Patent Publication Number: US-2023138399-A1

Title: Machine for drying inks of the uv type

Description:
TECHNICAL FIELD 
     The present disclosure relates to a machine for drying inks of the UV type. 
     BACKGROUND 
     As is known, in the industrial printing sector, particularly in the sector of the screen printing of containers, printing machines, commonly called “semiautomatic” machines, are currently used and marketed which are generally not provided with devices for drying the inks. 
     These machines are very widespread and are used since they provide fast and economical change of format, allowing to work on small samples or runs. 
     However, the lack of devices that allow to dry the inks immediately forces to use such machines only with inks of the solvent-based type, with consequent long times of execution of the related production processes and a printing quality that is not always satisfactory. 
     In fact, the production processes in which solvent-based inks are used require that after printing the operator stores the printed object in a storage area where the ink is left to dry in contact with the air for a time that can last up to 24 hours. 
     In other cases, the operator stores the printed objects in a carriage that is subsequently placed in a hot air oven, where the drying of the inks is obtained in few hours. 
     In an attempt to obviate these problems, solutions have been also proposed which entail the use of inks of the UV type which are dried by means of traditional UV lamps, particularly quartz and mercury or mercury and halide UV lamps, applied on the printing machines or arranged in their immediate vicinity. 
     The use of these lamps, however, affects negatively the overall dimensions of the machines and their convenience in use, since it entails the need to provide bulking housings to protect the operators from UV rays. 
     Furthermore, these lamps produce a large amount of heat and therefore need extraction systems to extract the heat and the ozone generated by them. 
     SUMMARY 
     The aim of the present disclosure is to provide a machine for drying inks of the UV type that is capable of improving the background art in one or more of the above mentioned aspects. 
     Within this aim, the disclosure provides a machine for drying inks of the UV type that is compact, so that it can be placed to the side of the printing machine, in order to allow the operator to use both machines from a single station. 
     The disclosure also provides a machine for drying inks of the UV type that is versatile, so as to not require further accessories for changing format, and can be of high productivity in order to be able to work at the current working rates of printing machines. 
     The disclosure further provides a machine for drying inks of the UV type that can dry the UV inks with reduced consumption and with a reduced environmental impact. 
     The disclosure provides a machine for drying inks of the UV type that is capable of ensuring maximum protection to the operators against UV rays. 
     Furthermore, the present disclosure overcomes the drawbacks of the background art in a manner that is alternative to any existing solutions. 
     The disclosure also provides a machine for drying inks of the UV type which, besides being capable of offering the greatest assurances of reliability and safety in operation and in use, can also be relatively easy to provide so as to be competitive also from a purely economic standpoint. 
     This aim and these and other advantages which will become better apparent hereinafter are achieved by providing a machine for drying inks of the UV type according to claim  1 , optionally provided with one or more of the characteristics of the dependent claims 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further characteristics and advantages of the disclosure will become better apparent from the description of a preferred but not exclusive embodiment of the machine according to the disclosure, illustrated by way of non-limiting example in the accompanying drawings, wherein: 
         FIG.  1    is a perspective view of the machine according to the disclosure; 
         FIG.  2    is a top plan view of the machine according to the disclosure; 
         FIG.  3    is a lateral elevation view of the machine according to the disclosure; 
         FIG.  4    is a front elevation view of the machine according to the disclosure; 
         FIG.  5    is a perspective view of the machine according to the disclosure with the closing doors of an exposure chamber in the open condition; 
         FIG.  6    is a partially cutaway lateral elevation view of the machine according to the disclosure; 
         FIG.  7    is a lateral elevation view of a carriage of the machine according to the disclosure; 
         FIG.  8    is an exploded perspective view of the carriage of  FIG.  5   ; 
         FIG.  9    is a lateral elevation view of a detail of the carriage of the machine according to the disclosure; 
         FIG.  10    is a sectional view taken along the plane VII-VII of  FIG.  7   ; 
         FIG.  11    is an exploded perspective view of a pan for supporting the printed objects of the machine according to the disclosure; and 
         FIG.  12    is an exploded perspective view of a portion of the pan. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     With reference to the figures, the machine for drying inks of the UV type, according to the disclosure, generally designated by the reference numeral  1 , comprises a supporting frame  2 , which forms at least one exposure chamber  3 , which can be accessed from the outside and accommodates inside at least one UV ray emission source  4 . 
     According to the disclosure, at least one carriage  5  is mounted on the supporting frame  2  and supports rotatably at least one supporting pan  6  for at least one object to be processed, such as for example a container or other type of object, which is provided, on its surface, with at least one print provided by means of UV inks, previously applied to the object to be processed, for example by a semiautomatic printing machine positioned conveniently in the vicinity of said machine according to the disclosure. 
     Again, according to the disclosure, there are means  7  for the rotational actuation of the pan  6  about its own axis in order to allow to rotate the object to be processed loaded on the pan  6 . 
     In particular, the carriage  5  can move with respect to the supporting frame  2  so as to be able to move the pan  6  from an exposure position, in which the pan  6  is arranged inside the exposure chamber  3 , in order to allow the execution of at least one step or cycle of drying of the UV inks by means of the exposure of the UV inks applied to the surface of the object to be processed arranged on the pan  6  to the UV rays emitted by the emission source  4 , to at least one respective access position, in which the pan  6  is arranged outside the exposure chamber  3 , in order to allow the loading of the object to be processed on the pan  6  or the unloading of the processed object, after its exposure to UV rays in the exposure chamber  3 , from said pan. 
     For example, in the access position of the pan  6  manual access to the pan  6  by a human operator is allowed, and said operator can thus manually provide, in each instance, for the loading on the pan  6  of an object to be processed on which said operator has previously applied printing with UV inks by means of an adjacent semiautomatic printing machine, so as to dry the UV inks following the subsequent movement of the carriage  5  with consequent movement of the pan  6  and of the object to be processed thereon in the exposure position. 
     More particularly, the rotational actuation means  7  of the pan  6  can be activated on command, at least when the pan  6  is in the exposure position. 
     Advantageously, the pan  6  comprises means for the centering and locking of the object to be processed with respect to the pan  6 , better described hereinafter, which allow the centering with respect to the axis of the pan  6  of any type of object to be processed, ensuring, at the same time, its appropriate retention in position in order to avoid its tipping during the drying cycle. 
     Conveniently, in order to allow high performances and a high production rate, it is possible moreover to provide means  8  for the automatic unloading of the processed object from the pan  6 , which can be activated on command when the pan  6  is in the access position, in order to allow the unloading of the processed object from the pan  6  without the need for a manual intervention by the human operator. 
     According to the preferred embodiment of the machine according to the disclosure, shown in the figures, the carriage  5  supports rotatably at least two supporting pans  6 , respectively at least one first pan  6   a  and at least one second pan  6   b,  each designed to support at least one respective object to be processed. 
     In this case, the carriage  5  is movable with respect to the supporting frame  2 , so that alternately one of the pans  6   a,    6   b  is in the exposure position and simultaneously the other pan  6   a,    6   b  is in the access position. 
     More particularly, the carriage  5  can, advantageously, move by translation, with an alternating back and forth motion, along a movement trajectory, between at least two stroke limit positions, respectively a first stroke limit position  9   a  and a second stroke limit position  9   b,  arranged at the opposite ends of the movement trajectory of the carriage  5 . 
     Again with reference to the illustrated embodiment, the exposure chamber  3  is formed advantageously in an intermediate region along the movement trajectory, between the first and second stroke limit positions  9   a  and  9   b  of the carriage  5 . 
     Conveniently, the pans  6   a  and  6   b  are arranged so as to be mutually aligned along a direction that is substantially parallel to the movement trajectory of the carriage  5 . 
     In particular, when the carriage  5  is in the first stroke limit position  9   a  the first pan  6   a  is in the corresponding access position and the second pan  6   b  is in the exposure position, while when the carriage  5  is in the second stroke limit position  9   b  the first pan  6   a  is in the exposure position and the second pan  6   b  is in the corresponding access position. 
     This solution allows the machine according to the disclosure to reach a high productivity with small space occupation, so as to be able to arrange the machine according to the disclosure conveniently to the side of the printing machine, thus allowing an operator to manually intervene, from a single station, on both machines, with consequent advantages also for the ergonomics of the repeated movement that said operator will have to perform manually with his arms several times over time. 
     It should be noted that the opposite sides of the exposure chamber  3  arranged along the movement trajectory of the carriage  5  are conveniently provided with respective access openings  3   a,  which allow the entry and exit of the carriage  5  and of the objects arranged on the respective pans  6   a  and  6   b  with respect to the exposure chamber  3 , and can be closed, during each cycles for drying the UV inks that occurs in the exposure chamber  3 , by means of respective protective doors  10 . 
     Conveniently, in order to keep the dimensions of the machine compact, the protective doors  10  are slidingly mounted on guides  11  and are actuated by automatic movement means. 
     Advantageously, the protective doors  10  are made of PMMA acrylic material, which is substantially transparent and of orange color, so as to reduce the glare of the UV radiation that otherwise would be unpleasant. 
     In this manner, the operator is capable of supervising the whole drying inside the exposure chamber  3  without being exposed to the UV radiation emitted by the emission source  4 . 
     More particularly, the protective doors  10  may, for example, be made of the material commercially known as ALTUGLASS 100.1500, which is specific for use with UV light, since it allows to filter UV radiation. 
     It should be noted that the UV ray emission source  4  in the exposure chamber  3  is advantageously constituted by at least one ultraviolet LED lamp  12  which, besides allowing the possibility to dry substantially instantly solvent-free inks by exposure to UV rays, offer considerable advantages both from the energy standpoint, due to their reduced consumption, and from the environmental standpoint, since they are free from mercury or other dangerous substances and do not emit ozone. 
     In the exposure chamber, the lamp  12  is mounted on a slider  12   a  which can be actuated in motion by means of a first worm screw  13   a,  which extends along a direction that is substantially parallel to the axis of the pans  6   a  and  6   b  and allows its optimum adjustment in height in the region to be dried. 
     In particular, said height adjustment of the position of the lamp  12  is provided by means of a first knob  14   a,  arranged outside the exposure chamber  3 , which acts on the first worm screw  13   a.    
     As shown in  FIG.  6   , the position of the lamp  12  can be adjusted also along a direction that is substantially at right angles to the axis of the pans  6   a ,  6   b,  preferably by means of a second worm screw  13   b  which can be operated by means of a second knob  14   b,  also arranged outside the exposure chamber  3 . 
     Advantageously, the centering and locking means comprise, for the pan  6  or each pan  6 , at least one sucker element  15 , for example made of silicone rubber, which is arranged axially with respect to the corresponding pan  6  and delimits a region which communicates with a suction duct  16  for connection to a vacuum source, not shown. 
     Conveniently, the centering and locking means of each pan  6  comprise moreover a plurality of claws  17  which protrude upward from the corresponding pan  6  and are designed to make contact with the object to be processed, which is arranged on the corresponding pan  6 . 
     The claws  17  are movable on command toward or away from the axis of the corresponding pan  6  in order to pass from a disengagement position, in which they are spaced from the object to be processed, to a retention position, in which they are arranged in contact with the object to be processed, and vice versa. 
     More particularly, each one of the pans  6  comprises a respective pair of plates, conveniently of a substantially disc-like shape, which are mutually superimposed and respectively constituted by an upper plate  18   a  and a lower plate  18   b.    
     The upper plate  18   a  has first sliding seats  19   a,  substantially shaped like a slot, which are each engaged by a respective claw  17  and extend, with a circular arc-like extension, in a direction that is substantially radial with respect to the axis of the corresponding pan  6 . 
     In turn, the lower plate  18   b  has, for each one of the first sliding seats  19   a,  a respective second sliding seat  19   b  engaged by the same claw  17  that engages the corresponding first sliding seat  19   a  in the upper plate  18   a.    
     The second sliding seats  19   b  extend in a substantially radial direction with respect to the axis of the corresponding pan  6  with a circular arc-like extension with the concavity directed oppositely with respect to the concavity of the corresponding first sliding seat  19   a.    
     In this manner, the claws  17  are movable along the corresponding first sliding seat  19   a  following a rotation, in one direction or the other, of the first plate  18   a  with respect to the second plate  18   b,  about an axis that is substantially parallel to the axis of the corresponding pan  6 . 
     In greater detail, the claws  17  can be constituted by respective knurled knobs  20 , axially crossed by a threaded hole  20   a,  in which respective threaded pivots  21  are screwed which respectively engage the first and second sliding seats  19   a  and  19   b  of the corresponding claw  17  and have a respective wider head  21   a  designed to abut against the face of the lower plate  18   b  which is directed opposite with respect to the upper plate  18   a.    
     In order to adjust the position of the claws  17  with respect to the axis of the corresponding pan  6  it is sufficient for the operator to loosen the claws  17 , by unscrewing the corresponding knurled knob  20  from the respective threaded pivot  21 , so as to unlock the possibility of relative rotation between the upper plate  18   a  and the lower plate  18   b,  about the axis of the corresponding pan  6 , and then rotate the upper plate  18   a  with respect to the lower plate  18   b,  about the axis of the corresponding pan  6 , so as to allow the threaded pivots  21  of the claws  17  to slide along the first and second sliding seats  19   a  and  19   b.    
     Once the position of the claws  17  has been adjusted at the desired distance from the axis of the corresponding pan  6 , it is sufficient for the operator to tighten the claws  17  by screwing the knurled knobs  20  along the threaded pivots  21  in order to block the claws  17  and the possibility of relative rotation between the upper plate and the lower plate  18   a  and  18   b.    
     In this manner it is possible to adjust the centering of the objects to be processed that have the most widespread diameters without the aid of accessories. 
     With reference, particularly, to  FIGS.  7  and  8   , the carriage  5  comprises a base body  22  mounted so it can slide along longitudinal guides  24   a,    24   b  on a face that is directed upward of a supporting plate  23 , which is fixed to the supporting frame  2 . 
     Substantially at its opposite ends arranged along a direction that is substantially parallel to the longitudinal guides  24   a  and  24   b,  the base body  22  of the carriage  5  supports, so as to allow rotation about the corresponding axes, the first and the second pans  6   a  and  6   b.    
     The actuation in motion of the base body  22  of the carriage  5  along the longitudinal guides  24   a  and  24   b  is provided by a closed-loop flexible motion transmission element  25 , such as for example a belt or the like, which is extended between at least a motorized pulley  26 , connected to a driving motor  27 , and a driven pulley  28 , so as to define at least one active portion  25   a  for moving the base body  22  of the carriage  5 , which is fixed to said base body. 
     Conveniently, the motorized pulley  26  is supported, with the corresponding movement motor  27 , by a housing  26   a,  which is fixed to the supporting plate  23 , on which an auxiliary guiding pulley  26   b  also can be optionally mounted so that it can rotate and has a diameter that substantially corresponds to that of the driven pulley  28 , engages the motion transmission element  25  and is arranged so that the corresponding axis is substantially parallel and spaced from the axis of the driving pulley  26 . 
     In particular, the flexible motion transmission element  25  extends below the supporting plate  23  and conveniently the actuation unit  26  and the guiding pulley  28  are supported by the face of the supporting plate  23  that is directed downward. 
     More particularly, the base body  22  is connected to the active portion  25   a  of the flexible motion transmission element  25  with a connecting portion  22   a  thereof, which passes through a through slot  29 , formed in the supporting plate  23 , between the longitudinal guides  24   a  and  24   b,  for example by means of connection elements  30 , which form, on the active portion  25   a  of the flexible motion transmission element  25 , folds or bends  30  at its points for fixing to the base body  22 . 
     It should be noted that conveniently on the supporting plate  23  it is possible to fix, at the opposite ends of the longitudinal guides  24   a  and  24   b , stroke limit sensors  27   a,    27   b,  functionally connected to the movement motor  27 , which are designed to detect the reaching, by the base body  22 , of the corresponding positions that correspond to the stroke limit positions  9   a  and  9   b  of the carriage  5  and to send a corresponding signal to the movement motor  27  to command its halting and the reversal of the direction of the rotation after a preset time. 
     A covering casing  32  can be conveniently fixed above the base body  22  of the carriage  5  and is provided with circular openings  33   a  and  33   b  through which the first and the second pans  6   a  and  6   b  are respectively accessible from outside. 
     Two lateral closure walls  34  are fixed at the ends of the supporting plate  23  arranged along a direction that is substantially parallel to the direction of extension of the longitudinal guides  24   a  and  24   b,  and are substantially at right angles to the face directed upward of the supporting plate  23 . 
     Bellows-like covering elements  35  can be interposed between the covering casing  32  and the lateral closure walls  34 . 
     As shown in particular in  FIGS.  10  and  11   , each pan  6   a  and  6   b  is axially fixed, for example by means of a flange  36 , to an axial end  37   a  of a respective hollow shaft  37  which, in turn, is conveniently mounted so that it can rotate in a bushing  38 , which is fixed to the base body  22 , advantageously by means of the interposition of a pair of bearings  39 . 
     The rotational actuation, with respect to the base body  22 , of the hollow shaft  37  about its axis and therefore of the corresponding pan  6   a,    6   b  about the corresponding axis is, for example, provided by means of a first gear  40 , which is keyed on the hollow shaft  36  and is functionally connected to an actuation motor  41  conveniently by means of a belt drive element  42  that is extended between the first gear  40  and a second gear  43 , which in turn is keyed on the output shaft  41   a  of the actuation motor  41 . 
     Preferably, the actuation motors  41  of both pans  6   a  and  6   b  are of the step type and are controlled by a respective control unit managed by a suitable software. 
     This solution offers the possibility of precise control of the rotation of the pans  6   a,    6   b,  so as to allow the possibility to introduce in the exposure chamber  3  even objects to be processed that have protrusions. 
     Advantageously, the hollow shaft  37  passes through a central hole  44  which is formed in the corresponding pan  6  and in practice is provided by two axial holes  44   a  and  44   b  which are mutually aligned and are formed respectively in the upper plate  18   a  and in the lower plate of the pan  6   a  and  6   b , so that its axial end  37   a  is directed outward. 
     More particularly, a recess  45  is formed axially in the hollow shaft  37 , is open at the axial end  37   a  of the hollow shaft  37  and accommodates the sucker element  15 , while the suction duct  16  is connected to the other axial end  37   b  of the hollow shaft  37  and is in communication with the sucker element  15 . 
     Preferably, as shown particularly in  FIG.  10   , the sucker element  15  is provided by a bellows-type sucker  15   a,  which is provided peripherally with two folds which allow its compression in an axial direction. 
     In particular, with this structure, when the sucker  15   a,  as a result of the vacuum created inside it via the suction duct  16 , grips the object to be processed which is arranged on the corresponding pan  6   a,    6   b,  by virtue of its particular structure, it compresses, in this way retaining the object to be processed toward the pan  6   a,    6   b  and thus ensuring a stable grip for the entire drying cycle. 
     In order to obtain this effect in the best way depending on the object to be processed, the sucker  15   a  is assembled to the hollow shaft  37  by means of a screw  46  which is crossed axially by a passage  47 , which allows to connect the internal cavity of the sucker  15   a  to the vacuum source, through the suction duct  16 . 
     In particular, the head  46   a  of the screw  46  rests against the bottom of the internal cavity of the sucker  15   a,  while its threaded stem  46   b  is screwed into an axial female thread  48  formed in the hollow shaft  37 , so that by screwing or unscrewing the screw  46  with respect to the female thread  48  it is possible to provide the height adjustment of the sucker  15   a.    
     It should be noted that the degree of vacuum obtained in the sucker  15   a  and therefore its grip strength can be adjusted conveniently by a not shown pressure regulator interposed along the suction duct  16 . 
     With reference again to the preferred embodiment shown in the figures, substantially at each one of the stroke limit positions  9   a  and  9   b  of the carriage  5  there are advantageously corresponding automatic unloading means  8 . 
     In particular, the automatic unloading means  8  arranged at the first stroke limit position  9   a  are adapted to act on the processed objects arranged on the first pan  6   a,  when the carriage  5  reaches the first stroke limit position  9   a,  while the automatic unloading means  8  arranged at the second stroke limit position  9   b  are adapted to act on the processed objects arranged on the second pan  6   b,  when the carriage  5  reaches the second stroke limit position  9   b.    
     More particularly, the automatic unloading means  8  comprise pusher means capable of producing, on the processed object arranged on the corresponding pan  6   a,    6   b,  a thrust in the direction of a respective unloading chute  49  which is provided on the supporting frame  2  and extending, conveniently, laterally to the region affected by the movement of the carriage  5  and on the opposite site with respect to the corresponding pusher means, along a direction substantially at right angles to the trajectory of movement of the carriage  5 , in order to allow the conveyance by gravity of the processed objects, expelled by the respective pusher means from the corresponding pan  6   a  and  6   b,  into an adapted collection tank, not shown. 
     In greater detail, the pusher means are advantageously each provided by a device for the emission of at least one jet of compressed air directed toward the corresponding pan  6   a,    6   b.    
     Conveniently, each emission device includes at least one respective nozzle  50 , which can be provided by a tubular element, supported by the supporting frame  2 , which extends substantially parallel and laterally to the trajectory of movement of the carriage  5  and has on its own lateral surface at least one outlet for the compressed air. 
     The advantage of the use of a device for the emission of a jet of air in order to provide the pusher means, instead of mechanical elements, is to provide the unloading of the processed objects from the pans  6   a  and  6   b  at a higher speed, with consequent higher productivity, and with a reduction of space occupation. 
     Conveniently, each nozzle  50  provides for suitable adjustments for optimizing the unloading depending on the objects to be processed. 
     A first possible adjustment of each one of the nozzles  50  is of the mechanical type and is provided by rotation of said nozzle about its own axis, in order to direct the jet of air in the best way, especially in presence of objects of small size; the second adjustment of each nozzle  50  can be performed by a pressure adjustment device arranged in the pneumatic supply circuit of said nozzle, which allows to adjust the pushing force of the emitted air jet; the third adjustment that can be performed on each one of the nozzles  50  includes the possibility to vary the duration in seconds of the jet of air emitted by said nozzles. 
     By means of these adjustments it is possible to unload from the pans  6   a  and  6   b  any object in a controlled manner, preventing the objects from being both accidentally retained on the machine and propelled to the ground by falling outside the chutes  49  or, in any case, the collecting tank. 
     Advantageously, on the supporting frame  2  there is a data setting and control panel  51 , which is connected functionally to an electronic control and command unit of the machine, which allows the operator to set various operating parameters of the machine. 
     In particular, in the common case in which the objects to be processed have a cylindrical shape, the operator may, for example, set on the panel  51  the cycle of rotation of the pans  6   a,    6   b,  i.e., the parameters related to the number of revolutions of each pan  6   a  and  6   b  and to the rotation rate with which these revolutions must be performed by each pan  6   a  and  6   b.    
     Experimental tests have allowed to determine the combination between number of revolutions of the pans  6   a  and  6   b,  rotation rate of said pans and intensity of the UV radiation emitted by the emission source  4  that allows to provide the perfect drying of the UV inks applied to the printed surface of the objects to be processed. 
     In the case of objects with protrusions, such as for example a cup with a handle, the possible small distance between the lamps  12  and the object would instead risk causing a collision between the rotating object on the corresponding pan  6   a,    6   b  and the lamp  12 , preventing the possibility to rotate the object through 360°. 
     In this case, by virtue of the panel  51  the operator can set a cycle with alternate rotation of the pans  6   a,    6   b,  i.e., setting, for the pans  6   a  and  6   b,  a partial rotation expressed in degrees, actuated in one direction and in the other, so as to be able to dry the printed region of the objects without them colliding against the lamp  12 . 
     The operation of the machine, according to the disclosure, is as follows. 
     Once the appropriate settings of the machine have been performed by means of the panel  51 , with the carriage in the first stroke limit position  9   a , the operator arranges on the first pan  6   a  an object to be processed on which printing with UV inks has been applied in a printing machine. 
     At this point, the operator activates the means for centering and locking the object to be processed on the first pan  6   a.    
     In particular, in order to do this, the operator loosens the claws  17  of the first pan  6   a,  by unscrewing the knurled knobs  20  from the threaded pivots  21 , and rotates the upper plate  18   a  of the first pan  6   a  with respect to the lower plate  18   b,  so as to make the claws  17  slide along the first sliding seats  19   a  until they are arranged in contact with the object to be processed. 
     At this point the operator tightens the claws  17  by screwing the knurled knobs  20  on the threaded pivots  21  so as to lock the claws  17  in the position of contact with the object to be processed. 
     The operator then operates the vacuum source so as to cause the activation of the sucker element  15  of the first pan  6   a,  thus obtaining a suitable retention of the object to be processed on the first pan  6   a.    
     At this point, after opening the protective doors  10  of the exposure chamber  3 , the carriage  5  is actuated, so as to bring it from the first stroke limit position  9   a  to the second stroke limit position  9   b,  with consequent movement of the first pan  6   a  with the corresponding object to be processed in the exposure chamber  3  and simultaneous movement of the second pan  6   b  in the corresponding access position. 
     At this point the protective doors  10  of the exposure chamber  3  are closed. 
     While it is in the exposure chamber  3 , the first pan  6   a  is rotated about its own axis, so as to produce the rotation of the object to be processed that is arranged thereon, and at the same time the lamp  12  is activated, so that the object to be processed can receive the UV radiation on its lateral surface with consequent drying of the UV inks. 
     Also while the first pan  6   a  is in the exposure chamber  3 , the operator positions on the second pan  6   b  another object to be processed and, in a manner similar to what he did on the first pan  6   a,  performs the centering and locking on the second pan  6   b  of the corresponding object to be processed. 
     Once the drying cycle of the object arranged on the first pan  6   a  has ended, the protective doors  10  of the exposure chamber  3  are opened and the carriage  5  is moved again into the first stroke limit position  9   a,  so as to bring the first pan  6   a,  with the processed object arranged thereon, into the corresponding access position, and the second pan  6   b,  with the corresponding object to be processed, into the exposure chamber  3 . 
     At this point the protective doors  10  are closed again. 
     While it is in the exposure chamber  3 , the second pan  6   b  is rotated about its own axis, so that the corresponding object to be processed is also rotated, and at the same time the lamp  12  is activated, so as to perform the drying cycle also on the object to be processed that is arranged on the second pan  6   b.    
     In the meantime, the means for the automatic unloading of the processed object arranged on the first pan  6   a  are activated. 
     In particular, when the carriage  5  reaches the first stroke limit position  9   a  and therefore the first pan  6   a  reaches the corresponding access position, after exiting from the exposure chamber  3 , the connection between the vacuum source and the sucker element  15  of the first pan  6   a  is interrupted, so that the processed object is no longer retained by the sucker element  15 . 
     The nozzle  50  that corresponds to the first stroke limit position  9   a  of the carriage  5  is then fed so as to strike the processed object arranged on the first pan  6   a  with a jet of compressed air which causes it to fall toward the corresponding chute  49  from which it reaches the collecting tank. 
     At this point, the first pan  6   a  is again ready to receive from the operator a new object to be processed, which is centered and locked on the first pan  6   a  by virtue of the corresponding centering and locking means, similarly to what has been described before. 
     Once the drying cycle of the object to be processed arranged on the second pan  6   b  has ended, the protective doors  10  are opened and the carriage  5  is actuated again in order to move it into the second stroke limit position  9   b , so as to bring the second pan  6   b,  with the processed object positioned thereon, into the corresponding access position and the first pan  6   a,  with the new object to be processed positioned thereon, into the exposure position. 
     While a new drying cycle of the object to be processed arranged on the first pan  6   a  occurs, the processed object arranged on the second pan  6   b  is unloaded by the corresponding automatic unloading means, by means of the activation of the nozzle  50  arranged at the second stroke limit position  9   b,  so as to free again the second pan  6   b  and thus make it ready again to receive from the operator a further object to be processed. 
     At this point, the operation of the machine may continue as described above. 
     In practice it has been found that the disclosure achieves the intended aim and objects, a machine for drying inks of the UV type having been provided which is compact and has a high performance. 
     A particular advantage of the machine according to the disclosure resides in that, by virtue of the centering and locking means provided on the pans with the sucker element arranged axially, it is possible to obtain a correct and safe grip of the objects to be processed on the pans, without the need for accessories for format change. 
     It should be noted, moreover, that the possibility to adjust the position of the lamp  12  in the most correct position allows an efficient and fast drying of the inks. 
     It should be noted that the use of sliding and transparent doors of the drying chamber allows a view of the object being dried while keeping the machine safe, according to current regulations, without having to resort to bulky tunnels or protections in order to keep the UV radiation inside the exposure chamber. 
     Another aspect to be pointed out is that by virtue of its small dimensions, the machine according to the disclosure is easy to position to the side of the printing machines, thus allowing the operator to work ergonomically both on the printing machine and on the machine according to the disclosure from the same station. 
     It is also noted that the fact of providing two pans on the carriage allows the machine to reach high production levels, reaching up to 900/1000 pieces/hour. 
     It is also possible to provide the possibility for the user to choose the use of only one of the two pans, particularly the one that is easier to reach for its position, leaving the other locked in rotation and unused. 
     The use of the machine according to the disclosure in the sector of screen printing allows to avoid the use of solvent-based inks, which are harmful to the health and the environment. 
     It should also be added that the use in the machine according to the disclosure of lamps with UV-LED technology allows furthermore to avoid the drawbacks of traditional UV lamps, such as high consumption and maintenance, presence of harmful substances such as mercury, generation of unwanted heat and ozone. 
     By virtue of the machine according to the disclosure, the production process as a whole benefits from considerable advantages, also in terms of time, since it is possible to print and dry immediately the objects to be processed without long waiting times. 
     The disclosure thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims; all the details may furthermore be replaced with other technically equivalent elements. 
     In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art. 
     The disclosures in Italian Patent Application No. 102019000018977, from which this application claims priority, are incorporated by reference.