Classifications

• • 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
  • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
  • B29C44/20—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of indefinite length
  • B29C44/32—Incorporating or moulding on preformed parts, e.g. linings, inserts or reinforcements
  • B29C44/322—Incorporating or moulding on preformed parts, e.g. linings, inserts or reinforcements the preformed parts being elongated inserts, e.g. cables
  • B29C44/324—Incorporating or moulding on preformed parts, e.g. linings, inserts or reinforcements the preformed parts being elongated inserts, e.g. cables the preformed parts being tubular or folded to a tubular shape
• • 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
  • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
  • B29C44/34—Auxiliary operations
  • B29C44/36—Feeding the material to be shaped
  • B29C44/46—Feeding the material to be shaped into an open space or onto moving surfaces, i.e. to make articles of indefinite length
  • B29C44/461—Feeding the material to be shaped into an open space or onto moving surfaces, i.e. to make articles of indefinite length dispensing apparatus, e.g. dispensing foaming resin over the whole width of the moving surface
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
  • Y10S264/84—Conversion of foamed resinous buns into foamed billets having geo metrical crosssections

Definitions

• the present invention relates to a method and a device for manufacturing strips of polymer foam and product obtained.
• the technical sector of the invention is that of apparatus for the implementation of flexible or rigid foam strips.
• the currently known continuous casting methods consist, for the most part, in distributing the liquid reactive mixture as uniformly as possible over the width of an inclined conveyor, formed by a bottom and two side walls which move perpendicular to the distribution.
• This distribution of a mixture of liquid reactants, low viscosity, and rapid reactivity implies a retention zone capable of containing the liquid spilled for the time necessary and sufficient for this operation.
• the inclination of the conveyor is generally 4 to 6 ° over the length necessary for the expansion of the foam and its gelation: between fifteen and twenty meters. The movement is then made on a horizontal plane to the cross cutting equipment: about fifty meters from the casting point.
• the most conventional devices include a pouring head animated by a transverse movement back and forth and the reactant retention zone is formed, upstream by the bottom of the conveyor, generally consisting of a sheet of flexible material: sheet of paper or polyethylene, laterally by continuously scrolling walls made of the same material as that of the bottom and downstream, by the product itself which enters its initial reactive phase called "cream line".
• cream line designates the state of the mixture of reactants occurring immediately after the liquid phase and in which this mixture reaches a high viscosity preceding the formation of the foam.
• the viscous product adheres to the bottom support and constitutes, constantly renewed, a barrier to the flow of the liquid mixture along the slope of the conveyor.
• an obstacle is placed downstream of the casting head at the start of manufacture, the role of which is to retain the liquid mixture at start-up.
• the upstream wall is always formed by the bottom of the conveyor which must necessarily be inclined.
• the main drawback, arising from this design, is the difficulty of controlling the parasitic flow of the liquid phase of the reactants, under the cream line.
• the mixture As has just been exposed, the mixture, during its expansion, progressively passes from the liquid state to the solid state, the finished product possibly being rigid or flexible depending on the degree of crosslinking of the polymer.
• the rapidly viscous then pasty state of the mixture causes against the walls of the shaper whatever it is: a closed or open mold on top, a retainer which slows down the expansion of the cells coming into contact with the walls.
• a known method and device consists in lining the lateral movable walls with a polyethylene film drawn first at a determined angle to the point of completion of the expansion of the foam, from which, after forming a fold , it then accompanies the foam block to the exit of the conveyor.
• the foam in formation is compressed using weighted pads bearing on the upper face of the block, by means of a strip of paper or a strip of non-woven fiber, which accompanies the block when moving on the conveyor.
• Another process described in French patent 71 31528 consists in placing the pouring point at substantially the same altitude as the upper face of the block to be obtained and the foam is ensured by the controlled inclination of the conveyor.
• the drawbacks of the first method lie in the fact that it requires the use of sheets of a very flexible material with a view to its deformability.
• a material preferably polyethylene
• the fold formed at the end point of the expansion of the foam leaves traces on the side faces of the strips, which make it necessary to straighten the blanks, which results in significant losses of material.
• the disadvantages of the second method are first of all that it requires complex apparatus and delicate adjustment.
• any variation in the cream line generates air inclusion between the paper strip and the upper face of the block, which then has deep, sometimes significant cracks, which results in the loss of part Of the band.
• the upper paper can only be removed after total gelation of the block, that is to say twenty-five to thirty meters after casting and consequently the defects are only visible by the operators from this moment, which causes a considerable delay in corrective maneuvers.
• the drawback of the third method lies in the complexity of the device for varying the width of the strip of foam during manufacture.
• the rigid foam sheets of controlled thickness and each side of which is made up of a protective material: paper, fabric, plasterboard, wood, etc. are generally manufactured continuously, in standard width preferably one meter. twenty centimeters, by means of horizontal conveyors known as double belts, one lower of which supports a band which receives the reactive mixture and the other upper comprises a band which limits the expansion of the product and also ensures the flatness of the product. the upper side.
• An objective of the invention consists in the implementation of means for the manufacture of flexible or rigid polymer strips and allowing:
• Another objective of the invention is to produce strips of flexible polymer foam with a rectangular cross section whose upper face is flat.
• Another objective of the invention is the manufacture of rigid foam plates loaded and / or lightened, in particular âe.s plates having in their thickness longitudinal and parallel channels between them while the currently known techniques only allow the production of panels full of virgin material.
• the foam taken up by a U-shaped conveyor, animated in a continuous movement takes the form of a section strip rectangular right, characterized in that the volume of said container is determined to form a zone of retention of the mixture of reactants in the liquid phase and in that the level of this mixture is maintained at a level slightly higher than the plane over which the mixture flows in the liquid state, so that the primary phase of the expansion of the mixture and its expansion occur outside the container on a surface animated by a continuous movement under the effect of the conveyor, which surface is maintained in a substantially horizontal plane.
• the volume of the container is in particular determined by acting over at least its length, so that the retention zone defines the width of the foam strip.
• the device according to the invention for producing strips of polymer foam obtained from a mixture of liquid reactants generating an expanded foam and comprising a container, means for continuously introducing into this container , said mixture of liquid reactants and a U-shaped conveyor, driven in a continuous movement on which the foam is deposited to adopt the shape of a strip of a rectangular cross section, characterized in that the container has a front wall, a rear wall and two side walls, the front and rear walls of which also constitute the bottom of the container and in that the front wall, which is situated on the side of the conveyor, is a curved wall constituted by a cylinder, driven in rotation around a axis substantially horizontal in the same direction and at the same speed as the conveyor and in that the edges of the side walls, located on the side of the wall c curved, are of a circular outline and partially surround the cylinder in order to allow the relative movement of the cylinder and the other walls while ensuring the tightness of the container.
• the upper edge of the rear wall and the side walls of the container are located at a level higher than that of the front wall, which tangents a substantially horizontal surface over which the liquid reactant mixture flows, which horizontal surface is animated. of a continuous movement under the effect of the conveyor.
• the assembly rear wall, side walls, comprises means for obtaining its pivoting around the axis of said cylinder in order to raise or lower said assembly relative to said horizontal surface in order to modify the volume of the container, and to immobilize in position said assembly after adjustment.
• the rear wall of the container is a curved wall constituted by a cylinder, driven in rotation in the same direction as the front cylinder, which cylinders are mounted on two axes parallel to each other and are substantially tangent, the line of tangency constituting the bottom of the container and in that the side walls are parallel to each other and are above the cylinders and their lower edge is delimited by two concurrent circular lines at a point located in the vicinity of said line of tangency, which side walls partially surround the cylinders in order to allow on the one hand the rotation of the cylinders and on the other hand the relative movement of the rear cylinder / side walls assembly around the front cylinder while ensuring the tightness of the container.
• the rear cylinder has a larger diameter than the front cylinder and is rotated at a slower speed than that of said front cylinder.
• the rear cylinder is immersed in a solvent tank and is subjected to the action of a squeegee extending in the longitudinal direction of the cylinder to detach the polymerized particles adhering thereto at its periphery.
• Each of the side walls has a counterplate extending from the side of said horizontal surface on which the mixture of reactants in the liquid phase is deposited to seal at the junction of the side walls and said surface, which counter plates are adjustable in position on the walls.
• Said side walls include means for bringing them towards one another or away from one another and for immobilizing them in position.
• At least one of said cylinders comprises a bundle of conduits parallel to each other and to the axis of rotation of the cylinder, in which conduits a coolant is circulated to raise or lower the temperature of the cylinder and correspondingly the temperature of the mixture of reactants in liquid phase.
• the curved wall formed by said cylinder located at the front of the container on the side of the conveyor and the rear wall of the container, define a space in which a flexible sheet has passed, which partially wraps around said cylinder on which it moves. in the container, which sheet continues to run while being supported by the conveyor and constitutes said horizontal surface on which the mixture of reactants is deposited.
• the flexible sheet is applied against the lower part of said front cylinder, below the bottom of the container, by means of a roller subjected to the action of elastic means.
• the flexible sheet is applied against the lower part of the rear cylinder beneath the tangential line of the two cylinders by means of a rou ⁇ water subjected to the action of elastic means, which sheet is then passed between the two cylinders and partially surrounds the front cylinder from above to extend tangentially thereto in a substantially horizontal position.
• the mixture of which is introduced as a source into the container a characteristic is that it comprises at least one tube passing through each of the side walls, which tube is slidably mounted to be positioned in the casting head and comprises along its length of the openings to ensure the distribution of the mixture in the liquid state in said head.
• the tubing consists of several coaxial tubes, arranged in the extension of one another and of tapering section with respect to the circulation of the mixture, so as to reserve between them substantially annular spaces of the same section, which corresponds approximately to the section of the smallest central tube.
• the device according to the invention also comprises a substantially horizontal plate, of a width at least equal to that of the conveyor and the upper face of which is tangent to the front cylinder of the container, which plate extends from said front cylinder to the conveyor and supports the leaf on which the foam develops.
• the U-shaped conveyor consists of a mat carrying the flexible sheet on which the foam develops and the side walls of which consist of two flexible sheets, each from a vertical roller located at the front of the device on the container side, which sheets extend over the length of the conveyor and are wound around a vertical roller situated at the rear of the device, said sheets moving at the speed of the mat while being attached to the side of their lower edge along the lateral edges of said sheet, carried by the conveyor, a characteristic consists in the fact that it also comprises parallel and close to each of the internal faces from the side walls of the conveyor, another inclined flexible sheet, which coming from a roller situated on the side of said container, extends over at least the part of the device where the reactants deposited in liquid phase on said horizontal sheet enter into reaction and become develop until the total expansion of the foam, which sheet moves in this part in a rectilinear direction from the inlet to the outlet of the device and from bottom to top to be supported by a roller located above the conveyor , its inclination being such that its lateral edges are
• the inclined parts of said sheet are located above the conveyor and the casting head and one of the parts is inclined up and down and folded along a parallel rectilinear member and adjoining the horizontal sheet and the other part is returned from bottom to top at the same inclination as that of said first part.
• the device according to the invention comprising a lower conveyor, carrying a flexible sheet on which is deposited the mixture of reactants and a second conveyor disposed above said lower conveyor and parallel to this and on which a flexible sheet is applied to the lower strand of the upper mat, which conveyors define a space which determines the thickness of the rigid foam panels, is characterized in that the container into which the reactants are introduced liquid is movable in the longitudinal direction of the device and comprises means for being immobilized in position relative to the conveyors.
• the tray which extends between the container and the lower conveyor, consists of at least two thin plates, mutually parallel and adjacent, which plates are telescopic to adjust the length of the tray so to connect the container and the conveyor.
• This device comprises, in the space existing between the lower conveyor and the upper conveyor, bars parallel to each other and arranged in the same plane, which bars are cantilevered and are fixed to the structure of the device on the side of said container and extend towards the conveyors, so that their free end, which is between said conveyors, is located substantially at the place where the solidification of the foam occurs.
• Each of these bars is enveloped by a sheath slightly larger than the bar so that it can be moved along the latter under the effect of the foam during its expansion in order to continuously produce and delimit channels in the foam panels.
• the invention also relates to a new product consisting of a rigid foam panel whose large faces are covered with sheets of protective material, characterized in that it comprises, in its thickness, parallel channels between them, the peripheral wall is protected by a sheath adhering to the foam.
• the upstream wall of the retention zone formed either by the rear cylinder or by the wall of the tank, is always at an altitude higher than that of the front cylinder.
• the downstream wall is formed, at its lower part, by the flexible bottom support conforming to the shape of the front cylinder and at its upper part by the line of cream with this peculiarity that the retained volume of reactive liquid, therefore of the layer of flow which determines the height of the block, can be controlled to a large extent, approximately in a proportion of 1 to 2.
• the substantially horizontal position of the conveyor no longer causes parasitic flow of the liquid phase under the expanding phase, drawback already reported on inclined conveyors and which requires a minimum speed. In the proposed method, the speed can be reduced as much as the reactivity of the mixture allows, resulting in a proportional reduction in the length of the installations.
• the invention offers the possibility of regulating the temperature of the cylinders or the tank. As it is recalled that the foaming reaction generates heat, it is important to be able to maintain the mixture and. switchgear at a constant temperature. It is preferable to use a heat transfer fluid passing through the cylinders and capable of removing the calories produced or, on the contrary, providing them if necessary. Experience having shown that a high temperature (50 to a high temperature (50 to a high temperature (50 to
• the arrival of the reagent liquid can be carried out either by runoff on a chute, or at source by two lateral pipes crossing the movable sides and each constituted by a series of concentric nozzles with decreasing sections from downstream to downstream, the nozzles have all the same section or neighboring sections to avoid any turbulence in the liquid mixture and to ensure the distribution of the mixture in the container. It is possible to integrate a powdery or granulated, dry or impregnated charge, spread over the rear cylinder, using, for example, a hopper and a suitable distributor. The addition of fillers in polyurethane foam, which has always encountered difficulties in conveying them into the mixture, is resolved by this process. This characteristic is especially interesting for the production of rigid foam insulation panels between two facings.
• the apparatus as described above can easily be adapted to existing conveyors, in particular for the manufacture of flexible foam, without losing the advantage of the formation of the cream line on a horizontal plane.
• This adaptation can be extended to rigid foam production machines, known as "double band” machines, while retaining the option generally offered by these machines, of adjusting the distance between the casting head, here the retention zone, and the inlet. of the double belt conveyor.
• the method and the device according to the invention also make it possible to obtain strips of flexible foam of a rectangular cross section having no deterioration of the sides and having a planed upper face.
• the angle of climb can be adjusted at sight 'and without delay
• the method and the device according to the invention finally allow the manufacture of rigid defoaming plates.
• the adoption of a source-fed cylinder head allows the placement of a device capable of creating longitudinal channels in the thickness of the panel being formed and thus achieving significant savings in raw material.
• FIG. 1 is a very schematic elevational view of a device according to the invention for manufacturing strips of flexible polymer foam and comprising a casting head with cylinders
• - Figure 2 is a sectional view of the device of the Figure 1 along line II II
• FIG. 3 is a partial schematic sectional view on a larger scale of the front part of the device of Figure 1, illustrating the casting head in one embodiment and in its arrangement where the retention area is maximum ,
• FIG. 4 is a schematic view of the pouring head of FIG. 3 in its arrangement where the retention zone is minimal
• FIG. 5 is a schematic half-view from above of the casting head of Figure 3,
• FIG. 6 is a partial elevation view of the mechanical part of the container making up the casting head
• FIG. 7 is a partial top view of the mechanism of FIG. 6,
• FIG. 8 is a schematic sectional view of a casting head in another embodiment and comprising a single cylinder. In this figure, the container is adjusted so that its capacity is maximum;
• FIG. 9 is a schematic sectional view of the pouring head of FIG. 8, the container of which is adjusted so that its capacity is minimal,
• FIG. 10 is a schematic longitudinal sectional view of a device according to the invention for the production of rigid polymer foam panels
• FIG. 11 is a schematic longitudinal sectional view of the front part of the device of Figure 10, comprising arrangements for obtaining rigid panels comprising longitudinal channels
• - Figure 12 is a top view of one of the forming cores said channels and its accessories and which illustrates the use of the ducts of the channels of the rigid panels according to one embodiment
• FIG. 13 is a partial perspective view of a rigid foam panel according to the invention.
• FIG. 14 is a view in longitudinal section of one of the supply pipes at the source of the mixture of reactants in the cylinder containers according to the invention.
• FIG. 15 is a view along F 1 of the duct of Figure 14.
• Figures 1 to 7 of the drawing illustrate the invention, in one embodiment for obtaining strips of foam of flexible polymer.
• the device of Figure 1 consists of a conveyor 1, extending in a substantially horizontal plane whose supporting strand supports a flexible sheet 2, from a roll 3.
• This sheet 2, for example of paper is of 'first passed through a casting head 4 and is supported, while being able to slide, on an intermediate plate 5, arranged between the head 4 and the conveyor 1.
• the plate 5 and the carrying strand 1a of the conveyor 1 are substantially in the same plane.
• the side walls of the conveyor 1 are formed in a known manner by flexible sheets 6, coming from two rollers 7.
• the rollers 7 are arranged perpendicular to the conveyor 1 and the sheets 6 are, adjacent to the lateral edges of the horizontal sheet 2
• the set of sheets 2/6 forming a corridor of a straight U-shaped section, moves at the speed of the conveyor 1 in the direction of the arrow F.
• the rollers 7 are for example located at the level of the front drum 1b of the conveyor 1. We will return later to this figure to complete its description concerning other arrangements relating to the invention.
• the casting head 4 is shown in Figures 3 to 7 of the drawing.
• the device in which the liquid phase reactants are introduced with a view to their mixing and ensuring the function of distributor of this liquid mixture is called pouring head before its expansion occurs until the final phase where it takes the consistency of 'a foam.
• the method consists in determining the volume of a container to form a retention zone for the mixture of reactants in the liquid phase and the level of this mixture is maintained at a level slightly above the plane in which the sheet 2 moves.
• FIGS 3 to 7 show a preferred embodiment of the casting head, which consists of a container 8 composed of two cylinders of the same length 9/10 and two side walls 11.
• the cylinders 9/10 are of diameters different, so that the cylinder 9 is smaller than the cylinder 10.
• These cylinders are parallel to each other and are arranged horizontally and transversely to the conveyor 1.
• the cylinder 9 is located near the plate 5 and is very close to the other cylinder 10 so as to leave a slight space between them for the passage of a film, for example a sheet of paper 2.
• the cylinders are substantially tangent and the line of tangency marked 12 constitutes the lower end part of the container.
• This comprises two animated curved front / rear walls, which are constituted by said cylinders 9/10 as well as side walls 11 which are arranged above the cylinders, are parallel to each other and extend perpendicular to the generatrices of said cylinders 9 / 10.
• Their lower edge is formed by two curved lines 11a / 11b which converge at point 11e, which is located in the vicinity of the line of tangency marked 12.
• Line 11a is a circular line of radius R 1 having as its center the axis of rotation of cylinder 10. This circular line 11a closely circumvents the periphery of cylinder 10.
• Line 11b is a circular line of. radius R 2 , having centered the axis of rotation of the cylinder 9. The circular line 11b bypasses the periphery of the cylinder 9 and is in abutment on the sheet of paper 2.
• the curved line 11b ' is extended by a straight line 11d s extending above the plate 5.
• the upper part of the cylinder 9 is substantially tangent to the plane in which the plate 5 is located and in which the flexible sheet 2 moves.
• the sheet 2 is first supported on a first roller 3a, mounted for free rotation on the structure of the machine and is applied against the cylinder 10 by a roller 3b.
• the sheet 2, from the paper roll 3 first partially bypasses the cylinder 10, passes into space 12, bypasses the upper part of the cylinder 9 to continue its race horizontally on the plate 5 and the carrying strand 1a of the conveyor 1 .
• the eusemble cylinders 9/10 and side walls 11 is pivotally mounted around the axis of the cylinder 9, so that the volume of the mixture retention zone 8 can vary, depending on the angular position of said assembly.
• the angular movement ⁇ is for example 15 °.
• the cylinder 10 being in its lower extreme position, the volume of the retention zone 8 is maximum.
• the cylinder 10 is in its extreme upper position and the volume of said zone 8 is minimum.
• each wall 11 comprises, on the side of the plate 5, a counter plate 13 intended to mask the vacuum existing between the line 11d and the sheet 2
• This counter plate 13 has, at its lower part, a circular edge 13a extended by a straight line 13b.
• the lower edge of the plate 13 thus follows the contour of the upper part of the cylinder 9 and extends over part of the plate 5.
• the counter plates 13 also have a curved opening 13c to allow their positioning on the side walls 11 and their fixing is ensured for example, by means of two bolts 14 or by any other equivalent means.
• the cylinders 9/10 are rotated in the direction of the arrows F2 which is also the direction of the conveyor 1.
• the cylinder 9 is driven at the speed of the conveyor 1.
• the cylinder 10 rotates at a slower speed.
• the admission of the liquid mixture into the container 8 can be carried out in two ways: either by means of a dispensing head 15 which pours the liquid mixture onto a distribution chute 16, situated above the cylinder 10, or by means two horizontal tubes 17 introducing the source liquid through the side walls of the container. Each of these tubes passes through one of the side walls 11 and brings the mixture of reactants without turbulence into the container.
• An embodiment of such tubing 17 is illustrated in Figures 14/15 of the drawing.
• annular space 17g / I7h / 17k substantially of the same section, which approximately corresponds to the section of the smallest tube 17d.
• the positioning of the tubes between them is obtained by means of spacers 17l, distributed around the tubes.
• the mixed in the liquid state is thus distributed in the casting head at the same flow rate and s ans turbulence by the annular spaces 17g / 17h / 17k as well as by the central tube 17d.
• FIG. 9 An embodiment of the supporting structure of the cylinders 9/10 and the side walls 11 is given with reference to Figures 6 and 7.
• the cylinders 9/10 are rotated by being mounted on two arms 18 parallel to each other and arranged on either side of the cylinders.
• the large cylinder 10 is mounted adjustable on the supports 18 in bearings 19 mounted on slides and comprising adjustment means 19a and stop I9b to allow it to move away from or closer to the cylinder 9, and to immobilize it in position .
• the cylinder 9 is mounted in a fixed position at one end of the arms 18.
• the assembly is carried by bearings 20 fixed to the chassis of the machine.
• the arms 18 and all of the elements which they carry can pivot around the axis of the cylinder 9, marked 21.
• the roller 3b intended to press the sheet of paper against the cylinder 10, is carried by two links 22, articulated by their middle around an axis 23 carried by a tab extending to the lower part of the arms.
• the links 22 are subjected to the tension of a spring 24, hooked to the arms 18, so that the roller 3b is pivoted on the side of the cylinder 10.
• the arms 18 are interconnected by a crosspiece 25 and have two extensions 26 extending perpendicularly from bottom to top. These two extensions 26 are mutually parallel and carry at their upper part a threaded rod 27, the thread of which is reversed right / left from its middle. This rod 27 is connected by one of its ends to means for driving it in rotation.
• the choice of the volume of the re-ention zone 8 is obtained by modifying the angle ⁇ of the line XX 1 on which the cylinders 9/10 are located and / or by modifying the length of the container by displacement of the side walls 11. acting on the screw 27.
• the walls 11, guided in translation by the supports 30. can be brought towards each other or distant from each other symmetrically to the longitudinal axis of the device.
• the arm 30 is held parallel to the arm 18 by means of a sliding stop 36 indented at 36a which is integral with it and which cooperates with a slide 37 extending transversely to the casting head and which is parallel to the screw 27.
• This abutment 36 extends perpendicularly to the arm 30 and below the latter each arm 30 has a stop.
• the adjustment of the spacing of the side walls 11 determines the width of the strip of foam obtained.
• the mixture of liquid reactants contained in the retention zone 8 and whose upper level lies substantially in the plane of the plate 5 or slightly above, is entrained in the liquid state by the flexible sheet 2, so that the expansion and expansion of the foam occur outside the container on the tray 5, the total expansion continuing on the conveyor 1.
• the cylinder 10 which constitutes the rear wall of the container, is partially immersed in a solvent tank 38, placed at the bottom of the casting head.
• This tank 38 includes a squeegee 39 extending transversely to the cylinder and kept in position at a suitable angle to detach from the wall of the cylinder the particles of polymerized material which could have adhered to it.
• the tank 38 moves with the assembly when the volume of the retention zone 8 is adjusted and its shape is such that no spillage of solvent can occur.
• the cylinders 9/10 also have conduits 9a / 10a equidistant from the axis of rotation of the cylinders and extending longitudinally, parallel to said axis of rotation.
• the cylinders have rotating joints at their ends to seal at these locations.
• These conduits 9a / 10a have the function of channeling a heat-transfer fluid, for example water, for the purpose of heating or cool the cylinders and correspondingly the mixture of reactants.
• This design is advantageous because, since the foaming reaction generates heat, it is important to keep the mixture and the equipment at a constant temperature. It allows in particular to control the temperature at various points in the container. For example, the rear cylinder 10 can be cooled while the cylinder 9 can be heated.
• FIG. 8 and 9 of the drawing Another embodiment of a casting head according to the invention is illustrated in Figures 8 and 9 of the drawing.
• This consists of a cylinder 40 rotated in the direction of movement of the conveyor belt of the conveyor 1 and on which cylinder 40 is applied a sheet of paper 2 from a reel 3.
• the partial winding of the sheet 2 on the cylinder 40 is obtained by means of a roller 41 extending parallel to said cylinder.
• the flexible sheet 2 is supported by a horizontal plate 5 and is supported by a conveyor also horizontal.
• the cylinder 40 covered with the flexible sheet 2, constitutes the front wall of the container into which the mixture of liquid reactants is introduced.
• the rear and bottom walls of the container and the side walls form an assembly which can pivot around the cylinder 40 while remaining tightly applied by the side walls to the flexible sheet 2.
• its upper part is always at a level higher than the plane of the plate 5 in which the sheet 2 moves.
• the container consists of a rear wall 42, which partly follows the contour of the cylinder 40 ′ and comprises at its lower part a "return" 42a, directed towards the side of said cylinder.
• a space 43 is reserved between the parts 42a and the cylinder, to allow the passage of the flexible sheet . 2.
• the side walls 42b of the container are delimited on the side of the cylinder by a circular line 42bj, which is extended to the upper part of the container by one. straight line 42b2. In- the position illustrated in the figure 9, this straight line 42b2 is applied against the flexible sheet 2, which seals the container at this location where the mixture, in the liquid state, begins its expansion.
• the device comprises, inside the container and against the internal faces of the side walls 42b, against plates 44 which have the function of masking the vacuum existing between the side walls 42b and the flexible sheet 2, as illustrated in particular in FIG. 8 of the drawing.
• the counter plates 44 have a fixed position relative to the cylinder 40 and include means for being adjusted and fixed at a determined position relative to the side walls 42b of the container. They comprise a circular 44a extended by a ⁇ right tie board 44b, so as to cooperate closely with the flexible sheet 2. They take the form of a curved strip with lateral parallel edges whose width is greater than the maximum space E left in line with the side walls 42b of the container.
• the device described in FIGS. 8 and 9 can include a source supply in the side walls 42b of the container or by means of a dispensing head located above the container. . Also the side walls 42b can be brought closer or further apart from one another in order to determine the width of the strip of foam to be obtained.
• the temperature of the mixture of liquid reactants contained in the container can be controlled by admitting into the cylinder a heat transfer liquid circulating in longitudinal conduits as has been described with reference to FIG. 3.
• the casting head shown in FIGS. 8 and 9, allows the mixture of reactants to flow in the liquid state, outside the container, in line with the plate 5, the extension of the foam being made on the plate 5 to end on the conveyor 1.
• FIG. 1 of the drawing in which the evolution of the mixture of reactants flowing in the liquid phase at station A is illustrated schematically and which, entering into reaction develops progressively along a regular slope to adopt at point B the final structure of a strip of foam.
• the upper face 45 of the strip of foam thus formed is planar and that the upper corners of the strip are substantially right angles, it is necessary to accompany the foam during its evolution between points A and B to prevent the he first viscous then pasty state of the mixture does not cause against the walls of the shaper a restraint which slows the expansion of the cells in contact with the walls.
• the problem has been solved according to the invention by placing inside the conveyor and against each of the side walls thereof, constituted by sheets of paper 6, a flexible sheet 46 also made of paper ", which is unwound in a oblique direction as illustrated in figure 1.
• the sheet of paper 46 from a roll 47 located in front of and above the cylinder casting head 4 extends in a vertical plane first in a direction inclined up and down to the sheet 2 carried by the plate 5.
• the sheet 46 is then folded around a member 1b constituted by a very thick wall, the lower edge of which is straight and extends parallel by adjoining said sheet 2, so that the parts 46a and 46b move in parallel planes.
• the part 46b is thus inclined from bottom to top and is wound around a coil 48 situated above the shaping device for the strips of foam, which is constituted by the horizontal sheet 2 and. by the two sheets 6 delimiting the side walls of the conveyor.
• the inclination of the part 46b is appreciably that of the mold 49 during development.
• FIG. 10 of the drawing illustrates a device according to the invention for manufacturing rigid foam panels.
• This consists of a horizontal conveyor belt 50 extending in a horizontal plane above which is disposed a second conveyor 51.
• the two conveyors 50/51 are mutually parallel and are spaced apart from one another of a distance d which corresponds to the thickness of the plate to be obtained.
• the lower strand 51a of the conveyor 51 is covered with a sheet, for example of paper 52 from a reel 53 located in before and above the device.
• the cylinder casting head 54 which is of the type described with reference to FIGS. 3 to 7, is mounted on a carriage 55 guided by rails 56.
• the carrying strand 50a of the lower conveyor 50 is covered by a sheet of paper 57, which from a supply reel is supported on a roller 58 and passed into the casting head 54 partially surrounding the front cylinder 54a of the latter.
• the distance separating the casting head 54 from the lower conveyor 50 is filled by a plate 59 made up of two telescopic parts 59a / 59b.
• Each of these parts is constituted by a thin metal plate preferably made of copper or aluminum, which are adjacent and superimposed so as to be able to slide relative to each other depending on the position of the casting head 54 by report to conveyors.
• the length of the plate 59 can thus be modified in a proportion close to 1 to 2 in order to determine a zone of expansion of the mixture and to control its expansion, the heating being ensured by a battery of infrared emitters 60 with adjustable position and the distribution of which is determined by the length of the zone chosen.
• bars 61 are arranged parallel to the direction of movement of the conveyors 50/51. These bars are of a section less than the thickness of the panels and extend horizontally in the middle of the space d existing between the conveyors 50/51.
• the device comprises several bars 61 parallel to each other, which are located in the same plane.
• the bars 61 are fixed to the structure of the machine to supports 62, located at one of their ends and extending in cantilever above the casting head 54 and between said conveyors 50/51 so that their free end is located substantially at the point where the foam takes its consistency.
• Said bars constitute the cores around which sheaths 63 are formed, obtained from strips of paper 64 or polyethylene film for example, continuously folded by means of conical forming rollers 65 according to a known principle.
• a roller 66 Upstream of each bar 61, is disposed a roller 66 on which the sheet 64 is supported from below.
• the roller 66 is arranged so that the sheet comes to tangent the bar 61 at its lower part. This is of a reduced section and profiled at its part 61a to accompany the sheet 64 before it is brought into contact with the forming rollers 65. These are arranged so as to bring one of the edges of the sheet into overlap on the other, as illustrated in FIG. 12.
• the sheath thus formed at the level of station A is closed by gluing or by welding by means of two knobs 67 which apply the edges to each other.
• the sheaths are driven at the same speed as the conveyors 50/51 initially by means of a mooring clamp and then by the material itself by adhesion of the latter to the sheaths.
• the foam in formation develops around the sheaths 63 between the conveyors 50/51 until total expansion.
• the panel obtained at the outlet of the conveyors comprises longitudinal channels which are parallel to one another and delimited by said sheaths. A panel thus obtained is illustrated in Figure 13 of the drawing.
• the foam layer 68 calibrated in thickness between the two conveyors 50/51 is protected on the large faces of the panel by sheets of paper 52/57.
• the channels 69 formed by the cores 61 adopt the shape of the latter and extend in the longitudinal direction of the panel.
• the example shown comprises channels 69 of a circular cross section whose peripheral wall is delimited and protected by the sheaths 63 which adhere to the foam. It is specified that the sheaths 63 can also be constituted by rigid tubes made of cardboard or plastic.

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• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
• Materials For Medical Uses (AREA)
• Laminated Bodies (AREA)

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Publications (1)

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ID=9256658

Family Applications (1)

Country Status (7)

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Citations (11)

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• 1981
  • 1981-03-24 FR FR8106043A patent/FR2502541A1/fr active Granted
• 1982
  • 1982-03-23 AT AT82430006T patent/ATE14397T1/de not_active IP Right Cessation
  • 1982-03-23 WO PCT/FR1982/000056 patent/WO1982003357A1/fr not_active Ceased
  • 1982-03-23 US US06/441,514 patent/US4559003A/en not_active Expired - Fee Related
  • 1982-03-23 EP EP82430006A patent/EP0061412B1/fr not_active Expired
  • 1982-03-23 DE DE8282430006T patent/DE3264848D1/de not_active Expired
  • 1982-11-23 NO NO823917A patent/NO823917L/no unknown

Patent Citations (11)

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