Abstract: A sewer pipe, transport pipeline, or other circumferentially enclosed passageway is lined by inserting into and along it a flexible tubular material of given diameter, with its corresponding circumference being less than the inside perimeter of the passageway. The tubular material is a laminate having a dimensionally stable skin layer facing the interior of the passageway and a contiguous layer of a composition foamable to form an expanded cellular structure. After insertion of the tubular material the contiguous layer is foamed to expand cellularly so as to fill the space between the inner skin and the inside wall of the passageway and to solidify in place. The tubular material may have an expansible outer skin layer also.

Abstract: Reduced breakage and reduced internal gas pressure is achieved in the trapped bubble process for the preparation of film by applying vacuum to the region of the tube where the bubble starts to form.

Abstract: The specification discloses an apparatus and method for concurrently manufacturing at least two semiround tubing structures. An extruder including plasticizing means for a plurality of plastic resins extrudes semiround and linear strips of plastic material in generally two back to back D-shaped sleeves. Between the D-shaped sleeves, a strip of adhesively non-compatible material is extruded so that the D-shaped sleeves may be separated. The rounded portions of the D-shaped sleeves are molded in a continuous blow molding arrangement to form the top wall of the semiround tubing. The tubing is cooled, and the two semiround tubing lengths separated from the adhesively non-compatible strip inbetween. Optionally, the base of the semiround tubing may be perforated. The two lengths of semiround tubing are folded with the base inside the top wall and coiled into large reels.

Abstract: A process for simultaneously, biaxially orienting tubular ethylene polymer film by expansion and extension of the tube under particular conditions for heating the expanding tube, to give a heat shrinkable film. The heat shrinkable film has excellent heat shrinkability, shrinkage stress, transparency, heat sealability and impact resistance, and is very suited for use in shrink packaging.

Abstract: Disclosed is a biaxially drawn polyhexamethylene adipamide film having a relative viscosity of at least 3.2 as measured at 25.degree. C. in aqueous 96% H.sub.2 SO.sub.4, a degree of crystallinity of from 35% to 45%, a birefringence (.DELTA.n) of not more than 0.006, as determined at any point in its entire area, and an initial modulus of elasticity in tension of at least 230 kg/mm.sup.2 as determined in ay direction across substantially its entire area. The film may be produced by a process wherein molten polyhexamethylene adipamide is extruded through a circular die gap and the tubular extrudate is brought in sliding contact with the outer periphery of an inside mandrel, thereby to be cooled, which process is characterized in that polyhexamethylene adipamide having a relative viscosity of from 3.3 to 5.0, as measured at 25.degree. C. in aqueous 96% H.sub.2 SO.sub.4, is used; the tubular extrudate formed therefrom is cooled at a cooling rate (X.degree. C./sec.

Abstract: This invention relates to an improvement in an externally held cylindrical expander for tubular ware with a central support for radially adjustable, spreading rest means and sector-shaped longitudinal elements borne by said rest means, in particular for the treatment of the tubular ware with liquid treatment means, the longitudinal elements extending between bodies tapering in the longitudinal direction, mounted between the ends of the support, and acting as entry and exit means, the improvement comprising: (a) rollers with axes of rotation transverse to the ware transport direction T mounted on the outsides of the individual longitudinal elements in transverse planes of the expander, (b) the rollers located in a common transverse plane covering the gaps between rollers located in an adjoining transverse plane, (c) the rollers from adjoining transverse planes mounted on one longitudinal element overlap by their ends at the center of the longitudinal element, (d) the other ends of the rollers project beyond th

Abstract: Process for the production of alveolar modules comprising rows of parallel channels, certain of which issue onto the sidewalls of the module, the process consisting of producing the module by extrusion using at least two independent systems each producing rows of identical channels, whereby the formation of one of the systems is interrupted when the row of channels being produced is to issue onto the sidewalls of the module.The apparatus for performing this process comprises a first extrusion system incorporating first extrusion material supply means and a first spinneret complementary to the cross-section of the rows of channels issuing onto the sidewalls of the module and a second extrusion system incorporating second extrusion material supply means and a second spinneret complementary to the cross-section of the other rows of channels, the first and second supply means being controlled independently of one another.

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 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: This invention relates to a method of making a tube of thermoplastic material, comprising longitudinal channels of circular cross-section and having such wall stresses that, after axially cutting the tube, the edge parts along the cut edge overlap each other for less than 8% of the outer circumference of the tube.

Abstract: The present invention relates to a process for extruding a thermoplastic sheath in the form of a tubular film provided with perforations and to a device for carrying out the process, according to which the extruded film passes over a skirt through which are blown jets of hot air provoking the perforation and formation of openings in the film; in the areas where the film is not to be perforated, air jets are also blown through channels of smaller width, therefore with a reduced pressure, so that the jets do not provoke the perforation of the film but form an air-cushion facilitating the flow of the film on the skirt; the channels are supplied from a pneumatic chamber with interposition of a rotary distributor formed by a ring made of graphite or self-lubricating material. The invention is applicable to the manufacture of partially perforated tubular films with a view to making packings.

Abstract: Extrusion of a homogeneous single phase fusion melt of acrylonitrile polymer and water through a circular die into a steam-pressurized solidification zone enables the tubular film formed to be drawn longitudinally and expanded transversely to provide a biaxially oriented barrier film especially suitable for food wrapping.

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 method and apparatus for extruding a radiant energy heat exchanging panel structure having a multiplicity of parallel passages extending longitudinally therethrough defined by a multiplicity of longitudinally extending integrally interconnected exterior and interior thin wall sections, in which the temperature of the plastic material moving longitudinally away from the extrusion outlet is reduced by flowing fluid into said passages and on the exterior sides thereof, by contacting the exterior sides with pairs of cooled rollers, by rolling a liquid medium upon the operative exterior side, and by flowing a liquid spray thereon to provide a radiation absorbing coating on the exterior side of the panel structure opposite from the operative side thereof. Certain of the flowing fluids are reactant fluids which chemically react with the hot plastic material or condense thereupon to form molecular coatings thereon enhancing the properties thereof as a panel structure.

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: What is disclosed are methods and apparatus for coating a hollow synthetic resin tube with a pre-formed film coating by applying the film coating to an exterior surface of such a tube directly after extrusion, while the resin thereof is thermoplastic, and then passing them through a shaping channel while maintaining a modest pressure differential between the interior and exterior of the tube, whereby the film coating and tube are adhered by the compression thereof against the walls of the shaping channel.

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: An improved process of producing a predetermined textured surface on a polypropylene film is disclosed including the steps of extruding the polypropylene into a stalk, cooling the stalk to crystallize the polypropylene, passing the stalk through a heating zone and biaxially stretching the stalk into a thin film. The stalk emanating from the extruder has a section primarily temperature controlled and correlated to the stalk velocity to cause extensive, continuous and uniform spherulite formation with a predominantly type III polypropylene crystal structure on the outer surface of the stalk, which upon subsequent inflation of the stalk causes the desired texture to occur.

Abstract: A cylindrical stabilizing means (stabilizer) for resin bubbles useful to perform shaping of tubular films without causing the fluctuation or breakage of resin bubbles even in case where a take up velocity of the tubular film is relatively large, cooling of tubular body of molten resin extrudated from a die is not sufficient or amount of extrudate from a die is relatively large, is provided. Said stabilizing means has penetration holes on the circumferential wall close to the annular slit 16 of die, which communicate with an opening of the tip of the means, and also has continuous deep grooves of a depth of 0.5 mm or more extending from the portion of the circumferential wall close to said annular slit to the opening of the tip, which grooves are formed on the whole outer circumferential wall having fine concave and convex engraved patterns of the difference of height or depth of from 0.1 mm to 0.5 mm.

Abstract: This invention relates to a stretching apparatus of a flattened cylindrical film consisting of one or more layers of thermoplastic resin. The stretching apparatus has a heavy mandrel for heating and stretching a film. Due to suspending means suspending the heavy mandrel the cylindrical film of one or more layers is stretched smoothly without shaking, thereby a uniformly flattened, thin, strong cylindrical film is obtained.

Abstract: A quench bath for cooling an axially moving tubular form comprises an axially compressible jacket with a liquid-retaining annular seal assembly engageable with the tubular form, inlet and discharge means for cooling liquid, and means to releasably support the jacket in an extended configuration.The bath is suitable for cooling tubular extrudates in the production of oriented tubular film.

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: Tubular films having superior mechanical properties and extremely small deviation in thickness can be produced according to a method and an apparatus in which a means of downwardly tapered hollow inverted-truncated-conical shape is placed on the top of an annular die and used as a means for stabilizing bubbles of olefinic polymer synthetic resins which are extruded from the annular die in an air-cooling inflation process with a take-up speed of about 5 m to 50 m per minute.

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 variable size deflector disc directs cooling gas to the internal surfaces of a tubular plastic film drawn between an extruder die and a pair of rollers. The disc facilitates the starting process for pulling a narrow diameter tubing from the extruder over the disc to the rollers. The plastic tub can then be readily enlarged to the final maximum diameter followed by expansion of the deflector disc to control the flow of cooling gas. The disc is preferably in the form of an iris having a plurality of pivotable leaves which can be expanded outwardly from a contracted position. The outer edge of the leaves are designed to provide a relatively smooth rounded circumference of the variable diameter disc throughout the variation in diameter between the minimum and maximum tube dimensions for the tubular plastic film process. The expandable disc permits more efficient cooling and more rapid production of the plastic film.

Abstract: In a blown film process for manufacturing plastic film bags, the shape of the film bag being formed is dynamically controlled by sensors provided at specific locations. At these locations, any deviation of the bag shape from the ideal shape will result in significant differences in quality of the produced film bag, or may result in a break of the film bag. Such deviation in shape is prevented by using the output signals from the sensors to control various process parameters.

Abstract: In the manufacture of fiber-reinforced cellulose casing wherein a paper tube is passed downwardly over a mandrel, impregnated with viscose and subjected to the action of a coagulating liquid to regenerate cellulose, a gas stream is flowed upwardly within the tube as the tube is passed over the mandrel, the gas stream pressure being sufficient to maintain the cylindrical dimensions of the tube but insufficient to cause a measurable change in the dimensions of the tube walls whereby contact of the internal surface of the impregnated tube with the mandrel is reduced or substantially eliminated.

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: The present invention is concerned with the art of manufacturing film from synthetic thermoplastic resinous materials, and more particularly relates to an improved method and apparatus for the manufacture of thermoplastic resinous film in tubular form.

Abstract: The method permits selective cooling of tubular plastic material as formed to provide for an exchange of internal cooling air through the central opening of the blow head. Air supply rings having outlet slots facing the tubing, as well as air guide surfaces of small axial length, are provided inside the tubing and spaced from the annular die orifice to serve to support the tubing. The interior cooling air supply rings have axially directed passages for the flow of cooling air while the exterior air supply ring or rings deliver air at higher temperatures to provide a substantial thermal differential between the tube surfaces as formed to provide a flare-top edge upon severance. Also, the method permits forming a foam-film composite of thermoplastic materials by the blown bubble co-extrusion process.

Abstract: In a typical tubular extrusion of hydrolyzed ethylene-vinyl acetate copolymer having an ethylene content of 15 to 50% by mole and a degree of hydrolysis in the vinyl acetate units of not less than 90% by mole, an improved process for preparing the tubular film without wrinkle by controlling the surface temperature of the tubular film at the nip rolls within the range of 50.degree. to 100.degree. C.

Abstract: A method of treating the outer surface of a pipe of a thermoplastic resinous material produced by extrusion by extruding molten resin from an extruder and sizing the same by a sizing die, and supplying a lubricant to a front end portion of the sizing die along the front end portion which is disposed in spaced juxtaposed relationship with the extruder.An apparatus for treating the outer surface of a pipe of a thermoplastic resinous material produced by extrusion including a sizing die for sizing the pipe extruded from an extruder for extruding a thermoplastic resin in tubular form, and lubricant supply means disposed at a front end portion of the sizing die in spaced juxtaposed relationship with the extruder for supplying a lubricant along the front end portion of the sizing die.

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.