摘要:
The invention relates to pharmaceutical closures for containers made of flexible polyolefinic materials which are suitable to be filled with parentally administrable fluids prior to their sealing and sterilization. The polyolefinic closures have an excellent resealing capacity after being penetrated by a piercing device for establishing fluid communication with the container, even after multiple entries into the container.
摘要:
A caterpillar made from elastomer material and having a plurality of guide teeth projecting from the inside surface of the caterpillar, the said guide teeth having lateral faces and front and rear faces in the longitudinal direction of the caterpillar, with at least one insert arranged inside each guide tooth, the caterpillar being characterized in that each insert located inside each guide tooth has a generally hollow shape enclosing a free volume to absorb in large measure the expansion of the elastomer material of the guide tooth during the molding and cross-linking of the material.
摘要:
Process for moulding a make-up composition in a mould comprising a concave moulding surface forming the base of the mould and a bottom forming the upper component of the mould and closing off the space bounded by the said moulding surface, the composition being cast in the said mould in fluid form and subsequently solidifying to form a demouldable solid product capable of being packaged, in which the said composition is cast in a mould (1) whose bottom consists at least partly of a sheet (2) of open-cell plastic foam, so as partly to impregnate the said foam sheet (2) with the said composition and in which, after solidifying of the said composition, a moulded product consisting of the solidified composition and of the foam sheet which is bonded to it and which forms its support, is demoulded by removing the moulding surface (1).
摘要:
A stereolithographic method and apparatus for forming polymeric structures comprising a plurality of overlying layers, each layer formed by polymerizing a thin layer of liquid photopolymer on a prior layer. Crevices formed at the layer interfaces are filled by a stereolithographic method comprising lifting the multilayered structure from the liquid photopolymer, draining excess liquid therefrom, tilting the structure to provide an acute angle of incidence between an incident radiation beam and a side wall of the object, and applying radiation to the crevice to polymerize at least the surface of a quantity of liquid photopolymer therein. The structure may then be subjected to a separate final full cure to fully harden the structure. An exemplary use is the packaging of electronic components and the like.
摘要:
A method of compression moulding an article from rubber moulding material incorporating hollow inserts avoids damage to the inserts. Where compression moulding takes place in an enclosed mould at an elevated pressure, the pressure can distort and damage the hollow inserts especially if they are of plastics. In order to avoid such distortion and damage, the method compresses during moulding creating a pressure in a cavity of the insert which substantially balances the pressure exerted on the exterior of the insert by the rubber moulding material in the mould. The pressure in the cavity is preferably produced by introducing some rubber moulding material into the cavity of the insert. This material becomes pressurised during moulding and supports the interior of the insert.
摘要:
The invention relates to a plastic package for an integrated electronic semiconductor device to be encapsulated within a plastic body, the plastic bodyes formed using the step of molding said plastic body so as to fully enclose a semiconductor element, on which an integrated electronic circuit has been formed and which is placed onto a metal leadframe connected electrically to said integrated electronic circuit and carrying a plurality of terminal leads for external electric connection. To compensate the outward bends uncontrollably undergone by the plastic body due to thermal stresses during the molding step, a mold is used which has a cavity delimited by perimeter walls which define a concave-shaped volume. Preferably, at least one of the large walls, a bottom wall and a top wall, has a curvature inwardly of said mold. cavity. The curvature values are predetermined to compensate any outward curvature undergone by corresponding surfaces of said plastic body during the molding step. The plastic package thus obtained exhibits, at the end of the molding step, a body having a diversified thickness which is at a maximum near the edges and at a minimum in the central portion; the difference between these thicknesses is proportional to the amount of the relative deformation undergone by the central regions of the body surfaces with respect to the regions near the edges. The plastic body is within ideal overall dimensions.
摘要:
A method of encapsulating a workpiece, particularly a microelectronic device, to achieve a very thin encapsulating layer and reduce the finished device size. The method includes positioning the workpiece in the mold cavity of a mold capable of reducing its volume while the mold compound is in a liquid state from a first volume, where mold compound may be easily added without creating voids, to a second smaller volume which defines the finished workpiece size. The second volume is below the size which would permit the void-free encapsulation of the workpiece in a conventional thermosetting plastic transfer molding machine. The mold may be opened in two stages to prevent damage to thin molded microelectronic devices by opening the perimeter of the mold first while the molded device is still being supported by large molding surfaces. The invention also includes the mold used in the method.
摘要:
A method of compression moulding an article from rubber moulding material incorporating hollow inserts avoids damage to the inserts. Where compression moulding takes place in an enclosed mould at an elevated pressure, the pressure can distort and damage the hollow inserts especially if they are of plastics. In order to avoid such distortion and damage, the method compresses during moulding creating a pressure in a cavity of the insert which substantially balances the pressure exerted on the exterior of the insert by the rubber moulding material in the mould. The pressure in the cavity is preferably produced by introducing some rubber moulding material into the cavity of the insert. This material becomes pressurised during moulding and supports the interior of the insert.
摘要:
An apparatus and method for casting lens without using a gasket that can be used to form all powers and geometric shapes of lenses. An elastomeric strip is used to wrap around the edges of two molds to form a sleeve-like structure, which in turn cooperates with the molds to form a molding cavity. Moreover, this sleeve-like structure does not crumple or shrink during the lens polymerization process. Instead, it allows the molds to slide axially within it to compensate for any shrinkage that occurs during the lens polymerization process.
摘要:
A process for producing a hollow article in an assembly comprising first and second mold members movable relative to each other between a closed position in which an inner surface of the assembly defines a cavity and an open position. The cavity is shaped to define a corresponding configuration to the article. According to this process, a charge containing at least one molten thermoplastic resin is supplied at the first and/or second mold member while the mold members are not in the closed position. The first mold member is moved relative to the second mold member into the closed position so as to define the cavity, and a first clamping force F1 is applied to the first and second mold members. The charge is then compressed within the mold cavity under the first clamping force F1. Thereafter, the clamping force is reduced from the first clamping force F1 to a second clamping force F2 before the molten thermoplastic resin in the mold cavity has completely solidified. A compressed gas is supplied into at least one unsolidified portion of the molten thermoplastic resin subsequent to the step of closing the mold members and before the molten thermoplastic resin in the mold cavity has completely solidified. The molten thermoplastic resin can then be cooled in the mold cavity and solidified while supplying the compressed gas.