Abstract: Provided is a paper structure comprised of two outside layers and at least one inside layer. The two outside layers are comprised of substantially cellulosic pulp fiber, and the inside layer is comprised of a high temperature fiber and a polymeric binder, and preferably cellulosic pulp fiber. In a preferred embodiment, the structure comprises at least three inside layers, all comprised of cellulosic pulp fiber, high temperature fiber and a polymeric binder. The resulting paper structure finds particular use as a high temperature transformer paper in the manufacture of transformers.

Abstract: Provided is a process for preparing a smooth and glossy surfaced paper web. The process comprises subjecting the paper web to shear by using calender rolls driven at different speeds or calender rolls with different diameters. The resulting paper has a totally different structure than the original paper, as it has a much smaller void structure and a much higher degree of bonding between the elements of the sheet. The process is particularly applicable to improving the electrical insulation properties of an aramid paper web.

Abstract: The present invention relates to a method for forming a non-woven fibrous web comprised of aramid fibers and aramid fibrid which comprises forming a foam furnish by agitating the fibers and fibrid in a foamed medium, and passing the foam furnish onto a screen and defoaming the furnish. In effectively agitating the aramid fibers in the foamed medium, the agitating means is mounted for displacement within the foamed medium and includes a convex leading surface facing in the direction of displacement. The leading surface includes upper and lower portions converging in the direction of displacement to form a generally convex leading surface and driving means for displacing the agitating means in the direction of displacement for dispersing and mutually separating the aramid fibers within the foamed medium.

Abstract: The present invention relates to a method for forming a non-woven fibrous web comprised of aramid fibers and aramid fibrid which comprises forming a foam furnish by agitating the fibers and fibrid in a foamed medium, and passing the foam furnish onto a screen and defoaming the furnish. In effectively agitating the aramid fibers in the foamed medium, the agitating means is mounted for displacement within the foamed medium and includes a convex leading surface facing in the direction of displacement. The leading surface includes upper and lower portions converging in the direction of displacement to form a generally convex leading surface and driving means for displacing the agitating means in the direction of displacement for dispersing and mutually separating the aramid fibers within the foamed medium.

Abstract: The present invention relates to a nonwoven web comprised of metal or refractory fibers with nylon as a binder. The nonwoven web is prepared by forming a foam furnish by agitating the fibers in a foamed medium, and passing the foam furnish onto a screen and defoaming the furnish. It is preferred that the nylon binder is added to the foam furnish in the form of fibers. Once the furnish is defoamed to form a nonwoven web, the sheet is dried at a temperature sufficient to melt the nylon binder.

Abstract: The present invention relates to a method for forming a non-woven fibrous web comprised of aramid fibers and aramid fibrid which comprises forming a foam furnish by agitating the fibers and fibrid in a foamed medium, and passing the foam furnish onto a screen and defoaming the furnish. In effectively agitating the aramid fibers in the foamed medium, the agitating means is mounted for displacement within the foamed medium and includes a convex leading surface facing in the direction of displacement. The leading surface includes upper and lower portions converging in the direction of displacement to form a generally convex leading surface and driving means for displacing the agitating means in the direction of displacement for dispersing and mutually separating the aramid fibers within the foamed medium.

Abstract: Provided is a process for preparing a smooth and glossy surfaced paper web. The process comprises subjecting the paper web to shear by using calender rolls driven at different speeds or calender rolls with different diameters. The resulting paper has a totally different structure than the original paper, as it has a much smaller void structure and a much higher degree of bonding between the elements of the sheet. The process is particularly applicable to improving the electrical insulation properties of an aramid paper web.

Abstract: Provided is a paper structure comprised of cellulose pulp fiber, a polymeric binder, and an aramid component comprised of aramid fiber and/or fibrid. The paper structure can also comprise multiple layers of different composition, but at least one layer must comprise the aramid component and polymeric binder.

Abstract: The present invention relates to a nonwoven web comprised of metal or refractory fibers with poly(phenylene sulfide) as a binder. The nonwoven web is prepared by forming a foam furnish by agitating the fibers in a foamed medium, and passing the foam furnish onto a screen and defoaming the furnish. It is preferred that the poly(phenylene sulfide) binder is added to the foam furnish in the form of fibers. Once the furnish is defoamed to form a nonwoven web, the sheet is heated at a temperature sufficient to melt the poly(phenylene sulfide) binder.

Abstract: The present invention relates to an apparatus for effectively agitating non-cellulosic fibers in a foamed medium, comprising agitating means mounted for displacement within the foamed medium and including a leading surface facing in the direction of displacement. The leading surface includes upper and lower portions converging in the direction of displacement to form a generally convex leading surface and driving means for displacing the agitating means in the direction of displacement for dispersing and mutually separating the metal fibers within the foamed medium. The present invention further relates to a method for forming a non-woven fibrous web comprised of non-cellulosic fibers which comprises forming a foam furnish by agitating the fibers in a foamed medium with the aforedescribed apparatus, and passing the foam furnish onto a screen and defoaming the furnish.

Abstract: The present invention relates to a method for forming a non-woven fibrous web comprised of refractory fibers which comprises forming a foam furnish by agitating the fibers in a foamed medium, and passing the foam furnish onto a screen and defoaming the furnish. The present invention employs a unique apparatus for effectively agitating the refractory fibers in the foamed medium, the agitating means being mounted for displacement within the foamed medium and including a convex leading surface facing in the direction of displacement. The leading surface includes upper and lower portions converging in the direction of displacement to form a generally convex leading surface and driving means for displacing the agitating means in the direction of displacement for dispersing and mutually separating the metal fibers within the foamed medium.

Abstract: Provided by the present invention is a process for making wet-layed metal fiber nonwoven sheet. The process comprises dispersing a mixture of metal fibers, wood pulp and a fibrillated material into an aqueous dispensing fluid. The amount of metal fibers dispersed generally ranges from 60 to 80 weight percent, based on the weight of solids, with the amount of wood pulp ranging from 15 to 30 weight percent and the amount of fibrillated material ranging from about 5 to 10 weight percent. The dispersed mixture in the aqueous dispensing fluid is then applied to a screen, with the aqueous dispensing fluid being removed to thereby form a metal fiber sheet.

Abstract: Provided is a paper structure comprised of two outside layers and at least one inside layer. The two outside layers are comprised of substantially cellulosic pulp fiber, and the inside layer is comprised of a high temperature fiber and a polymeric binder, and preferably cellulosic pulp fiber. In a preferred embodiment, the structure comprises at least three inside layers, all comprised of cellulosic pulp fiber, high temperature fiber and a polymeric binder. The resulting paper structure finds particular use as a high temperature transformer paper in the manufacture of transformers.

Abstract: Provided by the present invention is a wet-layed, nonwoven sheet which is comprised of metal fiber and metal powder. Generally, the amount of metal fiber comprises from 20 to 95% by weight and the amount of metal comprises from 5 to 80% by weight of the sheet. Such a wet-layed nonwoven sheet is economically preferable to a sheet comprised totally of metal fiber, since the metal powder is much less expensive. Among other factors, the present invention is based upon the recognition that by using various process techniques, the combination of metal fiber and metal powder can be wet-layed to obtain a structure of sufficient strength for subsequent handling and sintering.

Abstract: Provided by the present invention is a wet-layed, nonwoven sheet which is comprised of metal fiber and metal powder. Generally, the amount of metal fiber comprises from 20 to 95% by weight and the amount of metal comprises from 5 to 80% by weight of the sheet. Such a wet-layed nonwoven sheet is economically preferable to a sheet comprised totally of metal fiber, since the metal powder is much less expensive. Among other factors, the present invention is based upon the recognition that by using various process techniques, the combination of metal fiber and metal powder can be wet-layed to obtain a structure of sufficient strength for subsequent handling and sintering.

Abstract: Provided by the present invention is a process for making wet-layed metal fiber nonwoven sheet. The process comprises dispersing a mixture of metal fibers, wood pulp and a fibrillated material into an aqueous dispensing fluid. The amount of metal fibers dispersed generally ranges from 60 to 80 weight percent, based on the weight of solids, with the amount of wood pulp ranging from 15 to 30 weight percent and the amount of fibrillated material ranging from about 5 to 10 weight percent. The dispersed mixture in the aqueous dispensing fluid is then applied to a screen, with the aqueous dispensing fluid being removed to thereby form a metal fiber sheet.

Abstract: A substrate such as a woven or nonwoven fabric bound with a light-activated dye alone or in combination with additional conventional antimicrobial agents. The substrate is impregnated with a light-activated non-leachable dye having antimicrobial and/or antiviral characteristics which can be imparted to the substrate. The dye is bound by a cationic or anionic binder such as a water soluble polymer or carrageenan. Upon exposure to normal light, the dye generates singlet oxygen that kills microorganisms and viruses.

Abstract: A pre-preg substrate, having a low dielectric constant and containing a substantially uniformly distributed hollow-glass-microsphere filler, and method for making the same. The pre-preg substrate is treated with impregnation and lamination techniques to form a laminate with a low dielectric constant, and good mechanical and electrical properties, suitable as a base material for surface mounted devices in high performance circuits. Improved pre-pregs for making high performance circuit boards and for making surface mounted integrated circuits. Improved high performance circuit boards for making surface mounted integrated circuits.

Abstract: A substrate such as a woven or nonwoven fabric bound with a light-activated dye alone or in combination with additional conventional antimicrobial agents. The substrate is impregnated with a light-activated non-leachable dye having antimicrobial and/or antiviral characteristics which can be imparted to the substrate. The dye is bound by a cationic or anionic binder such as a water soluble polymer or carrageenan. Upon exposure to normal light, the dye generates singlet oxygen that kills microorganisms and viruses.