摘要:
Method for moulding a body in a mould, comprising the following steps: • applying an adhesive tape to the inside of a mould, • distributing the layers of material forming the body over the adhesive tape, • curing the layers of material, • removing the body from the mould, where the adhesive tape has a backing on one side of which a self-adhesive has been applied in the form of a polymer mixture, the polymers being constructed of: (d) 60 to 99.5 wt%, preferably 75 to 94 wt%, more preferably 87 to 94 wt% of n-butyl acrylate and/or 2-ethylhexyl acrylate, (e) 0.5 to 10 wt%, preferably 1 to 5 wt%, more preferably 1 to 3 wt% of an ethylenically unsaturated monomer having an acid or acid-anhydride function, (f) 0 to 30 wt%, preferably 5 to 20 wt%, more preferably 5 to 10 wt% of one or more olefinic monomers different from (a), and the self-adhesive comprises between 0 to 60 parts by weight of one or more tackifiers (based on the mass of the polymer mixture).
摘要:
Methods of compression molding powdered polytetrafluoro-ethylene (PTFE) resins to produce composite articles having at least two distinct layers of PTFE resin, with each layer containing a different type of PTFE resin, are disclosed. A first layer of resin (100), preferably including a filter, is placed in a compression mold (200) and partially compressed at a relatively low pressure. A second layer of resin (102), preferably virgin (unfilled) resin, is then added to the mold and both layers are simultaneously fully compressed. After compression, the resulting composite preform is preferably sintered and coined to create a finished PTFE material or product. In a preferred embodiment, the partial compression step is performed at pressures of less than 500 psi. It has been found that modified PTFE resins provide improved resistance to cold flow and also provide better blending between filled and unfilled layers.
摘要:
Methods of compression molding powdered polytetrafluoro-ethylene (PTFE) resins to produce composite articles having at least two distinct layers of PTFE resin, with each layer containing a different type of PTFE resin, are disclosed. A first layer of resin (100), preferably including a filter, is placed in a compression mold (200) and partially compressed at a relatively low pressure. A second layer of resin (102), preferably virgin (unfilled) resin, is then added to the mold and both layers are simultaneously fully compressed. After compression, the resulting composite preform is preferably sintered and coined to create a finished PTFE material or product. In a preferred embodiment, the partial compression step is performed at pressures of less than 500 psi. It has been found that modified PTFE resins provide improved resistance to cold flow and also provide better blending between filled and unfilled layers.
摘要:
The present invention provides a process for preparing a polymeric medium, which process comprises (I) providing two or more non-woven sheets stacked one on top of the other, each said sheet comprising one or more polymer nanofibres, and (II) simultaneously heating and pressing the stack of sheets to fuse points of contact between the nanofibres of adjacent sheets.
摘要:
A gasket (13) for use in a medical syringe is provided, which includes a main body (14) made of an elastic material, and a lamination film (15) provided on a surface of the main body (14). The gasket (13) has a circumferential surface portion (17) to be kept in contact with an inner peripheral surface of a syringe barrel (11) of the syringe. The gasket (13) has a groove (22) provided in the circumferential surface portion (17) thereof as extending circumferentially thereof. The groove (22) has a depth of not less than 0.8D (µm), preferably not less than D (µm), wherein D (µm) is the thickness of a portion of the lamination film (15) present in the circumferential surface portion (17) of the gasket (13).
摘要:
Aspects of the present invention relate to systems and methods for customizing microwave energy distribution within a chamber to accommodate various load characteristics. Aspects of the present invention customized configurations of ports, deflectors, waveguides, conducting rods, and slots to shape and distribute energy.
摘要:
A tubular conduit comprising: a tubular portion made from a flexible material. There is an external helical formation extending around the exterior of, and parallel to the axis of, the tubular portion and defining a first region of the tubular portion. The external helical formation is for supporting the tubular portion. There is also an internal helical formation, protruding inwardly of the interior of the tubular portion and extending parallel to the axis of the tubular portion and defining a second region of the tubular portion. The internal helical formation is for imparting helical flow on fluid passing through the tubular portion. The first region does not extend throughout the second region.
摘要:
A method of fabricating a fluid seal for sealing a relatively rotatable member, wherein the fluid seal has an elastomeric sealing member bonded to a PTFE insert. A wafer of PTFE material has a body portion and an end portion of a greater thickness than the body portion. The wafer is placed in a mold cavity with one side of the wafer opposed to a surface portion of the mold cavity. Elastomeric material is forced into the mold cavity to form a molded preform of the elastomeric sealing member and bond the preform to an opposite side of the wafer. The molded preform and bonded wafer are removed from the mold cavity. The end portion of the wafer and an end portion of the preform are trimmed to form the fluid seal.
摘要:
A method of fabricating a fluid seal (10) for sealing a relatively rotatable member, wherein the fluid seal (10) has an elastomeric sealing member (18) bonded to a PTFE insert (30). A wafer of PTFE material (30) has a body portion (32) and an end portion (54) of a greater thickness than the body portion (32). The wafer (30) is placed in a mold cavity (62) with one side of the wafer (30) opposed to a surface portion of the mold cavity. Elastomeric material is forced into the mold cavity (62) to form a molded preform of the elastomeric sealing member (18) and bond the preform (18) to an opposite side of the wafer (30). The molded preform (18) and bonded wafer (30) are removed from the mold cavity (62). The end portion of the wafer (54) and an end portion of the preform (18) are trimmed to form the fluid seal (10).
摘要:
Polytetrafluoroethylene (PTFE) composite articles that have a macro textured surface. The composite articles include at least two different PTFE membranes in a layered or stacked configuration. The composite article has a macro textured surface characterized by a plurality of strands raised from the surface of the PTFE membrane. The strands may be formed of either interconnected nodes of PTFE or of at least one nodal mass of PTFE and have a length equal to or greater than about 1.5 mm. The macro textured surface provides a topography to the first PTFE membrane. The composite articles have a bubble point from about 3.0 psi to about 200 psi, a thickness from about 0.01 to about 3.0 mm, and a bulk density from about 0.01 g/cm3 to about 1.0 g/cm3.