Abstract: A method and apparatus that prevents premature drying of a layer of a water-based coating composition on a substrate are disclosed.

Abstract: The invention is a paper making machine and a method of making paper. The machine includes a section for forming a wet paper web having first and second sides and a dryer for drying the wet paper web. At least a first portion of the dryer is capable of preferentially drying the first side of the wet paper web to a dryness level of at least about 70% solids. In a variation of the paper making machine, the first portion of the dryer is capable of preferentially drying the first side of the wet paper web to a dryness level of at least about M, as represented by the formula:M=101-0.246 (WRV)in which WRV is the water retention value of the web. The method for drying a web of paper includes a forming step and a drying step. The forming step is carried out by forming a wet paper web having first and second sides.

Abstract: When drying a paper web (4) in a dryer section (1) of a paper machine provided with drying cylinders (2, 3) and drying wires (5, 6), shrinkage of the paper web in cross direction is counteracted by applying forces at its edge portions (11). According to the invention partial vacuum is maintained along the edge portions of the web within substantially the entire free draw (10) and is applied from the side of the drying wire (5, 6) facing away from the web (4) so that the web is sucked firmly against the drying wire by forces greater than the contracting forces acting in cross direction, thereby counteracting shrinking, said partial vacuum being set within the interval 0.1-0.8 bar, preferably 0.2-0.5 bar.

Abstract: Machine for manufacturing a web that may include a dryer section having a plurality of dryer cylinders and a plurality of guide rolls, a transport belt that guides the web through the dryer section in a meandering path, a moistening apparatus, and a controlling device. The controlling device may include a device for detecting a web break and a device that activates the moistening apparatus to cool the dryer cylinders in response to the detected web break.

Abstract: A method and device for drying a paper web in a dryer section having a number of successive dryer groups with a single-wire draw, and being situated after a press section of the paper machine. Each dryer group includes contact-drying cylinders arranged in a first row and reversing suction cylinders or equivalent suction rolls arranged in a second row, the rows being horizontal, diagonal or vertical rows. The paper web is dried by contact-drying cylinders from the side of its lower face across the entire length of the dryer section. The paper web is passed as a closed draw from one dryer group to the next group, and the paper web is guided, while it runs on the drying wire at the side of the outside curve, by the reversing suction cylinders having a curve radius selected in a range from about 250 mm to about 1000 mm.

Abstract: The present invention is directed to a coaxial waveguide applicator for an electromagnetic wave-activated sorption system which comprises at least one sorber having a metallic tubular housing defining an outer conductor and first and second ends which are sealed to define an enclosure within the outer conductor; a sorbate/sorbent compound located within the enclosure; the sorber including a port through which a sorbate may be communicated into or out of the enclosure; a metallic inner conductor extending into the outer conductor and parallel to the longitudinal axis of the sorber; an electromagnetic wave generator; and a waveguide for coupling electromagnetic waves generated by the electromagnetic wave generator to the inner and outer conductors; wherein electromagnetic waves transmitted by the electromagnetic wave generator are propagated through the enclosure by the inner and outer conductors to desorb the sorbate from the sorbate/sorbent compound.

Abstract: A machine for producing a sheet of material, e.g., a paper or cardboard sheet, including a pressing part having at least one pressing device and a dryer part that includes a plurality of dryer cylinders. A first dryer cylinder of the plurality of dryer cylinders may be disposed immediately adjacent to the pressing part to form transfer region therebetween. The sheet of material being directly transferred from a press roll of the pressing part to the first dryer cylinder. The first dryer cylinder being heated independently of the other plurality of dryer cylinders at a temperature to form a vapor layer between the first dryer cylinder and the sheet of material.

Abstract: A steam blast box for applying steam to a web of paper conducted over a roll of a paper machine. The box has a closed steam blast chamber which extends along the roll transverse to the direction of travel of the web and to which steam can be fed. The front wall of the box, which faces the roll, has a plurality of steam outlet openings. A steam propagation space is formed between the front wall of the steam blast box and the roll. For controlling the temperature and/or for regulating the amount of heat transferred to the web of paper in the steam propagation space, an air outlet channel, which extends transverse to the direction of travel of the web and is located at the web inlet end of the steam propagation space, is provided for the admixing of air in the steam. In this way, sensitive separate, zone-wise control of the heating of the paper web can be obtained. The steam propagation space can be cooled zone-wise by feeding air on the inlet side.

Abstract: A thread is formed of one or a plurality of fans of continuous filaments on which a sizing composition is deposited. The moisture content on the thread is controlled by subjecting the fans of filaments to a current of air transversely to the direction of movement of the filaments between the zone in which the size is deposited and the zone in which the filaments are gathered together.

Abstract: A Yankee hood comprises an integral air heating system combining the hood with circulating fans, air heaters and an air flow duct work distribution system into one assembly with the air system apparatus located inside the hood. Motors for circulating fans and the burner assemblies are mounted on the external face of the hood drive side.

Abstract: A drying section for a paper making machine. The drying section includes a plurality of single-tier dryer groups, optionally followed by one or more double-tier groups. To control curl in the final paper product, a moistening device extending over the width of the drying section is provided near the end of the single-tier dryer groups. The moistening device can be divided into various zones to control the profile of the paper. Alternatively, or in addition to the moistening device, a contact-less dryer such as a infrared dryer can be provided after the dryer section, upstream of a calendar section of the paper making machine. The moistening device can be provided to moisten the bottom or, optionally, the top side of the paper web. Where a double-tier dryer group is provided, to control curl the upper drying cylinders and the lower cylinders can be provided with different steam pressures to control curl. Alternatively, each of the cylinders can be individually controlled.

Abstract: A process and apparatus for controlling the surface temperature of a drying cylinder of a paper machine, in which air may be admixed with the steam introduced into the drying cylinder to adjust the partial steam pressure. The mixture ratio of air and steam is controlled as a function of the measured temperature of the mixture discharging from the drying cylinder. Also, pressure measurements are made of the pressure in the infeed and discharge lines of the cylinder, and valves control this dependent on the measurements. The valves are controlled to provide all steam to the cylinder above a predetermined minimum pressure in the cylinder below 1 bar and to provide a mix of air and steam below the predetermined minimum pressure. Arrangements for controlling one cylinder at a time, several cylinders together for supply of both steam and air, or several cylinders for controlling respective separate supplies of air and with one supply of steam are disclosed.

Abstract: A paper-making process control system is provided for a paper making machine to simulate a web drying operation performed by the drying sections of the paper machine, in order to enhance the reliability of controlling operation in the web product grade change and to reduce the time necessary for the grade change. In the control system, when a web product change is carried out during the paper-making process by passing a web (WE) along with a canvas belt (14b) around a steam-heated drums (14a) for the drying of the web (WE), the control system describes heat balance among the steam-heated drums(14a), the web (WE), and the canvas belt (14b) by heat balance equations on an assumption that there is no temperature differential in the temperature of the circumferential portion of each steam-heated drum (14a), and adjustably regulates supply of steam to the respective steam-heated drums (14a) on the basis of the heat balance equations to thereby bring a moisture content of the web (WE) to a desired value.

Abstract: An unrestrained drying capability is added to an existing series of rotating drying cylinders in a cost- and space-efficient manner to enhance cross-directional (CD) stretch and tensile energy absorption (TEA) in a paper web such as for sack kraft grade paper. High-intensity air glide drying devices are adapted for use in a variety of configurations to provide different levels of unrestrained drying capacity for a pre-existing series of rotating drying rollers. The air glide drying devices carry the paper web on a cushion of air which is heated preferably to 500.degree.-850.degree. F. The sheet moisture content of the paper web during heating in the unrestrained drying section decreases by at least approximately 5%, with an evaporation rate of approximately 15-30 lbm/hr/ft.sup.2. A preferred temperature range of the paper web upon entry to the air glide drying device is 160.degree.-210.degree. F. A pre-heater such as a convection or infrared heater may optionally be employed.

Abstract: An apparatus and method for treating a sheet material (3) with an arrangement of rollers (6, 7), including at least one heated roller (8, 9), which defines at least one roller gap through which the sheet of material is passed and acted upon with pressure and/or elevated temperature. A housing (32) surrounds the roller arrangement (6, 7) and the treatment takes place in an environmental atmosphere, the temperature and/or humidity of which can be adjusted to a specified value. A roll of the sheet material is subjected to pretreatment to provide it with desired temperature and humidity conditions before entering the housing (32).

Abstract: A process for correcting misregistration between imprinted images from successive printing stations comprising measuring the width of the imprinted image of each station and comparing the width to determine any difference, and creating a correction signal if a difference does exist to change the humidity in the web passing through the printing unit. The device includes photoelectric devices for determining the width of each image created at each station, an electronic device for comparing the width of each image and, if a difference exists, creating an error signal which is applied to the first drying unit and a secondary error signal applied to the second unit to correct the humidity of the web leaving each dryer.

Abstract: A method and device for drying a paper web in a dryer section having a number of successive dryer groups with a single-wire draw, and being situated after a press section of the paper machine. Each dryer group includes contact-drying cylinders arranged in a first row and reversing suction cylinders or equivalent suction rolls arranged in a second row, the rows being horizontal, diagonal or vertical rows. The paper web is dried by contact-drying cylinders from the side of its lower face across the entire length of the dryer section. The paper web is passed as a closed draw from one dryer group to the next group, and the paper web is guided, while it runs on the drying wire at the side of the outside curve, by the reversing suction cylinders having a curve radius selected in a range from about 250 mm to about 1000 mm.

Abstract: The position of the exhaust air flap of a through-flow dryer, for example, a screen drum dryer, is adjusted to determine the moisture content of the exhaust air. This is advantageously accomplished as a function of the desired drying temperature of the goods or their moisture content when the good leaves the dryer. Provision is made according to the invention to measure the temperature of the air after passing though the web, at least in the vicinity of the outlet of the dryer, to relate it to the temperature of the ambient air and thus to determine the temperature of the goods and hence their moisture content, since in the residual drying range, the moisture content of the goods is a function of the temperature of the goods. The exhaust air moisture content can then be regulated with this measured value.

Abstract: A method and apparatus for processing a web of material, which is dispensed from a roll and fed through at least one roller gap of a roller-gap system which includes a processing station, an unrolling station on the input side of the processing station, and a roll magazine on the input side of the unrolling station which magazine includes at least one roll storage position. When rolls of web material are processed, the processing delay times lead to an uneven distribution of the temperature and/or moisture within the roll which in turn causes nonuniformity of the results in the processing station. The web of material still on the roll is exposed, prior to being unrolled, to a preselected atmospheric environment for a predetermined minimum length of time. Accordingly, the roll storage position is located in a chamber, the atmosphere of which can be controlled to a preset temperature and/or humidity level.

Abstract: A method of printing a material web includes the steps of applying ink to the material web, subsequently drying the material web with the use of heat and subsequently drying the material web, and, after cooling and prior to further processing, moistening the material web while simultaneously applying heat to the material web, and subsequently once again cooling the material web. An apparatus for carrying out the method includes, in a travel direction, a printing unit, a drying section following the printing unit, a cooling section following the drying section, a moistening section following the cooling section, and an after-cooling section following the moistening section.

Abstract: A jacket with a thermally insulating layer partially surrounds, at a small spacing, a heatable roll which serves for the treatment of webs of material, in particular paper webs. Under production conditions the jacket reduces heat losses from the roll through convection and radiation to the environment. The jacket has a device which, with an interruption of production, ensures a forced convection at the heated roll for the cooling of the surface to a temperature level which is same or only insubstantially higher than in the production state. Several cooling nozzles are conceivable for the said apparatus which are secured to the jacket and direct a coolant onto the roll surface.

Abstract: In the method for controlling the temperature of an intermittently standing and flowing fluid which is at rest during standstill intervals and is flowing during flow intervals, a desired temperature for the fluid is predetermined and the actual temperature of the fluid is measured. The fluid is heated and/or cooled by a tempering device, depending on whether the actual temperature is higher or lower than the desired temperature. The tempering device is controlled by a control unit with at least one variable and self-adjusting control parameter. In the method, it is detected whether the fluid is presently at a standstill or in flow. The value of the control parameter of the control unit valid at the end of a flow interval is stored and at the beginning of the next flow interval is set as the current control parameter in the control unit.

Abstract: A method and apparatus for drying a fiber web is provided by pressing the web, preferably by impulse drying and then introducing the web into a gas pressurized zone followed by reducing the pressure in the zone, the reduction preferably being effected with cooling of the fiber web.

Abstract: Apparatus and method for drying a fibrous web. The apparatus comprises a plurality of drying cylinders arranged in groups from a first group to a last group, the web passing sequentially from the first group to the last group, each group having a single felt, the drying cylinders having vacuum transfer rolls arranged therebetween for guiding the fibrous web from one drying cylinder to the next drying cylinder, the vacuum transfer rolls being coupled to a vacuum source by a vacuum duct system, the duct system providing vacuum to the vacuum transfer rolls such that the vacuum level decreases from the first group to the last group. The vacuum level is preferably below about 1500 Pa, and in particular, in the range of about 100 to 1000 Pa.

Abstract: A drying apparatus is disclosed for drying a web of paper. The apparatus includes more than one top felted dryer group for drying the web. The web may be restrained against cross-machine and machine directional shrinkage during passage of the web through the plurality of dryer groups. A last dryer group is located downstream relative to the plurality of drying groups so that the web extends between the plurality of drying groups and the last dryer group. The last dryer group can be a double felted two tier dryer group. The web extends in an open draw between each dryer cylinder of the upper and lower tiers of the last dryer group, so any tendency of the web to curl is controlled during movement of the web through the last dryer group. Alternative arrangements are also described.

Abstract: A photosensitive material dryer apparatus including a drying chamber and a first drying application device wherein a photosensitive material having a photosensitive material conductivity drying profile is dried following a wet chemical process includes a sensor for electronically measuring and sensing the conductivity of the photosensitive material, and a controller in communication with the sensor and the drying application device for regulating the drying application device based on the sensed conductivity of the photosensitive material.

Abstract: A system for classifying and cooling particulate material produced by a fluid bed boiler comprises a vertical housing having an inlet for incoming particulate material and a first outlet for discharging exhaust and a second outlet for discharging solids. A fluidized bed of material is contained within the housing and is located directly above a bed of material. A gas distribution grid provides air to both beds for cooling the particulate material, and temperature measurement is used along with flow measurement to control gas velocity through the beds.

Abstract: The specification discloses an improved method for drying a paper or paperboard web emerging from the press section of a papermaking machine as it traverses a dryer unit. The method comprises continuously rewetting the web across its width during the initial web drying stage when the web has a solids content of no more than about 65 wt. %. The method improves the water removal rate and decreases the shrinkage rate of the web during drying.

Abstract: A paper web in a paper machine including a yankee dryer is dried and the moisture profile thereof controlled by arraying a plurality of gas burners in a cross-machine direction within the hood of the yankee dryer to direct heat toward different incremental width portions of the paper web. The burners are independently controlled by a scanning moisture gauge.

Abstract: Web offset printing paper having a high level of gloss and smoothness is prepared by finishing a paper web, either by supercalender or with a synthetic roll calender at a moisture content greater than the moisture content typically used for web offset finishing, and then drying the web to a moisture content of less than about 3.5% using convection, radiation or conduction. Under the preferred post-drying conditions, bonding of the previously wet paper fibers takes place to lock in the desirable printing characteristics and to prevent heat roughening on the offset press.

Abstract: In a temperature control method of a photosensitive material drying device relating to the present invention, a photosensitive material is heated and dried by drying air heated by a heating device. A temperature of a member heated by the drying air is detected, and operation of the heating device is controlled so that the temperature of the member is maintained within a predetermined range.

Abstract: A method of controlling the temperature of drying air in a photosensitive material drying apparatus for drying the photosensitive material processed by processing solutions. The method comprises the steps of: calculating an environmental absolute humidity Z.sub.E of a vicinity of the photosensitive material drying apparatus; calculating a processing amount S of the photosensitive material per unit time; calculating a drying air temperature T.sub.D on the basis of the environmental absolute humidity Z.sub.E and the processing amount S of the photosensitive material so that a difference between the drying air temperature T.sub.D and a wet-bulb temperature TW in the photosensitive material drying apparatus falls within a predetermined range of a value; and controlling a heater for heating the drying air on the basis of the drying air temperature T.sub.D.

Abstract: A drying section of a paper making machine has a series of single tier drying groups, all with their respective felt belts arranged so that the drying cylinders are in contact with and dry one side of the web. The single tier groups are followed by one double tier drying group wherein the web passes such that the top side, then the bottom side, then the top side, then the bottom side, etc. of the web is in contact with successive drying cylinders arranged in two rows. Steam under pressure is supplied to all the drying cylinders. In the double tier group of drying cylinders, the steam pressure supplied to a first set of drying cylinders in sequence is higher than the steam pressure supplied to a second set of drying cylinders.

Abstract: A drying control system and method for obtaining a substantially uniformly dried low moisture content web efficiently with reduced energy usage in a papermaking process is provided. The drying rate of the web in this process is precisely controlled by detecting and monitoring the web or felt low and high cross-direction temperature profiles and then actuating drying rate modulators as required to increase or decrease the drying rate to produce a substantially flat temperature profile in response to temperature profile information provided to an automatically or manually controlled central control system by web high temperature and low temperature sensors.

Abstract: A method for drying wood strands and the like is shown and described. In a preferred embodiment, the strands are fed onto a conveyor which then moves the strands as a bed through a dryer housing. The housing may be partitioned into various zones and levels, depending on the desired configuration. A volume of drying air is heated and then passed through the bed of strands to reduce the moisture content of the strands. In a preferred embodiment, the strands are agitated to promote the even exposure of the strands to the drying heat. The strands are then conveyed through a conditioning zone before being discharged from the dryer housing.

Abstract: A method for drying photographic materials from an initial moisture content to a desired final moisture content is provided. At least one side of a photographic material having an initial moisture content is heated, with a first heater stage, to achieve an intermediate moisture content in the material. The intermediate moisture content is less than the initial moisture content of the material and greater than the desired final moisture content. The intermediate moisture content of the material is measured and an output signal corresponding to the intermediate moisture content is provided to a control means. The material is then heated with a second heater stage to the desired final moisture content. The second stage heating is controlled using the output signal and the desired final moisture content.