Abstract: A preform for use in making a video recorded disc in a body of plastic material having substantially flat top and bottom surfaces and a peripheral surface extending between the top and bottom surfaces. The peripheral surface includes a first portion intermediate the top and bottom surfaces and of a peripheral size greater than that of the top and bottom surfaces. Second and third portions extend from the first portion to the top and bottom surface, respectively. Each of the second and third portions has a peripheral dimension which decreases from that of the first portion to that of the top or bottom surface so that the surface of each of the second and third portions is angled away from the top and bottom surfaces, respectively. When the preform is engaged by the molds for making a disc the angled surfaces of the second and third portions serve to minimize if not eliminate the trapping of air and gasses along the surface of the record being formed which cause defects in the record surface.

Abstract: Disclosed is a method for treating a thermoplastic substrate for improving the surface thereof without significant loss of physical properties. Such method comprises:(a) determining the solubility parameter, .delta..sub.T, of said thermoplastic substrate and the surface energy, .gamma..sub.T, of said thermoplastic substrate;(b) determining a set of destructive solvents which are detrimental to a physical property of said thermoplastic substrate;(c) determining a set of non-destructive solvents which are not detrimental to the physical properties of said thermoplastic substrate;(d) determining the solubility parameters for said set of destructive solvent, .delta..sub.D, and for said set of non-destructive solvent, .delta..sub.N ; and the surface tension for said set of destructive solvent, .gamma..sub.D, and for said non-destructive solvent, .gamma..sub.N ;(e) selecting a subset of said destructive solvents which possess solubility parameters, .delta..sub.

Abstract: A method of sealing an article by heating solid plastic material in a chamber into a flowable state and then forcing the material from the chamber into a reservoir in a manually portable device. While in the reservoir, the material is maintained homogeneously molten and flowable and the material is forced from the reservoir into a mould cavity at a sufficiently fast rate to fill the cavity before flow passages into the cavity become blocked with hardening material.

Abstract: Apparatus for making injection molded polymeric articles, comprising a vibratory pneumatic cooling assembly adapted to dissipate thermal energy from the polymeric articles after they are ejected from the mold cavities through use of an oscillating perforated vibratory grid adapted to maintain the articles in relative motion while at least partially supporting them on a substantially uniform cushion of air. A method for employing the apparatus of the invention to substantially reduce the cycle time required for injection molding polymeric articles is also provided.

Abstract: The invention relates to a process for preparing flat articles which are moulded in any desired shaped in dry moulds from defibrated components of wood. In this process, the moisture required to give good felting remains a constituent of the wood fibres until the moulding stage. These wood fibres are mixed with fibre- and/or moisture-reactive binders and, if appropriate, auxiliaries, are metered by means of a gravity-compensating air stream onto a preform sieve, and are then compression-moulded without a cooling cycle in sieve-free moulds between two surfaces which are smooth or embossed in any desired pattern.

Abstract: A molded article is formed by a reaction injection molding method wherein a starting material, e.g., an .omega.-lactam, is injected into a mold, the inner pressure of which is maintained at 0.5 to 20 kg/cm.sup.2 .multidot.G with an inert gas; and the inner pressure of the mold is maintained at a level higher than the pressure increased by injection of the starting material until the polymerization molding of the starting material is completed.

Abstract: An injection compression molding apparatus has a mold unit having a stationary die plate and a movable die plate movable toward and away from the stationary die plate with mold plates therebetween defining a mold cavity into which an injection nozzle is directed, a supporting plate, a main cylinder supported on the supporting plate and a main cylinder ram having the outer end connected to the movable die plate for moving the movable die plate between a position in which the mold is fully closed and a position in which the mold is open to permit discharge of a molded product, and a compression stroke setting device for setting the position of the movable die plate at a position spaced a distance away from the fully closed position corresponding to a desired compression stroke of the mold.

Abstract: A group of monolithic ceramic capacitors are made by repeatedly passing a substrate under a falling curtain of a ceramic slurry, drying each layer and screen printing an electroding ink pattern on successive of the dried ceramic layers to provide a green cake containing buried electrode patterns. The cake is diced using a razor blade. It is then removed from the supporting substrate and flooded with liquid nitrogen. The chilled cake is then mechanically stressed to provide near perfectly separated green bodies along the cutting planes.

Abstract: A device for use with a runner block and a multi-polymer co-injection nozzle having separate rear entrance ports for separate polymer streams, in a multi-coinjection nozzle, multi-polymer injection molding machine, for receiving from the runner block a plurality of separate polymer flow streams and for redirecting them to flow axially out of the forward end of the device into the nozzle rear entrance ports. The device has inlets cut radially into its periphery, each for receiving a polymer flow stream, and has feed channels, each in communication with an inlet and having an inward portion cut toward the device's central axis, and an axial portion communicating with the inward portion, running axially forward and terminating at an exit hole in the device's forward end, the exit holes being in a spaced pattern for feeding the separate polymer flow streams in spaced relation into the nozzle rear entrance ports.

Abstract: Disclosed are nucleating agents for polyethylene terephthalate molding compositions comprised of alkali metal salts of carboxylic acid-containing polymeric microgel particles which are prepared by polymerizing in aqueous emulsion a monomer mixture containing about 5 to 50 percent by weight of polymerizable carboxylic acid monomers, up to 10 percent of a multifunctional crosslinking monomer and one or more carboxylfree relatively water insoluble polymerizable vinyl monomers.

Abstract: An improved, essentially scrap-free, solid-phase process for making thermoplastic articles directly from resinous powder. The process can be particularly advantageous to forming large parts from thermoplastic resinous powders. The method essentially comprises taking resinous powder, briquetting the powder, sintering the briquette, repressing the powder in a warm state and then shaping the briquette into a preform or a blank which can then be thermoformed into a resulting container or other product, assuming the blank itself is not the desired end product. Alternatively, sintering can take place after repressing with preheating of the briquette prior to the repressing step.

Abstract: A method for controlling the dimensions of a hollow plastics product injection molded within the cooling cavity of a mold having a core section and a cavity section defining the cooling cavity therebetween and separated by a parting line comprising stabilizing the core section in the cooling cavity and comprising the steps of:1. Injecting a first plastics material into the cooling cavity so that only a part of the cooling cavity is filled.2. Cooling the injected first plastics material in the cooling cavity;3. Injecting subsequent to injecting the first plastics material a second plastics material into the cooling cavity so that the cooled injected first plastics material in said part of the cooling cavity stabilizes the core section by impeding movement of the core section caused by injecting the second plastics material and whereby the injected second plastics material fills the cooling cavity and fuses with the cooled previously injected plastics material.

Abstract: A conventional conduction pressing apparatus for consolidating of composite products by pressure and heat is converted to a press in which heating is carried out by convection. This is accomplished by providing caul plates for use on the working surfaces on the press plattens, the caul plates having a central permeable area and a peripheral impermeable area, as well as appropriate sealing elements. Holes are drilled through the press plattens in order to provide a passageway for steam from an outside source to the central permeable areas of the caul plates.

Abstract: A mold clamping device for an injection molding machine wherein a movable table which supports a movable mold is moved in directions approaching and moving away from a fixed table which supports a fixed mold to thereby bring the molds into open and closed states, and wherein mold clamping is effected in a closed state of the molds by mold clamping cylinders. The mold clamping device includes tie rods for guiding the movement of the movable table, the tie rods projecting upward from the fixed table and being each provided with an engaging groove such as threads or the like formed on the outer peripheral surface of its portion projecting from the movable table to the side opposite to the fixed table in the closed state of the molds; and split mold-like locking members capable of engaging with and disengaging from the tie rods each through each engaging groove in the closed state of the molds, the locking members being slidable in the axial direction of the tie rods.

Abstract: A mixing apparatus particularly useful in carbon black pelleting has two parallel pinned shafts. The pins on each shaft are arranged in a double helix fashion with the pins interdigitating. The pins of each double helix are composed of two subsets of pins arranged in a single helix which single helices are, however, axially offset from each other. Thereby at any given axial location alternatingly opposite pin action is provided in the interdigitating zone, while surging of power is avoided.

Abstract: A transparent record disc is provided which may appropriately have video signals optically recorded thereon, the record is composed of a lamination, for example, of pliant transparent plastic on a base of hard transparent plastic. The base provides strength for the record and the pliant plastic permits the video recording to be impressed into the record by simple embossing means, rather than by stamping or molding by which the surface of the record is actually raised above its melting point and caused to flow. An improved process for forming the video recordings on the disc record is also provided.

Abstract: A method for repairing cracked and broken plastic articles such as lenses for automobile signal lights and the like comprises the steps of placing a form against a first surface of the plastic article such that the form covers the broken area, preparing an adhesive sealing compound which cures by exothermic reaction, applying the compound to the damaged areas of the lens from an opposite surface of the lens, heat generated by the exothermic reaction causing decreased viscosity of the compound and widening of cracks in the lens, the compound flowing into the widened cracks before curing, and, removing the form after the compound has cured, whereby repaired portions of the lens diffuse light in a manner substantially indistinguishable from undamaged portions, and repaired portions are of comparable structural strength to the balance of the lens.

Abstract: A continuous molding apparatus and method is disclosed as providing a sliding seal chamber in which moving molding surfaces form and can provide means for the induction of such temperature changes required to produce finished products from the chosen raw material.

Abstract: This invention relates to reaction injection molding of a mixture of lactams in presence of a catalyst and a promotor which is carried out by mixing at least two lactams in a liquid state with the catalyst and promoter before injecting the mixture into a preheated mold. The use of a mixture of lactams results in a supercooled mixture which remains liquid at ambient temperature for at least 2 hours.

Abstract: A manufacturing technique for producing a monolithic concrete base for a manhole, wet well, junction chamber in an upright position that includes a jacket having a removable pallet that forms the bottom wall thereof. A core is suspended inside the jacket upon two sets of horizontally aligned spacer pins. The first set of pins is situated below the level to which the concrete is to be poured while the second set is situated above the pouring level. After the molding unit has been filled to the required level, the upper set of pins is removed and a contoured forming header placed over the top surface of the concrete before it has a chance to set in order to create a joint for receiving another section thereon.