+

WO1999012722A1 - Appareil pour fabrication de feuilles lenticulaires et procedes connexes - Google Patents

Appareil pour fabrication de feuilles lenticulaires et procedes connexes Download PDF

Info

Publication number
WO1999012722A1
WO1999012722A1 PCT/US1998/018717 US9818717W WO9912722A1 WO 1999012722 A1 WO1999012722 A1 WO 1999012722A1 US 9818717 W US9818717 W US 9818717W WO 9912722 A1 WO9912722 A1 WO 9912722A1
Authority
WO
WIPO (PCT)
Prior art keywords
pattern forming
plastic sheet
forming roll
lenticular
roll
Prior art date
Application number
PCT/US1998/018717
Other languages
English (en)
Inventor
Öystein MIKKELSEN
Original Assignee
Eastman Kodak Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eastman Kodak Company filed Critical Eastman Kodak Company
Priority to AU93091/98A priority Critical patent/AU9309198A/en
Publication of WO1999012722A1 publication Critical patent/WO1999012722A1/fr

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/54—Accessories
    • G03B21/56—Projection screens
    • G03B21/60—Projection screens characterised by the nature of the surface
    • G03B21/62—Translucent screens
    • G03B21/625—Lenticular translucent screens
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/22—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length
    • B29C43/222—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length characterised by the shape of the surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/07—Flat, e.g. panels
    • B29C48/08—Flat, e.g. panels flexible, e.g. films
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/355—Conveyors for extruded articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/911—Cooling
    • B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
    • B29C48/914—Cooling drums
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/911—Cooling
    • B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
    • B29C48/9145—Endless cooling belts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/911—Cooling
    • B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
    • B29C48/9175—Cooling of flat articles, e.g. using specially adapted supporting means by interposing a fluid layer between the supporting means and the flat article
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent

Definitions

  • the present invention relates to the field of machinery and processes, and, more particularly, to an apparatus and methods for producing lenticular screens.
  • Lenticular screens are typically formed from a transparent plastic sheet with lenses integrally formed on only one side that focus on the opposite and typically flat side.
  • the lenticular elements can have many shapes, such as, for example, cylindrical, angular, spherical, or shaped like cube corners.
  • the original lenticular image can be created photographically, electronically or by a combination of both. Images can be reproduced and mass produced using photo-sensitive materials, printed by lithographic means or by other means of printing or transfer of inks or dyes. Electronic displays, such as cathode-tubes or flat panel displays, may also be fitted with a lenticular screen if the resolution of the display is sufficient.
  • a lenticular screen includes cutting the lenticular lens pattern directly into transparent plastic materials.
  • a lenticular screen can also be formed by the casting of thermosetting resins onto flat forms including the lenticular lens pattern.
  • a lenticular screen may also be made by thermoforming a cast or extruded transparent sheet by heat and pressure between one polished plate and one plate with the lenticular pattern cut or engraved into its surface. Injection molding may also be used to form a lenticular screen.
  • a lenticular screen may also be formed by extrusion of resin onto transparent pre-produced sheet or film, wherein the lenticular pattern is embossed into the resin by an embossing roll.
  • a lenticular screen may also be manufactured using a machine similar to that normally used for flat sheet extrusion. As disclosed in U.S. Patent No. 2,724,312 to Gruetzner, for example, and as shown with reference to the prior art illustration of FIG. 1, such a machine 20 includes a sheet extruder 21 and a polishing stack 22.
  • the polishing stack 22 illustratively includes three rolls 23, 24 and 25, wherein the middle roll 24 has the lenticular pattern on its outer surface.
  • the upper roll 23 and lower roll 25 have a smooth outer surface.
  • a plurality of small rolls 27 support the sheet 26, and a pair of pull rolls 28 pull the sheet from the polishing stack 22.
  • This type of machine 20 and associated method are used for most of the lenticular sheet produced at present.
  • the lenticular image can be reproduced on the photographic material and thereafter be laminated to the lenticular screen. There are also applications where the photographic emulsion is coated onto the flat side of the screen.
  • the lenticular image can also be printed with inks or dyes on a suitable material which, in turn, is laminated to the back of the screen or printed directly onto the flat side of the screen.
  • the three roll polishing stack 22 is basically a simplified calendar.
  • the polishing rolls 23, 24 and 25, are also known as chill rolls in flat plastic sheet production or as embossing rolls, if a pattern is cut or engraved into their surface.
  • the functions of the rolls are to give the sheet, which initially is pre-formed by the sheet die at the end to the extruder 21, a more uniform gage, polish the sheet surface, transfer the pattern of the embossing roll to the sheet, and chill the material to a temperature lower than its softening point to keep the sheet in the shape formed by the rolls .
  • the embodiment of the prior art machine 20' of FIG. 2 illustrates that the rolls 23',
  • the upper roll 23 and middle roll 24 are held in position so they define a nip point therebetween.
  • the lower roll 25 is held within a short distance to the middle roll 24, since the plastic is shrinking, and therefore the circumferential speed of the rolls needs to be differentiated.
  • the plastic web 26 is taken away by the pull rolls 28 to keep the sheet in relative contact with the surface of the middle and lower rolls, but will also apply extra tension to the plastic web 26 as well. The tension caused by the pull rolls 28 will stretch the material .
  • the upper roll 23' can also form a nip with the middle roll 24'; however, its speed has to be slightly different to keep the plastic web 26' in contact with the middle roll.
  • pull rolls still have the task of keeping the plastic in contact with the upper roll 23' .
  • the sheet is held under pressure just in the nip between the first two rollers, and it is there that the lenticular lenses are created.
  • the time the plastic sheet is under pressure in the nip will depend on the diameter of the rolls, the speed of the web and the thickness of the material . Even with larger diameter rolls, a thicker sheet, and at the speeds somewhat less than recommended to ensure proper flow through the extruder, the time period is relatively short. In fact, the time period is often too short to ensure proper reproduction of the lenticular pattern onto the plastic web. Downstream from this nip point, only the tensioning of the sheet enables contact of the sheet with the embossing roll. Or course, the contact is limited by the tension that can be applied to the still hot plastic either by the upper roll 23' (FIG. 2) or by the pull rolls 28 (FIG. 1) .
  • the tensioning of the sheet can, for some materials that otherwise are suited for lenticular screens, cause a haze and/or make the sheet brittle. Excessive tensioning can result in stress that can be released even at temperatures lower than the softening point and cause the sheet to buckle. It is required, if the finished lenticular screen is to be optically acceptable, that the lenticular lenses in the plastic material replicate the pattern on the embossing roller as closely as possible.
  • the energy carried in the plastic sheet will have a significant negative effect on the valleys between adjacent lenses, and also on the lens curvature.
  • Some materials can, if cooled too quickly, leave a residue on the rolls, which if allowed to build up, would prevent the lenticular pattern from being accurately reproduced in the plastic. Accordingly, the machine is taken out of service and the residue removed, thereby resulting in a loss of production.
  • an apparatus for making a lenticular screen comprising a rotating lenticular pattern forming roll downstream from an extruder, and a conveyor belt for pressing the hot plastic sheet against the lenticular pattern forming roll to form the lenticular pattern in the hot plastic sheet.
  • the apparatus preferably includes tension adjusting means for adjusting a tension of the conveyor belt to thereby adjust a pressure applied to the hot plastic sheet.
  • the apparatus preferably further comprises contact adjusting means cooperating with the conveyor belt for adjusting a length of contact of the hot plastic sheet around a periphery of the rotating lenticular pattern forming roll. Accordingly, the dwell time of the hot plastic sheet on the lenticular pattern forming roll can be controlled, along with the pressure applied to the hot plastic sheet.
  • the lenticular pattern forming roll is preferably a chill roll for receiving a cooling fluid therethrough to cool the hot plastic sheet.
  • the conveyor belt may also be configured to include a flat portion downstream from the rotating lenticular pattern forming roll. Accordingly, the flat conveyor belt portion provides a flat surface during secondary cooling of the hot plastic sheet after the lenticular pattern is formed and allows for material shrinkage. Cooling means may also be positioned adjacent the flat portion of the conveyor belt for further cooling the hot plastic sheet, and/or the belt and sheet .
  • the apparatus may include at least one passive sheet guide roll positioned opposite the conveyor and downstream from the lenticular pattern forming roll to guide the hot plastic sheet on the conveyor belt without imparting tension to the sheet.
  • pull rolls are not used which have a tendency to stress the plastic material.
  • the apparatus may include a frame carrying the lenticular pattern forming roll, a first belt support roll positioned adjacent the lenticular pattern forming roll, and a second belt support roll spaced from the first belt support roll. Accordingly, a positioner may be associated with the second belt support roll, for example, for adjusting a tension of the conveyor belt.
  • the apparatus may also include a third belt support roll carried by the frame and positioned adjacent the lenticular pattern forming roll and between the first and second belt support rolls. Accordingly, a positioner may be associated with the third belt support roll for adjusting a length of contact of the hot plastic sheet around a periphery of the rotating lenticular pattern forming roll. In other words, control of the third roll provides one embodiment for adjusting the contact time of the hot plastic sheet on the lenticular pattern forming roll .
  • One or more additional bearings may be provided to press the underside of the belt and thereby press the plastic sheet against the lenticular pattern forming roll.
  • the second and third belt support rolls are also preferably arranged to define the flat portion of the conveyor belt downstream from the rotating lenticular pattern forming roll, and the flat portion may be horizontally oriented.
  • the conveyor belt itself preferably has a relatively smooth surface to thereby form a corresponding smooth surface on the reverse side of the plastic sheet.
  • the conveyor belt may comprise a metal fabric.
  • One or more brushes may be positioned to clean the surface of the belt.
  • a method aspect of the present invention is for making a screen having a predetermined pattern thereon, such as for making a lenticular pattern when using a lenticular pattern forming roll.
  • the method preferably comprises the steps of: extruding a hot plastic sheet; positioning a rotating pattern forming roll downstream from the extruder; and using a conveyor belt for pressing the hot plastic sheet from the extruder against the pattern forming roll to form a pattern in the hot plastic sheet.
  • the method also preferably further comprises the steps of: adjusting a tension of the conveyor belt to thereby adjust a pressure applied to the hot plastic sheet, and/or adjusting a length of contact of the hot plastic sheet around a periphery of the rotating pattern forming roll.
  • the method may also include the step of configuring the conveyor belt to include a flat portion downstream from the rotating pattern forming roll and providing a flat surface during cooling of the hot plastic sheet after the pattern is formed therein.
  • FIG. 1 is a schematic side cross-sectional view of an embodiment of an apparatus for making a lenticular screen in accordance with the prior art.
  • FIG. 2 is a schematic side cross-sectional view of another embodiment of an apparatus for making a lenticular screen in accordance with the prior art.
  • FIG. 3 is a perspective view of an apparatus for making a lenticular screen in accordance with the present invention.
  • FIG. 4 is a schematic side cross-sectional view of the apparatus as shown in FIG. 3 with several additional details being illustrated.
  • FIG. 5 is a greatly enlarged cross-sectional view of the entry contact area of the plastic sheet with the lenticular pattern forming roll and conveyor belt in the apparatus as shown in FIG. 3.
  • FIG. 6 is a greatly enlarged cross-sectional view of the exit contact area of the plastic sheet with the lenticular pattern forming roll and conveyor belt in the apparatus as shown in FIG. 3.
  • FIG. 7 is a greatly enlarged cross-sectional view of the area where the conveyor belt and plastic sheet leave the lenticular pattern forming roll area in the apparatus as shown in FIG. 3.
  • FIG. 8A is a perspective view of a mandrel for forming a lenticular pattern forming roll in accordance with a method of the present invention.
  • FIG. 8B is a perspective view of the mandrel with a metal layer deposited thereon in accordance with the present invention.
  • FIG. 8C is a perspective view of the mandrel and metal layer deposited thereon wherein a lenticular pattern is being formed to define a lenticular sleeve in accordance with the present invention.
  • FIG. 8D is a perspective view of the mandrel and lenticular sleeve illustrating removal of the sleeve from the mandrel in accordance with the present invention.
  • FIG. 8E is a perspective view of the lenticular sleeve being installed onto a chill roll in accordance with the present invention.
  • FIG. 9 is a flowchart of the method steps for making the lenticular pattern forming roll in accordance with the present invention.
  • FIGS. 10A-10D are cross-sectional views illustrating conversion of the lenticular sleeve into a flat lenticular form in accordance with the invention. Detailed Description of the Preferred Embodiments
  • the apparatus 40 includes a rotating lenticular pattern forming roll 44 downstream from an extruder 41, and a conveyor belt 47 for pressing the hot plastic sheet 46 against the lenticular pattern forming roll to thereby form the lenticular pattern in the hot plastic sheet.
  • the apparatus 40 preferably includes tension adjusting means for adjusting a tension of the conveyor belt 47 to thereby adjust a pressure applied to the hot plastic sheet.
  • the apparatus 40 preferably further comprises contact adjusting means cooperating with the conveyor belt for adjusting a length of contact of the hot plastic sheet 46 around a periphery of the rotating lenticular pattern forming roll 44.
  • the dwell time of the hot plastic sheet 46 on the lenticular pattern forming roll 44 can be controlled, along with the pressure applied to the hot plastic sheet.
  • the pressure and dwell time provide an improved quality of the reproduction of the lenticular pattern in the plastic sheet 46.
  • the dwell time can be longer or shorter depending on the properties of the plastic material, its thickness, the pattern to be transferred, and the desired speed of the plastic sheet as would be readily understood by those skilled in the art.
  • the lenticular pattern forming roll 44 is preferably a chill roll for receiving a cooling fluid therethrough to cool the hot plastic sheet 46.
  • the cooling fluid may be a liquid, such as water, for example, or may be a gas as would be readily appreciated by those skilled in the art.
  • the cooling fluid is supplied by the schematically illustrated cooling fluid source 50.
  • the conveyor belt 47 may also be configured to include a flat portion 47a downstream from the rotating lenticular pattern forming roll 44 as perhaps best shown in FIGS. 3 and 4. Accordingly, the flat conveyor belt portion 47a provides a flat surface during secondary cooling of the hot plastic sheet 46 after the lenticular pattern is formed and readily allows for material shrinkage without imparting undesirable stress to the plastic. Cooling means may also be positioned adjacent the flat portion 47a of the conveyor belt for further cooling the hot plastic sheet 46, and/or the belt and sheet. In the illustrated embodiment, an upper cooler 52a may direct cooling air onto the plastic sheet 46, and while the lower cooler directs air upward onto the back side of the conveyor belt 47 as would be readily understood by those skilled in the art .
  • the apparatus 40 illustratively includes at least one passive sheet guide roll 53 positioned opposite the conveyor belt 47 and downstream from the lenticular pattern forming roll 44 to guide the hot plastic sheet on the conveyor belt without imparting undesirable tension to the sheet, in contrast to the conventional puller rolls 28 (FIG. 1) .
  • the illustrated passive guide roll 53 is a rubber coated roll, although those of skill in the art will recognize that other types and compositions of rolls may also be used.
  • the passive guide roll 53 may be positioned by a positioner 54, such as may be provided by swing-arms and pneumatic cylinders, or other arrangements with linear motion and hydraulics or mechanical positioning as would be readily understood by those skilled in the art.
  • the passive guide roll 53 is positioned over the second belt support roll 58 so that the sheet 46 is pulled from the apparatus 40 along a line parallel to the flat conveyor belt portion 47a.
  • the passive guide roll 53 is only driven by the friction between itself, the plastic sheet 46 and the belt 47. Pressure on the passive guide roll 53, to ensure sufficient friction, can be applied mechanically or by pneumatic or hydraulic cylinders as would be readily understood by those skilled in the art.
  • the pull caused by the passive guide roll 53 which is only driven by the friction between itself, the plastic sheet 46 and the belt 47 passing over the second belt support roll 58, will not cause as much tension as a conventional set of pull rolls. Accordingly, it will also be easier to keep control of the distances in the lenticular pattern, like the pitch of the lenticular lenses. Some tension will be imparted because the plastic sheet 46 will have a higher expansion coefficient than the material in the belt 47. Since the lenticular screen is a finished product as far as the plastic is concerned, less stress is preferred as would be readily understood by those skilled in the art.
  • the apparatus 40 includes a frame 55 (FIG. 4) carrying the lenticular pattern forming roll 44, a first belt support roll 57 positioned adjacent the lenticular pattern forming roll, and a second belt support roll 58 spaced from the first belt support roll.
  • the first belt support roll 57 is illustratively fixed, but could be mounted such as to be movable.
  • the first belt support roll 57 could also be mounted to move horizontally to give sufficient distance in front of the nip with the lenticular pattern forming roll 44 so that a plastic web could be entered for extrusion coating with tie-layers and resin, or only resin, and which thereafter is contacted by the lenticular pattern forming roll.
  • a positioner 61 may be associated with the second belt support roll 58 for adjusting a tension of the conveyor belt 47 as would be readily appreciated by those skilled in the art.
  • the positioner 61 may be hydraulic, pneumatic, or electrically operated as would be understood by those skilled in the art without further explanation herein.
  • the apparatus 40 also illustratively includes a third belt support roll 63 carried by the frame 55 and positioned adjacent the lenticular pattern forming roll 44 and between the first and second belt support rolls
  • the positioner 65 may be associated with the third belt support roll 63 for adjusting a length of contact of the hot plastic sheet 46 around a periphery of the rotating lenticular pattern forming roll 44.
  • the positioner 65 may include swing arms and motorized screws, but mechanical guides like curved or straight linear guides and other mechanical means for positioning that provide the same functions are also contemplated by the present invention.
  • control of the position of third roll 63 provides one embodiment for adjusting the contact time and extent of the hot plastic sheet 46 on the lenticular pattern forming roll 44.
  • the relative positioning of the first belt support roll 57, the lenticular pattern forming roll 44, and the third roll 63 define the contact of the hot plastic sheet 46 with the lenticular pattern forming roll .
  • One or more additional bearings 67 may be provided to press the underside of the conveyor belt 47 and thereby press the plastic sheet 46 against the lenticular pattern forming roll 44 (FIG. 4) .
  • an arrangement with needles such as needle bearings, may be positioned between the conveyor belt and a pad or several pads, not shown, as wide as the belt, but relatively short in the machine direction, onto which pressure can be applied by hydraulic cylinders as would also be understood by those skilled in the art.
  • the second and third belt support rolls 58, 63 are also preferably arranged to define the flat conveyor belt portion 47a downstream from the rotating lenticular pattern forming roll 44, and the flat portion may be horizontally oriented as shown in the illustrated embodiment. In other embodiments, the roll may be oriented so that the flat conveyor portion 47a is at other angles as will be readily appreciated by those skilled in the art.
  • the conveyor belt 47 itself preferably has a relatively smooth surface to thereby form a correspondingly smooth surface on the reverse side of the plastic sheet 46.
  • the conveyor belt 47 may comprise a metal fabric, such as formed of stainless steel or titanium, for example, and as would be readily appreciated by those skilled in the art.
  • the conveyor belt 47 is preferably seamless and continuous with sufficient hardness and strength for carrying the plastic sheet 46 and applying the desired pressure thereto as would be understood by those skilled in the art. Polished, hard and corrosion resistant belts are today used in other industrial processes like wood chip board production, for example, and are therefore readily available.
  • One or more brushes 71 may be positioned to clean the surface of the belt 47 as would also be readily appreciated by those skilled in the art.
  • a vacuum arrangement, not shown, may also cooperate with the brush 71 to clean the belt 47.
  • the length of the belt 47 if kept clean will ensure a relatively long life compared to conventional polishing rolls, for example .
  • a positioner 77 may be operatively connected to the lenticular pattern forming roll 44 to control its relatively position, such as to move it between engaged and retracted positions.
  • the positioner 77 may include swing arms and associated hydraulic cylinders, for example, but other arrangements with linear guides, and/or pneumatic or mechanical positioning are also contemplated by the present invention.
  • the outer surfaces of the rolls 57, 58 and 63 may preferably be hardened for durability. These rolls are desirably ground parallel within the tolerances normal for the plastic extrusion industry, but do not necessary need to have a fine surface as provided by polishing. Instead, their surface roughness will somewhat depend on the hardness and thickness of the belt 47.
  • the rolls 57, 58 and 63 and any other rolls that will be in contact with the back of the belt 47 will be cheaper to manufacture, because they do not need the true mirror surface required in conventional polishing stacks.
  • the first and second belt support rolls 57, 58 and/or the third belt support roll 63 may be coated with a hard polyurethane rubber or other appropriate rubber material .
  • the apparatus 40 offers a number of important advantages including easy start-up, since no supporting reproduced sheet has to be thread trough the machine prior to starting the extruder 41.
  • the lenticular pattern forming roll 44 With the lenticular pattern forming roll 44 in a retracted position and with the belt 47 tensioned, one can start extruding onto the belt over the first belt support roll 57 and when the flow is even enough, the lenticular pattern forming roll 44 may be moved into the engaged position along with appropriate repositioning of the second and third belt support rolls 58, 63.
  • the nip between the lenticular pattern forming roll 44 and the first belt support roll 57 with the belt 47 function as the beginning of the nip, and, thereafter, the belt ensures proper holding and pressure for the plastic sheet 46.
  • the enclosed almost chamber-like arrangement for the plastic sheet 46 is kept for an adjustable period after entering the nip and improves the reproduction of the pattern, minimizes local gage variations, and gives better control of the cooling of the sheet.
  • the line speed can be faster and allow for a higher production rate than would be otherwise possible given the same thickness and kind of material being processed using a conventional polishing stack.
  • One method aspect of the present invention is for making a screen having a predetermined pattern thereon, such as for making a lenticular pattern when using a lenticular pattern forming roll 44.
  • the method preferably comprises the steps of : extruding a hot plastic sheet 46; positioning a rotating pattern forming roll 44 downstream from the extruder 41; and using a conveyor belt 47 for pressing the hot plastic sheet from the extruder against the pattern forming roll to form a pattern in the hot plastic sheet.
  • the method also preferably further comprises the steps of: adjusting a tension of the conveyor belt 47 to thereby adjust a pressure applied to the hot plastic sheet 46, and/or adjusting a length of contact of the hot plastic sheet around a periphery of the rotating pattern forming roll 44.
  • the method may also include the step of configuring the conveyor belt to include a flat portion 47a downstream from the rotating pattern forming roll and providing a flat surface during cooling of the hot plastic sheet 46 after the pattern is formed therein. Accordingly, the plastic sheet 46 may be formed to be relatively flat as is desirable for many applications.
  • the first belt support roll 57 may be a chill roll comprising a tubular body 57a through which the cooling fluid is passed.
  • the third belt support roll 63 may also be a chill roll comprising a tubular body 63a through which cooling fluid is also passed as would be readily understood by those skilled in the art. Of course, in other embodiments either or both of these rolls may not need the cooling fluid.
  • the lenticular pattern forming roll 44 may comprise a tubular body defining a chill roll 44a and a lenticular sleeve 44b positioned on the chill roll.
  • the 44b has a lenticular pattern formed on an outer surface for forming the corresponding lenticular pattern in the plastic sheet 46.
  • the sleeve 44b may be readily manufactured and transported to a desired location to be installed on the chill roll 44a.
  • the lenticular sleeve 44b may also be removed from the chill roll 44a and transported for resurfacing and without requiring transporting of the entire chill roll. Accordingly, considerable savings may be realized.
  • a spare sleeve 44b may be maintained in inventory in the manufacturing facility to thereby reduce downtime as would be readily understood by those skilled in the art .
  • the lenticular sleeve 44b may preferably comprise a nickel -phosphorous composition defining at least a radially outermost portion of the sleeve in which the lenticular pattern is formed. More particularly, the nickel -phosphorous composition is preferably an amorphous nickel-phosphorous composition comprising nickel in a range of about 75 to 86 percent by weight, and phosphorous in a range of about 14 to 25 percent by weight. This material is durable in use, yet the lenticular pattern is readily formed in the composition using conventional diamond cutting techniques as will be described in greater detail below. As would be readily understood by those skilled in the art, the nickel-phosphorous composition may be formed by electrodepositing or electroless depositing, for example.
  • the interior surface of the lenticular sleeve 44b may have a predetermined diameter to frictionally engage an adjacent exterior surface of the chill roll 44a.
  • the interior surface of the lenticular sleeve 44b may also have a predetermined surface roughness to frictionally engage the adjacent exterior surface of the chill roll 44a.
  • the interior surface of the lenticular sleeve 44a may preferably have a coefficient of friction of at least about 0.1.
  • One method aspect of the invention is for making a lenticular pattern forming roll 44 for forming a lenticular screen as is explained with reference to FIGS. 8A-8E and the flowchart 90 of FIG. 9.
  • the outer surface of a mandrel 80 is prepared, such as by polishing to define a desired surface (FIG. 8A) .
  • the amorphous nickel-phosphorous metal layer 81 is deposited onto the mandrel 80 using either an electroless or electrodeposition technique as would be readily appreciated by those skilled in the art.
  • Block 98 and as shown schematically in FIG.
  • the lenticular pattern is cut into the outer surface of the metal layer 81 by the illustrated diamond cutter 84 while on the mandrel 80 to form the lenticular sleeve 44b.
  • the thus formed lenticular sleeve 44b is removed or freed from the mandrel as shown in FIG. 8D.
  • the lenticular sleeve 44b may be freed from the mandrel 80 by the injection of air or another fluid into the interface between the sleeve and mandrel.
  • a difference in coefficients of thermal expansion may be used to separate the sleeve and mandrel as would be readily appreciated by those skilled in the art.
  • cooling or heating may be used to separate the sleeve 44b from the mandrel 80.
  • the lenticular sleeve 44b may typically be shipped to the location making the lenticular screen as set forth in Block 102. Because of the relatively high cost of the capital equipment for forming the lenticular pattern, the forming or a similar refinishing process is likely to only be performed at certain locations suitably equipped as would be understood by those skilled in the art.
  • the lenticular sleeve 44b may be installed onto the chill roll 44a (Block 104) as shown in FIG. 8E before the process ends
  • the step of installing the lenticular sleeve 44b onto the chill roll 44a may also be aided by the injection of air or other fluid into the interface between the sleeve and chill roll. Alternately, heating may be used to first expand the sleeve prior to positioning on the chill roll. Of course, the sleeve 44b may also be removed from the chill roll to facilitate changing to a new lenticular pattern or to permit refinishing of the lenticular sleeve 44b as would be appreciated by those skilled in the art.
  • the lenticular sleeve 44b can also be secured to the chill roll 44a using a hot-melt adhesive, for example, and with a suitable melting point so that the sleeve will not separate when being used for forming the lenticular screen as will be readily appreciated by those skilled in the art .
  • a hot-melt adhesive for example, and with a suitable melting point so that the sleeve will not separate when being used for forming the lenticular screen as will be readily appreciated by those skilled in the art .
  • Another form of an adhesive bond make be provided by a low melting temperature solder metal or alloy applied to one or both of the outer surface of the chill roll 44a and the inner surface of the sleeve 44b.
  • Nickel alloys may be especially suitable for cutting using single crystal diamond.
  • Adequate machinery for cutting in an amorphous nickel- phosphorous composition with properly prepared single crystal diamonds can allow for a relatively large areas with a surface roughness of less than RMS 10A. Cutting of optical surfaces and forms with single crystal diamonds is relatively well known by those skilled in the art, and requires no further discussion herein.
  • the inventor of the present invention previously developed chemistry and methods for making relatively thick deposits (50 to 500 micron) of amorphous nickel-phosphorous with 13 to 15% phosphorous content (by weight) by electroless depositing. At present, amorphous nickel -phosphorous compositions with even higher phosphorous content can also be deposited by electrodepositing as would be readily understood by those skilled in the art.
  • the mechanism is not entirely understood, tool wear is minimized when the phosphorus content of the deposit is greater than about 11% (by weight) . Accordingly, the nickel- phosphorous has good lubricating properties which makes it well suited for tools used in the forming of plastics.
  • Electrodeposition may be at a rate of up to 60 microns per hour and a phosphorous content of higher than about 15% can be obtained.
  • Another advantage of the electrodeposited nickel- phosphorous composition is the consistently higher density as compared to the electroless deposited material. It is believed without applicant being bound thereto that the electrodeposited nickel-phosphorous alloys contain a lower void volume than the electroless deposited alloys, that is, the nickel and phosphorous are more closely packed.
  • electrodeposited Ni-P can have a hardness of Rockwell C 45-51 as deposited, and by heat treatment can reach a hardness of Rockwell C 70-72. This hardness range is sufficient to obtain a lenticular sleeve 44b with a relatively long service life.
  • the lenticular pattern forming roll 44 including the lenticular sleeve 44b.
  • a cylindrical sleeve portion may be produced by depositing 100% nickel onto the mandrel 80, depositing required thickness of nickel-phosphorous alloy and cutting the lenticular pattern into the outer layer with diamonds.
  • the entire sleeve 44b may be formed either by the electroless depositing or electrodepositing of the nickel-phosphorous onto the mandrel 80, and thereafter the sleeve is given a lenticular pattern by cutting with diamonds.
  • a base portion of the sleeve 44b may be produced by electrodepositing the nickel-phosphorous onto the mandrel 80, another metal or metal alloy suited for cutting with diamonds is deposited onto the base portion, and the lenticular pattern is cut into the other metal or alloy with diamonds.
  • the base portion of the sleeve 44b may be produced by electrodepositing nickel onto the mandrel 80, another metal or metal alloy suited for cutting with diamonds is deposited onto the base portion, and the lenticular pattern is cut into the other metal or alloy with diamonds.
  • a cylindrical sleeve for fitting by expansion onto a suitable roll is produced by hot or cold rolling from a ring produced by casting and/or machining of a metal or alloy suited for cutting with diamonds.
  • the metal or alloy suited for cutting with diamonds is deposited onto the underlying cylindrical sleeve, thereafter the lenticular pattern is cut in the outer surface with diamonds.
  • the lenticular sleeve 44b (FIG. 10A) can be split or cut axially to produce the structure 44b 1 shown in FIG. 10B, then straightened to the intermediate structure 44" shown in FIG.
  • the roll itself need not be resurfaced when the lenticular sleeve is exchanged.
  • lenticular screens are commonly desired and the ability to reuse the same chill roll 44a (or a pair for speedy exchange) enable more economical production of shorter runs, and allow for special lenticular lenses, as compared to dedicated rolls with the lenticular pattern in the outer surface.
  • the cutting of the lenticular pattern may also take place on extremely accurate machines in accordance with the invention.
  • the lenticular sleeve 44b enables less weight to be manipulated during cutting as would be readily appreciated by those skilled in the art. Less weight to be handled during cutting results in one or both of easier cutting and higher accuracy.
  • the properties of the electrodeposited Ni -P are as follows :
  • a pull of 5,000 N (maximum) is needed for most of the known plastic materials when produced in a polishing stack or calendar.
  • the sleeve 44b should apply a pressure of Pt to clamp sufficiently around the chill roll 44a for adequate friction between the sleeve and the chill roll .
  • the apparatus 40 and the process can also be used for improved embossing of other kinds of patterns or even for reproduction of shallow forms into plastic sheets which in a secondary operation can be die-cut into single elements, for example. Accordingly, many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims .

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Shaping Of Tube Ends By Bending Or Straightening (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)

Abstract

LÆappareil (40) comprend un cylindre de formage de trame (44) pour Ëcrans lenticulaires situË en aval dÆune extrudeuse (41) et une bande transporteuse (47) dÆalimentation qui plaque la feuille de plastique chaude (46) contre le cylindre (44). LÆappareil devrait de prËference permettre de rËgler la tension de la bande transporteuse (47) et donc la pression appliquËe ? la feuille (46) ainsi que la longueur de contact de cette feuille ? la pËriphËrie du cylindre (44). Le cylindre de formage (44) est de prËfËrence du type refroidisseur et renferme un liquide destinË ? refroidir la feuille de plastique chaude (46). La bande transporteuse (47) peut Ëgalement prËsenter une partie plate (47a) en aval du cylindre (44) sur laquelle la feuille de plastique chaude (46) vient reposer et refroidir. LÆappareil peut comporter un ch§ssis supportant le cylindre de formage (44), un premier rouleau -suuport de bande transporteuse (57) implantË contre le cylindre de formage (44) et un second rouleau-support de bande (58) ? lÆËcart du premier rouleau. Dans ce cas, le second rouleau-support (58) peut Ètre assorti dÆun dispositif de positionnement (61) assurant le rËglage de la tension de la bande transporteuse (47). Un troisiÊme rouleau-support (63) peut Ètre montË contre le cylindre de formage (44), entre les deuxiÊme et troisiÊme rouleaux-suppports (57, 58) et permettre de rËgler la longueur de contact de la feuille de plastique chaude (46) ? la pËriphËrie du cylindre de formage (44).
PCT/US1998/018717 1997-09-11 1998-09-08 Appareil pour fabrication de feuilles lenticulaires et procedes connexes WO1999012722A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU93091/98A AU9309198A (en) 1997-09-11 1998-09-08 Apparatus for forming a lenticular sheet and associated methods

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US92795997A 1997-09-11 1997-09-11
US08/927,959 1997-09-11

Publications (1)

Publication Number Publication Date
WO1999012722A1 true WO1999012722A1 (fr) 1999-03-18

Family

ID=25455508

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/018717 WO1999012722A1 (fr) 1997-09-11 1998-09-08 Appareil pour fabrication de feuilles lenticulaires et procedes connexes

Country Status (2)

Country Link
AU (1) AU9309198A (fr)
WO (1) WO1999012722A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1285741A1 (fr) * 2001-08-07 2003-02-26 SML Maschinengesellschaft m.b.H. Dispositif utilisé dans une calendre pour la fabrication d'un film en matière plastique et procédé pour changer une bande sans fin
WO2006002003A1 (fr) * 2004-06-15 2006-01-05 Eastman Kodak Company Courroie souple lisse utilisee avec un rouleau de moulage
US7033723B2 (en) 2004-02-27 2006-04-25 Eastman Kodak Company Surface roughness frequency to control pits on foam core imaging supports
US7037634B2 (en) 2004-02-27 2006-05-02 Eastman Kodak Company Polymer foam surface smoothing materials and method
EP1570971A4 (fr) * 2002-12-12 2008-10-15 Cte Co Ltd Procede et appareil de production d'une feuille ou d'un film de resine synthetique thermoplastique
US7585557B2 (en) 2004-02-17 2009-09-08 Eastman Kodak Company Foam core imaging element with gradient density core
EP3124526A4 (fr) * 2014-03-24 2017-11-22 Toray Industries, Inc. Procédé de fabrication d'un film plastique microporeux

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2964251A (en) * 1956-09-21 1960-12-13 United States Pipe Foundry Roll structure
US4193959A (en) * 1964-08-31 1980-03-18 Lemelson Jerome H Pressure forming method
JPS56159039A (en) * 1980-05-09 1981-12-08 Dainippon Printing Co Ltd Manufacture of transparent television screen
JPS56164826A (en) * 1980-05-23 1981-12-18 Dainippon Printing Co Ltd Production of lenticular screen
JPH0471897A (ja) * 1990-07-12 1992-03-06 Dainippon Printing Co Ltd グラビアシリンダーおよびその製造方法
JPH0474864A (ja) * 1990-07-16 1992-03-10 Matsushita Electric Ind Co Ltd 薄膜の製造方法
WO1996009154A1 (fr) * 1994-09-23 1996-03-28 Karszes William M Procede permettant de fabriquer une feuille en plastique lenticulaire

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2964251A (en) * 1956-09-21 1960-12-13 United States Pipe Foundry Roll structure
US4193959A (en) * 1964-08-31 1980-03-18 Lemelson Jerome H Pressure forming method
JPS56159039A (en) * 1980-05-09 1981-12-08 Dainippon Printing Co Ltd Manufacture of transparent television screen
JPS56164826A (en) * 1980-05-23 1981-12-18 Dainippon Printing Co Ltd Production of lenticular screen
JPH0471897A (ja) * 1990-07-12 1992-03-06 Dainippon Printing Co Ltd グラビアシリンダーおよびその製造方法
JPH0474864A (ja) * 1990-07-16 1992-03-10 Matsushita Electric Ind Co Ltd 薄膜の製造方法
WO1996009154A1 (fr) * 1994-09-23 1996-03-28 Karszes William M Procede permettant de fabriquer une feuille en plastique lenticulaire

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 006, no. 042 16 March 1982 (1982-03-16) *
PATENT ABSTRACTS OF JAPAN vol. 006, no. 050 (M - 120) 3 April 1982 (1982-04-03) *
PATENT ABSTRACTS OF JAPAN vol. 016, no. 282 (M - 1269) 23 June 1992 (1992-06-23) *
PATENT ABSTRACTS OF JAPAN vol. 016, no. 283 (C - 0955) 24 June 1992 (1992-06-24) *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1285741A1 (fr) * 2001-08-07 2003-02-26 SML Maschinengesellschaft m.b.H. Dispositif utilisé dans une calendre pour la fabrication d'un film en matière plastique et procédé pour changer une bande sans fin
US6817856B2 (en) 2001-08-07 2004-11-16 Sml Maschinengesellschaft M.B.H. Calender installation
EP1570971A4 (fr) * 2002-12-12 2008-10-15 Cte Co Ltd Procede et appareil de production d'une feuille ou d'un film de resine synthetique thermoplastique
US7585557B2 (en) 2004-02-17 2009-09-08 Eastman Kodak Company Foam core imaging element with gradient density core
US7033723B2 (en) 2004-02-27 2006-04-25 Eastman Kodak Company Surface roughness frequency to control pits on foam core imaging supports
US7037634B2 (en) 2004-02-27 2006-05-02 Eastman Kodak Company Polymer foam surface smoothing materials and method
WO2006002003A1 (fr) * 2004-06-15 2006-01-05 Eastman Kodak Company Courroie souple lisse utilisee avec un rouleau de moulage
JP2008504980A (ja) * 2004-06-15 2008-02-21 イーストマン コダック カンパニー 成形ローラと共に使用される平滑なコンプライアント・ベルト
US7465163B2 (en) 2004-06-15 2008-12-16 Rohm And Haas Denmark Finance A/S Smooth compliant belt for use with molding roller
EP3124526A4 (fr) * 2014-03-24 2017-11-22 Toray Industries, Inc. Procédé de fabrication d'un film plastique microporeux

Also Published As

Publication number Publication date
AU9309198A (en) 1999-03-29

Similar Documents

Publication Publication Date Title
US6074192A (en) Lenticular pattern forming roll and method for making the roll
US6071110A (en) Polishing roll and method for making same
JP3285586B2 (ja) 光学素子集合体の連続的形成方法及びその装置
JP4506733B2 (ja) 光学フィルムの製造方法
KR101321682B1 (ko) 광학 시트 제조 장치 및 광학 시트의 제조 방법
WO1996009154A1 (fr) Procede permettant de fabriquer une feuille en plastique lenticulaire
CN100379546C (zh) 热塑性合成树脂制片材或薄膜的制造方法及其装置
US20180036937A1 (en) Extrusion-to-sheet production line and method
WO1999012722A1 (fr) Appareil pour fabrication de feuilles lenticulaires et procedes connexes
CN101142068A (zh) 制备树脂片的方法
EP1100671B1 (fr) Procede pour produire des elements de buse pour filiere d'enduction
CN101336153A (zh) 微结构模压鼓及其制品
US6182349B1 (en) Method for producing a seamless metallic belt
JP3308733B2 (ja) 薄肉シートの製造方法及び同法により得られる薄肉シート
JP3795999B2 (ja) 押出シート成形用ロールの製造方法
US20070240813A1 (en) Process for forming a multilayer film and the film formed therefrom
JP6075103B2 (ja) エンドレスベルト状金属金型およびその製造方法
CN209081063U (zh) 一种生产用于安装刮屑条的异型材的生产线
JP5678249B2 (ja) ベルト状金型の製造方法
JP6085193B2 (ja) 微細構造フィルムの製造方法および製造装置
JP2001172780A (ja) 平面状母型
WO1999022931A1 (fr) Methode et appareil pour fabriquer des matieres plastiques lenticulaires
JP3739187B2 (ja) 押出シート成形用ロール
JP2003094512A (ja) 矯正装置
JPH10151662A (ja) 押出シート成形用ロール

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: KR

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: CA

122 Ep: pct application non-entry in european phase
点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载