Abstract: In a screw-type cold feed extrusion molding apparatus is provided a size control device adapted to control the sizes of extrusion molded articles through detection of the load current of the motor for driving the feed screw and take-off conveyor of the extrusion molding apparatus at speeds which vary in such a manner as to enable a molding material to be fed smoothly from the inlet toward the extrusion die of the apparatus so that fluctuations which would otherwise be caused in the sizes of the extrusion molded articles due to the presence of a molding material stagnant in the inlet of the apparatus are precluded reliably.

Abstract: An apparatus for producing edible food products having a filling therein, the filling being introduced into the center of the food product by an injection nozzle that is contiguous with a nozzle from which the food product is discharged. A conveyor having a descending gradient is associated with the nozzles and advances the food product downwardly to a feeder apparatus which severs product to length. A sensor is positioned between the conveyor and the feeder apparatus to control the speed of the feeder apparatus.

Abstract: A ring nozzle for use with an extruder to continuously form a synthetic-resin tube has a substantially stationary back nozzle part having an axially forwardly directed front face and formed with an axially centered passage opening at the face. This part is typically bolted over the outlet of the extruder. An axially centered core rod is substantially fixed in the passage and extends axially forward past the front face. This rod is also fixed in the extruder so that same can emit a hot and thick tubular strand of a plastified synthetic resin. An annular and movable front nozzle part fits with spacing around the core forward of the front face and forms therewith an axially centered and forwardly open annular gap. The thick tubular strand formed by the extruder becomes a thin-walled strand that emerges from the annular gap.

Abstract: A nozzle ring of an extruder for blowing tubular plastics film is divided into cooling sectors provided with adjusting elements. The thicknesses of the blown film are measured over the circumference thereof and a number of film sectors of equal circumferential length corresponding to the number of cooling sectors is established from the measured thicknesses. Assuming that the film sector of maximum or minimum thickness has been extruded in the correct position for the purpose of determining the cooling sector associated with the film sector, the subsequent film sectors are in turn allocated to successive cooling sectors. From the measurements, the mean thickness distributions are determined over the individual film sectors. These values of mean thickness distribution define a measure for the correcting command for the adjusting elements of the cooling sectors that are associated with the respective film sectors.

Abstract: An apparatus adapted to be positioned downstream of a foam extrusion die in an environmental control or vacuum chamber for remote monitoring of the thickness and profile of foam boards, planks and like extrudates soon after the extrudate exits the die and takes its final shape, is characterized by opposed, relatively narrow shoes on opposite sides of the extrudate path and respective carriages therefor which together are movable transversely with respect to the extrudate path by respective worms and translating nuts and a common worm drive. One shoe is operative to support the bottom surface of the extrudate in a predetermined position while the other shoe rides on the extrudate and is position monitored by a transducer operative then to provide an output signal representative of the spacing between the shoes, and thus the thickness of the extrudate passing between the shoes, to remote monitoring circuitry located outside of the vacuum chamber.

Abstract: The thickness of plastic film extruded from a die is maintained at a desired uniform dimension by utilizing the thermal expansion and contraction of die adjusting bolts to control the width of the orifice of the die. A thickness gauge measures the film thickness across its transverse dimension and provides a signal to a microcomputer which uses the information to calculate the desired die bolt movements. The movements are converted to bolt temperature changes to change the set temperature of each die bolt. A temperature sensing element in the die bolt provides a temperature signal to the microcomputer which controls the amount of power output to each bolt to attain the new set temperature. The temperature sensing and control system provides greater sensitivity, accuracy, and faster response to changing conditions than systems relying only on measurement of thickness variations to control power output to the bolt heaters without using bolt temperature for feedback.

Abstract: A hydraulic press is provided including a frame having a pair of spaced-apart vertical side members and a crown, and a mold box rigidly supported between the vertical side members and including a vertical mold cavity. A lower plunger assembly is positioned below the mold box and includes at least one plunger adapted to extend upwardly into the mold cavity, and an ejection cylinder assembly is provided for causing selective vertical movement of the lower plunger assembly. An upper plunger assembly is positioned above the mold box and includes an upper plunger adapted to extend downwardly into the mold cavity, and a hydraulic ram is provided for supporting the upper plunger assembly for vertical movement with respect to said mold box and with respect to said lower plunger assembly. The hydraulic ram includes a cylinder fixed to the lower plunger assembly and a ram housed in the cylinder and adapted to selectively drive the upper plunger assembly downwardly.

Abstract: A foam extrusion die and monitoring apparatus, including a pair of adjustable die lip members having opposed, rigid die lips defining therebetween an elongated arcuate die orifice, is characterized by position sensors located along the arc of the die lips to monitor the die opening at such locations. The position sensors include sensing styli mounted for movement with the lip members at respective sensing locations such as at the arc ends and arc centers of the die lips, and provision is made for connecting the sensing styli as by precision push-pull, flexible cables to respective linear variable displacement transformers which provide electrical output signals representative of sensed positions to remotely located monitoring circuitry. The apparatus has particular application in a vacuum extrusion line wherein the extrusion die is located inside a vacuum chamber and thus is inaccessible during extrusion.

Abstract: In the production of a tubular extruded section of thermoplastic material, the actual length of an extruded section at the end of the extrusion operation may be smaller or greater than the length of the extruded section which passed through the discharge orifice of the extrusion head during extrusion. If the wall thickness of the extruded section is varied during extrusion in accordance with a given program, inaccuracies in regard to distribution of the wall thickness over the length of the extruded section can be reduced by detecting the length of the extruded section which passes through the discharge orifice, and controlling the means for producing the programmed variation in wall thickness, in dependence on that discharge length. The same effect can be achieved by controlling the means for producing the programmed variation in wall thickness, in dependence on discharge speed and time.

Abstract: An adjustable die mechanism (10) for extruding a profiled strip of plastic or elastomeric material wherein a plurality of adjacent segments (44) is located upstream and in spaced relation from a final extrusion die assembly (32), having a predetermined profiled opening (38), with this plurality of segments (44) being mounted for individual and independent adjustment thereof, each segment having one end (46) capable of extending into the extrudate flow channel (26). Means for actuating (64) move the segments (44) relative to the profiled opening (38) in a predetermined manner such that moving the segments (44) into the profiled opening (38) modifies the flow of the extrudate material downstream of the segments (44) as the profiled strip emerges from the die assembly (32). The die mechanism includes control means (82) for selectively operating the means for moving the segments so as to produce a strip of material having the desired characteristics.

Abstract: The apparatus includes a multi-compartment hopper into each compartment of which various particulated materials are fed at a grain size according to the quality of the particular layer desired in the end product, which can be in the form of a board or a animal feed cakes in strip form, and wherein the materials are continuously but controllably fed into a pressing chamber onto which a forward pressing piston operates in one preferred direction, namely the direction of the feed, and a pair of side pressing pistons act from both sides, the interaction of all pressing means forcing the pressed product into a canal at the output of the pressing chamber where it may undergo further treatment such as by heating.

Abstract: A method of producing an extrudate using a roller die is disclosed in which on-line adjustments are made to size and shape deviations by changing the rotational speed of the extruder screw, the feed rate to the extruder, or the speed of the take-away device and the rotational speed of the roller die. The size and shape dimensions of the extrudate are measured and used to calculate new values for the screw or take-away speed of the feed rate and the roller die speed. A measurement of the extrudate dimensions may also be obtained at the roller die to provide a faster response.

Abstract: To achieve a substantially uniform thickness of film extruded from or coated by a sheet die, the thicknesses of the film are measured over its width and the film is sub-divided widthwise into imaginary sections of equal length. Each film section is associated with a correcting section of the sheet die. If the thickness measurement reveals a thick or thin portion in a film section, the associated correcting section is cooled or heated, respectively. The mean thickness distributions are determined from the measurements and employed as a correcting signal for setting elements of the individual correcting sections.

Abstract: A method of producing an extrudate is disclosed in which on-line adjustments are made to size and shape deviations by varying the temperature conditions in the extruder and by varying the relative speeds along the extrusion line. The temperature conditions can be adjusted by varying the temperature of the stock while maintaining a fixed relationship of the die temperature to the stock temperature to produce deviations in the thickness of the extrudate with respect to the width of the extrudate, and by varying the temperature of the die with respect to the temperature in the stock to produce variations in different thicknesses of the extrudate. The relative speeds along the extrusion line can be varied by changing the speed of the screw in a cold-feed extruder, by changing the feed rate for a hot-feed extruder, or by changing the speed of the take-away device which regulates the speed by which the extrudate is taken away from the extruder.

Abstract: In an extruder for making blown tubular film, an extrusion nozzle is divided into equally long segments provided with temperature setting elements. The film thickness is measured over the circumference of the film and film sectors of equal cross-sectional area are allocated to the nozzle segments out of which they were extruded. To produce thick film portions, the associated nozzle segments are cooled accordingly and to produce thin portions the associated nozzle segments are heated accordingly.

Abstract: During the production of a preform of thermoplastic synthetic material by means of extrusion from an extruder head provided with a slot-shaped exit opening, the width of which is changed according to a specific program during the extrusion of the preform in order to change the wall thickness thereof, the wall thickness of at least one section of the preform should be controlled by at least one additional program, which is superposed on at least one portion of the first program, which is longer than the additional program. In this manner, one achieves greater flexibility in respect to fulfilling the requirements of each situation on the programming, namely both in respect to the resolution and in respect to precise determination of the location of the individual switch points, even when a very great number of changes of the slot width must be undertaken over a very short section of the preform or during a very short time period during the extrusion process.

Abstract: A novel method for producing a composite pipe having a desired wall thickness by using an endless steel belt as a mold which moves axially while rotating in the circumferential direction of a mandrel. In this method, a thickness regulating device spaced a predetermined distance from the outside surface of the endless steel belt is used to adjust the wall thickness accurately to the desired value. Examples of the thickness regulating device are a cylinder roll, a taper roll, and a conveyor belt.

Abstract: A method for controlling the thickness of an extruded, biaxially elongated film product, in which thickness deviations are controlled automatically and without supervision.In the method, correlation between positions along the widthwise direction of a film sheet and positions of die manipulation bolts of an extrusion die is obtained, and initially, a profile of the film sheet prior to lateral elongation is converged into a tolerable range; thereafter, the thickness of the film sheet after lateral elongation is measured, and if there are thickness deviations outside the tolerable range, a thickness regulation is effected by transmitting a signal corresponding to the thickness deviations to the appropriate die manipulation bolts.

Abstract: In apparatus for manufacturing an elongated cheese product, the extrusion of a heated mass of cheese is followed by a subsequent pulling or tensing of the extruded strand which develops a fibrous texture in the product and reduces the size of the strand. The pulling is carried out on a continuous basis by a tension applying device, downstream of the extruder, which may comprise a pair of drums around which the cheese strand is wrapped. The strand then passes down a cooling vat under tension from a second tension applying device which retains the properties of the strand as it cools. The second tension applying means may include pairs of driven rollers through which the cheese strand passes. After the pulling and cooling, the strand is cut in lengths suitable for packaging.

Abstract: A dough receiving, shaping, dividing and forming machine for making dough bodies of predetermined size and configuration from an initially unshaped batch of dough in a continuous manner in a single machine frame has an infeed conveyor for receiving a batch of unshaped dough and conveying it to a preshaping location, a pair of laterally spaced dough batch side roller shaping rollers at said preshaping side bath into a uniform width, a pair of verticaly shaped top and bottom roller preshaping and dough advancing rollers for preshaping said batch into a uniform height and advancing said batch from between said side shaping means to a divider location, dough divider means at the divider location for receiving the dough batch in a preshaped configuration, shaping it to two generally rectangular cross section strips of dough and advancing the strips to a cut-off location, dough cut-off knives at the cut-off location for dividing the two strips alternately into parts of determinable size, separating such parts in se

Abstract: Molten plastic material is extruded uniformly about an advancing core by dividing a single stream of the plastic flowing to a die assembly transversely to the direction of advance of the core, into a plurality of streams, in which one half of the plastic flows along a first path spaced around the core and then towards the core; the other half of the plastic flows in a second path which is, in essence, a mirror image of the first path; the divided streams are reunited as a tubular sleeve of flowing plastic flowing in the direction of the advancing core, spaced around the core and flowing towards the advancing core.

Abstract: A system for production of non-woven sheet material by the dry forming method, comprising a moving carrier web to receive a uniformly distributed layer of loose fibres and a fibre distributor unit located above and across the moving web. The distributor unit includes a closed conduit system for conducting a flow of air fluidized fibre material, this closed flow across the web being maintained by blowing action. The conduits located overhead the web are provided with outlet openings constituted by narrow slots or screen wall portion, and compressed air nozzles are arranged so as to cause fibres circulating in said flow crosswise to be moved crosswise in the flow outwardly through the outlet openings, whereby a high distributor capacity is obtained by simple means by forcing fibre material out of the outlet openings in a positive manner as distinguished from outlet by general suction from outside the outlet openings.

Abstract: A nozzle ring of an extruder for blowing tubular plastics film is divided into cooling sectors provided with adjusting elements. The thicknesses of the blown film are measured over the circumference thereof and a number of film sectors of equal circumferential length corresponding to the number of cooling sectors is established. Assuming that the film sector of maximum or minimum thickness has been extruded in the correct position for the purpose of determining the cooling sector associated with the film sector, the subsequent film sectors are in turn allocated to successive cooling sectors. The mean thickness distributions are determined from the measurements over the individual film sectors.

Abstract: A nozzle ring of an extruder for blowing tubular plastics film is divided into correcting sectors provided with adjusting elements. The thicknesses of the blown film are measured over the circumference thereof and a number of film sectors of equal cross-sectional area corresponding to the number of correcting sectors is established from the measured thicknesses. Assuming that the film sector of maximum or minimum thickness has been extruded in the correct position for the purpose of determining the correcting sector associated with the film sector, the subsequent film sectors of equal cross-sectional area are in turn allocated to successive correcting sectors. The throughput and cross-sectional area or temperature of the respective correcting sector is adjusted until the circumferential lengths of the film sectors are equal.

Abstract: A nozzle ring of an extruder for blowing tubular plastics film is divided into cooling sectors provided with adjusting elements. The thicknesses of the blown film are measured over the circumference thereof and a number of film sectors of equal circumferential length corresponding to the number of cooling sectors is established from the measured thicknesses. Assuming that the film sector of maximum or minimum thickness has been extruded in the correct position for the purpose of determining the cooling sector associated with the film sector, the subsequent film sectors are in turn allocated to successive cooling sectors. From the measurements, the mean thickness distributions are determined over the individual film sectors. These values of mean thickness distribution define a measure for the correcting command for the adjusting elements of the cooling sectors that are associated with the respective film sectors.

Abstract: An apparatus produces a continuous plurality of generally rectangular dough elements of a controllable weight from a continuous and irregular mass of dough. The invention includes separate forming, dividing, and cutting portions. The forming portion includes multiple rollers disposed both normal to as well as parallel and traverse to the path of movement of the dough which form the irregularly-shaped dough mass to have a uniform width, depth, and consistency. The dividing portion includes a horizontally-disposed, multichannel dividing drum and a plurality of compression rollers which divide the dough from the forming portion into multiple strips of uniform cross section. The cutting portion includes a multiblade assembly having the shape of and being occludable with the channels of the multichannel drum. The blades are driven at constant speed in a planetary fashion whereby the only motions of the blades relative to the strips of dough passing through multichannel drum are inward and outward.

Abstract: An extruder head for extruding an elastomeric composition to form a reinforced elastomer article such as a conveyor belt has a substantially rectangular die opening and a guide member disposed in the opening of the die for directing the reinforcing elements into the composition as it is shaped by the die.A device is provided for restricting the streams of composition, which flow on opposite sides of the guide member, to have said flow meet said reinforcement along two parallel fronts.

Abstract: A platen press, and a method of operating same, for the planar and parallel pressing of particle board and like materials comprises a press bed and a press plate, one of which is movable and is provided with a hydraulic system for developing the pressing force. A pair of spacer bars are provided on the press bed to flank the particle board and a set of bearing cylinders urges the movable press member to clamp the movable member against the spacers, thereby imparting a bend or distortion to the movable press member. According to the invention, this distortion is measured and the measured value is used to operate the main press cylinders to eliminate the distortion and ensure parallel compression of the particle-board mass.

Abstract: An improved single facer is proposed which is provided with a control system for automatically controlling the gap between the lower corrugating roll and the glue roll and/or that between the former and the press roll according to the thickness of the material passing between them. The thickness of the material and the gap between the rolls are detected and an electrical signal proportional to the difference between them is given to a drive motor, which moves the glue roll and/or the press roll toward and away from the lower corrugating roll.

Abstract: A heated platten press for the manufacture of particle board features a pair of heatable press plattens 1 and 2 which are located between relatively movable press beams. The platten 1 is constructed as a rigid platten to define a flat reference surface for one side of the board to be pressed and is constructed so that it does not deflect either mechanically or thermally during operation of the press. The second press platten 2 is constructed to be elastically deflectable and is supported on a plurality of individual piston-in-cylinder arrangements 4 forming an array of adjacent substantially contiguous support fields which are substantially uniformly distributed over the whole area of the compensation platten. In operation a board is pressed and the deviation in thickness of the board from the nominal thickness is measured at points corresponding to the positions of the piston-in-cylinder arrangements within the array.

Abstract: An adjustment mechanism for a restrictor bar in a die construction of the type in which such restrictor bar is movable into and out of the internal flow path of the die so as to regulate extrusion of material therefrom. The restrictor bar movement is in axial direction and is accomplished by means of axially restrained, rotatable spools connected to threaded ends of studs in turn extending through the die body and fixedly attached to the restrictor bar. Each of the spools includes a breakable segment to cause the spools to break prior to possible stud overstressing. The spools or portions thereof may be easily replaced at a position located outside of the die and accordingly eliminates die down time.

Abstract: In an improved die-nose assembly for a melt-blowing process wherein molten resin is extruded from a series of die-holes while heated gas is blown out through slots on either side of the die nose associated therewith, spacers which are movable widthwise of the die assembly are provided in the gas slots to provide effective uniformity in the gas streams across the width of the die.

Abstract: A process for producing a film of a thermoplastic resin, characterized in that the rotation of a cooling drum for cooling a molten film-like extrudate is controlled such that the variation rate (%) of instantaneous rotation under no load (as defined in the specification) is less than about 1%, and that the cooled film-like extrudate is withdrawn from the cooling drum so that substantially no tension in the subsequent stretching step is exerted on the film-like extrudate on the cooling drum. The process is preferably applicable to a film-forming apparatus which operates at high speeds. A film having markedly reduced thickness unevenness is produced.

Abstract: A platen press, for the planar and parallel pressing of particle board and like materials comprises a press bed and a press plate, one of which is movable and is provided with a hydraulic system for developing the pressing force. A pair of spacer bars are provided on the press bed to flank the particle board and a set of bearing cylinders urges the movable press member to clamp the movable member against the spacers, thereby imparting a bend or distortion to the movable press member. According to the invention, this distortion is measured and the measured value is used to operate the main press cylinders to eliminate the distortion and ensure parallel compression of the particle-board mass.

Abstract: A flexible lip die blade is provided in which local flexing of the blade is brought about by activation of heaters located in connector members connecting the flexible lip with the body of the die blade.

Abstract: A method of and a device for adjusting the capacity and the diameter of an electric conductor provided with an insulation coating of foamed plastics material in an extruder press. The press is provided with an adjustably rotating feed screw and adjustable heating means. The deviation of the capacity of the insulated conductor from a preset capacity and the deviation of the diameter of said conductor from a preset diameter are measured at the path of movement of the conductor. The rotation speed of said screw is adjusted in response to said capacity deviation and said diameter deviation and the temperature of said heating means is also adjusted in response to said capacity variation and said diameter deviation in order to correct said deviations.

Abstract: An improved slit die for extruding thermoplastic sheet and having the capacity for fine gauge control comprises a die blade and an opposed surface in which the local separation between the two is variable by the generation of localized expansion and contraction forces in the body of the die blade while isolating the die blade lip from temperature variations by the provision of a heat barrier means.

Abstract: In a film blowing plant comprising an extruder for the melt, a film blowhead, calibrating means for the blown tubular film, oscillatory take-off means for the film and a coiler for the flattened film, the output of the plant is set to an optimum figure by a process computer controlling the width and thickness of the film. The height of the line of solidification of the film above the blowhead is measured and, in response to a departure of this height from a given desired value, the output of the extruder is increased or reduced as the case may be.

Abstract: Density of products produced from a foam extrusion process is controlled by measuring the thickness and the basis weight. The density is calculated and is compared to a target, or desired value, to produce an error signal. The error signal is used to control the density.

Abstract: An extruding system for the production of continuously extruded elastomer, such as tread stock for the manufacture of vehicle tires, has an extruder, a first take-away conveyor belt for conveying the extrusion as it exits the extruder, a second conveyor belt for varying the thickness or weight of the extrusion after leaving the first conveyor belt, a sensor to measure the running-weigh-scale value and a targeted running-weigh-scale value. The weight or thickness of the continuously extruded elastomer is controlled by measuring the weight of the continuous extrusion at the running-weigh-scale. The measured value is compared to the target value to obtain a control signal. The control signal is used to adjust the difference in speed between the first conveyor belt and the second conveyor belt.

Abstract: A multi-platen press having a stationary press table, a movable press table and a simultaneous closing device, the same stroke between the stationary and movable press tables being maintained by having at least one cylinder on each corner of the movable press table, and by having a separate control device associated with each of the cylinders. The control devices are mounted on the press adjacent the corner of the movable table to which its respective cylinder is connected, and each control device is independently adjustable toward or away from the stationary press table. The control devices are each actuated by the movable table to stop the operation of its associated cylinder when the corresponding corner of the movable table reaches a specified distance from the stationary table.

Abstract: A control circuit is adapted to control the movement of a pintle relative to the die head of extrusion apparatus. A command signal is supplied to a signal generator, which produces a first output signal in the form of a series of continuous voltage triangles, and a second output signal in the form of unit pulses. An impedance matrix contains a plurality of potentiometers which may be remotely connected to a summing amplifier. The potentiometers are arranged in a numerical order. Odd-numbered potentiometers are supplied with the triangular output signal from the signal generator. Even-numbered potentiometers are supplied with the signal generator triangular output signal, but which has been phase-shifted by half the width of one triangle. The pulse output from the signal generator is supplied to a decoder, which successively connects pairs of numerically-adjacent potentiometers with the summing amplifier during overlapping time intervals.

Abstract: The multi-roll calender for producing a sheet of elastomeric material comprises a calender frame and a series of rolls mounted in the calender frame. The rolls including an intake roll and a series of vertically superimposed rolls, with all adjacent rolls being variably spaced so as to provide variable roll gaps between each adjacent pair of rolls. Means are associated with the rolls for sensing the pressure of the material being calendered in each roll gap and means are provided on opposite ends of certain of the rolls responsive to the sensing means for adjusting the width of each roll gap formed by adjacent rolls to cause the difference between the pressures in said gaps to be as small as is practicable. Means are provided for maintaining the adjusted pressures substantially constant.

Abstract: An apparatus for delivering a refractory mass with a sand-blast head along a ladle-lining surface and parallel thereto in a ladle. The sand-blast head is provided with a movement inside the ladle so as to continuously fill the lining along a helical trajectory and over the entire height of the ladle from the bottom to the top. For this purpose, the apparatus is mounted on a platform installed inside the ladle on a hollow supporting rod through which the mass is fed to the sand-blast head. Provision is made for a contact sensor which senses the current level of the lining plane, and controlled drives of the platform rotation, rod lifting and change in the radial jet of the mass thrown out of the sand-blast head.

Abstract: Apparatus is provided for handling heat-softenable batch material prior to melting it. The batch components are mixed together and then mixed with liquid and formed into balls or pellets of substantially uniform size and shape. The pellets are then collected into a heat-exchange chamber through which hot gases are passed from a melting unit in which the pellets are to be heated to a heat-softened state. The pellets thereby are preheated prior to entering the melting unit to save considerably on energy requirements. A physical characteristic and specifically the depth of a portion of the batch being formed into the pellets is sensed, the depth being related to moisture content. The ratio of the batch material and liquid is accordingly regulated to achieve uniformity in pellet size, which is influenced by the moisture content. Size uniformity is important in maintaining relatively free flow of the hot gases through the pellets in the heat-exchange chamber.

Abstract: The uniformity of the gauge profile of thermoplastic sheet material is improved by means of a method comprising the detection of areas of non-uniform thickness in the sheet after drawing it away from the extrusion die and the redirection of a controlled portion of the cooling fluid by means of adjustable deflector blades which extend into the flowing stream of cooling fluid and alter the angle at which the cooling fluid contacts and quenches the molten extrudate, thereby allowing additional stretching of thick areas or earlier solidification of thin areas, as appropriate to the problem at hand.

Abstract: A pipe insulation is made between an inner and outer mold core from a liquid which foams and then forms a solid. The foaming action may cause movement in the inner mold which is detected and then adjusted accordingly to maintain concentricity between the inner and the outer wall of the pipe insulation. The insulation may be used alternatively as pipe.

Abstract: A coupling circuit for the feedback loops of foil-thickness control circuit, a calibrator height-adjusting control circuit, a calibrator diameter-setting control circuit and a balloon-filling control circuit interlocks the control circuits and shifts the responses thereof upon start-up of a film or foil blowing apparatus. The latter also includes the usual blowing heads, connected to a worm extruder, the calibrating basket, the balloon-flattening device, the drawing rollers and the winding device which rolls up the flattened web of blown film.

Abstract: A cross-head die in which the manifold is provided with means for selectively varying the volume of the manifold at some locations relative to other locations, whereby the relative wall thickness about the annular configuration of the material flowing through the die is selectively adjusted about the periphery of the annular configuration of flowing material. Wall thickness and configuration are further controlled at the outlet orifice of the die by means movable to selectively expand, contract and alter the annular configuration of the die passage at the orifice.

Abstract: Apparatus is provided for handling heat-softenable batch material prior to melting it. The batch components are mixed together and then mixed with liquid and formed into balls or pellets of substantially uniform size and shape. The pellets are then collected into a heat-exchange chamber through which hot gases are passed from a melting unit in which the pellets are to be heated to a heat-softened state. The pellets thereby are preheated prior to entering the melting unit to save considerably on energy requirements. A physical characteristic and specifically the depth of a portion of the batch being formed into the pellets is sensed, the depth being related to moisture content. The ratio of the batch material and liquid is accordingly regulated to achieve uniformity in pellet size, which is influenced by the moisture content. Size uniformity is important in maintaining relatively free flow of the hot gases through the pellets in the heat-exchange chamber.