Abstract: A device for cooling foil tubing as it issues from an annular nozzle surrounded by an annular air outlet orifice. A first cylindrical chamber is connected in the direction of the course of the foil tubing to the air outlet orifice, and has an iris diaphragm at its upper end. The air flowing into the chamber flows out between the inner rim of the diaphragm and the foil tubing. At least one first additional chamber is connected to the first chamber at the other side of the iris diaphragm. The additional chamber has a first additional iris diaphragm at its upper end which has an adjusting mechanism independent of the iris diaphragm at its upper end of the first chamber. The walls of both chambers are constructed of solid material.

Abstract: A workpiece position control apparatus, specifically an apparatus for controlling the diameter of blown film tube, is disclosed. The apparatus includes at least one fluid nozzle, pressure sensing means for signalling the pressure of a fluid passing through the at least one nozzle and impinging on a workpiece when the workpiece is in a first position and for signalling the pressure of the impinging fluid when the workpiece is in at least one second position, and controlling means for adjusting the position of the workpiece in response to signals from the pressure sensing means.

Abstract: Cooling apparatus for air-cooling tubular plastic film which has been extruded from a film blowing head comprises spaced apart cooling rings, which in the direction of extrusion succeed the annular extrusion die of the film blowing head and are substantially concentric to the axis of the extruded tubular film and have air-guiding surfaces facing the surface of the tubular film and define annular nozzle gaps for delivering cooling air, which flows in contact with said air-guiding surfaces. The air-guiding surfaces are convexly curved in a longitudinal sectional view of the cooling rings. The nozzle gaps are defined by rings which in the direction of flow of the cooling air precede the cooling rings and which are so arranged that the cooling air discharged from said nozzle gaps flows in a direction which is approximately parallel or at an acute angle to the direction of travel of the tubular film.

Abstract: A polymeric film having preferential one-sided cling is prepared from a relatively crystalline polymer such as a copolymer of ethylene and an .alpha.-olefin having at least 3 carbon atoms, e.g., 1-octene (linear low density polyethylene); a relatively amorphous polymer such as low density polyethylene and a tackifying polymer such as a low molecular weight polybutene by extruding a film of the blend at melt temperatures and subsequently cooling the two sides of the extruded film at different rates.In addition to preferential one-sided cling, a film of a low density polyethylene, linear low density polyethylene and a low molecular weight polybutene which exhibits excellent film strengths and high resistance to tear, particularly in the cross direction, is prepared.

Abstract: Disclosed herein is a cooling/guiding method and a cooling/guiding apparatus that will be used when a film of a thermoplastic synthetic resin or the like is to be produced by the inflation method or the T-die method.According to the invention, a thermoplastic synthetic resin film is continuously passed through a section constituted by a single or a plurality of air-introducing members having air intake ports, the air surrounding said film is vacuumed by said air-introducing members so that the pressure differential imparted to the film is balanced, and the film is guided into a predetermined path under the condition where the film is separated away from the air-introducing members.Therefore, the apparatus cools and guides the film without coming into contact thereto, and without cooling the film irregularly and without marring the film, making it possible to markedly increase the film-forming speed and quality of the film.

Abstract: A cooling and guiding device for continuous tubular thermoplastic synthetic resin films comprises a support ring, and another ring which is vertically spaced from the support ring, one of the rings being rotatable relative to the other; each of a plurality of flexible conduits has one end connected to the support ring and its other end connected to the other ring, and each has a gas connection to a source of gas under pressure. The rings and conduits form an envelope the minimum diameter of which can be adjusted by relative rotation of the rings to accommodate a tubular film passing through the envelope; and each of the conduits has a series of orifices extending throughout the length of the conduit and arranged to direct gas jets against the exterior of such a tubular film to cool the film and to prevent the film from coming in contact with the envelope.

Abstract: Apparatus for cooling tubular plastic films extruded from a film blowing head. Air cooling means consisting of co-axial pipes extending axially through the film blowing head supply the cooling and inflating air and withdraw the same from the inflated parison. Vertically inner cooling rings are disposed substantially concentrically to the axis of the parison downstream of the annular extrusion die orifice of the blowing head. The inner cooling rings define nozzle gaps and have air guiding surfaces, which face the wall of the parison and are convexly curved in a longitudinal section of the inner cooling rings and during the operation of the apparatus are swept by the cooling air blown out of said nozzle gaps. An outer cooling air jet concentrically surrounds the extruded parison and serves to blow air in a direction which is approximately parallel to the direction of travel of the parison. The inner cooling rings are concentric to the parison.

Abstract: A method of blown film extrusion of polyolefins having high elongational viscosity which is independent of applied stress, and high melt strength wherein a first air ring is disposed adjacent an extrusion die to assist in the formation and stability of a stalk bubble configuration, and a second air ring is disposed downstream of the first air ring to assist in controlled expansion of the bubble at a point where the bubble has dissipated its melt elasticity.

Abstract: A process for extruding biaxially oriented high density polyethylene film in which an additional secondary gaseous cooling medium is applied at strategic strain inducing locations of the blown bubble to control the final product properties of the extruded material.

Abstract: Apparatus for cooling plastic film or sheet obtained by blowing tubing, comprising at its intermediate section an intensive blowing ring for directing air towards the tubing and at its upper section an upper chamber in which the tubing is in contact with an air flow directed in the drawing direction of the tubing. At the lower section of the apparatus is a non-closed lower chamber provided with at least one opening. The apparatus can be used to form blown films having superior optical properties, particularly clarity and turbidity, from a large number of resins.

Abstract: A high stalk blown film extrusion apparatus and method is described which produces a stabilized high stalk for increasing the production rate of blown, low to high molecular weight polymers, while increasing the film's physical and mechanical properties. The high stalk is stabilized by application of high velocity, low volume flow rate of air over the interior and exterior surfaces of the extruded film.

Abstract: Disclosed is an air plenum for surrounding and cooling a tubular extruded film. The plenum has an annular air flow chamber defined in part by an apertured annular distribution plate to which is mounted an annular channel-like one-piece molded housing forming a main flow chamber and having a cross-sectional area which progressively decreases from an air inlet in said housing to a point farthest removed therefrom. The annular air flow chamber receives air from the main air flow chamber through the apertures of the distribution plate and redirects it to an annular outlet nozzle.

Abstract: Apparatus for the production of plastic film by the extrusion of a tube thereof includes a first air ring disposed at the die exit and delivering an annular stream of cooling air to the surface of the emerging tube, which is in a stable expansion phase as it escapes the die internal pressure. Preferably the stream is directed axially of the tube path. The apparatus includes the combination of a sizing cage and a second air ring that is mounted for longitudinal movement along the tube. The tube is established with the air rings close together and they are moved as soon as possible as far apart as possible. The second air ring is located just below where the tube begins to expand and delivers an annular stream of air, preferably in a known manner away from the tube to form a vacuum which stabilizes the tube. The cooling air stream from the second ring can be high since the tube is again in a stable expansion phase with the material at an appropriate temperature.

Abstract: In the manufacture of an inflation film for forming a thermoplastic resin having a melt tension of not more than 4 g into a tubular bubble, a tubular bubble extruded from an extruding nozzle is cooled from the inner circumferential surface thereof by air supplied from a first air supply opening. The outer circumferential surface of the bubble is cooled with air from a first external air-cooling ring arranged at the outside of the bubble. The first air-cooling ring has a guide plate for guiding the bubble, a second air supply opening for supplying air between the guide plate and the bubble from an inlet port arranged at the lower end of the guide plate, and a third air supply opening for supplying air to the bubble from an outlet port arranged at the upper end of the guide plate. The bubble which is cooled by the first external air-cooling ring is further cooled by the air supplied from a second external air-cooling ring. The bubble is solidified.

Abstract: A tubular film process wherein molten resin is extruded from an extrusion die into a tubular resin, blown by an internal pressure, cooling air is discharged at least at a point between the vicinity of the extrusion die and the vicinity of a bubble expansion ending point in a direction of the extrusion of the resin and in a direction opposite to the extrusion of the resin to, thereby cool the tubular resin, and the tubular resin is continuously taken up upon being cooled and solidified. The cooling air has higher flow rate in the extrusion direction. The cooling air is discharged not only in the direction of the extrusion of the resin but also in the direction opposite to the extrusion of the resin, whereby hot air stream is prevented from accompanying the flow of the resin, thus enabling to effectively cool the tubular resin.

Abstract: The invention contemplates the manufacture of a wrinkle-free, amorphous, unoriented polyester film which is produced by an extrusion blowing process. The process consists of extruding a bubble of polyester, expanding the bubble, and then collapsing the bubble at a temperature above the polyester's glass transition temperature to prevent the formation of wrinkles. The collapsing step is effected through the use of a shroud which receives the bubble and has a low friction surface.

Abstract: A process for forming a blown film from a thermoplastic resin wherein a source of cooling air is induced to flow from the atmosphere in contact with another source of pressurized cooling air whereby increased production rates can be obtained.

Abstract: A method and apparatus for the formation of a continuous web of a tubular thermoplastic film from an extrudate of a thermoplastic polymeric material or resin, wherein the thermoplastic film has a profiled wall contour extending in the direction of the longitudinal axis of the film. The apparatus for forming a profiled tubular thermoplastic film, and the method which is implemented through the intermediary of the apparatus, provides for an annular cooling ring extending about the extrusion die orifice and which incorporates a central aperture through which the extruded plastic material is conveyed while still in a molten or heat-plastified state, and is adapted to direct a uniformly distributed flow of a cooling medium, such as air, against the circumferential surface of the extruded tubular plastic film material.

Abstract: This invention provides an improvement in a method of cooling molten extruded tube produced by a blown-tube process. The improvement comprises cooling the tube utilizing the heat of evaporation of moisture in steam. The steam is brought into contact with the molten tube after extrusion of the molten tube from an extrusion die, whereby the steam is permitted to expand prior to, during or subsequent to contact with the molten tube. An apparatus is also provided for carrying out the above-described method.

Abstract: A process is disclosed for forming blown film of a low strain hardening polymer, such as a low pressure polymerized-low density ethylene copolymer, including an improved film bubble expanding technique which permits high production rates to be achieved with good film bubble stability. Advantageously, most of the films produced by the process have a relatively high degree of film clarity.

Abstract: The present invention relates to a method and apparatus for the extrusion of thermoplastic film which comprises extruding a melt of thermoplastic through an annular orifice to form a bubble or tube and while the tube is still in a semi-molten condition, passing the tube through a cooling and stabilizing means which surrounds the tube and is characterized by having a variable diameter to accommodate varying sizes of tubing.

Abstract: A plastic film is formed by annealing a molten tubular film in a first enclosed space and immediately thereafter directing cold air perpendicular to the axis thereof and expanding and solidifying the film in a second enclosed space while in contact with cold air flowing parallel to film travel.

Abstract: An air ring of the type mounted concentrically with a moving tube of plastic at a point close to where the plastic emerges from an annular die to receive, guide and discharge air in a desired direction to expose cooling air to the surface of the tube, the air ring having a circular array of a multiplicity of substantially parallel, cell-like passages, each passage having orthogonal lateral dimensions (X and Y directions) transverse to the local direction of flow (Z direction) that are less than one-half of the flow length, and divide the flow path to the outlet into a multiplicity of individual cell-like flow paths, the aggregate flow area presented by the passages being at least 80% of the inlet surface of the array.

Abstract: A casing of stretched plastic material, whether or not filled with a fluid such as gas or air, is wound with some tension about a smooth heated mandrel. During its curved path of travel said casing is on the one hand subjected to a contact or a radiation heat and on the other hand to a convection heat, said contact radiation heat prevailing during a period of time which is greater than that of the convection heat, thus causing the inner curved portion of the said casing to set during the time that the outer portions of the casing windings have already cooled down, so that smooth curved surfaces are obtained.

Abstract: An apparatus for making biaxially stretched tubular films of thermoplastic synthetic resin which permits operation in a stabilized manner and economically by using the hot air used in stretching a bubble again in heating a raw film. In said apparatus, a suction ring is provided in the section where a heated raw film is inflated by the gas filled therein under pressure, and the diameter of the resulting stretched bubble reaches its maximum diameter. The suction ring sucks the air used for heating the stretching part simultaneously with the air used for cooling it after stretching to attain a thermal interception effect between the stretching part and the cooling part after stretching. Air flow around the stretching bubble is made uniform.

Abstract: A stretched plastic casing is tensioned by means of a fluid medium after having been introduced into two clamping rollers, and conveyed to a bending member in front of or at the location of which it is subjected to a thermal treatment such, that it is bent out of its original path, while being thermally deformed, and is subsequently conveyed in the same direction of curvature, in a bent form, so as to be cooled down.

Abstract: A composition for shrinkable film which excels in heat-sealability, transparency, strength, and particularly low-temperature quick shrinking property and, therefore, suits production chiefly of packaging materials, a film made of the composition and a process for the manufacture of the film are disclosed. Specifically, the composition comprises one of the specific combinations of components (A), (B) and (C), i.e. the combinations of (A)+(B), (B)+(C) and (A)+(B)+(C), wherein (A) is non-rigid polyolefine resins such as ethylene vinyl acetate, (B) is an elastomer comprising a specific ethylene-.alpha.-olefin copolymer, and (C) is rigid polyolefin resins such as polypropylene.

Abstract: A method for smoothly evaginating a tubular material under pressure, if necessary, within a pipe line with simultaneous bonding the evaginated tubular material onto the inner surface of the pipe line, which comprises placing in a pressure container having a discharge pipe a part or whole of a tubular material, if necessary, with one terminal end thereof being connected to a first like material rope having a length at least equal to that of the tubular material, if necessary forming a reservoir of a binder enclosed in the interior of the tubular material placed in the pressure container to apply the binder onto the inner surface of the tubular material, fixing the other open terminal end in evaginated state to an annular fastener of said discharge pipe, and applying a pressurized fluid to the pressure container to evaginate the tubular material over its full length as it is propelled from the discharge pipe and, if necessary, moved forward within the pipe line and at the same time bonding the evaginated tubula

Abstract: A process and apparatus are disclosed for forming blown film of a low strain hardening polymer, such as a low pressure polymerized-low density ethylene copolymer, including an improved film bubble cooling technique which permits high production rates to be achieved with good film bubble stability. The disclosed process comprises cooling a molten film bubble by contacting the outside of the film bubble with separate annular streams of cooling fluid fed through at least two stacked annular cooling rings disposed around the film bubble, wherein all or substantially all of the cooling fluid exits the system through a common plane formed by the last cooling ring.

Abstract: A molten thermoplastic resin is extruded in the form of a double-layer cylindrical hollow film with the two film layers being interconnected with each other by a number of spaced legs and is then immediately passed through an annular gap defined by annular side walls of inner and outer vessels in such a manner that the two film layers are in contact with the respective side walls defining the gap. Coolant is supplied to the inner and outer vessels and overflows above the side walls to bring the coolant into contact with the resin. The level of the coolant overflowing above both side walls is adjusted to be equal and also to have a liquid pressure on the extruded resin balanced with a gas pressure supplied in between the two film layers and the legs of the extruded resin.

Abstract: In the process of extruding tubular thermoplastic film or tape, the production rate can be improved by using a smooth support plug to stabilize and shape the extrudate after it has been cooled and at least partially solidified. A principal function of the support plug is to assist in supporting the long slender column of partially solidified extrudate which is above the plug. The result is a significant increase in the output of the extrusion process.

Abstract: A composition for shrinkable film which excels in heat-sealability, transparency, strength, and particularly low-temperature quick shrinking property and, therefore, suits production chiefly of packaging materials, a film made of the composition and a process for the manufacture of the film are disclosed. Specifically, the composition comprises one of the specific combinations of components (A), (B) and (C), i.e. the combinations of (A)+(B), (B)+(C) and (A)+(B)+(C), wherein (A) is non-rigid polyolefine resins such as ethylene vinyl acetate, (B) is an elastomer comprising a specific ethylene-.alpha.-olefin copolymer, and (C) is rigid polyolefin resins such as polypropylene.

Abstract: Air ring for cooling a hot extruding tube of plastic film in which a lubricating air bleed port communicates with air from the air ring plenum independent of the cooling air flow path. The bleed port communicates with a bleeded air passage that extends to an annular lubricating air outlet positioned in advance of a guide surface that precedes the cooling air outlet. In an exterior air ring a valve arrangement limits the bleeded flow to the minimum desired.

Abstract: A process and apparatus for producing a ribbed pattern on extruded film by differential cooling of the film during its stretching process. The film is extruded through a tubular film die, stretching as it leaves the die. Cooling mechanisms rotate about the tube as it is being extruded to define a large plurality of narrow strips on the melt as it is being extruded. The film is fixed in space to maintain a close proximity to the cooling mechanisms in order to achieve sharply defined ribs. A cross-ribbed pattern can be obtained by counter-rotating the cooling mechanisms. Increased tear strength is imparted to the film without increasing the amount of resin necessary to make the film. Such tube can be formed into high strength film products such as trash bags and the like.

Abstract: The invention provides a new air ring for use with a die in a blown film process line to apply cooling air to the exterior surface of an extruded tube of film-forming material passing through the air ring. Air is discharged from a first downstream gap in the air ring radially outward from the path of movement of a tube in unexpanded state so as to create a vacuum force that urges the tube outward and causes the cooling air to flow along the surface, permitting the use of much higher velocities than hitherto, the increased cooling permitting increased output for a given size of die. A second upstream gap delivers a tubular stream that precools the tube and prevents it from sticking to the structure between the upstream and downstream gaps.

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: A picture frame and method of making the same from a rising tube of fluent extruded plastic. The rising tube collapses inwardly to form the frame body as a ring of interfolded wrinkly sinuous corrugations. A stepped annular ring on the face of the extruder die is shaped to form a flat back for the frame along with a rabbeted inner rim edge suitable to seat a picture, mat and a backing plate.

Abstract: The woven tubing is continuously advanced and is opened and backed from the inside in a certain region, in which plastics material tubing which is larger in diameter than the woven tubing is extruded and oriented around and is forced in a soft condition against the woven tubing and then cooled.

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: Substantial and commercially important increases in polypropylene film production rates without adversely affecting film quality are obtained in a tubular water film process. The improvements comprise modifications in the die lip, in the mandrel air (fluid) slot affecting the cooling gas velocity, and in the upper bubble pressure control. The improvements are especially useful to obtain mill rolls 60 to 80 inches wide.

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: This invention is a process for making a self-welding packaging film by blending at least two ethylene polymers, one of the polymers having a melt flow substantially greater than any of the other polymers in the blend, and thereafter extruding a film from the blend. The film may be self-supporting or it may be an inner layer in a multi-ply film. Preferred ethylene polymers for the blend are the ethylene-vinyl acetate copolymers wherein one copolymer has a melt flow of less than 5.0 and the other has a melt flow greater than 28.0.

Abstract: Apparatus is provided for preparing continuous, seamless blown thermoplastic film tubing by extruding a melt of the thermoplastic through an annular orifice into a tubular shape, inflating the film tube thus formed and cooling such inflated tubing. In the apparatus, the extruded tube while still plastic is passed through an external cooling means having one or more multi-perforated air rings shaped in congruance to the desired shape of the inflating tube. Additionally, final cooling means is provided which cools the precooled film tube with air supplied from a continuous, non interrupted annulus surrounding the tube. A major advantage of this apparatus is that production speeds can be increased while maintaining bubble stability.