Abstract: An air permeable sheet-like structure comprising 20% to 60% by weight of single discrete reinforcing fibres having a high modulus of elasticity (as herein defined), and being between about 7 and about 50 millimeters long and 40% to 80% by weight of wholly or substantially unconsolidated elements of thermoplastics material, and in which the fibrous and thermoplastics components are bonded into an air permeable structure, at least some of said elements of thermoplastics material each having a first dimension of not more than 1 millimeters, a second dimension of between 1.5 millimeters and 30 millimeters, a total volume of not more than 30 cubic millimeters and a surface area to volume ratio greater than about 4:1, with any further elements of thermoplastics material present each having a volume of less than about 1.8 cubic millimeters.

Abstract: Microcapsules are applied in metered quantity to a paper web passing through an ingoing nip between a hard applicator roll and a soft backing roll. Metering is achieved by means of a deformable metering roll in adjustable pressure contact with the applicator roll and rotating in an opposite sense thereto to define an ingoing nip. Coating composition is fed to this nip from a pipe or by the roll dipping into a bath of coating composition. The metered coating emerging from the metering nip is re-distributed and smoothed by a deformable smoothing roll rotating in the same sense as the applicator roll and in contact therewith. The process facilitates application of relatively high solids microcapsule compositions at low wet coatweights.

Abstract: In a process for the production of microcapsules by coavervation of gelatin, carboxymethyl cellulose (CMC) and a second anionic polymer such as a polyvinylmethylether/maleic anhydride copolymer or an ethylene/maleic anhydride/copolymer, the weight ratio of gelatin:CMC is chosen to be in the range 1:0.14 to 1:0.05, and the CMC used is chosen to have a viscosity in the range of from 50 to 140 mPas (cps), when measured in 6.0% by weight aqueous solution at 20.degree. C. using a Brookfield RVT viscometer, Spindle No. 1, 10 r.p.m. The use of the specified weight ratio and CMC type permits significant increases in the solids content at which encapsulation can be carried out without increasing process viscosities to an unacceptable extent and/or giving rise to poor quality microcapsules. The process is particularly suitable for producing microcapsules for use in pressure-sensitive copying paper.

Abstract: An air permeable sheet-like structure comprising 5% to 50% by weight of reinforcing fibres, and between about 5 and about 50 millimeters long, and from 50% to 95% by weight of wholly or substantially unconsolidated particulate non-cross-linked elastomeric material, and in which the fibrous and elastomeric components are bonded into an air permeable structure.

Abstract: A process for the manufacture of a stiff permeable sheet-like fibrous structure which includes forming a web with 20% to 60% single fibres having a high modulus of elasticity (as herein defined) and between 7 and 50 millimeters long, and 40% to 60% by weight of a wholly or substantially unconsolidated particulate plastics material, and then treating the web by heating to melt the plastics material and passing it between a pair of nip rollers so that the plastics material can flow and wet out the fibres, the nip between the rollers being set to a dimension less than the thickness of the unconsolidated web and greater than that of the web if it were to be fully consolidated, and allowing the web to expand and remain substantially permeable after passing through the rollers.

Abstract: A process for forming a homogeneous sheet from particulate elements, (as herein defined), at least some of which have an inherent vertical mobility (as herein defined) in water at normal temperature and pressure of from about 1 to about 21 cms/sec, which comprises the steps of forming a foamed dispersion of said particulate elements, and depositing and draining said dispersion on a foraminous support.

Abstract: Microcapsule-coated paper for use in a pressure-sensitive copying set contains a higher than conventional filler loading, namely 15% to 23%, based on the total weight of the paper. The use of filler loading levels within this range increases the maximum number of legible copies obtainable in a pressure-sensitive copying set.

Abstract: A fibre reinforced thermoplastics material structure having a first layer which is fully consolidated with uniformly dispersed fibres and a second layer which is formed as an absorbent matrix.

Abstract: Record material comprising a paper sheet having on its front a printable pigment coating and on its back isolated droplets of colour former solution each confined within a pressure rupturable barrier, wherein the pigment coating comprises a binder for the pigment together with a synthetic reactive sizing agent or a coating structure agent or both the sizing agent and the coating structure agent.

Abstract: A laser beam is used to mark a longitudinally moving web of paper both at intervals along its length and at plural locations across its width so that each of the sheets finally cut from the web bears a mark. The web passes over a cylinder having windows bearing masks carrying a logo or the like to be marked on the web. Mirrors are arranged on a drum assembly coaxially located in the cylinder to rotate therewith. The mirrors are disposed in helical sets extending along the axis of the drum to successively intercept a laser beam directed parallel to the axis of the drum and to reflect the beam to successive mask windows. The mirrors are plane mirrors set at 45.degree. to the axis and cause the beam to scan the mask in the circumference direction. The beam is collimated but not focussed and has a diameter that encompasses the transverse width of the mask. A ring mode laser beam is preferred.

Abstract: A release paper for the manufacture of artificial leather, characterized by the release coating of the paper being essentially of a flexible poly(4-methyl pentene-1) resin (TPX) loaded with particulate mineral filler.

Abstract: Laminated reinforced thermoplastic sheets are made by preparing first and second porous sheets, each having 20% to 60% by weight of reinforcing fibers having a high modulus of elasticity and 40% to 80% by weight of a thermoplastic material differing from the thermoplastic material in the other sheet and applying heat and pressure to cause the sheets to consolidate and adhere together to form the laminate.

Abstract: A layer of particulate material is formed by forming a foamed dispersion of a particulate material, supplying the foamed dispersion to a predetermined zone of a plane through which a foraminous element is moving, applying a vacuum to said plane across the zone on the other side of the foraminous element, so as to drain foam and form a particulate layer thereon, removing any free air from the drained foam, and continuously recycling the resulting foam for re-use in forming the foamed particulate dispersion. An apparatus is provided for carrying out the process.

Abstract: A process for moulding articles of fibre reinforced plastics material which includes pre-heating a sheet of consolidated thermoplastics material which has dispersed therein from 20% to 70% by weight of reinforcing fibres which have a high modulus of elasticity (as herein defined) and between about 7 and about 50 millimeters long to cause the sheet to expand due to relief of the stresses in the reinforcing fibres, placing the expanded sheet in a compression mould and closing the mould to form an article of predetermined shape having portions of different density.

Abstract: Aqueous suspensions of papermaking fibres and filler are each separately treated with an anionic or a cationic polymer, after which the filler (preferably) or the papermaking fibre is treated with a polymer of opposite charge to that used in the initial treatment. The filler and papermaking suspensions are then mixed to form a papermaking stock, with dilution as necessary before, during or after the mixing operation. This stock is then used to form a loaded paper web in conventional manner. The initial treating polymer is preferably a papermaking retention aid or flocculant, e.g. a cationic polyarcylamide or an amine/amide/epichlorohydrin copolymer in the case of cationic materials or an anionic polyacrylamide in the case of anionic materials. The further treating polymer is preferably an anionic or cationic starch, depending on the charge of the initial treating polymer.

Abstract: A pack of paper suitable for use in xerographic, ion deposition of magnetographic printing processes, the pack including a stack of paper sheets having a moisture content of not more than 6% and a reclosable carton made of semi-stiff sheet material and comprising a container portion containing said stack, and a closure portion, said container and closure portions having mutual parallel planar surfaces which slidably interengage upon closure of the carton to restrict air ingress to the carton there-between, and means for limiting the (WVIR) to not more than 30 grammes per square meter of the surface area of the carton in 24 hours at 90% Relative Humidity and a temperature of 32.degree. Celsius.

Abstract: Disclosed is a method of testing the propensity of a paper or board to dust. The method is one which includes pressing a reference surface to the surface to be tested at a predetermined pressure. The dust adhering to the reference surface is then measured such that an indicative reading is obtained.

Abstract: A shaped article of fiber reinforced material is made by forming a foamed aqueous dispersion having single discrete fibers, and unconsolidated particulate thermoplastic or thermosetting material, laying down and draining the dispersion to form a web, transferring the web to an oven and heating it to form a self-sustaining permeable sheet, transferring the sheet to a through-air heating oven, passing heated air through the sheet to cause substantially uniform and homogeneous heating of the thermoplastic component, transferring the heated sheet to a compression mold, and subjecting the sheet to compression molding to form a shaped fiber reinforced plastic article.

Abstract: The energy of a laser beam (32) is used to form images at intervals along a lengthwise moving web (10). The images are formed along a plurality of axes spaced transversely of the web so that after slitting and cutting an image appears on each sheet. The laser beam (32) is directed across the web and is repetitively and successively switched by rotating optical mirrors in assemblies (71a-71g, 72a-72g) located at intervals across the web to scan image-bearing masks (FIG. 2) rotating with the mirrors. The beam impinges on respective mirrors of successive assemblies. The mirror assemblies are conical mirror segments (78) or plane mirrors cooperating with a fixed conical mirror segment (FIG. 5) to produce a focussed line (82) that is fixed in space and scans the rotating mask. The scanning line is re-imaged (90) on the web (10).

Abstract: An aqueous conductivising composition for conductivising paper or other sheet material, for example for producing a conductive base for use in dielectric paper or other electrostatic imaging material, is produced by (a) removing sodium magnesium trifluoride impurity (neighborite) from a synthetic hectorite clay conductivising agent, and (b) adding a binder. These measures reduce dust formation experienced in production or use of electrostatic imaging material incorporating a base which has been conductivised with a synthetic hectorite clay conductivising agent.