Abstract:
The present invention is directed to an apparatus for advancing the leading edge of a corrugated web for positioning the web for a secondary operation, such as a cutting operation to cut a discrete sheet from the web. The web has a plurality of alternating peaks and valleys. The apparatus comprises an endless loop conveyor including a plurality of spaced support bars for contacting the valleys of the web. At least one vacuum source holds the web against the support bars. A motor and a distributed control system repeatedly advance the conveyor and the leading edge of the web from the entrance end to the exit end of the conveyor. A rotary encoder and a sensor sense the presence of a support bar near the position for applying the cutting operation. The vacuum source is de-activated, and at least one pressure source is activated to remove the cut sheet from the support bars. The de-activation of the vacuum source and the activation of the pressure source are done progressively from one end of the conveyor to the other to progressively remove the cut sheet from the conveyor.
Abstract:
The present invention relates to an apparatus and a process for a half-cell structure to make a hexagonal-cell honeycomb core. The structure has a plurality of peaks and valleys and a diagonal surface between each consecutive peak and valley. The apparatus comprises a stack holder for stacking the structure so that as one sheet is placed on top of a stack comprising at least one sheet, the peaks of one sheet contact the peaks of an adjacent sheet. The apparatus also comprises an air blower disposed beneath the top of the stack for reducing the air pressure surrounding the stack to a pressure below the air pressure on the top of the stack, thereby pressing the layers together to form the core.
Abstract:
An apparatus for cutting a honeycomb half-cell structure into sheets includes a blade for cutting the structure and a conveyor for positioning a length of the half-cell structure so that the blade cuts across the diagonal surface of the half-cell structure, thereby forming the sheets. The conveyor comprises platens including a plurality of bars contacting the valleys on one side of the half-cell structure and a space between each consecutive bar. The half-cell structure is cut along the diagonal surface alternating between one side of a first predetermined bar and one side of a second predetermined bar. A process for cutting a half-cell structure into sheets includes positioning a length of the half-cell structure so that the diagonal surfaces of the structure are positioned adjacent a blade for cutting and cutting across the diagonal surface to form the sheets. A honeycomb core is made by this process, where the honeycomb core includes a plurality of sheets cut across the diagonal surface of the half-cell structure.
Abstract:
The present invention relates to a process for making a hexagonal-cell honeycomb core from a honeycomb half-cell structure. The structure has a plurality of peaks and valleys on each side thereof and a diagonal surface between each consecutive peak and valley. The process comprises the steps of applying a first adhesive component, which is preferably a cyanate ester and an epoxy, to a first group of peaks and applying a second adhesive component, which is preferably the epoxy and a catalyst, to a second group of peaks. The structure is then stacked so that the first adhesive component on the first group of peaks comes into contact with the second adhesive component on the second group of peaks, thereby mixing the components to bond the half-cell structure together and form the honeycomb core.
Abstract:
The present invention relates to an apparatus and a process for a half-cell structure to make a hexagonal-cell honeycomb core. The structure has a plurality of peaks and valleys and a diagonal surface between each consecutive peak and valley. The apparatus comprises a stack holder for stacking the structure so that as one sheet is placed on top of a stack comprising at least one sheet, the peaks of one sheet contact the peaks of an adjacent sheet. The apparatus also comprises an air blower disposed beneath the top of the stack for reducing the air pressure surrounding the stack to a pressure below the air pressure on the top of the stack, thereby pressing the layers together to form the core. The present invention also relates to a transfer head and a process for holding a half-cell structure. The transfer head comprises a plurality of support bars for supporting the half-cell structure and at least one space formed between each support bar, where the width of each space is about the distance between adjacent valleys of the structure, and the depth of the space is greater than the height of the peaks.
Abstract:
Provided, are multi-layer chip carriers comprising an asymmetric cross-linked polymeric dielectric film, and processes for making the chip carriers.
Abstract:
Provided according to the invention are cross-linked polymers comprising an anhydride or partially hydrolyzed anhydride functionalized polymer having oligomeric polyimide cross-links, providing a polymeric composite on a molecular scale, and shaped articles made therefrom. In some embodiments the shaped articles are particularly well suited for electronics applications. The shaped articles are characterized by low CTE (coefficient of thermal expansion), low dielectric constant (Dk), low dissipation factor (Df), high strength, high modulus and high toughness.
Abstract:
Provided is a film having a thickness of less than 500 μm comprising a polymer and a plurality of surface-modified hexagonal boron nitride particles dispersed therewithin. The polymers can be polyimide or epoxy. A process for preparing the film by casting is provided.
Abstract:
Quaternary ammonium bicarbonates are suitable for use as catalysts in curable epoxy compositions. The curable compositions prepared therewith are used to prepare coated substrates, and to produce conformally sealed printed wiring boards and flexible circuits. Methods for preparation and curing are also provided. Of particular utility are compositions comprising benzytrimethyl ammonium bicarbonate. The curable composition is coated onto a first film or sheet, including a polyimide film or sheet. The coated sheet is then contacted to the surface of second film or sheet, where preferably there are discrete metallic conductive pathways disposed thereupon.
Abstract:
Provided is a composite comprising a polymer and a plurality of surface-modified hexagonal boron nitride particles dispersed therewithin. Suitable polymers include polyimide and epoxy. A process is also provided. The surface modified hexagonal boron nitride particles comprise surface-bonded substituted phenyl radicals.