Abstract: A method and apparatus for supplying two different components at two different flow rates to an extrusion head. A first component is delivered to an extrusion head through a first hose at a predetermined pressure. A second component is delivered to the extrusion head through a second hose at substantially the same predetermined pressure as the first component. The second hose extends partially through the first hose so that both components are delivered to the extrusion head at constant equal pressures.

Abstract: A method for recycling waste plastic material, from polymeric film or hydropulper waste, including plastic and cellulosic fiber or organic contaminants. The method includes the steps of introducing the waste plastic material into a size reduction unit, and reducing the size of the waste plastic material to particles having a maximum dimension ranging between about 1 inch and about 8 inches; mechanically hammering and rubbing the plastic material for separating a portion of the cellulosic fiber from the plastic; separating another portion of the cellulosic fiber from the plastic by flotation with agitation; further reducing the particle size of the plastic to a maximum dimension of about 1/2 inch; dewatering the plastic; drying the plastic to a moisture content of less than about 10 weight percent; and rolling the plastic into pellets.

Abstract: A method and apparatus for determining the location and stability of location of the edges of an object such as an extruded blown film polymeric material annulus. By real time detection of the edge location and mathematical and statistical manipulation of the data in both time and frequency domains, the stability and effects of extrusion parameters on the object can be determined.

Abstract: A method and apparatus for injecting and mold clamping control of an injection blow molding machine, wherein a parison injected downward from a die between mold halves defining a cavity is detected to thereby determine the dynamic locus of its free end. In every run the mold clamping is commanded to start before the end of injection is commanded and is effected according to the clamping operational conditions determined based on the parison locus determined in the instant or preceding run. In one method a clamping starting time is determined by a calculation with a predetermined clamping stroke speed. In another alternative method an initial clamping stroke speed is determined by a calculation with a predetermined clamping starting time and following stroke speed.

Abstract: Apparatus and methods for mixing plastic materials having different densities to supply a substantially uniform quantity of the mixture of such materials to an extruder or other processing machine. The mixture of materials is fed forcibly from the mixer to the processing machine by a variable speed auger. The mixture exerts a reactive force on the auger commensurate with the bulk density of the mixture. A sensor detects variations in the reactive force and produces signals which adjust the rate of rotation of the auger in inverse relation to the variations in the bulk density of the mixture to maintain the quantity of the mixture discharged from the mixer per unit of time within a selected range.

Abstract: A plastic material, controlled at a desired temperature, is fed on an upstream side of a gap between a pair of rotating forming rolls arrayed almost in parallel and controlled at a desired temperature from a device for feeding the plastic material. The plastic material is pressed and formed into a sheet by the forming rolls therebetween while forming a bank or an accumulation of the plastic material on an upstream side of the gap of the forming rolls and is carried out on a downstream side of the gap. The bank quantity monitoring is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and estimating the quantity of the bank in accordance with measured temperature information. The sheet formation is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and controlling various forming conditions according to a measured temperature information.

Abstract: An article conformity discriminating apparatus for an injection molding machine is capable of automatically discriminating the conformity of articles with accuracy without using a conforming article sample. In molding cycles for mass production of articles executed according to optimum molding conditions of a mold file read from a shared memory (105), an actual resin pressure detected by a pressure sensor (4) is periodically sampled according to an output of an address generator (118), while a reference resin pressure sampled in the same sampling period or a corresponding sampling period on a pressure transition pattern, in a conforming article molding process for determining the optimum molding conditions made before the mass production of the articles, is read from the shared memory, (105) by a processor (114), and the actual resin pressure is compared with the reference resin pressure.

Abstract: A process and apparatus for producing an elongated body changing in elastic modulus longitudinally thereof with use of polymers without resulting in variations in the outside and inside diameters of the body even when the polymers are different in extrusion characteristics or swelling characteristics. The apparatus may include a feeder 1 for extruding a first polymer in a molten state and a feeder 2 for extruding a second polymer, which is different from the first polymer in elastic modulus and similarly in a molten state. The feeders alternately discharge the respective polymers, which are continuously fed to a long-land die 5 along with a lubricant supplied from a lubricant applicator 4. The polymers are formed into the desired shape and cooled in the die 5, and thereafter extruded.

Abstract: A controller for an injection molding machine controls the injection ram by means of profiles having segments with programmable setpoints and boundary points. A profile associated with a particular stage of the injection molding cycle may be assigned one of several control functions having dependent variables of velocity or pressure and independent variables of time or ram position. The particular control function may be changed between injection stages. The programmable setpoints permit accurate representation of complex profiles with a limited number of segments.

Abstract: To determine and/or automatically control the degree of orientation of tubular films which have been made in a film-blowing plant including an extruder having a film-blowing head and apparatus for internal cooling and also including flattening and take-off apparatus, the rate of exchange of the air for internal cooling, the speed of the extruder, the temperature of the plastic composition being extruded and/or the take-off velocity are controlled. To ensure that the degree of orientation can be determined and/or automatically controlled in a simple manner and without an occurrence of trouble, that shape of the flaring portion of the bubble which corresponds to the desired degree of orientation is determined and/or adjusted and is recorded as the desired shape of the bubble. The actual shape of the flaring portion of the bubble is detected and compared with and adapted to the desired shape.

Abstract: Tubular bodies are extruded from thermoplastic material by forming a tubular preform at an exit of an extruder head die after which the tubular preform is then blown to the configuration of a cavity of a blow mold. The position of the preform relative to the blow mold is regulated and/or controlled, and waste portions produced in the blow mold are separated from the blown hollow body. The weight of the separated lower waste portions and/or the net weight of the hollow body when in accumulation head operation is measured in order to control and/or regulate the position of the preform and to change the die slit in the event of a weight deviation from a reference value.

Abstract: A method of controlling the extrusion of a multilayer parison so that the injection pressure for an auxiliary resin and that for an adhesive do not act on the annular fluid passages while a main resin, an auxiliary resin and an adhesive are stored in a main resin accumulator, an auxiliary resin accumulator and adhesive accumulators, respectively. The injecting pressure difference between each pair of auxiliary resins and the adhesive is maintained within a prescribed range and the injection of the resins and the adhesive from the accumulators is terminated simultaneously for all the materials.

Abstract: A plurality of cores are covered with the same jacketing material by passing the cores through respective dies of a plate, while flowing the jacketing material through sub-channels in the plate and into coating relationship with the cores. Any of the sub-channels can be shut off by diverting the jacketing material a flow diverting path without affecting the flow in the other sub-channels.

Abstract: An injection compression molding method and an apparatus therefor are provided, which are capable of accurately performing a molten resin compression operation during execution of an injection/hold operation or a metering operation, so as to produce high-quality molded products with no substantial variations between these products.

Abstract: A rotary plastic blow molding machine (20) including a base (22), a wheel (24) mounted for rotation on the base about a rotational axis A and a programmable logic controller (PLC) (100) mounted on the wheel for rotation therewith to control operation of a plurality of mold stations (40) on the wheel. The blow molding machine (20) as disclosed also has at least one sensor (62) mounted on the wheel (24) for rotation therewith to sense an operating parameter of each mold station and to generate an associated operation signal. The PLC (100) is coupled to the at least one sensor (62), processes the sensed operation signal and controls the machine (20) operation in response to the signal.

Abstract: Valve gated injection molding apparatus for coinjecting and/or sequentially injecting two different fluids through a gate into a cavity. An elongated valve pin member is received in an elongated valve sleeve member in alignment with the gate and both are reciprocated rotatably as well as axially by separate actuating mechanisms to control the flow of the fluids through the gate. Each actuating mechanism has a piston driven rack member to provide rotary motion which is then converted to axial movement of the corresponding valve member between the retracted open and forward closed positions. In one embodiment, helical threads on the valve members engage fixed teeth extending inwardly from the surrounding nozzle to convert the rotary motion of each valve member to corresponding axial movement. Linear position transducers on the rack members provide for accurate control of the valve members.

Abstract: A meltblowing system with a modular die design and on-line monitoring of web properties is described. The modular die consists of individually fed side-by-side meltblowing units. Automated control of the polymer feed rates to the units have been shown to produce a web with excellent uniformity of basis weight. The die also features a valve assembly for minimizing polymer afterflow and die tip plugging.

Abstract: A compression-resistant spacer is provided between the lower track of a hauler and the calibrator mounting platform of a calibrator or sizer in a extrusion line to prevent vibration of the calibrator and minimize wall thickness variations and surface markings of extruded profiles such as window profiles.

Abstract: Method, apparatus, and films, related to coextrusion of heat-sensitive polymer materials. The sensitive melt stream element (12) is encapsulated in a second polymeric melt stream element (16). Transport means (36) is preferably employed between the encapsulating means (20) and the die (42). A third melt stream element (68) is joined to one or both opposing surfaces (70) of the second melt stream element (16) between the encapsulating means (20) and the die (42). In the die (42) the encapsulated melt stream element (12) becomes an interior layer (46) between encapsulating layers (48A, 48B) derived from the second melt stream element (16). The third melt stream element (68) forms layers (72, 74) positioned outwardly of the encapsulating layers (48A, 48B). The positioning, on the interior of the extrudate, of edges (54) of layer (46) is adjusterd independently of the combined thicknesses of a layer derived from the third melt stream element (68) and an adjacent layer (48).

Abstract: A method for manufacturing a retardation film having a suitable retardation using a film casting method but without requiring any special heat-treating process. The post-drying process in the film casting method is divided into three or more chambers, and the tension applied to the film is controlled under the condition that the tension does not exceed a yield value determined based on the amount of solvent content and the temperature of the film in each of the chambers, so that stretch of the film is carried out under the above condition and, if necessary, under the condition that the solvent content is not more than 10%.

Abstract: A dough-stretching roller apparatus is provided to produce a continuous web of dough in a process to manufacture confectionery and bread. The apparatus includes a pair of upper rollers and a pair of lower rollers, a sensor that measures the width of the dough that contacts the lower rollers, and a controller that controls a motor driving the upper rollers in response to a signal from the sensor. The controller increases the rotational speed of the upper rollers when the sensors detect that the width of dough is less than a preset width while the controller decreases the rotational speed of the upper rollers when the sensors detect that the width of the dough is greater than the preset width. Thus, even if the quantity of dough supplied from a hopper is unstable, the stable production of a stretched web of dough having a constant volume over its length can be continued.

Abstract: With the described method, fibrous compression molded articles are produced and the material components to be used are prepared in a suitable ratio and are deposited positively to form relief-like molded article blanks. The blanks are subjected to a heat treatment for condensation of the binding agent and are set in a parison mold into parison blanks, before they are fed to a compression mold. An especially suitable depositing device for this method for formation of the molded article blank is connected in one preferred embodiment with a carousel-like feed table and a governing device with which a plurality of compression molds can be charged and utilized optimally.

Abstract: The present invention feeds a plurality of different molten resin jet streams into a T die adapted to produce film members such as plastic films. A plurality of molten jet streams extruded from a plurality of extruders, respectively, are fed from their predetermined directions into one resin feed passage in communication with the T die and combined or united without causing the mixture with each other. The relative positional relationship between the intersurfaces between the adjacent molten resin jet streams defined when the molten resin jet streams are combined or united on the one hand and an elongated discharge port of the T die can be adjusted so that the relative positional relationship between a plurality of extruders and the T die can be freely changed.

Abstract: The invention provides a control system and method for curing composite articles such as corrugated fiberglass resin plastic (FRP) panels. An exemplary system of the invention includes a curing oven, at least one infrared pyrometer sensor which is located within the oven curing zone and which provides an output indicating the temperature of the resin being cured, a tractor unit for moving the panel through the oven, and a comparator circuit which adjusts the speed of the tractor unit in predetermined response to sensor output. The invention thereby provides for the detection of the peak temperature or gelation point of resin in the panel, and allows its specific location in the oven to be controlled to optimize the performance and efficiency of the panel production line.

Abstract: An apparatus is disclosed for producing a continuous belt-like sheet of bread dough. The apparatus includes a dough hopper, vertical conveyors mounted on the facing side walls of the hopper, a dough outlet provided at the bottom of the hopper, and a pair of discharging rolls constituting part of the dough outlet, facing each other, and which are rotated so as to downwardly pass the bread dough passing therebetween. The width of the outlet and the peripheral speed of the discharging rolls are controllable so that a high-quality sheet of bread dough is continuously produced, while the gel structure of the dough is maintained uninjured.

Abstract: A process and apparatus for controlling the thickness of film made in a blown film machine having a rotating die, wherein a variable speed motor is used to control the haul-off speed of the film from the machine, by subdividing the die rotation into angular segments, measuring the blown film thickness at a point fixed in space and across each of the angular segments, and calculating an average film thickness for an angular segment, and comparing the measured thickness against a preselected desired thickness, and increasing or decreasing the speed of the variable speed motor to change the haul-off speed to bring the measured thickness into agreement with the preselected thickness.

Abstract: An apparatus is provided for quantitatively dividing bread dough. The apparatus includes a hopper having vertical side walls. The internal space surrounded by the walls has the same horizontal sectional area at any position along the vertical walls. The apparatus also includes a pair of vertical conveyors extending along the side walls. A dough outlet is formed in the bottom wall of the hopper. A dividing device is located in close proximity to the dough outlet. When the dough is continuously and quantitatively divided by the dividing device into small pieces, the vertical conveyors are driven at a speed of X m/min. in line with the speed of the dough flowing downward on its same level. Each of the dough pieces is then conveyed toward the shaping station. Thus the dough can be quantitatively divided so that a high quality dough is obtained without the gel structure of the gluten being destroyed.

Abstract: A parison thickness control system includes an extruder die and a mandrel which are movable relative to each other to change wall thickness of a parison extruded between the extruder die and the mandrel during an extrusion or forming cycle of the parison. A parison control pattern is derived by manually inputting master points each defined in terms of a target parison wall thickness and an elapsed time during the parison extrusion cycle. A further parison control pattern is derived by performing the spline interpolation to interpolate between the master points. A still further parison control pattern is derived by correcting the above-noted further parison control pattern to allow the maximum or minimum value of the master points to indicate a limit value for the target parison wall thickness during the parison extrusion cycle. The parison extrusion cycle is divided into a given number of equal time intervals to define cycle points.

Abstract: An embossing apparatus in an extrusion line for the production of sheet extrusions like vinyl siding, can include a revolver above the backing roll and supported in a pair of cradles so that selected embossing rolls can be juxtaposed with the backing roll and can define the embossing gap therewith. The revolver is indexed in position by pneumatically-operated locking members on the cradles. The revolver allows embossing roll change on the fly, if desired.

Abstract: A control apparatus having an inference function includes an input unit for inputting situations of problems in a product and a storage unit storing the situations of the problems in the product, causes corresponding to respective situations of the problems and countermeasure plans corresponding to the respective causes, and infers countermeasure plans which are most suitable according to contents stored in the storage unit and the situations of the problems input by the input unit. The apparatus displays countermeasure plans in the course of inference on a display unit during the process of inference, performs the control of an injection machine according to a countermeasure plan when the countermeasure plan has been selected from among the countermeasure plans displayed, and performs the control of the injection machine according to the most suitable countermeasure plan inferred by the inference function when a countermeasure plan has not been selected.

Abstract: A windshield molding comprises a pair of extruded side molding parts, a pair of corner molding parts, and an extruded upper molding part integral with and extending between the side and corner molding parts. Each of the molding parts includes an exterior wing and a connecting portion. The exterior wing has an outward wing portion and an inward wing portion for covering the peripheral edge of a vehicle body panel and a peripheral edge of a windshield, respectively. The inward wing portion of each of the side molding part is increased its height to define a space between the peripheral surface of the windshield associated with a side panel. This space serves as a water drain channel for guiding rain water to a predetermined position.

Abstract: Method and apparatus for fabricating multiple layer sheet materials while minimizing the time during which a sensitive polymeric melt stream is in contact with metal. The method comprises encapsulating the sensitive melt stream with a second polymeric melt stream, preferably of a lower viscosity, at the outlet of the apparatus which produces the sensitive melt stream. When the encapsulating melt stream has a lower viscosity than the sensitive melt stream, a transport means is preferably employed between the encapsulating means and the die, whereby thickness variations about the circumference of the encapsulating melt stream are reduced.

Abstract: A controller of an injection molding apparatus has a plurality of injection apparatuses from which different molding materials are injected into a cavity of a mold to fill the cavity so that molding is performed. The controller includes a first control unit for controlling operation of a specific injection apparatus on the basis of a previously set target value, for example, in the feedback control manner, a physical amount detection unit for detecting a physical amount (screw velocity, screw position, injection pressure, temperature or the like) concerning the operation of the specific injection apparatus, and a second control unit for obtaining a linkage target value for other injection apparatus from the detected physical amount (detection value) to control operation of the other injection apparatus on the basis of the linkage target value, for example, in the feedback control manner.

Abstract: Extrusion of a tubular parison for blow molding is controlled according to a program of set point data defining parison wall thicknesses and extrusion rates. Progress of purge of plasticized material from an accumulator through a variable annular gap is measured. Parison profile set point signals defining wall section thickness at points correlated with progress of purge of the accumulator are produced in response to the measured progress. Purge velocity set point signals defining purge velocities correlated to selected profile points are produced in response to progress of purge of the accumulator. Variation of the annular gap is controlled in response to the parison profile set point signals and velocity of purge of the accumulator is controlled in response to the purge velocity set point signals.

Abstract: An improved system and method for effectively controlling the operation of a continuous mixer/melter having an adjustable exit opening and connected to a melt pump is provided. The melt pump, which is preferably a gear pump, is operatively connected to an extruder/pelletizer. Operation of the gear pump is controlled in proportional relation to the energy requirements of the mixer/melter motor, the energy applied to adjust and maintain the exit opening of the mixer/melter, and the suction pressure measured at the interface between the mixer/melter and the gear pump. A microprocessor unit which receives and processes the input signals, calculates the energy requirements of the gear pump motor and compares these requirements with the actual torque, makes the necessary adjustments to the gear pump.

Abstract: Mobile structural unit molding and assembling apparatus includes a support portion, a raw material supplying portion, a molding portion, a unit transferring portion and a control portion. The support portion includes at least one base section with a wheeled carriage. The raw material supplying portion includes a plurality of reservoirs disposed on the base section. The molding portion includes at least one rotatable mold assembly disposed on the base section including at least two separable mold sections. A mixing chamber adjacent the mold assembly connects with raw material reservoirs through independent conduits. The unit transferring portion includes a tiltable unit positioning assembly selectively movable with respect to the molding portion. The control portion includes a programmable memory, a coordinator, sensors, actuators, a unit orienter and circuitry therefor.

Abstract: A system for controlling the outer diameter of a strand, particularly of a cable or the like including a measuring device for measuring the outer diameter of the strand of plastic material emerging from the extruder. The signal of the measuring device is fed to a comparator which compares it with a reference diameter and generates a difference signal. A control unit receives the difference signal to control the rotational speed of the extruder and/or the speed by which the strand emerges from the extruder. A computing stage is connected to the control unit which generates a comparison signal modulated by the actual diameter signal and fed to the control unit.

Abstract: Apparatus for producing sheets or foils of plastic or rubber mixtures includes a calender having two rollers rotatably supported by spaced calender stands with a gap between the rollers and an extruder having an extruder head with wide mouth for extruding a sheet of material into the roller gap of the calender. One part of the extruder head is fixed while another part is pivoted for movement relative to the fixed part by a cylinder-piston unit. The calender is stationary while the extruder is mounted by screws, providing vertical adjustment, on a base having wheels for horizontal movement of the extruder toward and away from the calender to vary the distance between the extruder mouth and the roller gap of the calender. The base of the extruder is coupled with the calender by a threaded spindle rotatable through a reducing drive by a reversible motor to move the extruder toward and away from the calender.

Abstract: Apparatus for handling large diameter horizontally extruded plastic tubing includes a number of driven endless belts positioned around the path of travel of the extrusion to transport the extrusion while it cools. The belts are individually driven either by hydraulic or electric motors, the speed of travel of each belt is continuously monitored and a feedback system including a microprocessor controls the driving motors so as to maintain the speed of travel of the extrusion at an adjustable controlled value. The belt positions are hydraulically controlled to accommodate tubing of a range of sizes and the level of the hydraulic fluid in its reservoir, its pressure and its temperature are also monitored by the microprocessor. In the event of component fault or failure, the microprocessor returns the affected belt or belts to manual control so that the product line need not be shut down.

Abstract: An elastomer masterbatch or a compounded productive elastomer stock is made using a twin screw extruder to mix elastomer components in multiple mixing zones at controlled temperatures. Elastomer and other ingredients are fed into the twin screw extruder continuously through precise loss-in-weight or volumetric feeders. The degradation temperature and/or cross linking temperature of the elastomer determines the rate at which the elastomer can be processed, since friction created during mixing heats the elastomer. Accordingly, the maximum rate of compounding is a function of the torque limit, cooling efficiency, and conveying capacity of the extruder. The conveying capacity and torque limit are also a function of the size of the extruder. The viscosity of the elastomer compound in the extruder, as measured by a Mooney viscosimeter (ASTM D1646), is typically in the range of about 20 to 250 units (ML(1+4)100C).

Abstract: A plastic material, controlled at a desired temperature, is fed on an upstream side of a gap between a pair of rotating forming rolls arrayed almost in parallel and controlled at a desired temperature from a flat die connected to an extruding machine and having a slit outflow portion. The plastic material is pressed and formed into a sheet by the forming rolls therebetween while forming a bank or an accumulation of the plastic material on an upstream side of the gap of the forming rolls and is carried out on a downstream side of the gap. The bank quantity monitoring is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and estimating the quantity of the bank in accordance with measured temperature information. The sheet formation is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and controlling various forming conditions according to a measured temperature information.

Abstract: A low cost crank operated injection apparatus is capable of driving an injection screw with a desired driving force without the need of employing a high output type electric motor. The injection apparatus includes a crank mechanism for converting forward and reverse rotation of a driving shaft into reciprocating motion of an injection screw mounted on a pusher plate. The driving shaft is coupled through a reduction gearing unit to the power output shaft of a servomotor controlled by a numerical control device, and the apparatus operates, during the injection process, so as to cause the injection screw to move forwardly with a great driving force.

Abstract: A compact and precision extrusion system and method for extruding strips of rubber compounds with profiles of accurate dimensions. Strips of rubber compound are uniformly heated and mixed in an extruder and then passed through a low pressure drop strainer to remove foreign matter. The strained compound then is fed directly into a gear pump which delivers precise volumes of the rubber compound immediately into the spread chamber of an extrusion head after which it passes through a die to form a precise strip of the rubber compound. The strainer and extrusion head are movably mounted with respect to the gear pump for axial separation from the gear pump for easy removal of the rubber compound from the various components of the system to facilitate compound changes. A control system regulates the speed of the extruder to provide a near constant pressure at the entrance port of the gear pump to precisely regulate the rate of extrusion of the compound from the extrusion head.

Abstract: The maintenance of the exact metering ratio during the production of plastics, particularly foams, from free-flowing reactants loaded with pulverulent to fine-grained or fibrous additives can be improved by mixing the additive in compacted form in a preliminary mixer with at least one of the reactants. The pressure in the preliminary mixer is kept constant.

Abstract: An extruder temperature controller for an extruder barrel and a method for controlling the temperature of an extruder barrel, includes a device for determining an actual screw speed and for storing a plurality of screw speeds. Each member of the plurality of stored screw speeds has a corresponding stored temperature reset value. The extruder temperature controller has a device for comparing and selecting that compares the actual screw speed to each of the plurality of stored screw speeds and selects a default screw speed. The default screw speed has a smaller deviation from the actual screw speed than any other member of the compared, stored screw speeds. The controller further includes a device for generating a control output driver signal to a heat exchanger. The control output driver signal is the corresponding stored temperature reset value for the default screw speed.

Abstract: Apparatus for automatically dispensing food product such as hard food product, having a refrigerated container for holding a supply of food product, a chamber adjacent the container for receiving food product and for delivery therefrom of a serving portion of food product, and a mechanism in the container for removing food product from the supply for delivery to the chamber thereby to pack the chamber with food product. A method of dispensing food product such as hard ice cream is also disclosed.

Abstract: An extruded, smooth finished solid sheet or film of thickness <1 mm is prepared from a thermoplastic plastic having a glass transition temperature >50.degree. C., by extruding the plastic in the thermoplastic state through a slot nozzle to form a flat extruded strip, which is introduced into the roll gap of a roll stack having a smoothed upper roll and a lower roll, with the upper roll being maintained at a temperature below the glass transition temperature of the thermoplastic plastic and with the lower roll being maintained at a temperature in the plastic state domain of the thermoplastic plastic, and, after exiting the roll gap, the extruded strip is moved resting on a smooth-finished endless belt which passes around the lower roll, thereby smoothing the surface of the strip; and cooling said extruded strip below the glass transition temperature.

Abstract: A feedblock is provided for producing a laminated plastic sheet with each layer of the laminated sheet being of substantially uniform thickness. The feedblock includes a plurality of lamella channels each of which is of non-rectangular cross-sectional shape. The particular non-rectangular cross-sectional shape of each lamella channel is selected to offset the tendency of the extruded plastic to thin and spread non-uniformly. Thus, the thinning and spreading of the extruded plastic will urge the plastic into a layer of substantially uniform thickness.

Abstract: An apparatus and method for coextruding substrate and coating materials having different temperature dependent properties, wherein one or more predetermined amounts of the coating are metered onto one or more predetermined surfaces of the substrate. A facefed coextrusion die, including a die plate for sizing and shaping the substrate and a feed block/metering tube assembly nested in the die plate for metering the coating onto the substrate, is mounted adjacent to an outlet opening of an extruder for the substrate. The metering tube is rotatably adjustably mounted in the feed block at one of its ends, and communicates with an extruder for the coating material at its other end. The metering tube has a pair of spaced gates formed therein which are generally alignable with a pair of spaced channels formed in the feed block to enable coating material to flow through the metering tube feed block and into contact with the substrate being extruded through the die plate.

Abstract: The injection molding machine is designed to produce molded pieces in a predetermined shape by moving back and forth a screw inside a cylinder so as to inject a molten molding material in the cylinder into a metal mold. The evaluation of molding stability of this injection molding machine is carried out in the following steps. First, an injection pressure imparted to the molten molding material by the screw at each screw position is detected, every time a molded piece is produced, and the injection pressure so detected is then integrated so as to obtain the work done of the injection molding machine. Following this, a molded piece so produced is weighed. Thus, a correlation between work done and the weights of molded pieces is statistically obtained on the basis of a plurality of corresponding data in relation to work done and the weights of molded pieces so obtained. Molding stability is then evaluated from the correlation so obtained.