Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D1/00—Processes for applying liquids or other fluent materials
  • B05D1/28—Processes for applying liquids or other fluent materials performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C1/00—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating
  • B05C1/04—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length
  • B05C1/08—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line
  • B05C1/0856—Reverse coating rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C1/00—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating
  • B05C1/04—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length
  • B05C1/08—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line
  • B05C1/0826—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line the work being a web or sheets
  • B05C1/083—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line the work being a web or sheets being passed between the coating roller and one or more backing rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C1/00—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating
  • B05C1/04—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length
  • B05C1/08—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line
  • B05C1/0826—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line the work being a web or sheets
  • B05C1/0834—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line the work being a web or sheets the coating roller co-operating with other rollers, e.g. dosing, transfer rollers

Definitions

• Films formed of materials such as polypropylene, polyethylene, polyvinyl alcohol, polyvinyl chloride, polymethylmeth-acrylate, or polyethylene terephthalate typically have favorable release properties.
• the release properties of films may also be enhanced with physical processes such as manipulating the surface tension of the firm (for example through a conventional corona treatment) or chemical processes such as the application of various conventional release agents.
• Films having so-called release properties are well known in the prior art; see for example, EP 1 053 793 Al and EP 0 573 676 Bl.
• the prior art includes both paper-based films and films made of a resin, the surfaces of which are prepared such that the film comprises release properties.
• EP 0 573 676 Bl discloses a process of decorating an object wherein a layer of varnish is applied on a film having release properties. That layer of varnish is partially cured. A layer of colour is applied onto the partially cured varnish layer and a second layer of varnish is applied onto the colour layer.
• the second layer of varnish is also partially cured. Thereafter, the layers of varnish and colour, respectively, are transferred onto the object to be decorated (the
• the films in question here typically have a width of more than 100 cm, e.g. a width in the range of 160 to 180 cm.
• the machines according to the prior art were only capable of applying varnish layers having a thickness typically less than 60 ⁇ m.
• the present invention aims at providing an apparatus that is capable to be adapted to apply a variety of varnish layers of different thickness, in particular relatively thick varnish layers.
• the present invention provides an apparatus and process for applying varnish onto a film.
• the apparatus comprises a coating roller for transferring varnish from the coating roller onto the film and a pressure roller arranged adjacent the coating roller.
• the means for advancing the film advances the film in a first direction through the gap between the coating roller and the pressure roller, and the means for rotating the coating roller rotates the coating roller such that the circumference of the coating roller adjacent the film moves in a second direction opposite to the first direction.
• the film enters the gap at an angle ( ⁇ ) different from zero with a plane that is tangential to both the coating roller and the pressure roller.
• the coating roller comprises a rubber surface.
• a means is provided for moving at least one the pressure roller or coating roller in a direction parallel to the plane that is tangential to both the coating roller and the pressure roller.
• Figure 1 illustrates schematically one embodiment of the present invention for applying varnish onto a film.
• the apparatus comprises a coating roller 10 and a pressure roller 12. Pressure rollers are also sometimes called “counter rollers”.
• the pressure roller 12 is non-steered; i.e. it is not powered and may rotate freely.
• a dosing roller 14 is arranged adjacent the coating roller 10 for transferring varnish from a supply (not shown) onto the coating roller 10.
• a plane 16 is tangential to both the coating roller 10 and the pressure roller 12, i.e.
• the plane 16 passes in-between the rollers, which are adjacent to each other.
• a film 18 having release properties is advanced in the figures from the right hand side to the left hand side.
• the release properties may be defined as the film having a surface tension (or surface energy) of between approximately 30 and 42 dynes. This surface tension may be obtained by selection of a material naturally having this surface tension or by modification of the surface tension, such as by a corona treatment process.
• the coating roller 10 is rotated around its axis 20 in a counter-clockwise direction as indicated by arrow 46 in the figure.
• Pressure roller 12 rotates about its axis 22 and is driven at the speed at which the film 18 is advanced. Both coating roller 10 and pressure roller 12 are driven by a conventional drive mechanism such as seen in co-pending application PCT Application Serial No. , filed on 23 July 2004, to inventor
• the film 18 is guided via rollers 24 and 26 such that, before being advanced between the coating roller and the pressure roller, it is not positioned in the tangential plane 16, but rather defines an angle ⁇ between the film 18 and the tangential plane 16, as indicated in the figure. That angle ⁇ is acute, and is preferably in the range between about 10° and 30°. As described above, film 18 is advanced in the figure from right to left. Pulling means for pulling the film in the direction 42 are not shown, but they are typically arranged in the figure to the left of the coating roller 10 and the pressure roller 12.
• a conventional driven collecting roller would be suitable for pulling the film in the direction 42.
• Varnish is transferred by the coating roller 10 onto the film 18, and in particular onto the upper surface of film 18, as shown in the figure.
• the varnish is, preferably, curable by so-called cross-linking, which as such is well known in the art.
• curing means may be arranged to the left of the coating roller 10 and the pressure roller 12.
• a varnish container 28 is arranged underneath the pressure roller 12 to collect excess varnish not used for coating the film 18, e.g. varnish applied at the edges of the film 18.
• a support 30, which supports both the pressure roller 12 and the coating roller 10, allows rotation of the coating roller 10 and the pressure roller 12 in the direction of arrows 32, i.e. both the coating roller 10 and the pressure roller 12 can be rotated about an axis A that is passing through the axes 20 and 22 in the middle of both rollers. Since the figure shows a centre cross section through the rollers, the axis A is also in the plane of the drawings.
• Coating knifes 36, 38 which may be "soft" knives formed of a polyolefin material, are arranged to control the transfer of varnish from the dosing roller onto the coating roller, as is known in the art as such.
• the coating roller 10 and the dosing roller 14 rotate typically in opposite directions, as indicated by the arrows 46, 48.
• the amount of varnish transferred to the film may be regulated by the distance between the coating knives and rollers and the pressure exerted on the film by coating roller 10 and pressure roller 12.
• the coating roller 10 may have a typical diameter in the range between 180 and 300 mm, preferably about 240 mm.
• the pressure roller 12 may have the same dimensions.
• the dosing roller 14 has a diameter in the range of 100 to 200 mm, preferably about 160 mm.
• the dosing roller 14 is smaller than the coating roller.
• the width of the film is typically 160 to 180 cm.
• a soft knife 40 is arranged near the varnish collecting container 28 in order to clean the pressure roller 12 from excess or non-used varnish.
• the film 18 is advanced in the direction of arrow 42. The film 18 passes through a gap 44 between the coating roller 10 and the pressure roller 12.
• the direction of rotation 46 of coating roller 10 and the speed of rotation are controlled such that the circumference of the coating roller 10 adjacent the film 18, i.e. the circumference of the coating roller actually transferring the varnish onto the film, is moving in the opposite direction with reference to the movement of the film. Therefore, the circumferential surface of the coating roller 10 has a velocity relative to the velocity of the film 18 in the opposite direction. That is, in a (moving) coordinate system in which the film 18 is at rest, the circumferential surface of the coating roller 10, which transfers the varnish onto the film, moves relative to the film with a definite velocity different from zero. Most preferably, in a stationary (non-moving) coordinate system (i.e.
• the coating roller 10 has a circumferential surface that rotates counter-clockwise as indicated by arrow 46 in the figure.
• the dosing roller 14 rotates in a direction opposite to the direction of rotation of the coating roller 10, i.e. dosing roller 14 rotates clockwise.
• Typical examples of the velocities are as follows:
• the speed of advancement (velocity) of the film 18 in direction 42 may be in a range of 1-50 m/min, and more
• the preferred rotational speed of the coating roller 10 is such that its surface velocity is 10 m/min.
• the rotational speed of the coating roller is such that its surface velocity is in a range of 30-70% of X.
• the drum and film velocities are in the same direction, i.e. the film is advanced in direction 42 and the coating roller rotates clockwise. If, on the other hand, the speed of advancement (velocity) of the film 18 is relatively slow, e.g.
• the coating roller may rotate anti-clockwise in direction of arrow 46 with surface velocities in the range of 5-10 m/min.
• the velocities ares adjusted in accordance with the specific requirements of the varnish coating to be applied onto the film, in particular the thickness of the varnish and the properties of the varnish.
• the coating roller 10 may also rotate clockwise (i.e. opposite to arrow 46) with a0 circumferential speed smaller than the speed of advancement of the film 18 in the direction of arrow 42.
• a thicker layer may be applied by adjusting the circumferential speed of coating roller 10 in clockwise direction (opposite to arrow 46) to be between 3 m/min and 7 m/min, resulting in a corresponding lower relative5 speed between be circumference of the coating roller and the film.
• the amount of varnish applied onto the film 18 can also be controlled by how varnish 50 is fed in between the coating roller 10 and the dosing roller 14 as shown in the drawing. By adjusting the pressure between the dosing roller 14 and the coating roller 10 and/or the relative velocity between coating roller 10 and dosingo roller 14, the amount of varnish applied by the coating roller 10 onto the film 18 is variably controllable.
• the dosing roller 14 may rotate in opposite direction as compared to the coating roller 10. This is indicated by the double-arrow 48.
• layers of varnish can be applied onto the film 18 which are much thicker than possible with prior art machines, e.g. it is possible to apply a varnish layer having a thickness in the range of 120 ⁇ m to 130 ⁇ m with a constant thickness along the width and length of the film 18.
• a film 18 having release properties and coated with a varnish layer having a thickness in the afore-mentioned range is very suitable for applying varnish onto an object with a high degree of homogeneity of the varnish layer, especially in the area of the edges. Cracks and similar imperfections in the varnish layer are eliminated to a substantially greater degree than in the prior art.
• the present invention is described in terms of applying a varnish layer, the invention's scope could include applying coating materials other than varnish.
• the term "velocity" is a vector quantity having both magnitude and direction. Thus, if film 18 is moving at 5 m/min in a first direction and the circumferential speed of coating roller 10 is 5 m/min in a second direction, the velocity of film 18 and coating roller 10 should be considered different.

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• Application Of Or Painting With Fluid Materials (AREA)
• Coating Apparatus (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=38813060

Family Applications (2)

Family Applications After (1)

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Citations (5)

Family Cites Families (3)

• 2004
  • 2004-07-23 WO PCT/US2004/023683 patent/WO2005084823A1/en active Application Filing
  • 2004-07-23 CN CNA200480042831XA patent/CN1942253A/zh active Pending
  • 2004-07-23 EP EP04778962A patent/EP1755791A4/de not_active Withdrawn
• 2005
  • 2005-03-15 EP EP05005644A patent/EP1618967A1/de not_active Withdrawn

Patent Citations (5)

Non-Patent Citations (1)

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