents the penetration of the liquid resin through the entire thickness of the felt layer 220. In another embodiment, the second material it can be transformed to have a substantially increased viscosity, as compared to its viscosity when it is first applied to the felt layer 220. By substantially increasing the viscosity of the second material, it is meant that the viscosity of the second material is increased by a factor of at least 10, and preferably at least 100. For example, the second material may comprise a solvent and a solute, such as a mixture of water and a solute component, which is soluble in water. The water soluble component can comprise a water soluble resin, such as a polyvinyl alcohol, applied to the felt layer at an elevated temperature and a low solids content. By "water soluble", it is meant that a component is soluble in deionized water at 25 ° C at a level of at least 1.0%. Specifically, the second material can include 8% by weight of a solution of Elvanol HV (available from Dupont Company, Wilmington, DL) in water. The second material can be applied to the substrate at a temperature of approximately 71.1 ° C. Said solution has a viscosity of about 250 centipoise and easily fills the voids in a layer of felt 220. The concentration of the solution can be increased to approximately 14% by evaporating the water, and the temperature of the solution can be increased to approximately 21.1 °. C to increase the viscosity of the second material to approximately 35,000 centipoise. After the photosensitive resin is applied and cured, Elvanol can be resolubilized, preferably with hot water. In another embodiment, the second material may comprise a water soluble gum dissolved in water. The preferred gums show a pseudoplastic behavior (shear thinning). The "shear thinning" refers to the reduction of the viscosity of a material when the material is subjected to shear forces. In one embodiment, a 1-3% solution of a high viscosity guar gum is added to the substrate-containing gap, while the gum and water solution is subjected to a shear rate and at an elevated temperature. At a shear rate in excess of about 10 reciprocal minutes and at a temperature of at least about 60 ° C, the viscosity of the rubber and water solution is reduced sufficiently to allow easy filling of the felt layer 220 with the rubber and water solution. The shear rate in the gum and water solution is then removed, and the solution is allowed to cool to approximately 21.1 ° C to provide the gum and water solution with a viscosity greater than or equal to about 50,000 centipoise. The increased viscosity of the gum and water solution prevents displacement of the gum and water solution from the felt layer 220 by the curable liquid resin. The document "Handbook of Water Soluble Gums and Resins", edited by R.L. Davidson, McGraw-Hill, 1980, p. 6-1 to 6-8 is incorporated herein by reference for the purpose of describing suitable water-soluble gums and the application and measurement of shear rates. In another embodiment, the second material may comprise a mixture of water and a second component, wherein the water may be removed from the mixture, such as by drying or evaporation. For example, the second material can be added to the felt layer 220, and the water can be removed from the second material, such as by evaporation, to provide a barrier to the penetration of the photosensitive resin of the substrate. The barrier can then be removed from the substrate by flushing the substrate with water to wash the substrate barrier. For example, the second material may comprise a water solution and a high molecular weight polyvinyl alcohol plasticized with glycerol. Said solution can be liquid at approximately 21.1 ° C, and it is transformed to a film as the water evaporates in the solution. Suitable polyvinyl alcohols include Elvanol 90-50 and Elvanol 71-30 (available from Dupont Company, Wilmington, DL). A suitable aqueous solution comprises approximately 6-8% by weight of polyvinyl alcohol. Before mixing the polyvinyl alcohol in water, the polyvinyl alcohol can be plasticized into a mixture of about 90 to 95% polyvinyl alcohol, and about 5 to 10% by weight glycerol. The mixture of polyvinyl alcohol and glycerol can then be added to the water to form the aqueous solution comprising about 6-8% by weight of polyvinyl alcohol.

In another embodiment, the second material may comprise a solid dispersed in a liquid. For example, the second material may comprise a latex rubber with a low glass transition temperature dispersed in water. The dispersion may comprise about 40% by weight of the polyacrylate latex resin in water. The polyacrylate latex resin may comprise the Roplex TR-520 polyacrylate latex resin available from Rohm and Haas Company. After evaporation of the water in the dispersion, the solid latex spheres are put together in a rubber film that easily disperse with the water as long as the temperature of the film remains below the interlacing temperature of the latex rubber . Alternatively, a blowing agent may be added to the dispersion, which produces a gas after heating. For example, diazocarbamide can be added to the latex resin and water dispersion to produce nitrogen after heating, thus forming a latex foam upon evaporation of the water in the dispersion. In one embodiment, the second material may comprise a water-soluble wax as the material, such as polyoxyethylene glycol (PEG). The PEG may have a melting point below the degradation temperature of the curable photosensitive resin, such that the second material is a solid at or near about 21.1 ° C, and may be liquefied below the degradation temperature of the photosensitive resin. For example, a PEG having a molecular weight in an excess of about 600 is suitable. More specifically, the second material may comprise PEG 1500 with a melting point of about 46 ° C, PEG 4000 with a melting point of about 56 ° C, PEG 6000 with a melting point of about 60 ° C, and mixtures of the same. Alternatively, the second material may comprise a PEG of relatively low molecular weight, such as PEG 400, which may remain as a liquid during the application and curing of the photosensitive resin.

The second material 2000 may also comprise water soluble surfactants and water dispersible surfactant systems. For example, the second material may comprise a liquid detergent solution, such as a detergent solution comprising anionic and nonionic surfactants, an assortment agent of ethyl alcohol and water. The detergent solution can be applied to the substrate before the application of the resin to the substrate. Said detergent solution is commercially available as Joy Brand Dishwashing Liquid from Procter & Gamble Company of Cincinnati, Ohio. The second material 2000 may also comprise a water soluble surfactant or a water dispersible surfactant system, which is a solid below about 21.1 ° C. Examples of water-soluble surfactants include anionic derivatives of sulfosuccinic acids. Applied as water solutions, these materials dry flexible plosive films suitable to provide a barrier to the penetration of the substrate through the liquid photosensitive resin. An example of an anionic surfactant is Aerosol OT-75 (available from American Cyanimid). The surfactant, Aerosol OT, is a dioctyl ester of sodium sulfosuccinic acid. An example of suitable water dispersible systems includes mixtures of long chain alkyl quaternary surfactants blended with polyoxethylene glycol 400 or glycerin. More specifically, a mixture of about 70% by weight of di (tallow hardened tallow) dimethyl ammonium chloride with about 30% by weight of PEG 400 (which is a pasty wax at about 21.1 ° C and a liquid at about 65.5 ° C) ) can be used to form the second material 2000. In another embodiment, the second material can comprise reaction components that are liquid at room temperature or are soluble in water and can be polymerized to a water soluble solid of higher molecular weight or high viscosity paste. For example, the second material may comprise a mixture of about 10% by weight of acrylic acid, about 20% by weight of sodium acrylate, about 70% by weight of water and a free radical initiator. The free radical initiator can be activated by heat. An example of a free radical initiator is V-50, a 2,2'-azobis (2-amidino propane) dihydrochloride available from Wako Chemicals of Dallas Texas. In another embodiment, the second material may comprise a gelling agent. Sule gelling agents include, but are not limited to, plant gelling agents, such as pectin, carrageenan, animal protein gelatins, hydrogel-forming polymeric gelling agents, and soap gelling agents. An example of a gelling agent that can be dissolved in water to form the second material 200 is the JELLO brand gelatin from General Foods Company of White Plains, NY. Sule hydrogel-forming polymeric gelling agents include at least partially entangled polymers prepared from acid-containing, polymerizable, unsaturated monomers, which are either soluble in water or made soluble in water after hydrolysis. These include monoethylenically unsaturated compounds having at least one hydrophilic radical, including olefinically unsaturated acids and anhydrides containing at least one olefinic carbon-carbon double bond. The patent application of E.U.A. 08 / 307,951, "Mild Gel Deodorant Composition Containing Soap, Polymeric Hydrogel Forming Polymer and High Level of Water "(Composition Deodorant in Gel Containing Soap, Polymeric Polymer Hydrogel and High Water Level), presented on September 16, 1994, in the name of Trandai and others, is incorporated herein by reference in its entirety for the purpose of describing gel forming agents.

Soap gelling agents comprise monovalent metal salts of fatty acids containing from about 12 to about 40 carbon atoms (C12-C40), and most preferably C12-C22 salts of fatty acids. Salt formation cations for use in these gelling agents include metal salts such as alkali metals, for example, sodium and potassium. In one embodiment, the second material comprises a salt of fatty acids selected from the group consisting of sodium salts of fatty acids, potassium salts of fatty acids, and combinations thereof. Examples of fatty acids useful for synthesizing soap-gel forming agents include myristic, palmitic, stearic, oleic, linoleic, margaric and mixtures of said acids. Sources of such fatty acids include, but are not limited to, coconut oil, beef tallow, lanolin, fish oil, beeswax, palm oil, peanut oil, olive oil, cottonseed oil, soybean oil, corn oil, rapeseed oil, colophonic acids, fats, castor oil, linseed oil, ocydic oil, cow paw oil, safflower oil, sesame oil, sorghum oil, sunflower oil , by-product oil of wood chemical pulp, stick oil, butter fat, bird fat, whale oil and rice bran. Fatty acid soap gel forming agents include sodium laurate, sodium myristate, sodium palmitate, sodium stearate, potassium laurate, potassium myristate, potassium palmitate, and potassium stearate. In one embodiment, the second material 2000 comprises a solution of sodium myristate in water. A suitable solution comprises between about 5 and about 30% by weight, and most preferably between about 5 and about 20% by weight of sodium myristate in water. Said solution can have a temperature of about 32.2-48.8 ° C. Sodium myristate can be formed by reacting myristic acid (C13H27COOH) with NaOH in water. The base and the acid are added stoichiometrically so that they react completely. The NaOH is added to the water and heated to about 82.2 ° C. The myristic acid is then added gradually to the water / NaOH solution. The reaction is continued for about one hour. The sodium myristate solution thus formed is then cooled to about 60-71.1 ° C before application to the felt layer 220. Said soap gelling agent solution has the advantage that it can be solidified to a gel phase at a temperature between about 10 ° C and about 65.5 ° C before applying the resin to the substrate. The gel phase in this manner can resist the displacement of the liquid photosensitive resin at room temperature (approximately 21.1 ° C) without requiring refrigeration equipment to provide solidification. In addition, the solution is mainly water (at least about 70% water by weight, when added to the felt layer 220). Accordingly, the removal and disposal of the second material removed from the felt layer 220 is simplified, and the environmental aspects are minimized.

Procedure to Form a Continuous Band that Has a Felt Layer and a Modeled Resin Layer Figure 5 schematically illustrates a method according to an embodiment of the present invention for forming a weft support apparatus 200 in the form of a continuous web comprising a felt layer 220 having a cured resin layer 250. In the modality shown in Figure 5, the felt layer 220 may comprise an Amflex 2 felt commercially available from Appleton Mills of Appleton, Wisconsin, and the photosensitive resin may comprise an MEH-1000 resin commercially available from Hercules Chemical. A forming unit 1513 is provided in the form of a drum having a work surface 1512. The forming unit 1513 is rotated through unshinned driving means. A backup film 1503 is provided from a roller 1531, and is taken through a roller 1532. Intermediate to the rollers 1531 and 1532, the backing film 1503 is applied to the work surface 1512 of the forming unit 1513 The function of the backing film is to protect the working surface of the forming unit 1513 and to facilitate the removal of the partially completed weft support apparatus 200 from the forming unit 1513. The backing films 1503 can be made from any suitable material including, but not limited to, a polypropylene film having a thickness of from about 0.01 to about 0.1 millimeters. As shown in Figure 5, the felt drainage layer 220 in the form of a continuous band is conveyed around the forming drum 1513 and a number of return rolls 1511 in a closed path. Before applying the second material and the liquid resin to the felt layer 220, the felt drainage layer 220 can be transported past an infrared heating lamp 2310 to preheat the felt layer 220. The felt layer 220 after it is transported in a horizontal direction at a speed of approximately 0.3048-3.048 meters / minute, adjacent to a collection pipe 2410 containing the second material. The manifold 2410 has an opening through which the second material is deposited on the second surface 232 d of the felt layer 220. The opening in the manifold 2410 is placed against the second surface 232 of the felt layer 220. The second directed material of the collector 2410 is a solution of about 10% by weight of sodium myristate in water having a temperature of about 48.8-65.5 ° C.

Approximately 0.9 grams of the second material per 2.54 cm2 of the surface area of the felt layer 220 is deposited on the felt layer 220. The felt layer 220, on which the second material is deposited, is then carried through a 2470 contact line between two rollers 2472. The space between the rollers 2472 provides a contact line, which is approximately 0.0254 cm less than the thickness of the felt layer 220. The contact line 2470 ensures the distribution of the second material to through the felt layer 220 and compress the excess of the second material of the felt layer 220. The second material deposited on the felt layer 220 is allowed to cool to a temperature below about 32.2 ° C to solidify the second material.

The cooling of the second material results in the formation of a stable gel phase of the sodium myristate in the recesses of the felt layer 220. After a stable gel phase of the second material has been formed, the felt layer 220 it is transported adjacent to a 2510 water sprinkler at a speed of 0.6096-1.8288 meters per minute. The water sprinkler has nozzles placed approximately 7.62 cm from the first surface 230 of the felt layer 220 to be used in the removal of some, but not all, of the second gelled material from the felt layer 220. The nozzles provide a plurality of nozzles. fan-shaped spray patterns arranged in an overlapping manner. The water sprinklers 2510 provide a water spray of approximately 5,622 liters per 0.9290 square meters of surface area of the felt layer 220. The nozzles are Spray Systems Tee Jet brand nozzles, model 50015 having a hole diameter. of approximately 0.07874 cm. The sprinkling of water supplied by showers 2510 has a pressure of approximately 35.15 kg / cm2 gauge. The water sprinkler 2510 is operated to remove the second material adjacent the first surface 230, to thereby provide a portion of the thickness of the felt layer 220, which is substantially free of the second material. Water sprinklers 2510 can be used to remove a layer of the second gelled material having a thickness between about 0.00508 cm and about 0.508 cm. The thickness of the layer of the second gelled material removed is less than the thickness of the felt layer 220, so that between about 75% and about 98% of the thickness of the felt layer 220 remains impregnated with a second gelled material, and most preferably between about 85% and about 95% of the thickness of felt layer 220 remains impregnated with the second gelled material after washing with water showers 2510. A vacuum manifold 2520 provides a vacuum of approximately 0.0703-0.2812 kg cm / cm2 in the first surface 230 of the felt layer 220 to remove the second liquefied material and the water spray. Once the first surface 230 of the felt layer 220 has been prepared by removing something, but not everything, from the second material of the felt layer 220, the photosensitive resin can be applied to the first surface 230. Felt drainage layer 220 is placed adjacent to the backing film 1503, so that the backing film 1503 is interposed between the felt drainage layer 220 and the forming unit 1513, and so that the second felt material 232 of the felt drainage layer 220 is placed adjacent the backing film 1503. A photosensitive liquid resin coating is applied to the first felt surface 230. The coating of the photosensitive resin 1502 can be applied to the first felt surface in any suitable form. In Figure 5, the coating of the resin is applied through a nozzle 1520 to form a resin pond on the felt layer 220 upstream of a nip through a pressure roller 3100.

The coating thickness of the resin applied to the felt layer 220 is controlled to a preselected value corresponding to the desired difference in elevation 262 between the elevation of the first surface 230 and the elevation of the upper surface 260 contacting the weft of the patterned layer 250. In Figure 5, the thickness of the resin coating is controlled by mechanically controlling the gap between the pressure roller 3100 and the forming unit 1513. The pressure roller 3100 together with the mask 3010 and a mask guide roller 1542 tend to soften the surface of the resin and control its thickness. The second gelled material prevents the liquid photosensitive resin from penetrating through the thickness portion of the felt layer 220 through the second material. The mask 3010 can be formed of any material, which can be provided with opaque and transparent portions. The transparent portions are arranged in a pattern corresponding to the desired pattern of the pattern modeling layer 250. A material in the nature of the flexible photographic film is suitable. The opaque portions may be applied to the mask 3010 in any suitable manner, such as photography, engraving, flexographic, or rotary screen printing. The mask 3010 may be an endless belt, or alternatively, supplied from a supply roll 3012 and taken by the feed adjusting roller 3016, as shown in Figure 5. As shown in Figure 5, the mask 3010 is transported around the rollers 3100, 1542, 3014 and 3016. Intermediate to the rollers 3100 and 1542, the mask 3010 travels with the felt layer 220 around the forming unit 1513, and is positioned adjacent to the liquid resin, with the intermediate mask to the resin and a source of actinic radiation, which is suitable for curing the liquid resin. The photosensitive resin is exposed to actinic radiation d an activation wavelength through the mask 3010, thus inducing at least a partial cure of the resin in those portions of the resin layer, which are in accordance with the portions of the mask 3010. In Figure 5, ultraviolet radiation having an activation wavelength is supplied through first healing lamps 3150. The activation wavelength is a characteristic of the resin, and can be supplied by any suitable source of illumination, such as mercury arc lamps, pulsed xenon, without electrodes and fluorescents. For the MEH-1000 resin, suitable curing lamps 3150 are F450 Fusion Lamps equipped with "D" or "H" bulbs, and commercially available from Fusion Systems, Inc. of Rockville, Md. The felt layer 220 can be transported adjacent to the 3150 healing lamps at a rate of approximately 0.3048-0.9144 meters per minute during casting. The partial cure of the resin is manifested through a solidification of the resin according to the transparent portions of the mask 3010, while the unexposed portions of the resin according to the opaque portions of the mask 3010 remain liquid. To obtain a uniform initial curing of the resin on the felt layer 220, the energy provided by the UV light to the photosensitive resin should be uniform across the width of the felt layer 220. The output of each of the lamps of healing 3150 must be matched so that it is within at least about 5% of each other. The healing lamps 3150 can be placed collaterally in the transverse direction of the machine (perpendicular to the plane of Figure 5). For example, three 3150 healing lamps can be placed collaterally in the machine direction. A pair of aperture plates are disposed intermediate the lamps 3150 and the felt layer 220, and are spaced apart in the machine direction to form an aperture opening., through which the ultraviolet light is directed from the lamps 3150 towards the stagnant resin on the felt layer 220. The energy directed towards the felt layer 220 can be measured through a "flashing light beacon" such as EIT UV Integrating Radiometer, Model No. UR365CH1 made by Electronic Instrumentation Technologies located in Stirling Virginia. The flashing beacon can be attached to the casting drum 1513 to measure the energy integrated in milijoules per cm2 applied to the felt layer 220. Repeating this measurement "every 1.27 cm across the width of the drum 1513, a profile of the imparted energy of the lamps 3150 to the photosensitive resin can be determined. If the gap between the opening plates is uniform along the width of the drum 1513, the energy profile will generally not be uniform. The gap between the aperture plates can be varied as a function of the position in the transverse direction of the machine to provide a uniform energy profile supplied by the 3150 lamps to the stagnant resin on the felt layer 220. After partially curing the resin layer applied to the first surface 230, substantially all of the uncured liquid resin can be removed from the felt drainage layer 220. The uncured liquid resin can be removed from the felt layer 220. Uncured liquid resin can be removed from the felt layer 220 through high pressure jet application of the felt layer 220 with water, or alternatively, a mixture of surfactant and water. At a point adjacent the roller 1542, the mask 3010 and the backing film 1503 are separated from the felt layer 220 and the partially cured resin layer. The composite felt layer 220 and the partially cured resin layer are transported adjacent to the water sprinklers 2530. The water sprinklers 2530 can be angled to remove the uncured resin 2010A from the openings in the patterned resin layer. The 2530 sprinklers provide a spray at a temperature of approximately 15.5-26.6 ° C through nozzles, such as the Spray Systems Tee Jet brand nozzles, model 50015, which have a hole with a diameter of approximately 0.07874 cm. The supply pressure of the shower is approximately 35.15 kg / cm2 gauge. The showers 2530 and the felt layer 220 can be moved laterally (perpendicular to the plane of Figure 5) relative to one another to eliminate the streaks and provide a uniform removal of the liquid resin across the width of the felt layer 220. The composite felt layer 220 and the resin layer can then be carried through a 1620 bath of distilled or deionized water. At this point, the second gelled material is still present in the second felt layer 220. The post-cure lamps 3180 placed on the bath 1620 are turned off, while the composite felt layer 220 and the resin layer is carried through the 1620 bathroom for the first time.

The post-cure lamps are ignited in a final healing step described below. After leaving the bath 1620, the composite felt layer 220 and the resin layer is brought intermediate to infrared heating lamps 3170 and a vacuum manifold 2560 at a speed of approximately 0.3048-0.9144 meters per minute. The heating lamps 3170 heat the second gelled material to a temperature of about 60 ° C, which is above the temperature of the second material, so that substantially all of the second material is liquefied for the removal of the felt layer 220 The heating lamps 3170 are positioned adjacent to the first felt surface 230, and the vacuum manifold 2560 is positioned adjacent to the second felt surface 232. The heating lamps 3170 can be placed approximately 7.62 cm from the felt layer 220. A suitable infrared heating lamp 3170 is a Protherm heating lamp manufactured by Process Thermal Company, and has a power rating of approximately 20 amps. The vacuum manifold 2560 provides a vacuum of approximately 0.0703-0.3515 kg / cm2 gauge on the second felt surface 232. The composite felt layer and the resin layer is then transported intermediate to the 2550 hot water sprinklers and a manifold vacuum 2570. The hot water shower 2550 directs a spray against the first surface 230 of the felt layer 220. The 2550 showers supply a sprinkling of distilled water at a temperature of approximately 60 ° C using Tee Jet brand nozzles. The supply pressure of the shower is approximately 3.515-14.06 kg / cm2 gauge. The vacuum manifold 2570 provides a vacuum of approximately 0.0703-0.3515 kg / cm2 gauge in the second surface 232 of the felt layer 220 to remove the second liquefied material and any remaining uncured liquid resin from the second surface 232. Preferably substantially all the second material is removed from the felt layer 220 through the heating lamps 3170, water sprinklers 2550, and vacuum manifolds 2560 and 2570. If desired, the composite felt layer 220 and the resin layer can be transported around the closed path defined by the roller 1513 and the rollers 1511 for multiple passes through the heating lamps 3170, the water sprinklers 2550 and the vacuum manifolds 2560 and 2570. It will be understood that if the composite felt layer 220 and the resin layer is carried around the closed path several times to remove the second material of felt layer 220, multiple passes are made without adding more second material or liquid resin to felt layer 220, and with ultraviolet lamps 3150 and 3180 off. The frame support apparatus 200 can be inspected with a microscope to verify that all the uncured liquid resin and the second material have been removed from the felt layer 220. Alternatively, the cleaning of the felt layer 220 can be measured using a drainage test as follows. The weft support apparatus 200 may be placed between upper and lower Plexiglas hole plates having openings of 8,255 cm. The upper orifice plate is attached to a straight cylinder having an internal diameter of approximately 10.16 cm. Distilled water is added to the cylinder to maintain a column of water with a height of 10.16 cm in the cylinder. The volume of water passing through the apparatus 200 is measured during a drain period of 1 minute. The drainage velocity (cubic centimeters / sec / square meters) of the weft support apparatus 200 should be generally uniform when measured at different locations on the weft support apparatus 200, and should be at least equal to the velocity of drainage of the felt layer 220 multiplied by the fraction of the projected area of the apparatus 200 not covered by the modeled layer of weft 250. A final step to practice the present invention may include a second post-cure step to complete the healing of the resin layer on the first surface of the felt layer 220. Once substantially all of the second material and all uncured liquid resin have been removed from the felt layer 220, the composite felt layer 220 and the liquid resin may be transported through the bath 1620. The post-cure lamps 3180 placed above the 1620 bath provide the final cure of the resin layer. The composite felt layer 220 and the resin layer are immersed in the bath 1620, which preferably contain water and a reducing agent, such as sodium sulfite, to remove oxygen dissolved in the water, which would otherwise extinguish the reaction of curing in the bath 1620. The composite felt layer 220 and the resin layer 250 are carried through the bath 1620 at a rate of approximately 0.3048-0.9144 meters per minute with the post-cure lamps 3180 turned on. The appropriate post-cure lamps 3180 are the F450 lamps listed above. The water in the bath 1620 allows the passage of the actinic radiation of the post-curing lamp 1605 to the resin layer 1521, while avoiding the oxygen that can quench the free radical polymerization reaction. The depth of the water in the bath 1620 can be approximately 2.54-10.16 cm. After leaving the bath 1620, the composite felt layer 220 and the resin layer 250 (Figure 4H) can be carried on a vacuum manifold to remove water from the felt layer 220. The post-cure sequence of making pass the composite felt layer 220 and the resin layer through the bath 1620 with the post-cure lamp 1605 on can be repeated about 1-3 times until the resin layer 250 is no longer tacky. At this point, the felt layer 220 and the cured resin, as a whole, form the weft support apparatus 200 having a patterned ramp layer 250 fully cured. The post-cure sequence can be repeated by bringing the composite felt layer 220 and the resin layer around the circuit provided by the rollers 1513 and 1511 from one to three times with the lamp 3150 off. In one embodiment, the mask 150 may be provided with a transparent portion in the form of a continuous network. Said mask can be used to provide the weft support apparatus 200 having a patterned weft layer 250 having a continuous network weft that is in contact with the upper surface 260 having a plurality of discrete apertures 270 therein, as shown in Figure 1. Each discrete opening 270 communicates with the first felt surface 230 through a duct formed in the patterned weft layer 250. Suitable shapes for the openings 270 include, but are not limited to, circles, elongated ovals in the machine direction (MD shown in Figure 5), polygons, irregular shapes, or mixtures of these. The projected surface area of the continuous net upper surface 260 may be between about 5 and about 75% of the projected area of the weft support apparatus 200 as seen in Figure 1, and is preferably between about 20% and about 60% of the projected area of the branch support apparatus as seen in Figure 1. In the embodiment shown in Figure 1, the upper continuous network surface 260 may have less than approximately 700 discrete openings 270 per cm2 of the area. projected from the weft support apparatus 200 and preferably from about 70 to about 700 discrete apertures 270 therein per cm2 of the projected area of the weft support apparatus as seen in Figure 1. Each discrete opening 270 in the upper surface continuous network can have an effective free opening, which is between about 0.5 and about 3.5 millimeters, where the free opening effected iva is defined as the area of the opening 270 divided by a quarter of the perimeter of the opening 270. The effective free opening may be between about 0.6 and about 6.6 times the elevation difference 262. An apparatus having said pattern of openings 270 it can be used as a drying band or compression fabric on a paper making machine to make a patterned structure having a continuous network region, which can be a compact region, of relatively high density, corresponding to the surface of contact with the branch, 260, and a plurality of scattered domes, generally not compacted, across the entire continuous network region, the domes corresponding to the placement of the openings 270 in the surface 260. The discrete openings 270 are preferably placed bilaterally in quincunx in the machine direction (MD) and the cross machine direction (CD), as described in the tente of E.U.A. 4,637,859, issued January 20, 1987, which is incorporated herein by reference. In the embodiment shown in Figure 1, the openings 279 are overlapped and bilaterally staggered, with the openings dimensioned and spaced apart, such that in the directions of both the machine and machine transverse, the edges of the openings 270 are they extend beyond one another, and so that the line drawn parallel to the direction either of the machine or transverse to the machine will pass through at least some of the openings 270.

Measurement of Rack Support Apparatus Elevations The elevation difference 262 between the elevation 231 (Figure 2) of the first felt surface 230 and the elevation 261 of the contact surface with the weft, 260, is measured using the following procedure. The branch support apparatus is supported on a flat horizontal surface with the patterned weft layer facing upwards. A stylet having a circular contact surface of approximately 1.3 mm2 and a vertical length of approximately 3 mm is mounted on a Federal Products dimension gauge (model 432B-81 amplifier modified for use with the EMD-4320 Wl rupture probe). ) manufactured by Federal Products Company of Providence, Rhode Island. The instrument is calibrated by determining the voltage difference between two precision diaphragms of known thickness, which provides a known elevation difference. The instrument was leveled to zero at a slightly lower elevation than the first felt surface 230 to ensure the unrestrained trajectory of the stylet. The stylet was placed on the elevation of interest and lowered to make the measurement. The stylet exerts a pressure of 0.24 grams / mm2 at the point of measurement. At least three measurements were made on each elevation. The difference in the average measurements of the individual elevations 231 and 261 is taken as the elevation difference 262. Figures 6 and 7 are photomicrographs of a frame support apparatus 200 made in accordance with the present invention. The weft support apparatus 200 in Figures 6 and 7 comprises a layer of resin 250 cured on a layer of drainage felt 220. The cured resin layer 250 penetrates a surface 230 of the felt layer 220, so that the The cured resin layer extends to a portion of the thickness of the felt layer adjacent to the surface 230. The cured resin layer 250 also extends 230, so that the surface 260 of the resin layer is separated from the surface 230. In the embodiments described above, the substrate comprises a felt layer 220 of drainage 220. However, the method of the present invention can also be used to form patterned resin layers on other substrates. For example, the substrate may comprise a forming or drying fabric for making paper comprising woven filaments, said fabric may have an air permeability of about 141.57 and about 707.85 l / sec. A non-limiting example of an alternative substrate is a papermaking fabric described in the following patents of E.U.A. issued to Trokhan and incorporated herein by reference, US patent. 4,191, 609, issued March 4, 1980 and the patent of E.U.A. 4,239,065 issued December 16, 1980.

Claims (10)

1. - A method for applying a photosensitive resin to a substrate, the method comprising the steps of: providing a substrate having a first surface, a second surface, and a thickness, the substrate having intermediate recesses to the first and second surfaces; provide a liquid photosensitive resin; provide a second material different from the liquid photosensitive resin; provide a source of actinic radiation; applying the second material to the substrate to occupy at least some of the voids in the intermediate substrate to the first and second surfaces of the substrate; Apply the liquid photosensitive resin to the substrate; exposing at least some of the liquid photosensitive resin to actinic radiation; and curing at least some of the photosensitive resin to provide a layer of resin on the substrate.

2. The method according to claim 1, further comprising the step of substantially changing the viscosity of at least some of the second material applied to the substrate before the step of curing the resin.

3. The method according to claim 1 or 2, further comprising the step of removing at least some of the second material from the substrate after applying the resin to the substrate.

4. The method according to claims 1, 2 or 3, further comprising the step of removing something, but not all, of the second substrate material before applying the resin to the substrate.

5. The method according to claims 1, 3, or 4, further comprising the step of changing the phase of at least some of the second material applied to the substrate before the step of curing the resin.

6. The method according to claims 1, 3, 4, or 5, further comprising the step of solidifying at least some of the second material applied to the substrate at a temperature between about 50 degrees Fahrenheit and about 150 degrees Fahrenheit before applying the resin to the substrate. The method according to claims 1, 2, 3, 4, 5 or 6, further comprising the step of cooling at least some of the second material applied to the substrate before the step of curing the resin, and the step of heating to the less something from the second material applied to the substrate before the step of removing the second material from the substrate. 8. The method according to claims 1, 2, 3, 4, 5, 6 or 7, further characterized in that the second material comprises water. 9. The method according to claims 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that the second material comprises a component selected from the group consisting of glycerol, polyoxyethylene glycol, polyoxypropylene glycol and combinations thereof. 10. The method according to claims 1, 2, 3, 4, 5, 6, 7, 8, or 9, characterized in that the second material comprises a gel-forming agent selected from the group consisting of laurate of sodium, sodium myristate, sodium palmitate, sodium stearate, potassium laurate, potassium myristate, potassium palmitate, potassium stearate and mixtures thereof.