Abstract: A method of controlling a molding system for fabricating a molded article from a settable mixture includes the steps of priming several discharge containers with different components of the settable mixture and evacuating the discharge containers through a conduit into a mixing head. The mixing head combines the components to form the settable mixture that is then injected into the mold. During the priming step, pressure within each of the discharge containers is monitored to detect air being drawn into the system. Pressure of the settable mixture is monitored at the mixing head and at the mold tool to detect any blockages that can cause damaging pressure fluctuations. To prevent built up of residual settable mixture within the settable mixture, all parts of the system that contact the settable mixture are flushed with a solvent and then air-dried to rid the system of the solvent.

Abstract: A hot isostatic pressing apparatus (HIP apparatus) comprises a vertically cylindrical high-pressure vessel comprising a high-pressure cylinder 1 and upper and lower lids 2 and 3; a bottomed cylindrical casing 6 capable of housing workpieces 9 and a resistance-wire heater 11, a heat insulating structure 16 equipped with a gas flow regulating valve 15 and formed in a bottomed cylindrical shape on the outside of the casing 6 so as to cover the casing 6, and a heat sink 17 having a water cooling mechanism provided in the space defined by the heat insulating structure 16 and the inner surface of the high-pressure cylinder 1, which are provided within the high-pressure vessel; and a pressure medium gas stirring fan 12 for promoting the temperature uniformity of the space of the treatment chamber 7 for housing the workpieces 9, the stirring fan being arranged on the lower lid 3 side within the casing 6, whereby the cooling to a temperature range of 100° C.

Abstract: A curing apparatus wherein rapid curing is provided by using light, pressure, pressure and light, or purge, pressure and light to cure resinous materials by application of energy from an external source to excite polymerization in a polymerizable system. An air-tight chamber is provided to house the polymerizable dental material. The apparatus provides an automated system for curing the polymerizable material under light and pressure in the same unit. A purge cycle may be included to minimize or eliminate bubbles and provide an oxygen-free atmosphere.

Abstract: An apparatus and method for molding balloon catheters is disclosed. The balloon may be molded by providing a polymeric tube within a mold having an interior cavity in the shape of the desired balloon. Microwave energy, which may be generated by a gyrotron, may then be directed toward the mold, to heat the polymeric material without heating the mold. Once heated, pressurized fluid may be injected into the tube to blow the polymeric material against the interior cavity whereupon the material can cool to form the balloon or can be further heatset by additional microwave energy and be cooled to form the balloon. In accordance with one embodiment, microwave energy can also be used without a mold to form a medical device.

Abstract: The present invention includes processes for making fibers, which processes include an extrusion step wherein molten polymers are extruded through an extrusion die, thereby forming at least one extruded filament; and an orientation step, wherein the filament is drawn to align the molecules of the filament, and wherein multivariate data analysis techniques are used to analyze data regarding various process variables and, optionally, process variables are adjusted in response to the multivariate data analysis.

Abstract: A rapid throughput method for the preparation, analysis or both of libraries of material samples is provided. According to the method, a plurality of samples is provided. The plurality of samples is then formed into a plurality of films. Thereafter, the plurality of films is plastically deformed. Preferably, the plurality of films is deformed into a configuration appropriate for testing of properties or characteristics of the samples.

Abstract: An apparatus for producing an extruded film tube and supplying said tube to a collapsing and roller assembly includes a die for extruding a molten material in the form of a tube which is in a molten state below a frost line and in a solid state above the frost line. A blower system supplies and exhausts cooling air to and from an interior portion of the tube, and is regulated by a valve. At least two sensors are provided, one below the frost line for sensing the position of said tube, and one located proximate the tube in a position above said frost line. The upper sensor is used for sensing the position of the tube prior to collapsing and flattening it. A controller receives feedback signals from both sensors and controls operation of the valve.

Abstract: A system and method are provided in which the rate of material flow to a plurality of gates can be controlled by a single controller. According to one embodiment, material is provided to first and second runners, the first runner comprising a plurality of distribution nozzles, and the flow to the first runner being controllable independently of the flow to the second runner.

Abstract: In an injection molding machine having first and second nozzles for delivering melt material from a common manifold to one or more mold cavities, apparatus for controlling delivery of the melt material from the nozzles to the one or more mold cavities, each nozzle having an exit aperture communicating with a gate of a cavity of a mold and being associated with an actuator interconnected to a melt flow controller, the apparatus comprising a sensor for sensing a selected condition of the melt material through at least one of the nozzles; an actuator controller interconnected to each actuator, each actuator controller comprising a computer interconnected to a sensor for receiving a signal representative of the selected condition sensed by the sensor, the computer including an algorithm utilizing a value corresponding to a signal received from the sensor as a variable for controlling operation of an actuator for the at least one nozzle; wherein the melt flow controller controls the rate of flow of the melt materi

Abstract: A method and apparatus for monitoring the momentum of a meltspun jet thermal core used for making thermoplastic filaments is presented to aid in the uniformity of formation and elimination of waste in thermoplastic filament nonwoven web formation. The apparatus is easily and economically constructed and is relatively insensitive to positioning variations in the air stream of the filament formation apparatus.

Abstract: A processed material in which a fibrous binder is mixed with chip-like solid matters such as soft urethane foam is quickly injected into a preform mold having a flat molding surface with a uniform filling density, and then fed to a main mold having a molding surface whose shape corresponds to that of a sound-proof product to be formed, so that main molding is performed under sufficient pressure and heat. With the main molding carried out after the preform molding, it is possible to manufacture sound-proof products of excellent quality.

Abstract: An apparatus and method for spinning a synthetic yarn, wherein a heated polymeric melt is extruded through a spinneret and the resulting filaments are combined and wound to a package by means of a take-up device located downstream of the spinneret. A cooling tube for the filaments is positioned below the spinneret, and an inlet cylinder which has a gas permeable wall is positioned between the inlet cylinder and the cooling tube. The cooling tube connects to an air stream generator in such a manner that an air stream develops in the cooling tube in the direction of the advancing yarn. The air stream is formed by a quantity of air that enters the cooling tube via the inlet cylinder, and the inlet cylinder is subdivided in the direction of the advancing yarn into several zones, each with a different gas permeability, for controlling the quantity of air entering the inlet cylinder. It is thereby possible to influence with advantage the precooling of the yarn and the formation of the air stream.

Abstract: An internal bubble cooling air control system in a blown film apparatus has sensors arranged to increase response time and reduce interference, and includes a high speed valve for fast actuation of air flow from a controller in response to signals received from the sensors.

Abstract: In the extrusion of feed-stuff pellets and relevant consumer products, the extruded products are subject to expansion as a result of the boiling of their water content when the products, after being exposed to high extrusion pressure and a correspondingly high temperature, are discharged to the atmosphere through the extrusion nozzles. Such an expansion is directly aimed at, but it is desirable to be able to control it, which is difficult by adjustment of the ordinary process parameters. With the invention it has been found that the expansion which arises can be controlled in a highly constant manner, i.e. by carrying out the extrusion into a closed chamber in which an over-pressure of a few bar is established in relation to the atmospheric pressure, and which can be regulated. The extrusion products can be continuously discharged from this chamber, or they can be discharged intermittently in portions.

Abstract: An injection molding machine includes a plasticating unit for plasticating a thermoplastic resin, and an injecting unit connected to the plasticating unit through a connecting passage to inject the plasticated resin into a mold. The injecting unit A includes a rotary pump having a suction port connected to the plasticating unit through the connecting passage and a discharge port connected to the mold. The plasticated resin is intermittently injected into the cavity of the mold through the injection port by means of the rotary pump. In the connecting passage, an accumulator is provided which reserves the resin plasticated in the plasticating unit in an amount equal to or more than the shot capacity, and feeds the resin to the rotary pump.

Abstract: A method for operating actuators, such as pneumatic valves, in an injection molding machine especially for CD or DVD discs, or other molded articles. The timing of auxiliary processes (such as blowing air into the mold cavity or applying suction to the molded article in the cavity) is set as a function of the instant of completion of a process in the main sequence of operations (especially, cooling the molded article prior to ejection from the mold). In a set and display section the user sets a preferred time tn for each actuator to operate after, or before, a set completion time T of the main-sequence process (e.g., cooling). The time tn can be negative or positive, so that the various actuators turn on before or after the set completion time. A CPU calculates a starting time T±tn, and keeps the actuators on during a following interval tp. The starting time T±tn may be input to a memory, and output to the respective actuator.

Abstract: The invention provides an injection molding method comprising supplying a gas into a molten resin in a plasticizing cylinder and injecting the molten resin having the gas dissolved therein, wherein when the resin is being plasticized, a gas space with a predetermined gas pressure is formed within the plasticizing cylinder in a gas supply section and the pressure at the front end of the screw is adjusted to be at least equal to the gas pressure in the gas space and within a range where the gas space can be maintained within the plasticizing cylinder in the gas supply section. According to the invention, the necessary amount of gas can be dissolved in the molten resin with good reproducibility in a quantitative manner.

Abstract: The invention relates to a process and apparatus for producing a foamed body that allows simple control of the dimensions and gives foamed body with the desired dimensions in a stable manner. According to the invention, P2 is pressure at the point where pressure in the die begins to fall after casting a molding material containing no blowing agent into the die, &Dgr;P2 is the amount of reduction in pressure in the die from P2, P3 is the minimum pressure between the time of casting a molding material containing a blowing agent into the die completely cast and the time of beginning to increase the pressure in the die, &Dgr;P3 is the amount of increase in pressure in the die from P3, and &Dgr;P4 is the sum of &Dgr;P2 and &Dgr;P3.

Abstract: An improved blown film extrusion apparatus is provided. The apparatus includes an annular die for extruding a film tube. At least one tube position transducer is provided and located adjacent to the extruded film tube. The tube position transducer transmits interrogating pulses to the extruded film tube and produces a position signal corresponding to a detected position under the extruded film tube. A bubble position control system is provided for receiving and processing the position signal. A valve is provided for varying a quantity of air within the extruded film tube in response to the bubble position control means. This urges the extruded film tube to a desired position. The apparatus further includes a collapsing frame assembly for receiving the extruded film tube and collapsing it. The collapsing frame assembly includes several frame boards. Typically, two opposing main boards and two opposing side boards are provided.

Abstract: The invention relates to a method for introducing additives into flowing or fluidized media. The spatially predetermined position of the additives in the flowing material, also called fluid bed, is obtained by controlling the pulsating injection, The introduction and exact dosing of additives, that is hardeners, dyes, gas producers and softener for instance, into a liquid plastic stream or metal stream (10) for instance or the fluid bed of bulk material, such as powder, granules and pellets, is carried out by means of an injector. The invention is used in melting units, in hot channel systems, in tools, componens of tools and injection moulding machines, extruder-, injection moulding-, pelleting-, burner- and injection arrangements.

Abstract: An extrusion molding method including plasticizing and kneading a raw material (1), composed of a synthetic resin material having high heat-resistance and strength, extruding the material from a molding die (3) to form a tubular body (51), passing the tubular body (51) on a sizing die (4) to give it a final inner diameter, cooling and hardening the tubular body (51). The molding die (3) and sizing die (4) are coupled to each other by a connecting pipe (6). The sizing die (4) is made of a carbon material. A first air (81) is supplied to an interior of the sizing die (4) through the connecting pipe (6). A second air (92) is supplied to an interior of the molding die (3) so that an air lubrication layer is formed between an inner surface (52) of the continuous product (5) and an outer surface (41) of the sizing die (4).

Abstract: The present invention is directed to a method and apparatus for startup of extruded film tubes. A controller member is utilized to provide control signals to a supply blower which supplies air to the extruded film tube in an amount corresponding to a supply control signal, and an exhaust blower which exhausts air from the extruded film tube in an amount corresponding to an exhaust control signal. The controller member executes program instructions which define at least one control routine for automatic and coordinated control of the supply blower and the exhaust blower during starting of the extruded film tube, by directing a series of supply control signals to the supply blower and exhaust control signals to the exhaust blower.

Abstract: Process and apparatus for injection molding of molded parts made from plastic material having at least one cavity, which includes: a) injection of plastic melt from an injection unit along a melt flow path into the cavity of an injection-molding die; b) injection of a fluid into the still molten plastic material, so that the latter is pressed against the walls of the cavity; c) allowing the plastic material to solidify until the latter forms the molded part in self-supporting manner; and d) releasing the molded part from the cavity of the injection-molding die.

Abstract: A method of and an apparatus for measuring and evaluating characteristics of material resin using an injection molding machine. Injections of resin are performed with different resin temperatures TCi and different injection velocities Vj to detect injection pressures Pr at set screw positions. Data of combinations (Pr, V, TC) of an N number of injection pressures, injection velocities and resin temperatures are obtained. An interdependency relation function Pvr(t, v(x),x) expressing correlation among the injection pressure, the injection velocity and the resin temperature is obtained as Pvr(t, v(x), x)=A(x)e−&agr;(x)Tv(x)&bgr;(x) according to a least square method using the obtained data, where &bgr;(x) represents a degree of dependency on injection velocity influencing the injection pressure and “log A(x)−&agr;(x)T” represents a degree of dependency on resin temperature influencing the injection pressure.

Abstract: A process for injection molding of molded parts made from thermoplastic plastic material having at least one cavity, which includes: a) injection of thermoplastic plastic melt from an injection unit along a melt flow path into the cavity of an injection-molding die; b) injection of a fluid into the still molten plastic material, so that the latter is pressed against the walls of the cavity; c) allowing the plastic material to cool until the latter forms the molded part in self-supporting manner; and d) releasing the molded part from the cavity of the injection-molding die.

Abstract: A tire mold 2 for curing new or retreaded tires 20 has an upper platen 4, a lower platen 6, and a central rim 30 with a frangible member 50 designed to open when a predetermined pressure P1 in excess of the normal curing pressure Pc is observed. The frangible member 50 preferably includes a rupture disk 60 that breaks upon exposure to the pressure P1.

Abstract: A method for injection molding plastic molded parts from thermoplastic, comprises the following steps: the production of a thermoplastic melt (1) through the rotation of a plasticizing and injection screw (2) in a preplasticizing cylinder (3); the addition to the thermoplastic melt (1) of a fluid (4) by introducing the fluid (4) into the preplasticizing cylinder (3); the mixing up the thermoplastic melt (1) to which the fluid (4) has been added, through the rotational motion of the plasticizing and injection screw (2); the injection of the mixture of thermoplastic melt (1) and fluid (4) into the cavity (8) of an injection molding tool (5).

Abstract: Thin, planar substrates are carried on a substrate carrier (20) through a polishing operation. The substrate carrier (20) is injection molded or modified-injection molded from a plastic material, and includes one or more receptacles for receiving the substrates to be carried through the polishing process. A drive force transmission arrangement is also included in the substrate carrier (20) through which the carrier may be driven in the polishing process. The substrate carrier (20) is relatively non-abrasive and composed of melt processable engineering polymers or blends. Non-abrasive fillers or reinforcing material may also be included in the plastic.

Abstract: A method for forming a three dimensional polymeric structure includes providing at least one paint layer and providing a bonding layer coupled to the at least one paint layer to form an insert having a bonding surface provided by the bonding layer. A mold having a hollow interior bounded by an interior surface is further provided. The insert is positioned within the interior along a portion of the interior surface. At least one charge of thermoplastic material is deposited into the interior. The interior is heated while the mold is rotated and rocked. As a result, the thermoplastic material melts and is deposited against the interior surface of the mold and against the bonding surface of the insert to form a three dimensional structure within the interior. The three dimensional structure is then removed from the interior of the mold.

Abstract: A method is provided for operating an injection unit of an injection molding machine for metering or injecting material, also to create a back pressure in the melt, or to create a holding pressure on the melt, by means of a screw drive including two electric motors, with a controlled electrical connection to one another, and by means of a spindle-nut combination, such that the two electric motors can be operated in the same direction of rotation or in the opposite direction of rotation. In one embodiment, the two electric motors are operated counter-rotationally to inject the material, or the two electric motors are operated synchronously in their direction of rotation to create a back pressure in the melt or a holding pressure on the melt, a difference rpm being set by means of at least one electric feedback signal.

Abstract: A blown film extrusion apparatus and method is provided including a tube position transducer transmits interrogating pulses to the extruded film tube and produces a position signal corresponding to a detected position under the extruded film tube. A bubble position control system is provided for receiving and processing the position signal. The apparatus further includes a collapsing frame assembly for receiving the extruded film tube and collapsing it. A position transducer is provided for detecting the position of at least one of the frame boards. At least one board position actuator is provided for adjusting the position of at least one of the boards. A board control system is provided for receiving the board position information from the board position transducer and for providing control signals to the board position actuator to maintain at least one of the boards in a predetermined position.

Abstract: A method of repairing leaking underground pipes, particularly gravity-flow sewer pipes, without excavation, by using a flexible liner tube containing a fluid under sufficient pressure to exclude groundwater, while forcing a fluid sealant material into leaking defects in a pipe wall, and through openings in the pipe wall into voids outside the pipe. The flexible liner tube is everted into the pipe to keep the sealant material in place and also to continue to exclude groundwater for a period of time long enough for the sealant material to cure in place to effect sealing repair of the defects in the pipe wall and also at least partially fill voids outside the pipe. Fluid is kept under great enough pressure in the liner tube to exclude groundwater and may be heated or chilled to assist in preparing the pipe for sealant or to cure the sealant material.

Abstract: A tube with a thin thickness or a thin tube made of a synthetic resin material having high heat-resistance and high strength (for example, PEI material, PEEK material or the like) is produced by means of extrusion molding. An extrusion molding method forms a continuous product (5) for a thin tube by plasticizing and kneading a raw material (1) composed of a synthetic resin material having high heat-resistance and high strength by means of an extrusion molding machine (2), extruding the plasticized and kneaded raw material from a molding die (3) to form a tubular body (51) having a circular cross section, further passing the tubular body (51) on a sizing die (4) to give a final inner diameter to the tubular body (51), cooling and hardening the tubular body (51). The molding die (3) and sizing die (4) are coupled to each other by a connecting pipe (6). The sizing die (4) is made of a carbon material. A first air (81) is supplied to an interior of the sizing die (4) through the connecting pipe (6).

Abstract: The invention relates to a method for injection molding a plastic molded part in an injection mold, comprising a) injecting a specified amount of plastic melt into the injection mold; b) introducing a compressed fluid between a part of the wall of the injection mold and the injected plastic melt; c) allowing the plastic melt to cool until the plastic molded part is self-supporting; and d) removing the plastic molded part from the mold. The invention specifies that, during or after step a) and during or before step b), the cavity of the injection mold is sealed against the environment, preferably by activating at least one seal.

Abstract: A method of manufacturing a non-woven material uses a contoured honeycomb drum with an outer microporous surface, more particularly with a contoured outer surface, for the manufacture of contoured non-woven fibrous materials. The method can use spunbonded, melt blown, or electro-static spun techniques for depositing solidifying filaments on the microporous surface such that the non-woven material conforms to the contour of the drum. The drum facilitates continuous production of non-woven articles with three-dimensional shapes such as surgical masks or pleated air filters. Airflow through the drum can be controlled with an internal adjustable manifold with independent valves to obtain non-woven material articles of various configurations and properties. In addition, efficiency can be improved by including turning vanes. Vacuum or pressure can be applied.

Abstract: Apparatus for monitoring application of air through a dual-stage blowhead to blow mold a container includes a first solenoid valve for applying final blow air through the blowhead to a container in a mold and a second solenoid valve for applying finish cooling air through the blowhead around the finish of the container in the mold. Electronic circuitry is coupled to the first and second solenoid valves for detecting timing of application of first and second electrical valve control signals to the valves. Air pressure sensors are operatively coupled to the first and second solenoid valves for generating associated electrical signals indicative of timing of application of air by the first and second solenoid valves to the blowhead.

Abstract: An injection assembly for an injection moulding machine, comprising a screw (2) mounted in a plasticising cylinder and an injection piston (8) which moves the screw (2) in the longitudinal direction and which is mounted in an injection cylinder, wherein there is provided a supply conduit for the injection cylinder having a control valve (13) which can be shut off and there is provided an additional conduit (14) which bypasses the control valve (13) and in which are arranged a device (17) for reducing the amount of the pressure fluid flowing to the injection cylinder (7) and possibly a device (16) for reducing the pressure.

Abstract: A mold block which is used in a moving mold tunnel comprises first and second mold block sections which meet at their parting faces to close the mold block. Each mold block section has a product shaping interior surface and an air movement passage having an entrance at the base of each mold block section, a first opening to the interior surface and a second opening to the parting face of each mold block section. An air flow controller is provided between the parting face opening and the interior surface opening of the passage in the first mold block section and an air flow controller is provided between the entrance and the interior surface opening in the passage in the second mold block section.

Abstract: A metering controller capable of making a metering time constant and kneading of resin uniform. A screw torque STRQ(n) is detected and stored at every processing period from a start of metering as reference data. A screw rotational speed command is changed over to a set value at each predetermined changeover position. A present screw torque is detected and subtracted from a corresponding screw torque STRQ(n) of the reference data to obtain a deviation &Dgr;TRQ. A correction amount SROT for the screw rotational speed command is obtained based on the deviation &Dgr;TRQ. The correction amount SROT is added to the set screw rotational speed command SRCMD and thus corrected command is outputted for controlling a servomotor for rotating the screw. A screw retracting speed and a screw retracting position may be adopted as reference data. Since a transition pattern of the screw retracting motion coincides with that in obtaining the reference data, the metering time is made constant.

Abstract: For the production of a particularly dimensionally stable cable set, the single conductors(22) of the cable set are initially inserted into a cavity (8) of a foam tool (2) and a foaming material is subsequently filled in. To dispense with involved and expensive hydraulic equipment, a vacuum is generated to press a top half (6) and a bottom half (4) of the foaming tool (2) against each other. For this, vacuum channels (6) are preferably provided, which extend along sides of the cavity (8).

Abstract: The process and device are intended for controlling the molding of a container during the manufacture of containers from a thermoplastic material. At least two previously injection-molded preforms are temperature-treated and delivered in succession to at least one blow station for blow molding of the preforms into containers. In order to compensate for nonuniform temperature distribution in the material of the preforms relative to one another, at least one blow parameter during molding of the preforms into containers is specified in a fashion that differs from one to the next. The differing specification is made in such a manner as to compensate for the nonuniform temperature distribution so that containers with approximately identical spatial distribution of wall material, orientation properties, and crystallization characteristics exist when the blow-molding process is finished.

Abstract: A transfer molding apparatus, wherein said top-half mold and said bottom-half mold form a plurality of cavities interconnected, and wherein said pressure adjusting means reduces the pressure of the cavities every time a specified amount of resin is supplied into any one of a plurality of cavities.

Abstract: An apparatus and method for spinning a synthetic yarn, wherein a heated polymeric melt is extruded through a spinneret and the resulting filaments are combined and wound to a package by means of a take-up device located downstream of the spinneret. A cooling tube for the filaments is positioned below the spinneret, and an inlet cylinder which has a gas permeable wall is positioned between the inlet cylinder and the cooling tube. The cooling tube connects to an air stream generator in such a manner that an air stream develops in the cooling tube in the direction of the advancing yarn. The air stream is formed by a quantity of air that enters the cooling tube via the inlet cylinder, and the inlet cylinder is subdivided in the direction of the advancing yarn into several zones, each with a different gas permeability, for controlling the quantity of air entering the inlet cylinder. It is thereby possible to influence with advantage the precooling of the yarn and the formation of the air stream.

Abstract: An injection is carried out under a certain molding condition with a nozzle in an injection molding machine left open to sample an injection pressure Pr in every certain cycle for storing. Detected pressure data Pr(0) to Pr(N) for one shot is stored as reference pressure data Pr0(0) to Pr0(N). When defective molding occurs or when a resin lot is changed or the like, the injection is carried out with the nozzle left open under the same molding condition as that used in obtaining the reference pressure data and obtain the detected pressure data Pr(0) to Pr(N). Waveforms of the detected pressure data Pr(0) to Pr(N) and reference pressure data Pr0(0) to Pr0(N) are graphically represented so that variation of the molding condition is observed. It is assumed that if there are any differences, a problem presumably resides in resin, while if there is no difference but the defective molding occurs, the problem presumably resides in a mold.

Abstract: An apparatus for producing an extruded film tube and supplying said tube to a collapsing and roller assembly includes a die for extruding a molten material in the form of a tube which is in a molten state below a frost line and in a solid state above the frost line. A blower system supplies and exhausts cooling air to and from an interior portion of the tube, and is regulated by a valve. At least two sensors are provided, one below the frost line for sensing the position of said tube, and one located proximate the tube in a position above said frost line. The upper sensor is used for sensing the position of the tube prior to collapsing and flattening it. A controller receives feedback signals from both sensors and controls operation of the valve.

Abstract: A blow molding process in which a gas is blown into a parison within a mold to inflate the parison, the parison makes intimate contact with a mold shaping portion to form a hollow molded product, and the gas within the hollow molded product is discharged for cooling, the blow molding process including setting an internal gas pressure of the hollow molded product to 5 to 8 kgf/cm2; and discharging a gas satisfying an expression, F≧10×W. while blowing, wherein F is a gas flow rate (N1/min) and W is a hollow molded product weight (g).

Abstract: A plastic hollow preform is drawn through a mold passage formed in a closed mold by applying a generally constant suction to a downstream end of a conduit having an upstream end connected to an output end of the mold passage. A flow cross section of the conduit is varied between its upstream and downstream ends so as to vary a rate at which the preform is drawn through the passage by the suction. The flow cross section is varied by displacing a valve element in the conduit between positions in which it differently blocks flow through the conduit.

Abstract: A method and apparatus for controlling the diameter of a clear extruded molten tube wherein the extruded tube contains a volume of a clear liquid and the level of the liquid is indicative of the tube diameter so the level rises as the tube diameter decreases. A light beam passing through the tube is refracted from a straight line path when the liquid level rises above the level of the beam. The refracting of the beam in turn triggers the introduction of air into the extruded tube to increase the diameter of the extruded, molten tube.

Abstract: Apparatus for producing plastic film by extrusion includes a plastic extrusion machine having an extrusion screw, a motor for turning the screw, a die connected to the screw barrel outlet, a manifold having an opening receiving the die, a blower delivering cooling air to the manifold, and an infared emitter and detector for monitoring phase transition of the molten plastic material into solidified plastic film in adjusting operation of the apparatus to maintain plastic material phase transition occurrence in a preselected position downstream of the die by either adjusting speed of the blower or adjusting speed of the motor or both.

Abstract: A large core polymeric optical fiber having improved light transmitting characteristics includes a cladding filled with a light transmitting core. The core is formed during a polymerization reaction within the cladding in which the pressure internal to the cladding is greater than the pressure external to the cladding to form a pressure differential supported by the cladding.