Soak on site and soak on press cleaning system and method using same

Abstract: An improved method and system for cleaning a cylinder (100) of a printing press. One method involves soaking a strip of cleaning fabric (13) on a press with a low volatility organic compound solvent (20). Excess solvent, if any, is removed to place the strip of cleaning fabric in functional equilibrium with the solvent. The cleaning fabric is then used to clean a cylinder (100). Alternatively, the strip of cleaning fabric is soaked on site by contacting the strip of cleaning fabric with the solvent and wrapping the strip of cleaning fabric into a cleaning fabric supply roll (10). The cleaning fabric is then brought in engagement with a printing press having a cylinder (100) to be cleaned without disposing a sleeve around the fabric roll and without substantially disturbing the distribution of the solvent in the fabric roll and detrimentally affecting the cleaning ability of the fabric.

Description: This invention relates to a cleaning system employing a strip of cleaning fabric wrapped around a core or a shaft to form a cleaning fabric supply roll. The strip of cleaning fabric is soaked at the site prior to use or is soaked on the press. A wide variety of blanket cleaning systems and apparatus employing the same to clean the cylinders of printing presses are known. Typical blanket cleaning systems and apparatus employing the same, including cleaning blankets and cleaning solutions, are exemplified by U.S. Patent No. 4,135,448 to Moestue which is directed to a mechanism for cleaning a cylinder that is provided with a cleaning cloth which is wetted with a cleaning fluid or solution prior to its encountering the pressure roller; U.S. Patent No. 4,934,391 to Futch et al. is directed to a composition for ink removal that exhibits a low vapor pressure and which is a low vapor pressure organic compound; U.S. Patent No. 4,986,182 to Sawaguchi et al. is directed to a cleaning apparatus in which a cleaning cloth is dampened by a liquid; U.S. Patent No. 5,009,716 to Gerson is directed to a wash for removing ink comprising a low volatile organic compound; U.S. Patent No. 5,012,739 to Loos is directed to a washing device comprising a cleaning cloth dampened with a washing medium and U.S. Patent No. 5,069,128 to Hara is directed to a device for cleaning a cylinder of a printing machine comprising a cleaning cloth impregnated with a cleaning liquid. In addition, U.S. Patent No. 5,104,567 to Staehr is directed to a liquid for cleaning ink from printing machines; U.S. Patent No. 5,125,342 to Hara is directed to a method for cleaning the cylinder of a printing machine; and U.S. Patent No. 5,143,639 to Krawack is directed to a cloth moistened with a low vapor pressure cleaning agent for removing ink; whereas U.S. Patent No. 5,188,754 to Weltman et al. is directed to a cloth soaked with a cleaning formula and U.S. Patent No. 5,194,173 to Folkard et al. is directed to a method for removing ink from printing machines. Still further, U.S. Patent No. 4,344,361 and 4,757,763 to MacPhee et al. is directed to automatic blanket cylinder cleaners provided with cleaner fabrics adapted to contact the blanket cylinders of printing presses. On the other hand, U.S. Patent No. 5,176,080 to Gasparrini et al. is directed to a cloth supply system for the blanket cylinder for use in printing presses. While the above-mentioned patents accomplish their purposes to a satisfactory extent, they still exhibit a variety of drawbacks. For example, they usually require apparatus, such as pumps, spray bars, manifold lines, valves, and the like as part of the automatic blanket cleaning systems for introducing the cleaning solvents or solutions to the cleaning fabric just prior to actual use. U.S. Patent No. 5,368,157 to Gasparrini et al., assigned to the present applicants, attempted to overcome these problems. That patent is directed to a pre-packaged, pre-soaked cleaning system for use with printing machines or the like to clean the cylinders of such machines and which comprises a pre-soaked fabric roll saturated to equilibrium with low volatility organic compound solvent and which is disposed around an elongated, cylindrical core and a sealed or a shrunken and sealed plastic sleeve disposed around and in contact with the fabric roll, whereby the pre-soaked saturated roll can be transported and stored vertically and/or horizontally until use without substantially disturbing the distribution of the solvent in the fabric roll and detrimentally effecting the cleaning ability of the fabric. While the invention disclosed in U.S. Patent No. 5,368,157 works for its intended purpose, improvements have been discovered. When the patented product is placed in the vertical position, the solvent would shift downward in the evacuated package. When the package is restored to the horizontal position, the solvent migrates back towards equilibrium in the roll. This migration is caused by air pockets in the fabric of the roll. There exists, therefore, a need for providing a blanket cleaning system which improves upon the above-mentioned conditions. It is therefore an object of the invention to provide a new and improved system for soaking a strip of cleaning fabric for use in a cylinder cleaning system. It is a further object of the invention to provide a new and improved system for soaking a strip of cleaning fabric which overcomes the drawbacks discussed above. Another object of the invention is to provide a new and improved method of soaking a strip of cleaning fabric on a cylinder cleaning apparatus while located on a press. A yet another object of the invention is to provide a new and improved method of soaking a strip of cleaning fabric on a press while the strip of cleaning fabric is still wound in a cleaning fabric supply roll on a core or shaft. A still further an object of the invention is to provide a new and improved method including the use of an adjustable means to remove excess solvent from the strip of cleaning fabric to control the amount of solvent retained by the strip of cleaning fabric. A further object of the invention is to provide a new and improved soak on press system in which a single roller is used to both soak and saturate the strip of cleaning fabric in solvent and to remove excess solvent for the strip of cleaning fabric. The foregoing specific objects and advantages of the invention are illustrative of those which can be achieved by the present invention and are not intended to be exhaustive or limiting of the possible advantages which may be realized. Thus, these and other objects and advantages of the invention will be apparent from the description herein or can be learned from practicing the invention, both as embodied herein or as modified in view of any variations which may be apparent to those of ordinary skill in the art, the same being realized and attained by means of parts, constructions, instrumentations and combinations pointed out in the claims. The present invention resides in the novel parts, constructions, arrangements, combinations, methods and improvements herein shown and described. According to the present invention there is provided a method of cleaning a cylinder of a printing press located at a printing site, with a strip of cleaning fabric fed from a roll thereof and soaked and saturated, prior to cleaning, with an organic solvent characterised in that soaking the strip of cleaning fabric with the organic solvent is performed at the site of the printing press by immersing the strip of cleaning fabric in the organic solvent or by applying the solvent to the strip of cleaning fabric by a roller. The strip of the cleaning fabric may be soaked in the organic solvent until the cleaning fabric absorbs the solvent such that the cleaning fabric is saturated with the organic solvent. The method may further comprise removing excess organic solvent from the soaked strip of cleaning fabric to obtain a strip of cleaning fabric saturated to functional equilibrium with the organic solvent. Preferably, removing the excess organic solvent comprises squeezing the excess solvent from the strip of cleaning fabric. The soaking may be carried out in an assembly mounted on the printing press. The method may comprise winding a used strip of the cleaning fabric on a take-up shaft. Preferably, at least one squeezing roller is used to squeeze the soaked strip of cleaning fabric and the roller may squeeze the soaked strip of cleaning fabric against a surface, wherein the surface may be the side of a container. The method may further comprise adjusting the gap between the squeezing roller and the surface to control the amount of the organic solvent in the strip of the cleaning fabric. Preferably, the excess organic solvent is collected in the container and the collecting container may be the same as the container used to contain the organic solvent used for soaking. The method may comprise unwinding the strip of cleaning fabric from the cleaning fabric supply roll prior to soaking the cleaning fabric in the organic solvent. Accordingly, soaking comprises dipping the unwound strip of cleaning fabric in the organic solvent. Preferably, dipping is performed using a dipping roller to dip the cleaning fabric in the organic solvent and a single roller may used to dip the strip of the cleaning fabric and squeeze the strip of the cleaning fabric against the side of the container. Preferably, the method comprises soaking the cleaning fabric with the organic solvent prior to unwinding the strip of cleaning sheet material from the cleaning fabric supply roll. Soaking the strip of the cleaning fabric may comprise dipping only a portion of the cleaning fabric supply roll in the organic solvent and rotating the cleaning fabric supply roll in the solvent to allow at least substantially all of the strip of the cleaning fabric to be soaked with the solvent. Soaking the strip of the cleaning fabric may comprise dipping at least substantially all of the cleaning fabric supply roll in the organic solvent and may further comprise removing the cleaning fabric from the organic solvent. Accordingly, soaking may be carried out in an organic solvent application device located adjacent to the printing press at the site, and a roll of soaked cleaning fabric is thereafter taken to the printing press to clean the cylinder. The method may further comprise wrapping the soaked strip of cleaning fabric to form a cleaning fabric supply roll and engaging the soaked cleaning fabric supply roll with the printing press having a cylinder to be cleaned. Preferably, squeezing comprises squeezing the strip of cleaning fabric between at least a pair of squeezing rollers. Accordingly, soaking of the cleaning sheet material is performed prior to wrapping to form the cleaning fabric supply roll and may comprise running the strip of cleaning fabric through a container filled with the organic solvent. A dipper may be used to dip the strip of cleaning fabric into a container holding said solvent. Preferably, the strip of cleaning fabric is squeezed between the dipper and a squeezer. Accordingly, the dipper is a roller and the squeezer is a roller. The method may comprise applying the organic solvent to at least one roller and soaking the unwound strip of cleaning fabric with the roller. The soaked cleaning fabric supply roll may be transported from the organic solvent application device to the printing press without packaging the roll for the purpose of preventing evaporative loss of the organic solvent. According to the present invention there is provided a printing apparatus including a printing press located at a printing site, and cleaning assembly for cleaning a cylinder of the printing press, with a strip of cleaning fabric fed from a roll thereof and soaked and saturated with an organic solvent prior to cleaning the cylinder characterised by a soaking assembly located at the printing site to soak the strip of cleaning fabric with the organic solvent by immersing the strip of cleaning fabric in the organic solvent or by applying the solvent to the strip of cleaning fabric by a roller. Preferably, the cleaning fabric soaking is received in the soaking assembly when containing the organic solvent such the cleaning fabric absorbs the solvent and becomes saturated with the organic solvent. Printing apparatus may further comprise removing means for removing excess organic solvent from the cleaning fabric, wherein the removing means may comprise a squeezing means for removing the excess organic solvent from the soaked cleaning fabric. Accordingly, the soaking assembly is mounted on the printing press. The printing apparatus may further comprise cylinder cleaning means for bringing the soaked strip of a cleaning fabric into contact with the cylinder and cleaning the cylinder and take-up means for collecting the strip of cleaning fabric after it has been used to clean the cylinder. The take-up means may comprise a shaft. Preferably, the soaking means comprises a rotating means for rotating the cleaning fabric supply roll to allow the cleaning fabric to be soaked. The soaking means may comprise at least one container containing the organic solvent in, which the cleaning fabric is soaked. Accordingly, the squeezing means comprises at least one squeezing roller and the squeezing means may further comprise a surface against which the cleaning fabric is squeezed. The surface may be the side of a collecting container. Accordingly, the squeezing roller is in a movedly fixed relationship with the surface so that the gap between the squeezing roller and the surface can be changed so that the amount of organic solvent in the strip of cleaning fabric may be adjusted. Preferably, the collecting container and the soaking container are one and the same container. The printing apparatus may include means to rotate the cleaning fabric supply roll so as to unwind the cleaning fabric prior to soaking and may further comprise a dipping means for placing the unwound cleaning fabric in the organic solvent to soak the strip of cleaning fabric. The dipping means may comprise a dipper roller. Accordingly, the dipping means and the squeezing means comprise a unitary structure. Preferably, the printing apparatus includes means to dip at least a portion of the cleaning fabric roll in the organic solvent so as to soak the cleaning fabric. The soaking assembly may be located adjacent to the printing press at the site. Preferably, the printing apparatus further comprises means for mounting a bulk supply roll having the strip of cleaning fabric wound around a shaft and means for forming a cleaning fabric supply roll. The printing apparatus may further comprise a calendaring means for reducing the thickness and increasing the length of the strip of cleaning fabric on the shaft without substantially increasing the diameter of the cleaning fabric supply roll. Preferably, the soaking means comprises at least one container for containing organic solvent. Preferably, the printing apparatus includes at least a pair of squeezing rollers, configured to squeeze the soaked strip of cleaning fabric passing between the rollers. The soaking assembly may include a dipper for dipping the strip of cleaning fabric into the organic solvent so as to soak the cleaning fabric and may also include a squeezer operatively associated with the dipper to squeeze the strip of cleaning fabric between the dipper and the squeezer. Accordingly, the printing apparatus includes an organic solvent applying roller to receive organic solvent from the soaking assembly and means to receive organic solvent from the applying roller and to apply the organic solvent to the cleaning fabric. It will be appreciated by those skilled in the art that the foregoing summary of the invention and the following detailed description are merely exemplary and explanatory of the present invention, but are not intended to be restrictive thereof or limiting of the advantages which can be achieved by the invention or various combinations thereof. The accompanying drawings referred to herein and constituting in part hereof, illustrate preferred embodiments of the invention and, together with the detailed description, serve to explain the principles of the invention. Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1A is a lateral, sectional, elevational view of a cleaning fabric supply roll formed around a core; Fig. 1B is a lateral, sectional, elevational view of a cleaning fabric supply roll formed around a shaft; FIG. 2 is a cross-sectional view of a soak on press assembly according to the present invention including soaking the cleaning fabric supply roll in solvent; FIG. 3 is a cross-sectional view of a soak on press assembly according to the present invention including a single duct or container for storing solvent; FIG. 4 is a cross-sectional view of a soak on press assembly according to the present invention including separate ducts for storing solvent to be applied and removed excess solvent; FIG. 5 is a cross-sectional view of a soak on press assembly according to the present invention including a single roller to dip and squeeze the strip of cleaning fabric; FIG. 6 is a cross-sectional view of a soak on site system according to the present invention; FIG. 7 is a cross-sectional view of an alternate embodiment of a soak on site system according to the present invention including separate rollers for applying solvent and removing excess solvent; FIG 7A is a cross-sectional view of an alternate embodiment of a soak on site system according to the present invention in which a same roller is used to both apply and remove solvent; and FIG. 8 is a partial cross-sectional view of a cylinder to be cleaned and a soaked on site cleaning system according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1A and 1B, a cleaning fabric supply roll 10 used with the present invention is shown. One embodiment, shown in FIG. 1A comprises an elongated core 11 made from, for example, relatively heavy cardboard of sufficient strength so that it can support thereon a strip of cleaning fabric 13. The strip of cleaning fabric 13 is wound around core 11 . Alternatively, if desired, the core 11 can be made from any other suitable material including, but not limited to, plastic or metal, such as steel, aluminum, and the like. Core 11 preferably has open ends to allow installation on an appropriate cylinder cleaning apparatus. Preferably, core 11 is completely hollow to allow a shaft, rod, or the like 15 to be inserted within core 11 to provide installation in the cylinder cleaning apparatus. In such an embodiment, cleaning fabric supply roll 10 comprises core 11 and strip of cleaning fabric 13. In an alternate embodiment shown in FIG. 1B, cleaning fabric supply roll 10 is formed by winding the strip of cleaning fabric 13 directly around shaft 15. Preferably, the core 11 and/or shaft 15 is cylindrical in shape. However, the core 11 and/or shaft 15 may be any other appropriate shape, such as having 3, 4, 5, or 6 sides or an oval. Such shapes are described in EP-A-0 741 036. The strip of cleaning fabric 11 from which the cleaning fabric supply roll 10 is made may vary widely. For example, it may be made of paper, cloth, film, a mixture of wood pulp and polyester, such as DuPont SONTARA (TM) , or any other suitable material. In those cases where a cloth fabric is employed, it may be a woven or non-woven cloth fabric made of synthetic or natural fibers or mixtures of the same. Exemplative, but not limitative, of suitable synthetic fibers which may be used in the cloth fabrics are polyester fibers, rayon fibers, nylon fibers, and acrylic fibers and the like. Exemplative, but not limitative, of the natural fibers which may be employed are cotton fibers, wood pulp fiber, hemp fibers and the like. In those cases where paper is employed as the fabric material, paper fabrics made from wood pulp modified chemically in accordance with paper manufacturing technology are suitable. On the other hand, no matter what fabric is employed in carrying out the practice of this invention, it is preferred that the materials used therein exhibit high acceptability to being soaked or wetted by a solvent or cleaning agent. Preferably, this solvent or cleaning agent is a low volatility organic compound used to saturate the fabric. In this regard, it is preferred that the fabric employed be one which has a caliper thickness in a range from about 0.08 mm (0.003 inches) to about 0.8 mm (0.030 inches), and preferably in a range from about 0.2 mm (0.008 inches) to about 0.5 mm (0.020 inches), and the ability, when saturated with low volatility organic compound solvent, to retain from about 0.003 cc to about 0.08 cc of solvent per cm 2 (0.02 cc to 0.5 cc per in 2 ) of fabric determined by routine testing methods. In general, woven and non-woven fabrics suitable for use in carrying out the practice of the invention have a basic weight in a range of from about 0.051 kgm -2 (1.5 ounces per square yard) to about 0.20 kgm -2 (6.0 ounces per square yard), a caliper thickness in the range mentioned above, a tensile strength in the longitudinal (machine) direction in a range of from about 3500 Nm -1 (20 lbs. per inch) to about 35000 Nm -1 (200 lbs. per inch) and in a width (cross) direction in a range from about 2600 Nm -1 (15 lbs. per inch) to about 22000 Nm -1 (125 lbs. per inch). When paper is employed as a cleaning fabric in the system of this invention, it preferably has a basis weight in a range of from about 18 kg (40 lbs.) to about 41 kg (90 lbs.), a caliper thickness in a range of from about 0.08 mm (0.003 inches) to about 2.5 mm (0.10 inches) a tensile strength in the longitudinal (machine) direction in a range of from about 3500 Nm -1 (20 lbs. per inch) to about 14000 Nm -1 (80 lbs. per inch) and in the width (cross) direction in a range of from about 2600 Nm -1 (15 lbs. per inch) to about 880 Nm -1 (50 lbs. per inch), a porosity in a range of from about 1.0 second to about 10 seconds when subjected to 100 cc of low volatility organic compound solvent or water, and a stretch ability in a range of from about 1.0 percent to about 6.0 percent all determined by routine testing methods. The low volatility organic compound solvent 20 employed in carrying out the practice of this invention may vary widely and generally it includes at least one low volatility organic compound solvent which does not readily evaporate, as well as mixtures of the same with similar low volatile organic compound solvents or with normally volatile organic compound solvents. Exemplative, but not limitative, of suitable solvent materials of this type are organic compound solvents selected from vegetable oils and citrus oils and the like. Generally, such solvent materials have a volatility in a range of from about zero up to about 30.0 percent, and preferably a volatility in a range of from about zero percent to about 20.0 percent, determined by routine testing methods. It is to be understood that within the purview of this invention, such suitable solvents also include normally volatile organic compound solvents, that is, those which readily evaporate and which are selected from mineral spirits and aliphatic hydrocarbon solvents and the like. Such solvent materials generally have a volatility of from zero up to about 100 percent determined by routine testing methods. Preferably, a low volatility solvent will be used because the lower the volatility of the solvent, the longer the fabric stays wet since less solvent evaporates. The closer the volatility is to zero percent, the longer the life of the presoaked fabric on the printing press cylinder cleaning apparatus It is to be understood that within the context of this invention, the terminology "saturated to equilibrium" as it is used in connection with the saturation of the fabric and/or fabric roll with solvent means by measured absorption or after removing the excess solvent from the fabric and/or fabric roll, the fabric and/or fabric roll retains therein sufficient solvent or cleaning agent in an amount to wet the fabric to the extent that it imparts efficient cleaning ability to the fabric to clean cylinders of apparatus, such as printing machinery, and the fabric has preferably retained therein by measured absorption or after removal of the excess, if any removal is required, from about 0.003 cc to 0.08 cc of solvent per cm 2 (0.02 cc to 0.5 cc per in 2 ) of fabric. The above described cleaning fabric supply roll 10 and low volatility, organic compound solvent 20 may be used in either a soak on press assembly or a soak on site system. A soak on press assembly 1 is shown in FIG. 2. Soak on press assembly 1 is a cleaning apparatus mounted on a printing press (not shown) to prepare a strip of cleaning fabric to clean a cylinder 100 . A mounting assembly 30 is affixed to the printing press and supports the soak on press assembly 1 . Mounting assembly 30 may be a unitary structure. Alternatively, mounting assembly 30 may comprise several discrete pieces which are individually used to attach elements of the soak on press assembly 1 to the printing press. In yet a third embodiment, the mounting assembly 30 comprises those elements of a printing press which supports elements of the soak on press assembly 1 . Cleaning fabric supply roll 10 is preferably rotatably mounted to mounting assembly 1 . A container 42 is used to store solvent 20 while strip of cleaning fabric 13 is soaked and saturated in solvent 20 . In one embodiment, the container 42 is in engagement with a mounting assembly 30 . In an alternate, container 42 is placed in a duct 32 of mounting assembly 30 . In another embodiment, container 42 is a duct 32 of mounting assembly 30 . Preferably, container 42 is removably connected to mounting assembly 30 to allow container 42 to be easily cleaned and solvent 20 easily replaced. Cleaning fabric supply roll 10 needs to be placed in contact with the solvent 20 so that strip of cleaning fabric 13 my be soaked and saturated. One method of achieving this result is to dip all cleaning fabric supply roll 10 into solvent 20 contained in container 42 . For purposes of this invention, cleaning fabric supply roll 10 includes only the portion of strip of fabric 13 wrapped around core 11 and/or shaft 15 and not the portion of strip of cleaning fabric 13 threaded through the rest of the soak on press assembly 1 . Preferably, cleaning fabric supply roll 10 is dipped in solvent 20 and strip of cleaning fabric 13 is soaked and saturated with solvent prior to any portion of strip of cleaning fabric 13 being threaded through the rest of soak on press assembly 1 . Alternatively, a portion of strip of cleaning fabric 13 may be unwound from cleaning fabric supply roll 10 prior to cleaning fabric supply roll 10 being brought in contact with the solvent 20 . After the strip of cleaning fabric 13 of cleaning fabric supply roll 10 has been soaked and saturated, all of cleaning fabric supply roll 10 may remain in solvent 20 , a portion of cleaning fabric supply roll 10 may be removed from solvent 20 , or all of cleaning fabric supply roll 10 may be removed from solvent 20 . In an alternate embodiment, only a portion, but at least half, of cleaning fabric supply roll 10 is brought in contact with solvent 20 and remains in contact during operation of the printing press. The unwinding of cleaning fabric supply roll 10 causes cleaning fabric supply roll 10 to rotate and the strip of cleaning fabric 13 wrapped around core 11 and/or shaft 15 that was not in contact with the solvent 20 is placed in solvent 20 and allowed to soak and saturate. In order for maximum efficiency, the strip of cleaning fabric 13 after it has been removed from cleaning fabric supply roll 10 should be in functional equilibrium with solvent 20 . Preferably, this is achieved through measured absorption of solvent 20 . Alternatively, excess solvent strip of cleaning fabric 13 can be removed by any appropriate means to obtain a strip of cleaning fabric 13 saturated to functional equilibrium with solvent 20 . One way of removing excess solvent from a strip of cleaning fabric 13 is to use a squeezer 50 to squeeze out excess solvent. In one embodiment, squeezer 50 may comprise at least a pair of rollers with a gap between them. The strip of cleaning fabric 13 is placed between the rollers and the excess solvent is squeezed from the strip of cleaning fabric 13 . By controlling the size of the gap between the at least two rollers, the amount of excess solvent removed is controlled and regulated. In an alternate embodiment, squeezer 50 may comprise a squeezing roller 52 , which is rotatably mounted, and a squeezing surface 54 . Squeezing roller 52 is disposed so that it is not engaged with squeezing surface 54 and a gap is formed between squeezing surface 54 and squeezing roller 52 . Squeezing roller 52 is preferably in a movedly fixed relationship with squeezing surface 54 such that squeezing rollers 52 in its position to facilitate the removal of excess solvent yet may be moved to change the size of the gap between surface 54 and roller 52 to control and regulate the amount of solvent being removed from the strip of cleaning fabric 13 . If squeezing roller 52 is movably mounted, it may be place adjacent to squeezing surface 54 . As with container 42 , container 44 may be engaged with mounting assembly 30 , may be placed within a duct 34 of mounting assembly 30 , may be duct 34 of mounting assembly 30 , or any combination of the above. Additionally, any other type of container 44 may be used. Preferably, surface 54 is an element of container 44 . Alternatively, squeezing surface 54 may be a surface of mounting assembly 30 . It is preferred that after the removal of excess solvent, the strip of cleaning fabric 13 is saturated to functional equilibrium with solvent. A cylinder cleaning means is used to bring the strip of cleaning fabric 13 in contact with a cylinder to be cleaned and causes the cylinder 100 to be cleaned. Examples of cylinder cleaning means can be found in our United States Patent No. 5 450 792 (and corresponding EP-A- 0 590 833) entitled "AUTOMATIC CLEANING SYSTEM FOR PRESS ROLLERS AND CYLINDERS", United States Patent No. 4,867,064 issued September 19, 1989 to Hara et al. entitled "APPARATUS FOR CLEANING A PRINTING CYLINDER", and United States Patent No. 5,150,653 issued September 29, 1992 to Hara entitled "METHOD OF AND APPARATUS FOR CLEANING A CYLINDER". After being used to clean cylinder 100 , the used portion of the strip of cleaning cloth 13 is taken up by a take-up means 70. Preferably, take-up means 70 is a take-up shaft 72 rotatably mounted to mounting assembly 70. A take-up roll is formed by winding the used strip of cleaning fabric 13 around the take-up shaft 72. Examples of take-up shaft 72 can be found in EP-A-0 741 036. FIG. 3 demonstrates an alternate embodiment of the invention. In this embodiment, cleaning cloth supply roll 10 is not soaked and saturated in solvent 20. Instead, the strip of cleaning fabric 13 is at least partially removed from the cleaning cloth supply roll 10 . A soaking means 80 is used for soaking and saturating at least a portion of the strip of cleaning fabric 13 in solvent 20. In this embodiment, the soaking means 80 includes a dipper 82 and a container 42 . Container 42 is used to store the solvent while dipper 82 is placed at least partially in the solvent 20 . Dipper 82 is used to place the at least a portion of the strip of cleaning fabric 13 in solvent 20 and to allow the strip of cleaning fabric 13 to soak and saturate in the solvent 20 . Preferably, dipper 82 is a roller rotatably mounted to the mounting assembly; however, any appropriate dipper may be used. The remainder of the soak on press assembly 1 functions the same as that described for the device shown in FIG. 2. An improved embodiment of the invention is shown in FIG. 4. In this embodiment, instead of having a solvent storage container 42 and a removed excess solvent storage container 44 , only a single storage container 46 is used. Because the removed excess solvent can be used immediately without the need to move it from one container 44 to a second container 42 , the soak on press assembly 1 can be operated for a longer period of time before the container needs to be cleaned and/or refilled. As with containers 42 and 44 , container 46 may be constructed in a variety of fashions. For example, container 46 may be fixed, either permanently or, preferably, removably, to mounting assembly 30 . Container 46 may be placed or fixed within a duct 36 of mounting assembly 30 . Alternatively, duct 36 may be used at the container. On the other hand, any combination of the above may be used. For example, container 46 may comprise a container placed within a duct and having the duct extend beyond the container. Alternatively, any other appropriate construction of container 46 may be used. In another embodiment, multiple containers 46 are used. In each of these containers 46 , the strip of cleaning fabric 13 is both soaked and saturated with solvent 20 and excess solvent is removed from the soaked and saturated strip of cleaning fabric 13 . Figure 5 an improvement to the single container embodiment described above, a single body 92 is used to both dip the strip of cleaning fabric into solvent 20 stored in container 46 to allow the strip of cleaning fabric 13 to soak and saturate in the solvent and to remove the excess solvent by squeezing the soaked and saturated strip of cleaning fabric 13 between the body 92 and squeezing surface 54 . Preferably, body 92 is a roller which is rotatably mounted to mounting assembly 30 . In this embodiment, body 90 may be mounted to allow movement relative to surface 54 to control and regulate the amount of excess solvent being removed. An alternate approach to achieving the advantages of the invention is to presoak the strip of cleaning cloth 13 on site, that is near enough to the press that the presoaked cleaning cloth can be brought to or in the proximity of the press containing the cylinder to be cleaned without disposing a sealed and/or heat-sealed plastic sleeve about the cleaning fabric roll 10 and without substantially disturbing the distribution of the solvent in the fabric roll and detrimentally affecting the cleaning ability of the fabric. In accordance with a method of this invention, a strip of cleaning fabric 13 is brought in contact with a low viscosity, organic compound solvent which does not readily evaporate at ambient pressure and temperature. Contact between the strip of cleaning fabric 13 and the solvent 20 may be achieved in a variety of ways. For example, solvent may be applied in measured amounts so that the fabric is presoaked to functional equilibrium. This preferred method of applying solvent is known as measured absorption of a solvent. If desired, instead of measured absorption, an excess amount of solvent may be applied to the strip of cleaning fabric. This may be done by soaking and saturating the strip of cleaning fabric in a vat of solvent. If this is done, the excess solvent must be removed to obtain a strip of cleaning fabric saturated to functional equilibrium with the solvent. Any appropriate method for removing the excess solvent to obtain a strip of cleaning fabric saturated to functional equilibrium can be used with any of the above methods of contacting, including draining the strip of cleaning fabric or spinning the strip of cleaning fabric. The strip of cleaning fabric is presoaked and saturated with a low volatility, organic compound solvent before or after the strip of cleaning fabric 13 is wound to form a cleaning fabric supply roll 10 . An alternative embodiment of a method of presoaking a strip of cleaning fabric on site is shown in FIG. 6. A strip of cleaning fabric 13 is initially wound around a shaft or core 115 to form bulk roll 110 . Bulk roll 110 is rotatably mounted to a roll forming assembly. The amount of fabric on bulk roll 110 may be sufficient to form multiple cleaning fabric rolls 10 . A portion of the strip of cleaning fabric 13 is unwound from bulk roll 110 . If desired, at least a pair of calendering rollers 150 may be used to calender the strip of cleaning fabric 13 . The at least a pair of calendering rollers 150 compress the strip of cleaning fabric 13 . Preferably, but not necessarily, the temperature of the at least a pair of rollers 150 is hotter than room temperature. Alternatively, the temperature of the at least a pair of rollers 150 is at about ambient temperature or less than ambient temperature. It has been found that the wettability and the distribution of the solvent is very good in the calenderized fabric. A surprising and unexpected result of the calendaring process is that the length of fabric is increased while not increasing the diameter of the cleaning fabric supply roll 10 . This provides an important advantage because cleaners are designed to accept fabric rolls of up to a certain diameter. For example, one of the assignor's automatic blanket cleaners will only accept a cleaning fabric roll having a diameter of about 70 mm (2.75 inches). Because of this extra length, a fabric roll of calenderized cloth will be usable for more washes than a regular fabric roll of the same fabric having the same diameter. This has two advantages. First, the cost per wash will be reduced. Second, the pressmen need not change a roll of cleaning fabric as often since there are more washes per roll of cloth. This will allow for the press to be run more often. These advantages can be realized regardless of whether the fabric is pre-soaked and/or pre-packaged. The amount of increase in the length of cloth due to calendaring is dependent on the fabric used and the amount of calendaring. For example when DuPont SONTARA (TM) cloth having a thickness of about 0.30 mm (.012 inches) and a length of about 11 m (12 yards) is placed about a core, having a diameter of about 38 mm (1.5 inches), the fabric roll has a diameter of 70 mm (2.75 inches). After being calendered the cloth has a thickness of about 0.22 mm (0.0085 inches) and a length of about 15 m (16 yards) and still has a diameter of about 70 mm (2.75 inches) when placed on the same core. Thus, in this situation, calendering results in an about 25% to about 30% increase in the length of the fabric without increasing the diameter of cleaning fabric supply roll 10 . Depending on the type of fabric and amount of calendering, results may range from about a 10% increase to about a 50% increase. Calendaring fabric and its advantages are discussed in more detail in EP-A-0 741 034. A solvent application system 120 is used to apply a measured amount of solvent 20 to the strip of cleaning fabric 13 . A container 122 is used to store solvent 20 . A solvent supply roller 124, which is rotatably mounted, is partially submerged in solvent 20 . A rotatably mounted application roller 126 is positioned adjacent to and in contact with the solvent supply roller 124 at a portion of the solvent supply roller 124 which is not submerged in the solvent 20 . Solvent supply roller 124 and application roller 126 are rotatably mounted such that they rotate in the opposite direction. The rotation of solvent supply roller 124 and application roller 126 cause solvent 20 to transfer from solvent supply roller 124 to application roller 126 via nip 125 . If desired, a plurality of solvent supply rollers 126 may be used to transport solvent 20 from container 122 to the application roller 126 . In such an embodiment, the plurality of solvent supply rollers 124 are adjacent to and in contact with each other to form a chain of rollers such that one solvent supply roller 124 is submerged in solvent 20 and another solvent supply roller 124 is in contact and adjacent to application roller 126 . The strip of cleaning fabric 13 is placed between and adjacent to a rotating roller 128 and application roller 126 . The rotation application roller 126 causes a measured amount of solvent 20 to be placed in contact with the strip of cleaning fabric 13 and allowing the fabric 13 to be soaked and saturated with the solvent 20 . Preferably, the strip of cleaning fabric 13 is soaked and saturated to functional equilibrium with the solvent 20 . Alternatively, an excess amount of solvent may be used to soak and saturate the strip of cleaning fabric 13 . Such excess solvent can be removed by any appropriate means including, but not limited to, running the strip of fabric 13 through at least a pair of rollers 160 . The soaked and saturated strip of cleaning fabric 13 is then wound around a core, shaft or any other appropriate body to form a cleaning fabric supply roll 10 . The excess solvent, if any is applied to the fabric, may be removed either before or after the cleaning fabric supply roll 10 is formed. When a cleaning fabric supply roll 10 of an appropriate diameter is formed, the strip of cleaning fabric 13 is cut or torn, cleaning fabric supply roll 10 is removed, and a new shaft or core is used to form another cleaning fabric supply roll. In the above described system, the winding of the strip of cleaning fabric 13 into a cleaning fabric supply roll 10 may cause the strip of cleaning fabric 13 to move through the solvent application system 120 , the at least a pair of calendering rollers 150 (if used) and the pair of rollers 160 (if used). The solvent application system 120 including all its elements, calendaring rollers 150 , pair of rollers 160 , and cleaning fabric supply roll 10 may all be attached to a roll forming assembly. A soak on site system using an alternate solvent application system 170 is shown in FIG. 7. At least one placement device 174 , preferably a roller, is used to place the strip of cleaning fabric 13 above a container 172 storing a low volatility, organic compound solvent 20 which does not readily evaporate at ambient pressure and temperature. A dipper 176 , preferably a rotatably mounted roller, is used to dip the strip of of cleaning fabric 13 into the solvent 20 . This allows the strip of cleaning fabric 13 to soak and saturate in the solvent 20 . Preferably, the strip of cleaning fabric 13 is soaked and saturated to functional equilibrium with solvent when it is removed from solvent 20 . If not, the excess solvent must be removed. Any appropriate method for removing excess solvent may be used. Preferably, the excess solvent is removed by squeezing the strip of cleaning fabric 13 between a pair of rollers 160 . Yet another possible embodiment is shown in figure 7A. In this embodiment, the solvent application system 180 includes a container 182 a dipping roller 184 and a squeezing roller 186 . Solvent or cleaning agent 20 is stored in container 182. The dipping roller 184 is used to dip the strip of cleaning fabric 13 into the solvent or cleaning agent 20 . The strip of cleaning fabric 13 is soaked and saturated in the solvent or cleaning agent 20 . The strip of cleaning fabric 13 is then removed from the solvent and the excess solvent is removed form the strip of cleaning fabric 13 so that it is saturated to functional equilibrium with the solvent 20. This removal may be accomplished by squeezing the strip of cleaning fabric 13 between dipping roller 184 and squeezing roller 184 at a point above solvent 20 . An advantage of such a system is that the removed excess solvent will drop into container 182 and thus a separate container for the removed excess solvent will not be required. Also shown in figure 7A is a positioner 190. Positioner 190 is preferably a roller. Positioner 190 may be used to properly position the strip of cleaning fabric 13 after it has been presoaked. Although positioner 190 is only shown in figure 7A, a positioner may be used in any embodiment of the invention. Positioners may also be used in the soak on press systems described earlier. It should be noted that the embodiments shown in figures 6, 7, and 7A do not need to have rolls 150 installed. If rolls 150 are not installed, standard uncalendered fabric is used and less solvent stability is obtained. After being presoaked on site, the cleaning fabric supply roll 10 having a strip of cleaning fabric 13 is then placed on a printing press having a cylinder 100 to be cleaned. The printing press further includes a means for properly positioning the cleaning fabric to allow cleaning of the cylinder 100 . Several ways exist for this result to be achieved. For example, the cleaning fabric 13 may be positioned so that it is adjacent the cylinder 100 to be cleaned. In another example, the cleaning fabric 13 may be adjacent to and operatively associated with the cylinder 100 to be cleaned. In yet another possible embodiment, the cleaning fabric 13 is operatively associated with the cylinder 100 to allow cleaning the cylinder 100 as the fabric 13 is fed past the cylinder 100 . One possible arrangement is shown in Fig. 8. The person of ordinary skill in the art will be aware of many other configurations that will work for the invention's intended purpose without undue experimentation. These examples are merely exemplary and are not meant to limit how the invention may be used. A distinct advantage of the cleaning system of this invention is that it eliminates the need for complex apparatus, such as pumps, spray bars, manifold lines, valves and the like, especially as part of the automatic blanket cleaning systems used on printing machinery to introduce cleansing solvents or solutions to the cleaning fabric just prior to use. In addition, the cleaning system of this invention provides numerous other advantages. For example, it is relatively simple in construction, employs readily available materials, and can be made in a relatively simple and forward manner without resort to highly complex and expensive procedures which necessitate the use of elaborate machinery. Additionally, the invention is preferable to the invention discussed in U.S. Patent No. 5,368,157 to Gasparrini et al. in that it provides for less solvent displacement during storage and thus less of a change in the fabric roll's center of gravity. Numerous other advantages of this invention will be readily apparent to those skilled in the art. It will remain understood by those skilled in the art that the present invention in its broader aspects is not limited to the particular embodiments shown and described herein, and that variations may be made which are within the scope of the accompanying claims.

Claims: A method of cleaning a cylinder (100) of a printing press located at a printing site, with a strip of cleaning fabric (13) fed from a roll (10) thereof and soaked and saturated, prior to cleaning, with an organic solvent (20) characterised in that soaking the strip of cleaning fabric with the organic solvent is performed at the site of the printing press by immersing the strip of cleaning fabric in the organic solvent or by applying the solvent to the strip of cleaning fabric by a roller. A method according to claim 1 wherein the strip of the strip of cleaning fabric (13) is soaked in the organic solvent (20) until the strip of cleaning fabric absorbs the solvent such that the strip of cleaning fabric (13) is saturated with the organic solvent. A method according to either claim 1 or 2 further comprising removing excess organic solvent (20) from the soaked strip of cleaning fabric (13) to obtain a strip of cleaning fabric saturated to functional equilibrium with the organic solvent. A method according to any preceding claim wherein removing the excess organic solvent (20) comprises squeezing the excess solvent from the strip of cleaning fabric (13). A method according to any preceding claim wherein the soaking is carried out in an assembly (30) mounted on the printing press. A method according to any preceding claim comprising winding a used strip of the cleaning fabric (13) on a take-up shaft (72). A method according to claim 4 wherein at least one squeezing roller (52) is used to squeeze the soaked strip of cleaning fabric (13). A method according to claim 7 wherein the roller squeezes the soaked strip of cleaning fabric (13) against a surface (54). A method according to claim 8 wherein the surface (54) is the side of a container (44). A method according to claim 8 or 9 further comprising adjusting the gap between the squeezing roller (52) and the surface (54) to control the amount of the organic solvent (20) in the strip of cleaning fabric (13). A method according to any one of claims 3 to 10 comprising collecting the excess organic solvent (20) in the container (44). A method according to claim 11 wherein the collecting container is the same as the container used to contain the organic solvent (20) used for soaking (46). A method according to any preceding claim comprising unwinding the strip of cleaning fabric (13) from the cleaning fabric supply roll (10) prior to soaking the cleaning fabric in the organic solvent (20). A method according to claim 13 wherein soaking comprises dipping (80) the unwound strip of cleaning fabric (13) in the organic solvent (20). A method according to claim 14 wherein the dipping (80) is performed using a dipping roller (82) to dip the cleaning fabric (13) in the organic solvent (20). A method according to claim 15 wherein a single roller (92) is used to dip the strip of cleaning fabric (13) and squeeze the strip of cleaning fabric sheet material against the side (54) of the container. A method according to any one of claims 1 to 12 comprising soaking the strip of cleaning fabric with the organic solvent (20) prior to unwinding the strip of cleaning fabric (13) from the cleaning fabric supply roll (10). A method according to claims 17 wherein soaking the strip of cleaning fabric (13) comprises dipping only a portion of the cleaning fabric supply roll (10) in the organic solvent (20) and rotating the cleaning fabric supply roll in the solvent to allow at least substantially all of the strip of cleaning fabric to be soaked with the solvent. A method according to claim 17 wherein soaking the strip of cleaning fabric (13) comprises dipping at least substantially all of the cleaning fabric supply roll (10) in the organic solvent (20). A method according to either claims 18 and 19 further comprising removing the cleaning fabric (13) from the organic solvent (20). A method according to any one of claims 1 to 4 wherein the soaking is carried out in an organic solvent application device (120) located adjacent to the printing press at the site, and a roll of soaked cleaning fabric (10) is thereafter taken to the printing press to clean the cylinder (100). A method according to claim 21 further comprising: wrapping the soaked strip of cleaning fabric to form a cleaning fabric supply roll (10); and engaging the soaked cleaning fabric supply roll (10) with the printing press having a cylinder (100) to be cleaned. A method according to either claim 21 or 22 wherein squeezing comprises squeezing the strip of cleaning fabric (13) between at least a pair of squeezing rollers (160). A method according to any one of claims 21 to 23, wherein soaking of the cleaning fabric (13) is performed prior to wrapping to form the cleaning fabric supply roll (10). A method according to any one of claims 21 to 24, comprising running the strip of cleaning fabric (13) through a container (120) filled with the organic solvent (20). A method according to claim 25, comprising using a dipper (176) to dip the strip of cleaning fabric (13) into a container (120) holding said solvent (20). A method according to claim 26 wherein the strip of cleaning fabric is squeezed between the dipper (184) and a squeezer (186). A method according to either claim 26 or 27 wherein the dipper is a roller (184). A method according to either claim 27 or 28 wherein the squeezer is a roller (186). A method according to any one of claims 21 to 26 comprising applying the organic solvent (20) to at least one roller (124) and soaking the unwound strip of cleaning fabric (13) with the roller. A method according to any one of claims 21 to 30 wherein the soaked cleaning fabric supply roll (10) is transported from the organic solvent application device (130) to the printing press without packaging the roll for the purpose of preventing evaporative loss of the organic solvent (20). Printing apparatus including a printing press located at a printing site, and cleaning assembly (1) for cleaning a cylinder (100) of the printing press, with a strip of cleaning fabric (13) fed from a roll (10) thereof and soaked and saturated with an organic solvent (20) prior to cleaning the cylinder characterised by a soaking assembly located at the printing site to soak the strip of cleaning fabric with the organic solvent by immersing the strip of cleaning fabric in the organic solvent or by applying the solvent to the strip of cleaning fabric by a roller. Printing apparatus according to claim 32 wherein a cleaning fabric soaking is received in the soaking assembly when containing the organic solvent (20) such the cleaning fabric absorbs the solvent and becomes saturated with the organic solvent. Printing apparatus according to either claims 32 or 33 further comprising removing means for removing excess organic solvent from the cleaning fabric. Printing apparatus according to claim 34 wherein the removing means comprises a squeezing means for removing the excess organic solvent (20) from the soaked cleaning fabric (13). Printing apparatus according to any one of claims 32 to 35 wherein the soaking assembly is mounted on the printing press. Printing apparatus according to any one of claims 32 to 36 further comprising: cylinder cleaning means for bringing the soaked strip of a cleaning fabric into contact with the cylinder (100) and cleaning the cylinder; and take-up means (70) for collecting the strip of cleaning fabric after it has been used to clean the cylinder. Printing apparatus according to claim 37 wherein the take-up means comprises a shaft (72). Printing apparatus according to any one of claims 33 to 38 wherein the soaking means comprises a rotating means for rotating the cleaning fabric supply roll (10) to allow the cleaning fabric (13) to be soaked. Printing apparatus according to any one of claims 33 to 39 wherein the soaking means comprises at least one container (42) containing the organic solvent (20) in which the cleaning fabric is soaked. Printing apparatus according to any one of claims 35 and 36 to 40 when appendant to claim 35 wherein the squeezing means (50) comprises at least one squeezing roller (52). Printing apparatus according to claim 41 wherein the squeezing means (50) further comprises a surface against which the cleaning sheet material (13) is squeezed. Printing apparatus according to claim 42 wherein the surface is the side of a collecting container (44). Printing apparatus according to claim 43 wherein the squeezing roller (52) is in a movedly fixed relationship with the surface so that the gap between the squeezing roller and the surface can be changed so that the amount of organic solvent (20) in the strip of cleaning fabric (13) may be adjusted. Printing apparatus according to either claim 43 or 44 wherein the collecting container (44) and the soaking container (42) are one and the same container (46). Printing apparatus according to any one of claims 32 to 45 including means to rotate the cleaning fabric supply roll (10) so as to unwind the cleaning fabric (13) prior to soaking. Printing apparatus according to claim 46 further comprising a dipping means for placing the unwound cleaning fabric (13) in the organic solvent (20) to soak the strip of cleaning fabric. Printing apparatus according to claim 47 wherein the dipping means comprises a dipper roller (82). Printing apparatus according to either claim 47 or 48 wherein the dipping means and the squeezing means comprise a unitary structure (92). Printing apparatus according to any one of claims 38 to 45 including means to dip at least a portion of the cleaning fabric roll (10) in the organic solvent (20) so as to soak the cleaning fabric (13). Printing apparatus according to any one of claims 32 to 35 wherein the soaking assembly (130) located adjacent to the printing press at the site. Printing apparatus according to claim 51 further comprising: means for mounting a bulk supply roll (110) having the strip of cleaning fabric wound around a shaft (115); and means for forming a cleaning fabric supply roll (10). Printing apparatus according to either claim 51 or 52 further comprising a calendaring means (150) for reducing the thickness and increasing the length of the strip of cleaning fabric on the shaft (115) without substantially increasing the diameter of the cleaning fabric supply roll (10). Printing apparatus according to any one of claims 51 to 53 wherein the soaking means comprises at least one container (122) for containing organic solvent (20). Printing apparatus according to any one of claims 51 to 54 including at least a pair of squeezing rollers (160), configured to squeeze the soaked strip of cleaning fabric (13) passing between the rollers. Printing apparatus according to any one of claims 51 to 55 wherein the soaking assembly includes a dipper (176, 184) for dipping the strip of cleaning fabric (13) into the organic solvent (20) so as to soak the cleaning fabric. Printing apparatus according to claim 56 including a squeezer (186) operatively associated with the dipper (184) to squeeze the strip of cleaning fabric (13) between the dipper and the squeezer. Printing apparatus according to any one of claims 51 to 55 including a organic solvent applying roller (124) to receive organic solvent (20) from the soaking assembly (122) and means to receive organic solvent from the applying roller and to apply the organic solvent to the cleaning fabric (13).

Inventors: ANSELMO PETER E, CANO WALTER H, GASPARRINI ROBERT C, ANSELMO, PETER E., CANO, WALTER H., GASPARRINI, ROBERT C.
Applicants: BALDWIN GRAPHIC SYSTEM INC, BALDWIN GRAPHIC SYSTEMS, INC
Application year: 1996
Main classification: B41F35
IPC codes: B41F35, D06G1