FR2848498A1 - Method of printing a graphic on a cylindrical or tapered object, uses transfer from printed layer onto thermo-reactive layer formed on surface of object to carry printing - Google Patents

Abstract

The printing method prints a representation of the graphic on the face of a transfer strip using digital printing, then progressively transfers the representation from the transfer strip to the cylindrical surface. Before the transfer application, a thermo-reactive layer is applied to the surface of the object (6) which is to receive the graphic, and the layer is dried.

Description

The present invention relates to a method

  printing of a graphic or similar representation on a hollow or solid object of cylindrical, frustoconical shape or the like and devices for carrying out said method.

  In the field of printing a graphic or similar representation such as a logo or an advertising message on a hollow or solid object of cylindrical, frustoconical shape or the like such as the body of a pen for example, it is known many printing processes such as pad printing, screen printing or transfer film. In this respect, the screen printing methods consist of scraping, that is to say, projecting ink onto a "nylon" (registered trademark) screen which lets said ink pass through the meshes. of the screen which have not been obstructed according to the motif to be reproduced, the object to be marked being positioned behind the "nylon" screen. The ink may consist of a "traditional" ink or of other types of ink which exhibit, for example, fast drying or fastness characteristics on the glass, thus making it possible to produce relief prints, the thickness the relief being proportional to the quantity of ink deposited.

  This type of method has the disadvantage of providing a poor definition of the printing and of not allowing sufficiently precise identification between the different colors on cylindrical parts.

  Known, moreover, pad printing which consists of transferring the ink contained in the hollow of a plate obtained by chemical photogravure, for example, on an object by means of a silicone rubber transfer pad. The use of elastic transfer stamps of different shapes allows printing on convex, concave or irregular surfaces.

  However, this type of process has the disadvantage of only allowing printing on more than a third of the circumference of cylindrical objects. -2

  Finally, a transfer film process is well known, which consists in depositing the same serial image by screen printing on a polyester film and then delivering the prefabricated marking in the form of a reel. The image deposited on the polyester film is then deposited on the object to be marked by transfer. This type of method also has the disadvantage of allowing the deposition of an image only on a part of the circumference of a cylindrical object. In addition, it has the disadvantage of not allowing precise reproduction of a four-color process.

  Furthermore, all of these methods have the drawback of depositing on the object to be marked a layer of ink or the like forming the image which resists neither impact nor abrasion, which is particularly troublesome for a pen which is constantly held in the hand, undergoing besides the friction of the rights, that of the nails as well as impacts with other pens or objects of any kind, so that the marking on a pen obtained by these methods, quickly disappears.

  One of the aims of the invention is therefore to overcome these drawbacks by proposing a process for printing in four colors a graphic representation or the like on an object which is hollow or full of revolution, such as cylindrical, frustoconical or the like, allowing to print a graphic representation on all or part of the circumference of said object while having a high impact resistance.

  To this end, and in accordance with the invention, there is provided a method of printing a graphic representation or the like on a hollow or full-of-revolution object such as the body of a pen, for example remarkable in that it proceeds at least from the following successive steps: a first printing step 35 of a graphic representation on one side of a transfer tape by a digital printing process, then a second progressive transfer step on the surface of the object of the graphic representation previously -3 printed on a transfer tape.

  In order to allow the printing of a graphic representation on a hollow or solid metal object of revolution, obtained in a rigid material such as metal, glass, wood or the like, the method advantageously comprises, prior to step for transferring the graphic representation, at least one step of applying a thermoreactive material to the external surface of the object on which the graphic representation is to be printed, then a step of drying the thermoreactive material applied to the object. The step of applying the thermoreactive material preferably consists in positioning the object on a support, then driving the object in rotation around its axis of symmetry, and finally in bringing the the external surface of the object driven in rotation about its axis of revolution with a roller for applying the thermoreactive material, said applicator roller being in contact with a feed roller immersed in the thermoreactive material. Said roller for applying the thermoreactive material is rotated in the opposite direction to the direction of rotation of the object at the same rotational speed as that of the object.

  Furthermore, the object being positioned on the support, the drying step consists in rotating the object around its axis of revolution positioned so that it coincides with the line of intersection of at least two infrared radiation emission plans. In addition, the step of progressive transfer onto the surface of the object of the graphic representation consists in applying the external surface of the object driven in rotation about its axis of revolution on a face of the strip, of transfer driven in translation tangentially to the external surface of the object, a heat source being applied to the opposite face of said transfer strip.

  According to an alternative embodiment of the step of -4 progressive transfer onto the surface of the object of the graphic representation, the latter consists in applying the external surface of the object to one face of the transfer strip, a source heat being applied to the opposite side of said transfer tape, and to move the object along the transfer tape so that said object is rotated about its axis of symmetry An essential object of the The invention relates to a transfer band 10 for printing a graphic representation on the external surface of a hollow or solid object in the shape of a revolution and of any size such as the body of a pen for example, remarkable in that said transfer band consists of a support strip 15 covered with a heat-sensitive material on which graphic representations are printed by digital printing means. The digital printing means preferably consists of a high-definition four-color digital printing means.

  Another object of the invention relates to a device for lacquering a hollow or full of revolution object of any size such as the body of a pen for example, remarkable in that it comprises a support consisting on the one hand, of a fixed headstock frame carrying a first centering point provided with a generally frustoconical bowl capable of receiving means for supporting the object and integral with the free end of the shaft of a motor, said shaft being mounted on a ball bearing, and on the other hand, of a movable headstock frame mounted freely in translation along guide means integral with the fixed headstock frame, said movable headstock frame carrying a second centering tip provided with '' a generally frustoconical bowl capable of receiving means for supporting the object and secured to an axis mounted on a bearing, said axis being coaxial with the motor shaft Another characteristic of the invention relates to a drying device d '' a lacquered hollow or full of revolution object of any size such as the body of a -5 pen for example, said device comprising at least one concave rectilinear reflector having a parabolic or elliptical section at the focal point of which is positioned a straight cylindrical emitting source infrared or the like, remarkable in that it comprises a frame on which is able to bear a support for the lacquered object and on which are secured at least two reflectors so that the planes of symmetry passing through the foci reflectors are concurrent along a straight line which coincides with the axis of revolution of the lacquered object.

  Finally, a last object of the invention relates to a device for transferring a graphic representation obtained by a digital printing process onto the external surface of a hollow or full-of-revolution object of any size such as the body of a pen. for example, remarkable in that it comprises a carriage capable of moving in translation in the same running direction of a transfer band on which the graphic representation is printed, said transfer band being unwound step by step by drive means above said carriage, two rollers mounted free in rotation on the carriage around axes extending perpendicular to the direction of travel of the conveyor belt so that the object is able to bear on the rollers and thermal means positioned above the transfer strip and able to bear on the upper face of said strip, the object then being in contact with the underside of the strip.

  Other advantages and characteristics will emerge more clearly from the description which follows of several variant embodiments given by way of nonlimiting examples of the printing process according to the invention and of the devices implementing the process with reference to appended drawings in which: FIG. 1 is a schematic representation in longitudinal section of the device for supporting a hollow object of revolution according to the invention,

D -6

  - Figure 2 is a top view of the support device for a hollow object of revolution according to the invention shown in Figure 1, Figure 3 is a diametrical sectional view of a support means of the device support according to the invention shown in Figures 1 and 2, - Figure 4 is a schematic representation in cross section of the device for lacquering a hollow object of revolution according to the invention, - Figure 5 is a schematic representation in cross section of the device for drying a lacquered hollow object of revolution according to the invention, FIG. 6 is a schematic side view of the device for transferring a graphic representation on the external surface of a hollow object of revolution according to the invention, - Figure 7 is a cross-sectional view of a transfer belt according to the invention.

  In order to print a graphic representation obtained by a digital transfer printing process, as will be detailed below, on the external surface of a hollow metallic and revolutionary object, or in any material other than plastic such as the tube of a pen or the body of a pencil for example, it is advisable beforehand to apply to said external surface of the object a layer of a thermoreactive material. In this respect, and in accordance with the invention , the device comprises, with reference to Figures 1 and 2, a support 1 consisting on the one hand, of a fixed headstock frame 2 30 carrying a first centering tip 3 provided with a bowl 4 generally frustoconical capable of accommodating support means 5 for the object 6 and secured to the free end of the shaft 7 of an electric motor 8 powered by a battery 9, said shaft 7 being mounted on a ball bearing 10, and other part of a movable doll mount 11 mount é free in translation along guide means 12 integral with the fixed headstock frame 2, said movable headstock frame 11 carrying a second point -7 for centering 13 provided with a generally frustoconical bowl capable of accommodating support means 5 of the object 6 and secured to an axis 14 mounted on a ball bearing 15, said axis 14 being coaxial with the shaft 7 of the electric motor 5. The guide means consist, for example, in two tubes 12a and 12b extending parallel forming rails, integral with the fixed headstock frame 2 and crossing the movable headstock frame 11 through two parallel cylindrical passages 16 formed 10 in the movable headstock frame 11. The tubes 12a and 12b forming rails are advantageously obtained in carbon in order to lighten the device and to avoid their deterioration by deformation in particular during the drying of the lacquered object by infrared as will be seen further on. It will be observed that the distance separating the fixed headstock frame 2 and the movable headstock frame 11 can be adapted according to the length of the object positioned on the support device by sliding the movable headstock frame 11 along the tubes 12a and 12b.

  With reference to FIG. 3, the support means 5 consist of a generally frustoconical body 5a capable of being positioned in the cups of the centering points 3 or respectively 13 and of a rod 5b extending coaxially with said body 5a from its large base outwards. The body 5a advantageously comprises a magnetic strip 5c positioned on its small base in order to allow the support means 5 to be maintained in said bowl 4. Said rod 5b has a section of dimensions just slightly smaller than the internal dimensions 30 of the hollow object 6 to allow the threading of the latter on said rod 5b at each of its ends.

  Thus, advantageously several support means 5 will be provided having rods 5b of different sections so as to position hollow objects 6 of revolution 35 of any size and shape on the support device. It is obvious that the body 5a of the support means 5 can comprise on its large base an obviously coaxial with said body 5a in place of the rod 5b in order to allow the support of objects 6 of full revolution.

  The lacquering device, with reference to FIG. 4, comprises at least one tank 17 containing a fluid and thermoreactive lacquering material 18, two rolls known as calibrators 19 and 19 ′, driven in rotation about their axes 20 and, respectively 20 'counterclockwise and clockwise as indicated by arrows f and f'. The calibrating roller 19 is in contact with an application roller 21 driven in rotation about its axis 22 anticlockwise, as indicated by the arrow g, that is to say in opposite direction to the direction of rotation of the calibrating roller 19. The axes 20, 20 ′ and 22 15 of said calibrating and application rollers 19 and 21 are mounted to rotate freely on a frame 23 on which the support device 1 is able to bear of the object to be lacquered 6 so that the external surface of said object 6 is in contact with the application roller 21, the 20 axes 20,20 ', 22 of the rollers 19,19', 21 and the axis of revolution of object 6 to be lacquered extending in parallel.

  It is obvious that the device also comprises means for driving the rollers 19,21 of the belt and pinion type secured to the axes 20,22 of the said rollers 19,21 which are not shown in the figure so as not to not overload it. In addition, the lacquering device comprises means for laminating the lacquer, well known to those skilled in the art, not shown in the figure for reasons of clarity.

  In addition, the body of the application roller 21 is coated with an elastic material 24 such as rubber, silicone or the like and the rotational speed of the application roller 21 is equal to the rotational speed of the object 6 to lacquer driven in rotation 35 about its axis of revolution clockwise, as indicated by arrow h in FIG. 4, by the electric motor 8 in order to apply a layer of thermoreactive lacquering material 18 uniform over the entire external surface of the object 6.

  In order to print a graphic representation on the external surface of the object 6 thus lacquered, it is necessary beforehand to dry the thermoreactive lacquering material 18; in this regard, with reference to FIG. 5, the device according to the invention comprises a drying device consisting of a frame 25 on which is able to bear the support device 1 for the lacquered object 6 as described previously. Said support device 1 is positioned between four concave rectilinear reflectors 26 having a parabolic section at the focus of which are positioned rectilinear cylindrical infrared emitting sources 27, that is to say tubular infrared lamps powered by an electric source not shown in the figure, said reflectors being secured to the frame 25 so that the planes of focal symmetry 28, shown in phantom, of the reflectors 26 are concurrent along a straight line D which coincides with the axis of revolution of l lacquered object 6. Thus, the four reflectors 26 are respectively positioned in a quadrant of a reference frame consisting of two orthogonal planes of symmetry P1 and P2 whose center is coincident with the axis of revolution of the object 6. Each reflector 26 is, for example, made of a parallelepipedal aluminum block provided with a longitudinal groove of paraboliq section eu or elliptical whose internal wall has been polished.

  Incidentally, the outputs of the reflectors 26 are provided with filters 29 in order to avoid any damage to the corneas of the eyes of the operators present around the drying device. It will be noted that all the energy dispensed by the infrared tubular lamps 27 in the form of heat 35 is concentrated on the axis of revolution of the object 6, the latter being driven in rotation around its axis of revolution in the clockwise, for example, as indicated by arrow i, so that the drying of the object is uniform and extremely rapid, less than 30 seconds and preferably less than 10 seconds. It is quite obvious that the drying device 5 can comprise only two reflectors 26 whose planes of focal symmetry are non-parallel and concurrent along a straight line coincident with the axis of revolution of the lacquered object without leaving the frame of the invention.

  The object 6 lacquered and then dried, or else an object 6 obtained 10 in a thermoreactive material such as certain plastics, is then placed, with reference to FIG. 6, on a carriage 30 sliding on a horizontal rail 31 secured to a plate 32 of a frame 33. Said carriage 30 comprises on its upper face two rollers 34 and 35 mounted free in rotation around axes extending perpendicular to the rail 31 so that the object 6 is able to bear on said rollers 34 and 35.

  Furthermore, the frame 33 comprises two uprights 36 and 37 integral with the plate 32, said uprights respectively comprising a reel 38 on which a roller 39 of transfer tape is mounted for free rotation and a reel 40 on which is driven in rotation, step by step, an empty roller 41 around which the transfer band 42 is wound which is stretched between two tension rollers 43 and 44 respectively secured to the uprights 36 and 37 so that the transfer band 42 extends horizontally above of the carriage 30, the underside of said transfer strip 42 in contact with the object 6, the direction of travel of the transfer strip being parallel to the rail 31.

  In a particularly advantageous manner, the axes of said rollers 34 and 35 are mounted on means 34 'and respectively 35' allowing the rollers 34, 35 to be tilted vertically and / or separated so that the object 6 is in contact with the underside of the transfer belt over its entire length. It will thus be noted that the spacing of the rollers will depend on the dimensions of the object 6 and that the rollers 34, 35 will be inclined for - there objects of frustoconical shape for example.

  It is obvious that the articulated arms 34 ′ and 35 ′ can be replaced by any other equivalent means without departing from the scope of the invention.

  With reference to FIG. 7, the transfer strip 42 consists of a support strip 45 one of the faces of which, in this case the underside, is covered with a thin layer 46, of the order of 1 to a few microns, of a heat-sensitive material, such as a thermo-adhesive for example, on which graphic representations are printed by a digital printing means.

  Furthermore, thermal means such as a thermoresistor 47 sliding on a vertical rail 48 is positioned above the transfer band 42, said thermoresistor being able to be moved vertically so as to bear on the upper face of the band transfer 42.

  It will be observed that the drive means of the carriage 30, the reel 40 and the thermoresistor 48 have not been shown for obvious reasons of clarity of the figure; however, they may consist of any suitable means such as hydraulic, pneumatic or electric cylinders, belt and pinion or rack and pinion means, electric motors or the like.

  The operation of the printing device will now be explained with reference to FIG. 6.

  An object 6 being positioned on the rollers 34, 35 of the carriage 30 and a graphic representation of the transfer band 42 being positioned in line with the heat resistance 47, the latter is lowered along its rail 48 until it is in contact with the upper face of the transfer band 42 then the carriage 30 is moved horizontally from left to right 35 along its rail 31 thus rolling the external surface of the object on the underside of the band of transfer 42. Under the effect of heat, the graphic representation is detached from the transfer band 42 and - 12 is fixed on the external surface of the object 6. The heat resistance 47 is then raised, then the carriage is moved from right to left to return to its initial position o the object 6 provided with its printing is removed. The transfer belt 42 is then driven by the reel 40 until a new graphic representation is at the right of the thermoresistor 47 ready for a new cycle.

  It will be noted that by limiting the movement of the carriage 30, the graphic representation can advantageously be printed only on a part of the circumference of the object 6 of revolution.

  Finally, it goes without saying that the printing process and the devices implementing the process can be adapted to all objects of revolution and that the examples which have just been given are only particular illustrations in any case. limiting as to the fields of application of the invention.

SLO-FR-1.OOA - 13

Claims (15)

  1 - Method of printing a graphic or similar representation such as a logo or an advertising message on an object (6) hollow or full of revolution such as the tube of a pen or the body of a pencil by 5 example characterized in that it proceeds at least in the following successive steps of - printing the graphic representation on one side of a transfer tape (42) by a digital printing process, then - progressive transfer onto the surface of the object (6) of the graphic representation previously printed on said transfer tape (42).   2 - printing method according to the preceding claim characterized in that it comprises, prior to the step of transferring the graphic representation, the method according to the invention comprises at least the following steps of: - application of a thermoreactive material (18) on the external surface of the object (6) on which the graphic representation is to be printed, then - drying of the thermoreactive material (18) applied to the object (6).   3 - Printing process according to claim 2 characterized in that the step of applying the thermoreactive material (18) consists successively in - positioning the object (6) on a support (1), then - driving the object (6) in rotation around its axis of revolution, and finally - bringing the external surface of the object (6) driven into rotation around its axis of revolution into contact with a roller application (21) of the thermoreactive material (18), said application roller (21) being in contact with a feed roller (19) immersed in the thermoreactive material (18).   4 - A printing method according to claim 3 characterized in that the application roller (21) of the SLO-FR-1. OA - 14 thermoreactive material (18) is rotated in the opposite direction to the direction of rotation of the object (6) at the same rotational speed as that of the object (6).   - Printing method according to any one of claims 5 or 4 characterized in that, the object (6) being positioned on the support (1), the drying step consists in rotating the object ( 6) around its axis of revolution positioned so that it coincides with the line of intersection of at least two emission planes 10 of infrared radiation.   6 - Printing method according to any one of the preceding claims, characterized in that the step of progressive transfer onto the surface of the object (6) of the graphic representation consists in applying the external surface of the object ( 6) driven in rotation about its axis of revolution on a face of the transfer band (42) driven in translation tangentially to the external surface of the object (6), a heat source (47) being applied to the face opposite of said transfer belt (42).   7 - Printing method according to any one of claims 1 to 5 characterized in that the step of progressive transfer onto the surface of the object (6) of the graphic representation consists in applying the external surface 25 of the object (6) on one side of the transfer tape (42), a heat source (47) being applied to the opposite side of said transfer tape (42), and moving the object along the tape transfer (42) so that said object (6) is rotated 30 about its axis of revolution.   8 - Transfer tape (42) for printing a graphic representation on the external surface of an object (6) hollow or full of revolution and of any size such as the tube of a pen or the body of a pencil by example, implementing the method according to any one of claims 1 to 7, characterized in that said transfer strip (42) consists of a support strip (45) covered with a material SLO-FR-1 .OOA - 15 thermosensitive (46) on which graphic representations are printed by digital printing means. 9 Device for printing a graphic representation 5 on the external surface of an object (6) hollow or full of revolution and of any size such as the body of a pen for example, implementing the method according to any one of Claims 1 to 7, characterized in that it comprises on the one hand a carriage (30) 10 provided with means for supporting the object (6) and able to move in translation in the same direction of travel of a transfer strip (42) on which the graphic representation is printed, said transfer strip (42) being unwound step by step by drive means above said carriage (30), and on the other hand thermal means (47) positioned above the transfer strip (42) and able to bear on the upper face of said strip (42), the object (6) then being in contact with the lower face of the strip (42 ).   10 - Device according to claim 9 characterized in that the object support means (6) consist of two rollers (34,35) mounted free in rotation on the carriage (30) around axes extending perpendicularly to the direction of travel of the transfer belt so that the object (6) is able to bear on the rollers (34,35).   11 - Device for lacquering an object (6) hollow or full of revolution and of any size, such as the tube of a pen or the body of a pencil for example, implementing the method according to any one of the Claims 2 to 7, characterized in that it comprises a support (1) consisting on the one hand, of a fixed headstock frame (2) carrying a first centering point (3) provided with a bowl (4) generally frustoconical integral with the free end of the shaft (7) of a motor (8) and capable of receiving support means (5) of the object (6), said shaft (7) being mounted on a ball bearing (10), and on the other hand, a movable headstock frame (11) freely mounted SLO-FR-1. OOA - 16 in translation along guide means (12) integral with the fixed headstock frame (2), said movable headstock frame (11) carrying a second centering tip (13) provided with a bowl (4) generally frustoconical integral 5 with an axis (14) mounted on a ball bearing (15) and capable of receiving support means (5) of the object (6), said axis (14) being coaxial with the shaft ( 7) of the motor (8).   12 - Device according to claim il characterized in that the guide means (12) consist of two tubes (12a, 12b) extending in parallel forming rails, integral with the fixed headstock frame (2) and passing through the frame of movable headstock (11) through two parallel cylindrical passages (16) formed in the movable headstock frame (11).   13 - Device according to claim 12 characterized in that the tubes (12a, 12b) forming rails are obtained in carbon.   14 - Device according to any one of claims 11 to 13 characterized in that it comprises a tank (17) containing a lacquering material (18) fluid, a feed roller (19) immersed in the lacquering material (18), driven in rotation about its axis (20) and in contact with an application roller (21) driven in rotation around its axis (22) in the opposite direction to the direction of rotation of the feed roller ( 19), the axes (20, 22) of said supply (19) and application (21) rollers being mounted free in rotation on a frame (23) on which is able to bear the support (1) of the object (6) to be lacquered so that the external surface of said object (6) is in contact with the application roller (21), the axes (20,22) of the rollers (19,21) and the axis of revolution of the object to be lacquered extending generally parallel.   - Device according to claim 14 35 characterized in that the body of the application roller (21) is coated with an elastic material (24) such as rubber, silicone or the like.   16 - Device according to any one of SLO-FR-1.OOA - 17 claims 14 or 15 characterized in that the rotational speed of the application roller (21) is equal to the rotational speed of the object (6) . to lacquer.   17 - Device for drying an object (6) lacquered hollow 5 or full of revolution and of any size, such as the body of a pen for example, said device comprising concave rectilinear reflectors (26) having a parabolic section or elliptical at the focus of which are positioned emitting sources (27) cylindrical 10 rectilinear, infrared or the like, said device implementing the method according to any one of claims 1 to 7, characterized in that it comprises a frame (25 ) on which is able to bear a support (1) of the lacquered object (6) and on which said reflectors (26) are secured so that the planes of focal symmetry of the reflectors (26) are concurrent in a right (D) which coincides with the axis of revolution of the lacquered object (6).   18 - Device according to claim 17 characterized in that it comprises four reflectors (26) respectively positioned in a quadrant of a frame consisting of two planes (P1, P2) orthogonal of symmetry.