Abstract: An extruder-housing part for a double-worm extruder for the plastification of thermoplastic synthetic resin and plastic mixtures has two chambers for receiving the worms and forming a figure eight cavity. A wear-resistant material formed as a hard-phase layer is provided to line the chambers. The extruder-housing part is a one-piece seamless structure with an isotropic lattice of powder metallurgical origin with a hot isostatic pressing configuration.

Abstract: A foil-blowing apparatus has at least one deformable lip defining the annular orifice from which the thermoplastic tube which is blown to form the coil is extruded. The lip can be provided with an array of effectors which, in response to a thickness-profile measuring unit, can radially deform the lip to correct thickness errors. The lip can be under prestress and the radial deformation is effected by measuring the thickness and superimposing a radial force on the prestress.

Abstract: In place of discrete orifice spinnerets, a nozzle unit for thermoplastified thermoplastic material in the production of nonwoven fabric has a wide-slit nozzle at least one lip of which is formed with sawtooth serrations so that a film emerges from the nozzle and is broken up by an air stream into continuous filaments or short fibers for the production of the nonwoven fabric by the normal spun-bond drawing process or by the melt-blown process.

Abstract: Platelike webs of thermoplastic material are produced by extruding a strip of the thermoplastic material and passing it through a roll unit having a pair of intake rolls upstream of which a bank of the material is formed. The delivery speed is controlled in response to the bearing pressure of the intake rolls.

Abstract: An apparatus for making a fleece comprises a horizontally elongated upright passage, flaps defining a stretching gap between the walls, and respective lower flaps have upper edges pivotal by actuators on the walls. A foraminous conveyor belt extends horizontally immediately underneath the passage and is advanced generally continuously horizontally past the passage. An array of spinnerets in the upper end of the passage forms filaments that move downward in the passage and that deposit on the moving conveyor as cool air is introduced into the upper end of the passage and is withdrawn from the passage through the lower end thereof and through the foraminous belt. The deposited length of the filaments on the belt downstream of the lower passage end is continuously monitored and an output corresponding thereto is generated and is compared with a set point and the lower flaps are pivoted to move their lower edges away from one another when the output of the sensor means exceeds the set point and vice versa.

Abstract: An extrusion die for a plastified thermoplastic resin has an outer part, an inner part inside the outer part and defining with it an annular passage, and webs supporting the inner part on the outer part and defining branch passages connecting an inlet passage formed by the parts to the annular passage. A restriction collar downstream of the branch passages is formed with teeth projecting only partly transversely across the annular passage and leaving an annular space clear for resin throughflow.

Abstract: The process for making a spun-filament fleece from at least two stretched thermoplastic monofilaments made of a thermoplastic material includes feeding thermoplastic material to at least two spinnerets each including a separate group or plurality of spinning nozzles arranged in rows over a rectangular cross section, then exposing each band or group of thermoplastic filaments issuing from each group of spinning nozzles separately to a transverse flow of cooling air in a blower shaft, next stretching the bands or groups of thermoplastic filaments jointly in a common central stretching shaft by outflowing stretching air, then depositing jointly the thermoplastic filaments which have been stretched in a spun band moving below the stretching shaft continuously to form the spun-filament fleece and drawing a suction air flow through the spun band and/or the spun-filament fleece being formed.

Abstract: A method of and apparatus for continuously stretching a thermoplastic web comprises the steps of feeding the thermoplastic web longitudinally to a heating chamber at a relatively low input speed, engaging the thermoplastic web in the heating chamber with a first member with a relatively low sliding friction between the web and the first member and engaging the thermoplastic web in the heating chamber with a second member spaced longitudinally downstream from the first roller with a relatively high sliding friction between the web and the second member. The thermoplastic web is pulled off the second member in a downstream stretch of the web at a relatively high stretching speed and the web is heated in the chamber to a temperature sufficient to substantially prevent plastic-deformation stretching of the web upstream of the second member.

Abstract: An apparatus for blow extruding a synthetic-resin tube has a nozzle having an annular mouth generally centered on a longitudinal axis for longitudinally outwardly extruding a tubular synthetic-resin strand, an inner stabilizing tube extending longitudinally outward from the nozzle within the mouth thereof and having an outer end spaced a predetermined longitudinal distance from the mouth, and an outer stabilizing tube surrounding the inner tube and defining a longitudinal passage therewith, extending longitudinally outward from the nozzle within the mouth thereof, and having an outer end lying between the outer end of the inner tube and the mouth. The passage opens outward between the outer ends. Cool air is fed to the passage at the mouth and to a space defined between the strand where it emerges from the mouth and the outer tube for flow of this cooling air longitudinally outward between the strand and the outer tube and from the outer end of the outer tube.

Abstract: A rotor and stator mixing system has mixing-chamber recesses in the outer periphery of the rotor and inner periphery of the stator which are generally similar, arrayed in peripheral and axial rows and are mutually axially offset. The guide radius R of the semicircular ends of each elongated recess is also the trough radius thereof and the trough depth is less than this guide radius. The length L of the mixing chambers is three to four times the guide radius, the web width between the recesses of each circumferential row is less than half the guide radius and the shear gap width W is so selected that the shear velocity which is realized is sufficient for effective mixing by a shear action.

Abstract: The process for making a thermoplastic foil involves the use of a wide-outlet or long-slit die which has at least one outlet-gap-defining adjustable die lip, an opposing gap-bounding lip and a group of piezotranslators distributed over the length of the outlet-gap-defining adjustable die lip, each of which is part of a control loop, acts as a positioning member and is associated with an individual section of an outlet-gap-defining adjustable die lip. At least one actual value of the foil thickness of the thermoplastic foil formed is measured with a measuring device and is fed to a controlling processor. Each of the piezotranslators is controlled by a controlling processor with a controlling variable.

Abstract: An apparatus and method for cooling a melt strip from a wide-slot die includes a cooling roller driven at a predetermined angular velocity and juxtaposed with a corona-discharge electrode in the form of a rotation symmetrical rigid bar which is rotated about its axis at an angular velocity much greater than that of the cooling roller. The rotating corona-discharge electrode can be received in a nonrotatable insulating chamber having air inlets on a side opposite a slot-shaped outlet training ionized air onto the melt strip.

Abstract: An extruder feeds a thermoplastified flow of synthetic resin to at least one mixing unit which is driven independently of the extruder and has a rotor and stator with mutually facing pockets and defining a gap between them traversed by the thermoplastified flow and into which an additive is pumped at an upstream end so as to obtain an especially homogenius distribution of the additive in the thermoplastified flow.

Abstract: A method of mixing a pumpable additive with a thermoplastified flow utilizes a pocketed rotor and stator structure integrated in a worm or screw plastifier and to which the additive is fed by a metering pump at the upstream end of the gap between the rotor and stator surfaces.

Abstract: Lowering mechanism is disclosed for the foil roll in a device for the winding of a foil web, particularly a synthetic-material foil web. A roll core with the finished foil roll can be received at its ends by lowering arms. It can be deposited on a discharge level by means of a lowering-arm drive. The lowering arms can again be raised with the aid of the lowering-arm drive. For each of the lowering arms, the lowering-arm drive has a lowering cam plate, these being identically built, congruently arranged and provided with an outer leading edge, which is basically shaped as a numeral 6. The lowering arms are guided on the leading edge by means of a guide element. The lowering cam plates are driven by a simple electromotor.

Abstract: A device for winding up a foil web, particularly a foil web of synthetic material, into a foil roll on a roll core, has two swivel arms having roll-core receiving portions at their ends, a contact roller, and an actuating cylinder-piston arrangement for the swivel arms and the roll core drive. The swivel arms are swung according to the indication of the increasing diameter of the foil roll. In the area of the contact roller, a winding device with two swingable winding arms is arranged. A roll-core magazine is assigned thereto, having two magazine disks, which are oppositely located and rotatable about a horizontal axis and have corresponding receiving portions for the roll-core ends. To each magazine disk, a basically L-shaped guiding element is assinged which on the vertical flank of the L has an arched leading edge following the path of the roll-core receiving portions, which--over an assembly trough--continues with a downwardly inclined level which is a discharge edge.

Abstract: A cuppable composite thermoplastic foil with a PVDC layer is subjected to a cupping process at a definite temperature and the container is formed by the cupping process, especially a vacuum cupping process. To provide a stronger and more stable container for food packaging the composite foil is heated to a temperature above the crystallization temperature of PVDC and because of that the crystal structure of the PVDC is broken up. The crystallization degree of the composite foil is reduced at least 50%, after which the composite foil is quenched at a temperature of less than 75.degree. C., advantageously below 50.degree. C. The cupping process is performed immediately after the quenching.

Abstract: The invention relates to an apparatus for calendering a plastic web extruded from a slot die, and a method of operating this apparatus, the apparatus having at least two cooled rolls, which work in conjunction, the plastic web passing through the calendering nip between them. The plastic is particularly a partly crystalline type, notably polypropylene. The slot die is arranged above the first nip, and the plastic web passing through the nip continuously comes off the first roll and passes around the second roll at about 180.degree. or more. Below the nip there is a blowing device for causing cooling gas to impinges along the entire width of the plastic web in the channel between the first roll and the plastic web coming off it.

Abstract: A plastic web is made by an extrusion apparatus having a plastics screw press, a metering pump with a volume flow depending on the rotation speed, an output die and a rolling unit with calendaring rolls. The flow of a thermoplastic material is regulated with the metering pump. The melt web issuing from the output die is cooled and calibrated. The process uses a metering pump which has substantially linear volume flow/rotation speed characteristics in the regulated range of rotation speeds and together with the rolling unit is part of a common computerized control system. The peripheral speed of the calendaring rolls is controlled so that it is proportional to the rotation speed of the metering pump. The special proportionality factor for the speed ratio is set by a computer which controls the roll speed so that no undesirable thickness variations or other product defects occur.

Abstract: The fleece-making apparatus includes a spinning nozzle system, a cooling shaft, a stretching aperture, a diffuser shaft, a fleece delivery conveyor and a device for feeding process air and for drawing outflowing air through the fleece delivery conveyor. The process air is divided into two partial flows as it is fed into the cooling shaft on each side of the cooling shaft. The upper partial flow serves for intensive cooling, the lower partial flow for additional cooling. Both partial flows are united in the cooling shaft. The cross section of the united process air flow is constricted by air control flaps positioned wedge like on opposite sides at the entrance of the stretching aperture. The process air flow issuing from the stretching aperture is influenced by pivoting wings movable about a horizontal axis at the entrance to the diffuser shaft on both sides and also by an adjustable damper which is located either above and/or below the fleece delivery conveyor.