Abstract: A method and an apparatus for automatic zero adjustment of an injection-molding machine, in which an axis driven by a servomotor can be automatically returned to its origin with accuracy and speed. When a one-revolution signal is produced after the axis reaches a deceleration position, a preset coordinate position of a reference point is written in a current-value register. Subsequently, when the axis driven toward an absolute position reaches the absolute position, the preset coordinate position of the reference point is corrected with use of a correction value calculated on the basis of a known coordinate position of the absolute position and the register value. When the axis driven toward the reference point reaches the corrected position, the preset reference point coordinate position is written in the current-value register.

Abstract: A method and apparatus for continuously forming a uniform layer of material that is being dispersed. This material, in the form of a stream of material, is deposited on an intermediate conveyer belt, as strips, transverse to the direction in which the material is fed to a dispersal mechanism. In the direction of travel of this intermediate conveyer belt, the strips abut one another in such a way that no gaps exist between them.

Abstract: A numerical control method and an apparatus therefor, in which a mold opening operation or an eject operation is performed during a metering operation so that the injection-molding cycle time is shortened. When a cooling period terminates or mold opening is completed during the metering operation, a programmable machine controller for sequentially controlling an injection-molding machine delivers information specifying a clamp axis or an eject axis, the displacement, moving speed, and moving direction of the axis, and a step feed command to a numerical control unit for controlling servomotors for axes of the injection-molding machine, through a common RAM. Pulse distribution for the clamp axis or the eject axis, based on this information, and pulse distribution for a screw rotating axis are alternately executed by a numerical control unit, which responds to the step feed command.

Abstract: A process for continuous fabrication of thermoplastic webs from at least one extruded thermoplastic web heated to processing temperature. This thermoplastic web is cooled under the application of area pressure down to a temperature at which smoothing of the surface is terminated. A calibrating and smoothing mechanism in the device for performing the process according to the invention consists of a double-band press which includes an apparatus for conducting heat away from the thermoplastic web in the reaction zone in which the area pressure is applied.

Abstract: In a method of controlling an injection molding machine wherein a pressure holding step is controlled in multiple steps, the transfer points of respective holding pressures are transferred in accordance with the temperature of injected resin or a metal mold detected by a temperature sensor provided for the metal mold.

Abstract: Stringent specifications for an extrudate are maintained by accurate control of tread weight per unit length without regard for dimensional changes of the extrudate. This is achieved simply by adjusting the speed of a single variable-speed conveyor, whether the running-weigh-scale ("RWS") conveyor, or, the take-away conveyor, without adjusting the extruder screw, or operation of the extruder, and without measuring any dimension (width or gauge) of the extrudate; therefore, with no regard either to the cross-sectional area, or surface area, or volume of the tread. The accuracy of control depends chiefly on how accurately one can measure the weight/unit length, and how precisely the speed of the single variable-speed conveyor can be controlled. Exceptional on-spec control in the continuous extrusion of a tread stock is achieved because it was recognized that dimensional changes of the tread stock, independent of its change in weight/unit length, do not adversely effect the specifications of the extruded tread.

Abstract: A position control system comprises a position command generator for generating a position command at a prescribed sampling time k for a time k+M which is at least one sampling cycle M ahead of the prescribed sampling time. A controlled object includes a speed control loop, and a control unit for generating a control input value determined by determining a weight coefficient of each of position commands at sampling times K+l (l=1, 2, . . . , M) and a weight coefficient for the position and speed which are outputs of the controlled object in order to minimize the value of an evaluation function so that the position command at the prescribed sampling time k and the position of the controlled object will be equalized, while the position commands produced by the position command generator at the sampling times k+l (l=1, 2, . . . , M), the position and speed of the controlled object, and a control input to be applied to the controlled object are being used as variables.

Abstract: The present invention provides a novel coextrusion apparatus that includes a first flow channel of a greater width than a second flow channel, and an adjustable vane blade between the channels. By the use of interchangeable plates, this unique apparatus is able to prevent any selected layer or layers of a laminate from extending to the full laminate width. This highly advantageous result is obtained by the formation of an isolating edge that is an integral part of a layer or layers that extend the full laminate width. Also provided is process for forming a laminate having an isolating edge.

Abstract: A die-base ring (11) has at its upstream end a tubular ring (12) provided with a collar (12a) and co-operating with means for fixing the ring to a support (1). The fixing device includes four radial screws (19), pressing against a cylindrical bearing surface (13) of the support and making possible a mechanically operated off-centering of the ring relative to the support, and a clamping collar (20) making it possible to place two cylindrical bearing surfaces (14 and 15) in strictly coaxial positions. Axial screws (16) pass through the support with sufficient radial play to allow the adjustment.

Abstract: A multicolored foam product and a method for the preparation thereof. Heat-plastified foamable gel of a thermoplastic resin or resins containing blowing agents are combined with different coloring materials added sequentially and extruded through an orifice of a die which is extended in length to facilitate laminar flow in the resin. This resin is expanded to form a multicolored layered foam product, such as multicolored foam planking, in a single extrusion. Multicolored foam planking produced is suitable for use as the body material for surfboards, body boards, and other recreational products.

Abstract: A take-away device for a flattened tubing foil forming machine having an improved foil edge position control. The take-away device for tubing foil is formed by an extruder with a tubing blow head carrying out a blowing process. The tubing foil is flattened between a pair of squeeze rollers, which pair of rollers can reversingly turn about a vertical axis of rotation. At least two turning rods are disposed following the squeeze rollers. The turning rods are pivotable about at least one vertical axis, and have, if necessary, at least one deflecting rod. The rods are pivoted by a frame member about a horizontal axis of rotation. A winding-up device receives the flattened tubing foil from the turning rod. A measuring instrument is disposed between the final turning rod from which the tubing foil is guided to the wind-up device, and the wind-up device.

Abstract: Apparatus for preparing and dispensing thermoplastic resin has a conveyor with a chamber provided with heating elements, a conveyor screw mounted in the chamber and connected to a drive motor, a resin inlet and a resin outlet. To ensure the intended continuous dispensing of the resin even during intermittent operation, a control device is provided having inputs connected to a resin pressure sensor, a conveyor speed of rotation sensor and a resin temperature sensor. Intended values for the conveyor speed, resin pressure and resin temperature are supplied to the control device, which regulates the pressure during interruption of the dispensing of the resin and effects a speed regulation or a pressure regulation with a superimposed speed regulation during dispensing of the resin. For plasticizing of the resin, which is supplied in solid, preferably granular form, and since the conveyor geometry is designed to produce minimum friction, external heating by the heating elements is required.

Abstract: Disclosed herewith is an injection control apparatus which is used for an injection-molding machine that is subjected to injection and hold pressure controls by means of a numerical control unit (30), and which controls the switching from the injection control to the hold pressure control based on the injection time and resin pressure so as to improve the operation reliability of the injection-molding machine and ensures production of good-quality molded articles.When the pressure on the resin filled in a mold that is detected by pressure detection means (26) exceeds preset pressure or when a predetermined time elapses after the start of the injection operation, hold pressure control means (30, 50, 60) starts the hold pressure control. When pulse distribution to a hold end position is not completed upon completion of the hold pressure control, an error register (51) of a servo circuit (50) is followed up by follow-up means (30) so that the pulse distribution is forcibly executed.

Abstract: An injection molding machine is provided which uses servo motors (M1, M2) as driving sources and in which a preset back pressure is correctly transmitted to a resin. The torque limit values and rotating directions of an injection servo motor in respective stages is set in accordance with the relationship in magnitude between the preset back pressure and the resistance during a transmission mechanism of the respective stages of metering. A servo circuit of an injection servo motor is torque-limited with a preset torque limit value, and the injection servo motor is driven in a preset rotating direction.

Abstract: A process for coextrusion blowmolding of multilayer polymer articles, wherein a multilayer parison is extruded through a die, introduced into a mold, and blowmolded, the flow of multilayer plastic material being periodically interrupted, and additional plastic material being injected into the extrusion die at timed intervals, so that this additional material forms portion of the parison which later are trimmed from the molded article and reprocessed for reuse.

Abstract: A method of and apparatus for controlled coextrusion of plastic bag making film and a reclosable fastener male profile comprising extruding the film through an orifice with which is aligned a profile orifice and one or more alignment rib orifices as well as one or more stablizing ridge orifice cooperating with the profile and/or rib orifices. The resulting extruded product provides a bag making material comprising a plastic film carrying the zipper profile and with one or more alignment ribs in spaced parallel relation to the profile, with a reinforcing ridge or ridges effecting stabilizing beam effect in respect to the alignment rib or ribs and/or the profile during the processing of the extruded product into its final bag making material form. The extrudate for the film and the extrudate for the alignment rib or ribs may be derived from separate sources so that different plastics of different density or characteristics may be supplied to the alignment rib or ribs.

Abstract: A process for producing a non-woven web of thermoplastic polymer fibers comprises extruding a thermoplastic polymer through a series of die openings while passing a stream of hot gas from both sides of the die openings to impinge and attenuate the molten extruded resin fibers, wherein the gas is passed through a plurality of flow distribution holes and through a flow detector to intermix gas jets discharging from the holes.

Abstract: A method and an apparatus for injection control for an injection-molding machine, adapted to perform injection control by means of a servomotor controlled by a numerical control unit, in which the injection control is completed by performing pulse distribution to the servomotor, up to a hold pressure end position, and a follow-up operation when injection-speed control and hold pressure control for individually predetermined times are finished, in order that the injection-speed control and the hold pressure control can be executed in a time-based manner.

Abstract: A method for manufacturing optical fiber cable in which at least one light waveguide, either alone or as a bundle forming a core, is loosely inserted into an outer sheath with a definite length allocation between the length of the core and sheath characterized by passing the cable around a deflection roller and varying the diameter of the deflection roller to obtain the desired length allocation between the sheath and core.

Abstract: A suckback method and apparatus is capable of positively effecting a suckback operation in an injection molding machine using a servomotor as an injection axis drive source for axially driving a screw. When the screw reaches a metering completion position, screw rotation is stopped and a follow-up operation for an error register is carried out so that an error amount accumulated in the error register becomes equal to zero (steps S1, S4, S5). Then, a torque limit for the servomotor and for application of back pressure is released (step S8), and the screw is driven backwardly by the servomotor by a predetermined suckback amount (step 11).

Abstract: Disclosed is an injection-molding machine in which the injection acceleration/deceleration time can be varied in accordance with parameters related to injectin, such as the properties of resin, etc., thus permitting injection-speed control under optimum conditions.Pulse distribution is preformed with a predetermined cycle in accordance with a set injection speed (V1.about.V3) for an injection-speed control step corresponding to a detected screw position. A certain number (Pb) of pulses are delievered as an output, the number being obtained by dividing, by a predetermined value (n), the result of addition of the number (Pa) of distributed pulses for the current cycle and the number (X1.about.Xn1-) of distributed pulses for a period equivalent to a predetermined number of cycles preceding the current cycle. Thus, the acceleration/deceleration processing is accomplished, and an injecting operation is performed with an optimum acceleration/deceleration characteristic.

Abstract: In a method of operating a screw extruder having a drive motor in which the speed of rotation of the drive motor is controlled, in order to achieve as constant a quality of product as possible, the speed of rotation is controlled depending on the specific energy input in such a manner that the specific energy input is maintained substantially constant. A control depending on the product temperature may advantageously be superimposed on the control keeping the specific energy constant in the form of a cascade control. A screw extruder for carrying out the method has a housing in which a screw is mounted, a drive motor having a variable speed for continuously driving the screw, feed devices for supplying basic products, additives and the like, and a control device for controlling the speed of rotation of the screw.

Abstract: The process for making at least one thermoplastic monofilament of an exact diameter from a thermoplastic material by spinning in an apparatus in which a thermoplastic material is fed to at least one spinneret, which has at least one spinning plate with a plurality of spinning holes for the thermoplastic monofilaments, and forcing the thermoplastic material through the spinning holes with at least one spinning pump. To provide a monofilament of a very exact diameter the process further comprises measuring the diameter of each of the monofilaments in or after the outlet of the associated spinning hole, feeding the resulting measured value of this diameter as the actual value to a controller associated with that monofilament and controlling the flow rate of thermoplastic material through the associated spinning hole according to the difference between the actual value and a predetermined setpoint value.

Abstract: A screw extruder and a method of operation thereof. The screw extruder comprises a barrel including a section that is supported for rotation about the longitudinal axis of the barrel. A screw extends and is supported for rotation in the barrel; and, in use, rotation of the screw rotates and advances plastic material through the barrel. Rotation of the screw also causes the rotatable barrel section to rotate, and a brake is connected to that rotatable section to maintain the rotational speed of the rotatable section less than the rotational speed of the extruder screw. The rotational speed of the screw relative to the rotatable barrel section controls the relative rates at which plastic is mixed, heated, and pressurized in the barrel.

Abstract: Improved melt spinning of friable, thermally sensitive organosilicon preceramic polymers is obtained by using externally-metered feed means for continuous feeding of the polymer to an extruder. Starve feeding by metering the feed at a rate less than that required to fill the feed screw flights prevents pulverizing and compaction of the friable polymer, leading to cross-linking of trapped polymer and solid plugging, which would cause the extruder to bind and cease to function. Metered feed can be obtained by either monitoring of screw loading or discharge pressure and adjustment of hopper feed rate or control based upon measured values of extruder speed or metering pump speed.

Abstract: The present invention provides a novel coextrusion apparatus including, in a preferred embodiment, a die within a feedblock. The apparatus includes edge seam-forming channels, which provide a core layer sandwiched within adjacent layers having integrally seamed edges. Also provided in a unique process for sandwiching a core stream within adjacent layers.

Abstract: The present invention provides a novel edge-laminating apparatus, in which an edge-laminating stream exiting from an edge-laminating flow channel, is driven by flow pressure into an edge of another stream. Also provided is a novel process for forming an edge-laminated stream, and for forming an extruded product.

Abstract: The apparatus for extrusion of a thermoplastic material comprises an extruder with an extruder screw and an extruder housing with a feed opening, a feed device, a drive with a variable speed motor and a regulating device cascade for the mass temperature. The regulating device cascade has a plurality of tempering zones, at least one mass temperature detector and at least one tempering device. One tempering zone connected directly to the feed opening is part of the regulating device cascade and the temperature in the one tempering zone is corrected by a set value during a mass temperature variation. To provide a temperature regulation range which does not experience disturbing decreases, the tempering zone at the feed opening has only a cooling device and has a grooved sleeve. The feed device is a gravity feed device and belongs to an additional regulating loop which controls the rotational speed of a variable speed motor.

Abstract: A method of mold opening/closing speed control wherein an opening/closing speed switching position for molds in a mold clamping unit in an injection molding apparatus can be taught by a control device. The control device is set in a teaching mode (101), a servo motor (M) is driven at a low speed to move (102) the molds, speed switching position P1, P2 and P3 are stored (103, 104, 205, 106, 109) by a teaching device and opening/closing speed control of the molds is performed (110, 123) by the servo motor in accordance with the stored positions.

Abstract: Shaped articles, especially ones containing a plurality of fine through passages, are made from a composition containing a refractory particulate material by extrusion, cutting the extrudate, while vertically hanging or suspending into lengths while in the green deformable state by a high velocity water jet, and then calcining to bind the refractory particles together. Depending on the nature of the refractory material, the articles are of use as catalyst supports or precursors, adsorbents, or absorbents. The extrudate is extruded horizontally and allowed to sag into a gap between the extrusion die and a transport device, which is driven positively to maintain the degree of sag within predetermined limits, and the frequency of cutting depends on the rate of movement of the transport device.

Abstract: A coating method and apparatus using an extrusion head to apply a liquid film to a running web. The thickness of the film is measured at two transverse points and a roller conveying the web is tilted to correct any difference. The amount of tilt per roller with a roller bearing span of 750 mm is 0.5 to 20 mm, preferably 0.5 to 15 mm.

Abstract: The invention relates to a method for producing insulations of foamed plastic material, in cabinets and doors of refrigerators, freezers and the like.According to the invention, a metered quantity of a foamable mixture is fed into the gaps between the inner and outer walls of a cabinet or door, placed in a foaming jig; the foaming process is controlled by sensing characteristic parameters, for example, the temperature of the jig, cabinet or door, or the pressure of the foaming plastic material, comparing them with reference parameters or data stored in a data processing unit. A control signal is generated to open the foaming jig and to unmold or remove the cabinet or door when at least one of the processing parameters has reached a pre-established value. The metered quantity of mixture fed in each subsequent foaming operation is corrected each time according to the changes in the peak pressure of the foam with respect to the previous foaming operation.

Abstract: A thickness control system for controlling the thickness of an extrudate includes a nested temperature control loop for controlling the temperature of a heat responsive element based upon a predetermined temperature set point. The temperature set point for the temperature control loop is computed based upon the measured thickness of the extrudate.

Abstract: The present invention is directed to the continuous production of microcellular plastic web material having integral unmodified laminar skin. In accordance with the invention a web of plastic material impregnated with an inert gas is delivered continuously to a degassing device in which the degree to which gas diffuses out of the surfaces of the web can be selectively and continuously controlled, whereupon the web enters a foaming station where it is reheated to induce foaming. The temperature of the reheated web and the duration of the foaming process prior to quenching are also selectively controllable to produce the desired web characteristics.

Abstract: In operation of a screw extruder, particularly a pin extruder, processing a rubber or a plastic mixture, troubling disturbances and on occasion heavy damage occur when foreign bodies are introduced into the extruder with the material to be processed causing damage to the extruder structure. In order to avoid this damage one possibility is to shut off the extruder at a sufficiently early time and of course immediately when an appropriate dangerous condition is detected. Therefore the drive torque which is taken by the extruder screw shaft is compared with the mass pressure in the mixture to be processed. As soon as this compared value no longer follows the functional dependence of the normal operating parameters such as the rotation speed of the extruder shaft, viscosity of the mixture, temperature lowering of the tempering medium, the volume increase of the mixture drawn in the extruder inlet or the like, the extruder is automatically shut off since a disturbance by foreign bodies is assumed.

Abstract: An automated method is provided for selectively separating resin pellets having a gel count below a specified maximum from pellets having a gel count above the specified maximum, while the pellets are flowing in a pneumatic conveyor. The separation is based on an essentially continuous measurement in which a laser beam is utilized to detect the number of gels in a film made from pellets withdrawn as a sample stream from the main pellet stream. In response to the gel count measurement, a control signal is established that is utilized to manipulate a diverter valve located in the pneumatic conveyor, which diverts plastic pellet flow between a preferred storage means storing pellets having a low gel count and a secondary storage means for storing pellets having a higher gel count.

Abstract: The present invention is directed to a process for the continuous production of articles or coatings with contours wherein a liquid material is introduced at one end into the mold cavity formed between at least two travelling continous shaping faces, said material being cured in the mold cavity and subsequently removed from the mold, characterized in that (i) the travelling faces are moved downwards at least in the region of the material feed, (ii) the stream of material supplied is moved to and fro transversely to the direction of advance of the faces, and (iii) the quantity of material supplied is controlled so as to fill the mold cavity with a uniform coating and an apparatus for use therein.

Abstract: A metering system of an injection molding machine which uses a numerical control unit (10), having a torque limit function, in order to control a rotating speed and a back pressure of a screw (1) in accordance with a screw position.The numerical control unit (10) reads out, from a non-volatile memory (14), a screw rotating speed command value and a torque limit value in accordance with a screw position detected by an encoder (P1), and outputs the readout screw rotating speed command value and torque limit value to a second servo motor (M2), which rotates the screw (1), and to a first servo motor (M1), which drives the screw (1) in the axial direction, respectively.

Abstract: A velocity control system for the injection shaft of an injection molding machine is adapted to drive an injection shaft (2") by an electric motor (20) and to control the electric motor (20) by a numerical control unit (30). The final position of the injection shaft (2") and the reference velocity of the injection shaft are commanded by data of a single block, and the velocity of the injection shaft (2") at each commanded position is obtained by correcting the reference velocity by means of a feedrate override value using an override table. Accordingly, an instruction of a single block suffices as an instruction for a single injection operation, thus simplifying CNC data processing.

Abstract: In the production of profiles from rubber and/or plastic mixtures, the throughput of the extruder should be kept constant. To this end, an identification of the mixture of material to be processed is fed in the form of a code to a computer system in which the characteristic mixture properties and the set-point operating values for a given profile to be made by the extruder are stored in memory. During the extrusion process, at least one operating variable, preferably the pressure occurring in the mixture of material being processed, is measured continuously, the difference between a measured value at a given time and the corresponding set-point value of the operating variable stored in memory is formed, and this difference is used as a control variable for a governing system for the speed or rpm of the extruder which is operated by the computer system.

Abstract: A pellet mill controller includes a plurality of temperature sensors to sense the temperature of material as it traverses the pellet mill, and a temperature sensor for sensing the temperature of the die to determine when it reaches the approximate nominal boiling point of water. As the die reaches the approximate nominal boiling point of water, the differential is measured between two of the temperature sensors and stored in the pellet mill to control the pellet mill in accordance with temperature differential control modes previously patented.

Abstract: A pipe of thermoplastic polymer, e.g. polyvinylchloride is extruded by an extruder comprising an extrusion die (2) having a moulding end part (2a) with heating elements (11) located about said end part. The wall thickness of the pipe is controlled in order to obtain a pipe of a substantially even wall thickness. For said control the wall thickness of the extruded pipe is measured at 360 points equally distributed over the circumference and moreover the average is determined in eight measuring sectors comprising 45 measuring points per sector. The average of the measuring values of one measuring sector is compared with the circumferential average of the 360 points, the deviation of the desired wall thickness in said one sector being counter balanced by the action of the heating elements. In a preferred embodiment a polyvinylchloride pipe obtained by means of a two screw extruder presents an even wall thickness over the circumference.

Abstract: An extrusion process is controlled by feeding the material to be extruded from a supply station (5) to an extruder (1) and repeatedly weighing the supply station to calculate the throughput of the extruder. The initial line speed necessary to produce a predetermined weight/meter of extrudate is calculated and the line speed is adjusted accordingly. Subsequently, the throughput and the line speed are increased simultaneously, such that the weight/meter is maintained substantially constant until any one of a plurality of parameters such as line speed, screw speed, motor load current, extrudate temperature, melt pressure, etc reaches a predetermined maximum value. Thereafter either the line speed or extruder throughput is adjusted such as to maintain the weight/meter of the extrudate substantially constant at the desired value.

Abstract: A space portion processing method and apparatus for preprocessing a slide fastener chain before attaching parts forming a separable end stop such as a retainer pin and a separable pin at the space portion of a slide fastener chain formed by cutting and removing a row of elements for a certain length from a row of coil-like continuous fastener elements of thermoplastic resin attached around a core cord along each of the facing side edges of a pair of fastener tapes are disclosed. After the space portion is detected and positioned and the slide fastener chain is held on a bed, fusion of the element cut edges at the end of the space portion into the tapes and press-forming of the core cords is carried out simultaneously by using the same pressing means. The space portion processing method and apparatus for a slide fastener chain according to the invention enables the apparatus to be made simple and compact, allows processing efficiency to be improved, and processing costs to be lowered.

Abstract: Apparatus for producing plastic pipes by an extrusion process in which the wall thickness of the plastic pipe is controlled by the takeaway speed at which a soft plastic pipe is removed from a metal sizing sleeve. To measure the wall thickness of the soft plastic pipe advancing through the sizing sleeve for regulating the takeaway speed, a transducer emits ultrasonic sound through a plastic transmission line mounted in or on the sizing sleeve and interposed between the transducer and the plastic pipe. The time interval between the emission of a sonic pulse by the transducer and the detection of a reflected sonic pulse from the inner wall of the advancing soft plastic pipe is a function of the wall thickness of the plastic pipe in a soft plastic state.

Abstract: An apparatus for supervising an injection stroke of an injection machine of the type wherein injection parameters are detected at a number of points in a filling stroke, and detected parameters are sequentially sampled at a plurality of points over the entire filling stroke, the filling stroke is divided into a plurality of regions, and the injection parameters measured in respective divided regions are judged as to whether the parameters can produce satisfactory products or not. Such parameters are used as reference values and sequentially sampled parameters are subtracted by the reference values. The differences are accumulated for respective regions and when accumulated differences exceed predetermined permissible values an alarm signal is issued.

Abstract: A method for continuously extruding an elastomeric material on the interior of a continuous tubular woven fabric in a loom, comprising motive means for creating relevant movement between the extruder and the woven fabric, sensing means for detecting stoppage of said loom, control means responsive to said sensing means directing said motive means to move said extruder relative to said woven fabric and a tubular woven fabric having an interior layer extruded directly onto the interior of the tubular woven fabric.

Abstract: The molding machine of the present invention comprises a screw extruder for extruding plastic material. A plurality of molds are moved one at a time to the outlet end of the extruder for receiving the plastic material therefrom, One end of the mold is open for receiving the plastic material and the opposite end of the mold includes a closure plate covering the end of the mold. The closure plate has a small fill sensing aperture therein. A sensing switch is mounted adjacent the fill sensing aperture and is adapted to sense when molded plastic exits from the fill sensing aperture so as to shut off the extruder and cause the mold to move away from the extruder so that an additional mold can be filled. A cylinder operated closure device clamps the opposite ends of the mold after the mold has moved away from the filling station so as to contain the plastic material within the mold while the plastic material cools and hardens.

Abstract: The method of the present invention utilizes a microcomputer in combination with a CRT and a multiplicity of transducers for monitoring process parameters in the operation of a reciprocating device having a linear stroke. A profile of the process parameters including pressure and velocity are generated as a function of stroke length and time and are stored in a non-volatile memory and graphically displayed on the CRT as master traces for comparison with current data profiles. The velocity is calculated by dividing distance transversed with time or by use of a velocity position transducer.

Abstract: A dwell control system of an injection molding machine is adapted to drive an injection shaft by an electric motor (20) and to control the electric motor (20) by a numerical control unit (30). At the time of a dwell operation, the numerical control unit (30) operates the electric motor (20) under the application of a torque limit to apply a predetermined pressure to a molten material in a mold (4).