摘要:
Apparatus and method for the rapid cleaning of the central drum of flexographic printing machines includes a cleaning device with presser, cloth and fluid. The presser brings the cloth into contact with the rotating drum. The presser undergoes a suitable oscillating movement parallel to the axis of the rotating drum. At the ends of the cleaning device, the shoulders of the base of the flexographic machine are equipped with any suitable opposed openings of the correct width through which the cleaning device can oscillate. The cleaning device periodically can be inserted or withdrawn axially through at least one of the openings to allow replacement of the cloth without the need to cut the substrate.
摘要:
At least one restriction (R) of the terminal part of the fluid mixture delivery channel (20) is introduced upstream of each bifurcation (B), preferably at the branching point of the said bifurcation, this restriction having the function of recompacting the said mixture on the mid-line of the said bifurcation, in such a way that the distribution of the said mixture can be carried out in an equal way in the two following channels. The aforesaid restriction also has the function of progressively calibrating the pressures in the fluid mixture transport circuits, in such a way that identical quantities and qualities of mixture reach the various outlet holes (10), even when the transport channels (1000) are made with sufficiently large dimensions to ensure that the quantity of air required for effective spraying of the transported detergent liquid reaches the final outlet holes (10).
摘要:
The method for cleaning the cylinders (C1-C1′, C2-C2′, C3-C3′, C4-C4′) of printing machines of the continuous type comprises a primary delivery stage which provides for delivering most or all of the solvent-containing cleaning fluid required for cleaning the printing machine's cylinders, that can be safely carried by the web (N) even in the subsequent drying stage, to one or both of the opposite surfaces of the paper web, upstream of the entire set of printing cylinders, by spraying or by any other controlled variable delivery technique, while the previously mentioned units (P) cleaning the sets of printing rollers have, in addition to the task of mechanical action, also been given the task of secondary delivery of the remaining quantity of the said solvent-containing cleaning fluid or a cleaning fluid containing little or even no solvent and proportionately rich in water, all so that the quantity of cleaning fluid delivered during the secondary stage by the cleaning units (P) equipping the printing cylinders is at least sufficient to keep the surfaces of the cylinders which are not in contact with the paper web.
摘要:
When the plate cylinder (D) is provided with at least one longitudinal channel (C) housing the sheet grippers (P) and when the ends of this channel have cams (Z) for contact with rollers mounted on the cleaning assembly, to ensure that when this assembly is actively working the presser (6) and cloth (T) do not interfere with the said grippers as they pass the said channel (C), the shoulders (2) of the said cleaning assembly are held stationary and the said cams (Z) of the cylinder (D) contact directly, or via interposed means, rollers (20) located at the ends of the presser (6), in such a way as to move only this component rather than the whole cleaning assembly as in the prior art. Compensating means are provided to cause the active length of cloth to remain suitably tensioned in the longitudinal direction and promptly to follow the presser's (6) movements of extension and retraction. When the end rollers of the presser are actuated by the interposition of pairs of pivoting levers (22, 25), arrangements are made to enable these pairs of levers to contact the cam (Z) located on one side only of the plate cylinder, the levers being connected to each other by at least one torsion bar (31).
摘要:
The equipment comprises means (17, 18) for causing a very small quantity of liquid for cleaning the said cylinders to be sprayed in a controlled and uniformly distributed way on to a sufficiently long portion of cloth, which, in the area directly acted on by the said sprayed liquids and in other areas, is kept in uniform and distributed contact with a transverse portion of the surface of the cylinder to be cleaned, and which is pushed, upstream and downstream of this portion, into close and uniformly distributed contact with the cylinder by a rectilinear deformable strip (6) and by a rectilinear deformable presser (9) respectively, each of these having an originally convex surface facing the cylinder, the whole being arranged in such a way that the cleaning liquid acts through the cloth on the cylinder to be cleaned in an extended, uniform and progressive way and in a very small quantity, and in such a way that the liquid is conveniently retained in the said cleaning area by the said cloth and the said rectilinear pressure elements, so that it does not fall off and so that it is transferred to the dirt on the cylinder in a gradual and controlled way, while the presser (9) facilitates the penetration of the liquid into the direct and promotes the elimination and removal of the said dirt. The active surface of the presser (9) has a suitable lowrelief configuration for better distribution of the cleaning liquid, to provide a better mechanical action for cleaning the cylinder and to retain in its channels (209) of originally outwardly diverging shape a large quantity of the paper particles which constitute the dirt removed from the cylinder.
摘要:
A cleaning device is attached at each end to shoulders pivoting on a pair of parallel arms hinged at the other end to the side walls of a machine. There pivots on at least one of the arms an assembly of pneumatic actuators, which actuators pivot at the other end on a lug integral with one of the shoulders, which shoulders are provided with spindles or rollers that run in cam paths formed in plates attached to the side walls. The cleaning device can be oriented and positioned against either of the two cylinders to be cleaned or can be set in a position remote from both of these cylinders. Mounted on at least one of the arms or on both of the shoulders are idle rollers designed to engage with corresponding cams, so that the cleaning device is moved away automatically whenever it passes over the clamps.