Abstract: A foamed aqueous dispersion of a mixture of particulate plastics material is formed when the fibers are between 5% and 35% of the volume of the mixture, where no more than about 7% of the volume of the mixture is conductive fibers between about 7 and 20 mm long, and where any other fibers are reinforcing fibers with a high modulus of elasticity and between about 7 and about 50 mm long. A web is formed from the foamed dispersion using a wet laying process. The web is dried and compacted under heat and pressure. The compacted web is cooled to form a consolidated element in which the conductive fibers extend as a conductive lattice. The resulting element can be formed or molded into shielding to provide attenuation of electrical or magnetic fields.

Abstract: Security paper carries an intricate tactile surface profile pattern which has been imparted to the paper during its manufacture, at a stage after initial de-watering but before final drying, by passing the paper through a nip between a forming surface corresponding to the desired pattern and a backing surface. The tactile pattern is of excellent durability, and its intricacy offers a high degree of security. The tactile pattern is visible when viewed under low angle light, which facilitates verification or authentication of security documents made using the patterned paper.

Abstract: Pressure-sensitive copying material comprises a substrate carrying isolated droplets of an oil solution of chromogenic material confined within respective pressure-rupturable barriers. The chromogenic material develops a colour other than blue or black on contact with colour developer and comprises a component which is fluorescent. This enables the authenticity of the copying material to be verified by irradiation with ultra-violet light to produce fluorescence. The fluorescent material can be, for example 2,2-bis(4-{2-?4-diethylaminophenyl!-quinazolin-4-yloxy}phenyl) propane or 1-(3-methoxy-4-dodecyloxyphenyl)-2-(2'-quinolyl)ethylene. Non-fluorescent chromogenic material(s) are preferably used in combination with the fluorescent chromogenic material(s).

Abstract: Casting paper of a desired surface texture or finish for use in the manufacture of artificial leather is produced by heating the polymer coating 1 of a polymer-coated paper 2 to a temperature sufficient to melt the polymer and then cooling the polymer coating from its molten state to a solid state as it passes through a nip between an embossing roll 3 having a surface configuration corresponding to said desired surface texture or finish and a backing roll 4, thereby to impart the surface configuration of the embossing roll to the polymer-coated paper. The polymer is preferably polyolefinic, for example poly (4-methyl-1-pentene) or a polypropylene/polyethylene blend. An anti-curl back-coat, for example of polyvinyl alcohol, can be applied after the embossing operation.

Abstract: Speckle-patterned paper is produced on the paper machine without the use of printing techniques by first preparing speckle-forming material and then introducing this into a contrasting color papermaking furnish. Paper is then made from the speckle-containing furnish in the normal way. The speckle-forming material is produced either by agglomerating a mixture of papermaking fiber, particulate pigment and, preferably, a latex or other binder or by dry comminution of cellulose fiber aggregates in the form of paper or entangled fiber clumps.

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: Pressure-sensitive copying material comprises 3,1 benzoxazine chromogenic material(s) in a solvent comprising vegetable oil and/or a mono-, di or tri-functional ester of a non-aromatic mono-carboxylic acid having a straight or branched hydrocarbon chain with at least three carbon atoms in the chain in addition to the carboxyl carbon atom and an inorganic colour developer. The surface pH of the colour developer is not more than about 8.7, which gives rise to enhanced image intensity and fade resistance compared with the use of 3,1 benzoxazine chromogenic materials in the same solvent with the same colour developer at higher surface pH values.

Abstract: A system is disclosed for detecting watermarks or other marks made along a web of paper at regular intervals. The watermarks are detected by a video camera activated by a frame grabbing pulse in a control loop. The video for each frame grab pulse signal is digitized and processed to detect the watermark and to measure its position within the frame. The error between the measured position and a frame reference is used to adjust the value of a parameter (NEWCOUNT) representing the distance or pitch between successive watermarks. This value is in turn used to determine the moment of the next or a succeeding frame grab pulse. All timing is done in terms of measured length of web run by measuring pulses from an encoder. The control loop acts to track variations in the watermark pitch.

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: A cell for measuring electrokinetic potential, such as a streaming potential, includes a housing having an interior chamber divided into an upper compartment and a lower compartment by a filter mesh on which is formed a pad of a fibrous dispersion to be measured. The cell is of particular utility in the manufacture of paper and is used in the manner described in U.S. Pat. No. 4,535,285. To assist flushing of the fiber pad from the filter mesh a nozzle assembly in the upper compartment is used to direct a jet of water at the filter mesh. An additional step to flush out fibrous material reaching the upper compartment is described. This uses an additional port.

Abstract: A binder formulation for improving the water resistance, especially the warm water resistance, of thermally-sensitive record material comprises a major proportion of an amide ammonium salt of a substantially non-esterified styrene/maleic anhydride copolymer and a minor proportion of polyvinyl alcohol.

Abstract: In a process for the recovery and re-use of raw materials from paper mill waste sludge, the sludge is subjected to a preliminary cleaning treatment at a relatively low consistency, thickened to a consistency of 10 to 30%, heated to at least 100.degree. C. and then passed through a disperser in the thickened heated state before being passed to a papermachine for re-use. Papermaking fibre from at least one other source is mixed with the sludge before and/or after treatment as just described, so that the final paper product typically contains up to 30% of raw materials recovered from sludge. The action of the disperser is to break up dirt and other debris, and as a result, the recovered raw materials can be re-used in the manufacture of high quality fine papers.

Abstract: A chromogenic composition for use in pressure-sensitive record material comprises chromogenic material in an ester vehicle. The ester may be mono-, di- or tri-functional and is of a non-aromatic mono-carboxylic acid having a straight or branched hydrocarbon chain with at least three carbon atoms in the chain. Suitable esters include fatty acid esters such as cocoates, isostearates, myristates, and palmitates and wax esters such as alkyl-branched esters of an aliphatic carboxylic acid and an aliphatic alcohol.

Abstract: Pressure-sensitive copying material utilizes a blend of rapid- and slow-developing chromogenic materials in vegetable oil solvent and an acid clay or synthetic inorganic color developer. The surface pH of the color developer is not more than 8.7, which gives rise to enhanced image intensity and fade resistance compared with the use of conventional higher color developer surface pH values.

Abstract: A solvent composition for use in pressure-sensitive copying papers comprises a mixture of vegetable oil and a mono- or di-functional ester of a fatty acid or other acid composed of a non-aromatic saturated or unsaturated straight or branched hydrocarbon chain and a single terminal carboxyl group.

Abstract: A chromogenic composition for use in pressure-sensitive record material comprises chromogenic material in a vegetable oil vehicle. The vehicle is made up of at least a major proportion of relatively high melting vegetable oil which is solid or semi-solid at ambient temperatures of around 20.degree.-25.degree. C., and is substantially free of esters of an acid derivable from an animal or vegetable oil. The high melting vegetable oil can be coconut oil, palm oil, palm kernel oil and/or a hardened vegetable oil such as hardened soya bean oil or hardened coconut oil.

Abstract: A styrene-acrylic ester copolymer latex is used for prevention of premature coloration in CFB pressure-sensitive copying paper which is neutral- or alkaline-sized with an alkyl ketene dimer and which utilizes an acid clay or other inorganic color developer composition. The copolymer may be carried by the base paper, e.g. as a result of size press or size bath application, or may be present in the microcapsule coating.

Abstract: Pressure or heat sensitive record materials with color-former sublimation problems reduced or eliminated whilst not reducing the color forming capability per unit weight of color former by providing what are in effect dimers of vinyl carbinols, with the vinyl carbinol residues, linked through the aryl groups of a diaryl amine.

Abstract: In treating the surface of a material with laser energy by sweeping a laser beam over the surface, a substantial uniformity of energy delivery is achieved across a major portion of the transverse width of the beam by using an unfocussed beam of a ring mode configuration and preferably one having an outer ring with at least some degree of interior fill as is achieved by a laser beam continuing TEM.sub.00 and TEM.sub.01 * modes. The specification discusses various beam configurations. The specification introduces the concept of "exposure integration" which is a function not only of the beam profile in the sweep direction but of the rate of sweep. An exposure duration for any scanned point of not more than 10 milliseconds is suggested. The application of the invention is particularly described with reference to marking the surface of paper.