Papermaker's fabric with anti-soiling nanoparticle coating and method for in situ application

Abstract

A papermaking fabric is treated by applying a coating in the form of nanoparticles to improve its resistance to contamination by foreign substances in a papermaking system. The coating is applied during fabric manufacture and cured during thermosetting. Alternatively, the coating is applied or refreshed in the dryer section by utilizing an existing shower or placement spray boom or other suitable coating application device, applying the coating in a controlled, uniform manner to the the fabric. Before applying the coating, the fabric is thoroughly cleaned, eg, by showering or spraying, and then dried. After the controlled application of the coating, any excess material is removed by suitable means (eg by vacuum) and the remaining coating on the fabric is then cured using ambient heat of the dryer or by means of a portable heater set Floor. In this way, it is not necessary to remove the fabric from the machine to apply or refresh the anti-stain coating.

Description

technical field [0001] The present invention relates to a method of in situ application of an anti-fouling nanoparticle coating on papermaking fabrics, and papermaking fabrics so coated, and in particular, the present invention relates to the application of a coating on papermaking fabrics to reduce machine downtime Method for in situ application of antifouling nanoparticle coatings. Background technique [0002] Papermaking fabrics are used with papermaking machines to form embryonic webs from pulp and to carry them through various dewatering and drying processes to form various forms of paper products. Papermaking fabrics are generally in the form of a fine mesh, which can take various forms depending on the location on the papermaking machine, and can contain additional layers of batt, such as in certain press fabrics and dryer fabrics. [0003] Particles suspended in the primary fibrous material used to form paper include rosin, binders, other glue-like substances, and ...

AI Technical Summary

Problems solved by technology

[0003] Particles suspended in the primary fibrous material used to form paper include rosin, binders, other glue-like substances, and materials that have a tendency to stick to papermaking fabrics, reduce fabric permeability, and negatively affect the properties of papermaking fabrics, as highlighted in previous papers on this issue Known solutions have proposed coating fabrics with anti-staining materials to enhance the anti-adhesive properties of the fabric and to keep the fabric cleaner for a longer period of time after installation on a paper machine, however, it was previously known that the fabric wears down through use, resulting in Reduced performance of papermaking fabrics, moreover, the thickness of the coating itself must be very small so that the coating itself does not reduce the permeability of the fabric

[0004] Despite the relatively short lifespan of the initial coating, a previously known anti-fouling coating has been developed to include polytetrafluoroethylene (PTFE) using a bath prior to installation of the fabric on the paper machine and then in 200 to 400 Applied to the fabric when cured at a temperature of 100°C, the anti-stain coating has a long life, but is still subject to abrasion

[0005] Nanoparticles are also known and described, for example, in: WO02 / 50191 Solvent-poor sol-gel lacquers; US Pat. Nanostructures and layers and methods for their manufacture; U.S. Patent No. 6,607,994 Nanoparticle-based permanent treatment of fabrics; U.S. Patent No. 6,649,266 Substrates with microstructured surfaces; U.S. Patent No. 6,629,070 Nanostructure molding body; WO03 / 014232A1 manufactures abrasion resistant hydrophobic and / or oleophobic coated materials which have been used in relation to various fabric forms, for example for anti-pollution or to increase wear life, however, they have not specifically related to the use of papermaking fabrics

[0006] In use, it is also known to remove papermaking fabrics with substantially remaining useful life from papermaking machines for recoating and then reinstalling to maintain the benefits of the anti-soil coating, however, this requires substantially additional cost and papermaking machinery Downtime

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