Abstract:
A mat containing highly machine direction oriented (90 % or greater), discontinuous reinforcement fibers, is produced on inclined wire or rotary paper making machinery. Fibers are first uniformly dispersed in an aqueous medium containing thickeners and wetting agents. In one embodiment, antifoaming agents are also added to prevent floating fibers which entangle and reduce orientation. Thermoplastic fibers or particles may also be included. Stock is brought into an open headbox in a flow pattern which allows the fibers to decelerate before approaching the porous suction belt (wire). As the fibers approach the suction belt, the fibers begin to turn and align in the streamline so as to present one end toward the suction wire. The leading ends of the fibers are gripped by the moving belt which drags the fibers out of the dispersion stock in a straight line. The porous mat produced may be dried and bonded through hot air, heat and/or pressure, or chemical binders. Stacks of such mats may be compressed partially to produce porous structures, or fully to produce impervious, rigid structural panels or shapes.
Abstract:
The invention relates to fraud-proof paper and to a method and device for the production thereof. The inventive method consists in forming a first paper web provided with a protective band whose width is equal to or less than 2 mm and which is incorporated into the web during the formation thereof with the aid of a cylinder mould machine in such a way that free-access areas (windows) are formed on protruded elements of the face side of the web. Said protective band is incorporated into the first paper web during the formation thereof and after formation of the free access areas which is associated with the formation of a fibre layer representing 35-50 % of the mass of the first paper web. A second paper web devoid of the protective band is produced simultaneously with the first web and afterwards is applied to the back side thereof in such a way that when they are connected to each other the defects of the said back side are hidden. Afterwards, the thus obtained two- layer material is pressed and dried. The protruded elements are embodied in the form of waterproof elements. An additional protective element is incorporated into the first and/or the second paper web during the production thereof. For the purpose of said invention, a protective band having a width ranging from 2 to 20 mm and comprising additional protective elements is used
Abstract:
A cylinder former (10) having a variable hydraulic pulse whilst drainage, for use in papermaking comprising a drainage means comprising a cylinder mould (12) and a contoured member (34) adjacent the cylinder mould having a plurality of hills and valleys which force entrained liquid through the fiber suspension forming on the cylinder mould so as to improve sheet formation. A baffle (39) is provided in the discharge portion of the former to prevent stock build-up therein.
Abstract:
The invention relates to fraud-proof paper and to a method and device for the production thereof. The inventive method consists in forming a first paper web provided with a protective band whose width is equal to or less than 2 mm and which is incorporated into the web during the formation thereof with the aid of a cylinder mould machine in such a way that free-access areas (windows) are formed on protruded elements of the face side of the web. Said protective band is incorporated into the first paper web during the formation thereof and after formation of the free access areas which is associated with the formation of a fibre layer representing 35-50 % of the mass of the first paper web. A second paper web devoid of the protective band is produced simultaneously with the first web and afterwards is applied to the back side thereof in such a way that when they are connected to each other the defects of the said back side are hidden. Afterwards, the thus obtained two- layer material is pressed and dried. The protruded elements are embodied in the form of waterproof elements. An additional protective element is incorporated into the first and/or the second paper web during the production thereof. For the purpose of said invention, a protective band having a width ranging from 2 to 20 mm and comprising additional protective elements is used
Abstract:
The invention relates to a rotary former for manufacturing paper or paperboard, in which a cylinder mould (1) is fitted with an endless foraminous forming band (4) on which paper making stock is deposited to form a web (6). The web (6) is transferred from the forming band (4) to a making felt (7) and the forming band is guided in a loop having a run (10) travelling adjacent the making felt for a predetermined distance downstream of the web transfer position (9).
Abstract:
A method for manufacturing watermarked paper (11), comprising: - a step of forming a first fibrous panel (1) which comprises at least one watermark element; - a step of forming a second, thin fibrous panel (2); - a step of removal, by way of suction, of at least one portion of the second, thin fibrous panel (2) in order to produce a localized reduction in thickness at a first face (2a) of the second, thin fibrous panel (2), so as to provide at least one accommodation seat (2b) intended to accommodate a security element; - a step of coupling between the first fibrous panel (1) and the face of the second, thin fibrous panel (2) which lies opposite the first face (2a).
Abstract:
A suction breast roll former (10) is disclosed which includes a suction breast roll (14) and a headbox (12). The suction breast roll has a support surface (20) with a plurality of apertures (22) formed therein that are operatively connected to a vacuum source (V). The headbox has a flexible roof (70) extending downstream from a slice opening (46) and disposed adjacent to a support surface of the suction breast roll. The headbox permits the flexible roof to bend over a range of movement relative to the support surface to match the shape of a drainage curve suiting current operating conditions. The method of forming a paper web using the suction breast roll and headbox is also disclosed. The method includes the steps of supplying an aqueous suspension of papermaking fibers to a forming zone (18) created between the suction breast roll and the headbox. The headbox includes a slice body (40) and an apron (42) that define a slice opening therebetween and also has a flexible roof extending from the slice opening and spaced from the support surface to define a forming zone therebetween. A forming fabric (16) is passed through the forming zone to receive the aqueous suspension of papermaking fibers. The flexible roof is permitted to bend over a range of movement relative to the support surface to match the shape of a drainage curve.
Abstract:
The gap between the pointed edge and the tangential line of the fourdrinier from the guide roller is a max. of 0.2 times the dia. of the guide roller. The guide roller has a facility to extract water from the fourdrinier, collected during the operation of the papermaking machine. The design allows the guide roller to extract and evacuate water effectively in a high speed papermaking machine.