Abstract: A method in a dryer section of a paper or board machine for controlling curl of paper, in which steam treatment and/or moistening of the paper web is/are employed. The operations carried out in order to control the curl of the paper web are carried out in a number of stages when the web temperature is, during at least one stage, lower than 85.degree. C., preferably lower than 75.degree. C., and when the dry solids content of the web is in the range of K1-K2, wherein K1 is the ultimate dry solids content of the web -7% and K2 is the ultimate dry solids content +3%. The paper or board machine includes at least a headbox, a former, a press, and a dryer section in steam boxes or moistening devices are employed for control of the curl. There are at least two curl regulation devices to enable regulation of the curl in a number of stages, and/or the curl regulation devices are arranged to operate in an area in which the web temperature is, during at least one stage lower than 85.degree. C., preferably lower than 75.

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: Apparatus and method are provided for improved washing and drying of semiconductor wafers utilizing an enhanced "Marangoni effect" flow of liquid off of the wafers for superior prevention of watermarks (water spots) on integrated circuits (ICs) on the wafers. The apparatus includes a housing 12 which may be hermetically sealed, an open-top wash tank 60 within a lower part of the housing, a moveable rack 16 for holding the wafers either in the tank for washing or in an upper part of the housing for drying, apparatus 34 for supplying chilled (near freezing) de-ionized water (DIW) to a lower part of the tank, the DIW flowing within the tank and overflowing the top thereof, a pump 20 for draining overflowing DIW from the housing, and apparatus 40 for supplying to the housing organic vapor such as isopropyl alcohol (IPA) in a dry gas such as nitrogen. During wafer drying operation of the apparatus the pressure within the housing is kept at about one Torr or less.

Abstract: A method and device for contact drying a paper web, wherein the paper web is dried initially in a number of successive groups with single-wire draw by pressing the paper web via drying wires of each groups against the heated faces of the drying cylinders and by guiding the paper web on support of the same drying wire from one drying cylinder onto the next drying cylinder over the reversing suction cylinders or rolls in each group with single-wire draw. In the groups with single-wire draw, the paper web is dried to a first dry solids content, after which the paper web is dried directly further by a single group with twin-wire draw to a second dry solids content, after which the paper web is dried further to its final dry solids content by a single normal group with single-wire draw. The limits of the first and second dry solids contents are selected so that, in the middle or in the beginning of the range, the tear strength index and the breaking strength index of the web are at their maximum.

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: 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 calender 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: Blistering of a wet paper web upon a yankee dryer drum is controlled by directing compressed dry air toward the wet paper web in the space between a pressure roll external of the yankee dryer hood and the entry opening between the dryer hood and the yankee dryer drum. The flow of compressed air is controlled so that air flow can be modified across the full width of the wet paper web.

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.