摘要:
Method and apparatus for DTR development of a lithographic printing plate of the type having a support possessing a natural deflection curvature under its ow weight and carrying an exposed silver halide emulsion layer in sandwiched relation an image receiving layer, wherein the plate is introduced into one end and removed from an opposite end of a DTR photographic developing bath for the emulsion layer. For such introduction, the plate is advanced through the nip of at least one pair of ingress feed rollers disposed one above the other above the bath surface along an ingress path that extends tangential to the nip at an angle of at least 5.degree. but less than 25.degree. to the horizontal and is unconstrained prior to its intersection with the bath surface. For its removal, the plate passes through a pair of egress feed rollers located above the bath surface along an egress path tangential to the egress roller nip at an angle of at least 5.degree. but not more than 25>to the horizontal. While within the bath, the plate is guided, e. g. by elongated guiding bars, along a curved immersion path that has a positive curvature not substantially greater than the natural deflection curvature of the support and at its opposite ends is substantially continuous with the ingress and egress paths, The distance separating the nips of the ingress and egress roller pairs measured along the paths is less than the length of the plate. The guide bars can diverge laterally from one another.
摘要:
A method and apparatus for making an offset printing plate according to the silver salt diffusion transfer process comprises the step of washing the imaging element by applying a curtain of an aqueous medium onto the surface of the element at its silver halide emulsion layer side, across the width of the element, substantially transverse to its processing direction, and in countercurrent to the processing direction of the element.
摘要:
A roller, for use in a photographic sheet material processing apparatus, comprises a core (32) provided with a covering of relatively soft material (34). The roller has a length (L) of from 0.4 to 2.0 m. The core has a maximum diameter (D) of less than 0.04*L m. The roller is characterised by having a deflection as measured by a specific test and a weight (W) below levels defined by a specified boundary condition formulae (1) & (2). Rollers satisfying this condition are characterised in that the core is formed of a composite material comprising fibers and a resin matrix. Such rollers have a relatively small diameter, are light and yet still have sufficient stiffness to avoid substantial wrinkling of the sheet material in the apparatus and to satisfy the requirements of high processing quality.
摘要翻译:用于照相片材处理装置的辊包括具有相对柔软材料(34)的覆盖物的芯(32)。 辊的长度(L)为0.4〜2.0μm。 芯的最大直径(D)小于0.04 * L m。 辊的特征在于具有通过特定测试测量的偏转和由指定的边界条件公式(1)&(2)限定的水平以下的重量(W)。 满足该条件的辊的特征在于,芯由包含纤维和树脂基质的复合材料形成。 这样的辊子具有相对小的直径,并且仍然具有足够的刚度,以避免装置中的片材的显着起皱并且满足高加工质量的要求。
摘要:
Apparatus for processing a photographic sheet material in at least one processing stage which includes a feed roller array for transporting the material to or from the stage. The feed roller array has a pair of rollers supported on shafts for rotation and mounted with one superposed generally above the other. The upper roller is driven in a transport direction by a drive mechanism acting on an end of its shaft. The opposite ends of the shafts of the two rollers are journaled in frame members with the lower roller being supported for limited independent movement toward and away from the upper roller. The lower roller is normally biased into contact with the upper roller and is adapted to be displaced vertically away from the upper roller by a cam arrangement acting on the ends of its shaft. The upper roller is adapted to be shifted axially to disengage an end of its shaft from its journal to permit the upper roller to be removed manually from the apparatus.
摘要:
Provided is an apparatus for processing a photographic sheet (9) which comprises at least one station (4) with inlet and outlet pressure roller pairs (42 to 45) for transporting the sheet, spray means (22) for spraying processing liquid (21) onto at least one surface of the sheet, characterised in that the station (4) comprises sealing means for maintaining a liquid seal (58, 59) between at least one roller of at least one roller pair and an adjacent wall of the washing station. Also provided is an apparatus for making an offset printing plate according to the silver salt diffusion transfer process, using the described station (4) as washing station. Also provided is a method for making an offset printing plate using the above described apparatus for processing an imaging element.
摘要:
Apparatus for processing rectangular sheets of photographic material in varying format sizes is equipped to calculate at least approximately the surface area of the sheets fed therethrough. For this purpose, the apparatus includes a sensor for determining a dimension, e.g. the length, of each sheet, a memory for storing the length and width dimensions of a plurality of sheet format sizes, and a control unit which compares the determined dimension of a sheet with the dimensions stored in the memory and upon finding a match therebetween gives an output signal indication of the surface area of the sheet. If more than one match is found, the unit gives an output signal corresponding to the largest format size having a dimension equal to the determined dimension. If no match is found by the control unit, the unit is adapted to give an output signal equal to the multiple of the determined dimension and the largest of the stored width dimensions or, alternatively, an output signal corresponding to a format size having a length greater than the determined dimension. The surface area indications can be used to regulate the replenishment of processing liquid consumed during processing.
摘要:
A sleeve segment for flexography has the shape of a sleeve with a first circular side containing a female registration element and a second circular side containing a male registration element. Also a method for manufacturing a flexographic sleeve segment, segmented sleeves and methods of flexographic printing.
摘要:
A photographic sheet material processing apparatus has a plurality of treatment cells (12', 12", 12'") mounted one above another in a vertical stack to define a substantially vertical sheet material path (20) through the apparatus. The apparatus is cleaned by feeding a cleaning liquid to a first cell (12'), allowing at least a portion of said cleaning liquid to pass by gravity from said first cell (12') to at least one further cell (12"), and discharging said cleaning liquid from the apparatus. This process provides a convenient and efficient method of cleaning a vertical photographic sheet material processing apparatus.
摘要:
Device for cleaning the wall (1, 23) of a silo, comprising a compressed-air gun (12) suspended from two cables (14, 15) which are connected to two separate winches (16, 17), bearing on two pulleys (9, 10) fastened to a frame (6) which is arranged inside the silo and which is fixed to a rotary plate (4) which can move on a circular track (5) above an opening (2) in the silo.
摘要:
A method is disclosed for diagnosing the cause of bad performance of a printing plate obtained using the silver salt diffusion transfer process. According to the method a problem table is used to relate a problem to one or more possible causes. A test table is used to identify tests to verify a possible cause of the problem and a toolkit is provided including equipment needed for carrying out tests. Using the method a technician can identify possible causes for a problem, identify the tests capable of verifying one or more causes and perform the tests to confirm the cause of the problem. In the event a cause is not confirmed the technician can investigate other possible causes.