Abstract: In the method of making a hollow plastic articles wherein a label is positioned in each of a plurality of spaced partible molds in a predetermined array, a preform is positioned in each set of partible molds and the molds are closed and the preform is blown outwardly to the confines of the mold to apply the label to the resultant hollow plastic article, the method and apparatus which comprises providing labels on a roll of labels, successively engaging the free end of the web of the roll of labels by a first endless vacuum conveyor, tensioning the portion of the web between a point upstream and the free end by the first endless vacuum conveyor, successively cutting a label on the free end from the remaining tensioned portion, transferring each label successively by moving the first endless conveyor adjacent a second endless vacuum conveyor which is transverse to the the first conveyor, indexing the second endless conveyor to provide an array of labels on the second endless conveyor which corresponds in spacin

Abstract: In the method of making hollow plastic articles wherein a label is positioned in each of a plurality of spaced partible molds in a predetermined array, preforms are positioned in each set of partible molds and the molds are closed and the preforms are blown outwardly to the confines of the molds to apply the label to the resultant hollow plastic article, the method which comprises providing labels on a roll of labels, successively die cutting the labels from the web of the roll and simultaneously delivering each label directly to an endless vacuum conveyor, indexing the endless vacuum conveyor to provide an array of labels on the conveyor which corresponds in spacing to the spacing of the array of molds, engaging the array of labels on the conveyor and removing them from the conveyor and depositing the array of labels in the array of molds.

Abstract: An in-mold labeling apparatus includes a label transfer assembly carrying a number of label carriages each with a number of label transfer heads. A continuously rotating drive arm raises and lowers the assembly in simple harmonic motion to move the label transfer heads between label magazines for pickup of labels and mold halves of a blow molding machine. Lost motion connections are provided at the top and bottom of the stroke to facilitate pickup of labels and placement of labels in the mold halves.

Abstract: A method and apparatus for applying labels in the molds of a plastic blow molding machine of the type wherein a plurality of sets of molds are mounted on a wheel rotatable about a horizontal axis and the molds are moved toward and away from one another to enclose a parison and the parison is then blown to the confines of the cavity between the mold sections which comprises successively die punching labels from a web directly onto vacuum cups and delivering the labels successively between the mold sections by moving the vacuum cups between the mold sections and thereafter moving the cups laterally into the cavities of the mold sections.

Abstract: A method and apparatus for placement of labels within the blow molds of an injection blow molding machine. The injection blow molding machine comprising a turret having plurality of circumferentially spaced surfaces, each of which supports a plurality of spaced core rods, a plurality of injection molds at an injection molding station for forming a plurality of preforms, and a plurality of blow mold sections at a blow molding station which close about the preforms so that the preforms can be blown outwardly against the confines of the mold to form hollow plastic articles. The blow molds include movable bases exposing the interior of the blow molds when the blow molds are closed about preforms on the core rods.

Abstract: A blow molded polyethylene terephthalate container (20) is disclosed as having a noncylindrical wall (28) to which at least one label (38) is secured with a textured surface provided by an in-mold labeling operation that prevents label shifting during the blow molding operation. The textured label surface includes isolated depressions (53) that are defined by mold projections (72) which define mold passages (74) through which a vacuum is drawn to provide the label securement. The label and wall depressions (53) of the container and the mold projections (72) that provide these depressions are preferably arranged in a repeating pattern of rows that are inclined in a crossing relationship preferably at 45 degrees with respect to the vertical direction of the container. Each depression (53) preferably has a square shape formed by the square shape of the associated mold projection such that the vacuum passages (74) have a generally straight shape.

Abstract: An in-mold labeling device for blow molding machines which includes a carriage assembly which moves a labeling head between a position in registry with a label storage magazine to a displaced position in registry with a cavities of molds. The labeling head includes a pick-up arm which is pivotable and supports a self aligning pick-up pad which carries one or more vacuum cups. In operation, the carriage assembly moves to a first position where the pick-up arm is pivoted to place the vacuum cups in contact with a label carried by the storage magazine. The pick-up arm is then pivoted back to pull off a label, and a slide is moved to position the labeling head into registering with an open mold. The pick-up arm is again pivoted to deposit the label in position onto the inside surface of the mold cavity and is maintained in that position through vacuum ports within the mold.

Abstract: In the making of a hollow plastic articles wherein a label is positioned in each of a plurality of spaced partible molds in a predetermined array, a preform is positioned in each set of partible molds and the molds are closed and the preform is blown outwardly to the confines of the mold to apply the label to the resultant hollow plastic article, the apparatus for indexing an endless conveyor in precise increments for receiving longitudinally spaced labels providing an array of labels which are thereafter simultaneously removed from the endless conveyor and delivered between the open partible molds which comprises a fixed conveyor gripper in a first position, a second conveyor gripper mounted for movement longitudinally of the belt and means for individually controlling the gripping of the first gripper and second gripper such that the second gripper can be actuated to engage the conveyor while the first gripper is disengaged and the second gripper can be moved longitudinally to thereby move the conveyor a pr

Abstract: An apparatus for manufacturing an embossed article of synthetic resin comprising heating a synthetic resin sheet to a softening temperature; overlaying the heated synthetic resin sheet on an embossing die made by an electro-chemical molding process and having an embossing surface with an embossing pattern thereon and a multitude of fine vacuum pores distributed uniformly over the entire embossing surface; and forcing the synthetic resin sheet against the embossing surface by applying suction through the fine vacuum pores to imprint the embossing pattern onto the synthetic resin sheet.

Abstract: A shuttle-type blow molding machine and in-mold labeling apparatus for placing labels within open mold halves during movement of the mold halves from the blow station to the extrusion station.

Abstract: In the making of hollow plastic articles wherein a label is positioned in each of a plurality of spaced partible molds in a predetermined array, a preform is positioned in each set of partible molds and the molds are closed and the preform is blown outwardly to the confines of the mold to apply the label to the resultant hollow plastic article, the apparatus for removing the labels from a conveyor and applying them to the open partible molds which comprises a vacuum head supported for movement between a position for picking up a label and a position for delivering a label to a partible mold. The head comprises an elongated body and a plurality of longitudinally spaced vacuum cups along the body. The body has a transverse cross sectional surface that generally conforms to the cross section of the internal surface of the mold to which the label is to be applied.

Abstract: The molding apparatus for molding compact discs defines an openable mold cavity and the information bearing disc which forms the impression on the compact disc in held in place by vacuum in the mold cavity in order to allow ready and easy removal and replacement of the insert when necessary.

Abstract: A shuttle-type blow molding machine and in-mold labeling apparatus for placing labels within open mold halves during movement of the mold halves from the blow mold station to the extrusion station.

Abstract: An in-mold label dispenser (10) is disclosed as including a label carrier shuttle (40) moved by an operator (46) mounted on a support (36) that is moved rectilinearly on a slideway assembly (34) by an actuator (38) between an aligned position with respect to an open mold (14) and a label transfer position. Label carriers (44) on the shuttle (40) transfer labels (32) from associated label magazines (30) to mold cavity sections (18) in order to perform an in-mold labeling operation of a plastic blow molding machine. A first locator (42) on the shuttle (40) and a second locator (48) mounted for rectilinear movement on the opposite side of the mold from the shuttle are engaged as the shuttle is moved to an inserted position with respect to the open mold. A second actuator (50) moves the second locator (48) between a mold aligned position and a transfer position with the locators engaged so as to provide the labeling operation of the mold.

Abstract: A method of operating a vacuum-forming machine and the machine which operates by this method, in which once the mold halves are closed on the foil webs for vacuum drawing and fusion of the vacuum drawn container halves come together to produce a hollow article, the mold halves move at the velocity of the web to a lower position spaced from the upper position by a distance sufficient to permit cooling of the molded articles. A spring or other force-storing element is stressed during this movement so that when the mold opens at the lower position, it is driven upwardly at a substantially higher velocity to return to the starting position.

Abstract: A laminate consisting of a number of air-permeable sheets of a material is placed on the supporting surface of a table, and a major portion of the periphery of the laminate, inclusive of a lower surface thereof, is covered with a sheet impermeable to air. A suction pipe is arranged on the supporting surface along at least one side surface of the laminate and has a suction port faced toward the one side surface. A periheral portion of the suction port is covered with the air-impermeable sheet, and the laminate is compressed in the direction of its thickness by evacuating air from within a space defined by the air-impermeable sheet by vacuum producing means connected to the suction pipe. The air-impermeable sheet and laminate can be moved together with the suction pipe in parallel relation to the supporting surface, and they can be stopped at a desired position, during the evacuation process.

Abstract: The invention refers to a method and apparatus for manufacturing a single-wall pipe, tube or like conduit (9,44) having smooth inner surfaces and a mechanical-strength enhancing pattern of walls, flanges or ridges on the outer surface thereof, the conduit being made of plastics or like extrudable material.

Abstract: Apparatus for the in-mold labeling of a blow-molded, thermoplastic article wherein one or more labels are tangentially attached to the outer surface of an extruded parison at a predetermined location before the parison is expanded into a finished article.

Abstract: Apparatus for applying labels in the molds of a plastic blow molding machine of the type wherein a plurality of sets of molds are mounted on a wheel rotatable about a horizontal axis and the molds are moved toward and away from one another to enclose a parison and the parison is then blown to the confines of the cavity between the mold sections which comprises removing labels successively from one or more magazines, depositing the labels on an endless conveyor which transports the labels to a position adjacent an open mold and laterally transferring the labels from the conveyor to a position within the molds such that when a mold closes about a plastic parison and the parison is blown, the labels become adhered to the blown plastic bottle.

Abstract: An in-mold label dispenser (10,10') for supplying labels to a plastic blow molding machine (12) is disclosed as having a dispensing head (36) on which a first locator (40) is mounted so as to be moveable from a withdrawn position at one side of the mold to an inserted position between open mold sections (16) and into engagement with a second locator (42) mounted at the other side of the mold. The engagement of the first and second locators from opposite sides of the mold provides accurate location of the dispensing head (36) during movement from a mold aligned position to a label transfer position to provide transferring of the labels (34) to the mold from one or more label magazines (30). First and second supports (48, 50) on which the locators are mounted are moved by first and second actuators (52,54) to provide the movement between the mold aligned and label transfer positions.

Abstract: An in-mold label dispenser (22) for a blow molding machine is disclosed as including a dispensing head (56) mounted for rectilinear movement along a first axis A between a label magazine (48) and an open mold (28) and having a label carrier (58) mounted on the dispensing head for rectilinear movement between retracted and extended positions along a second axis B transverse to the first axis A. Rectilinear movement of the dispensing head (56) along the first axis A and coordinated extending and retracting rectilinear movement of the label carrier (58) along axis B transfers a label (50) from the magazine (48) to the mold (28) in preparation for the blow molding operation. The label dispenser (22) has particular utility when provided with a pair of the label carriers (58) to simultaneously transfer a pair of labels (50) to the open mold (28) within the confined space limitations involved.

Abstract: In the making of hollow plastic articles wherein a label is positioned in each of a plurality of spaced partible molds, a preform is positioned in each set of partible molds and the molds are closed and the preform is blown outwardly into the confines of the mold to apply the label to the resultant hollow plastic articles, the method of handling the labels which comprises successively removing labels from a label magazine and positioning the labels in an array which corresponds in spacing to the spacing of the sets of molds, simultaneously moving said labels in the array from the first position to a second position within the open partible molds and depositing the labels in the molds.

Abstract: A method for seating a gasket in a plastic pipe bell is disclosed which includes providing a peripheral groove in a belling mandrel and seating a specially designed hard plastic ring in the groove. The hard plastic ring is molded to provide exterior ramps for forming an annular pocket in the pipe bell and is inwardly configured to provide a secure seating surface to receive and retain a resilient gasket thereon. The mandrel is urged into a preheated end of the pipe and vacuum forces are employed to pull the end of the pipe about the periphery of the mandrel and tightly against the exterior ramps of the hard plastic ring for forming the bell shape. Upon sufficient cooling of the pipe end, the mandrel is withdrawn and the plastic ring remains encapsulated within the bell shape. Upon removal of the mandrel, a resilient gasket is then seated within the bell in intimate overall contact with the seating surface of the plastic ring.

Abstract: A shuttle-type blow molding machine with a label transfer assembly for placing labels in mold halves before the mold halves close on a parison.

Abstract: Apparatus for producing a hollow molded synthetic resin article includes a split mold having an inner molding surface with a contour conforming to the configuration of the desired article, a space between the opposing mold members of the split mold for receiving a heated parison of a thermoplastic synthetic resin in the form of a tube or two parallel-laid sheets, vacuum suction holes provided in the molding surface and the parting surfaces of the split mold, means for opening and closing the split mold, means for applying negative pressure to the vacuum suction holes, and means for blowing heated compressed air against the inside surface of that portion of the parison which corresponds to the parting surfaces in the direction facing the parting surfaces. The attachment of the parison to the parting surfaces is thereby facilitated.

Abstract: An in-mold label dispenser (10) for a plastic blow molding machine (12) is disclosed as including a base (24) on which label magazines (26) are mounted along with a subbase (34) which is moved by a first actuator (40) between aligned and transfer positions with respect to open mold sections (16) of the mold (14). A shuttle (42) of the dispenser has label carriers (44) thereon and is movable with the subbase movement as well as being movable toward and away from the mold (14) by a second actuator (46) that moves with the subbase under the operation of the first actuator (40). An enlongated support (36) preferably mounts the shuttle (42) for sliding movement under the impetus of the second actuator (46) between a withdrawn position adjacent the label magazines (26) and an inserted position where the labels received by the label carriers (44) are aligned with cavity sections (18) of the mold to deposit the labels upon operation of the first actuator (40).

Abstract: An in-mold label dispenser (20) for a plastic blow molding machine of the rotary wheel type is disclosed as including a base (50) on which a carrier arm (52) is pivotally mounted by a support (58) to swing a dispensing head (60) on the carrier arm along a curved path between withdrawn and inserted positions with respect to mold sections (32) of an adjacent open mold (28) on the machine wheel (24). At least one label carrier (62) is mounted on the dispensing head for movement between retracted and extended positions, and at least one label magazine (64) is located adjacent the dispensing head with the carrier arm in the withdrawn position. A drive mechanism (66) of the label dispenser (20) includes a first drive (68) that pivotally moves the carrier arm and also includes a second drive (70) that moves each label carrier between the retracted and extended positions during cyclical operation that transfers labels from the label magazine to the molds on the machine wheel.

Abstract: An apparatus and a method of manufacture for discrete elastomeric material components comprising extending material through a die onto the surface of a component holding member, securing the leading end of the extrudate to said member, effecting relative movement to lay the extrudate on the holding member so that the component is produced on said member. The invention also provides for transfer of the component from the member.

Abstract: In a vacuum moulding flask, air is removed by suction from the flask, which has been filled with moulding sand, in order to consolidate the mould. To ensure satisfactory distribution of the vacuum, suction pipes are disposed inside the flask and the suction tubes must be resistant to the thermal and mechanical stresses during moulding. The suction surfaces are either cylindrical or plane and are covered by parallel, substantially triangularly-shaped profile wires so arranged as to define narrow nozzle-shaped gaps through which the air can be sucked away.

Abstract: The invention relates to a device for introducing and positioning a label the walls of a mold formed in two parts separated by a mold joint, in a machine with a reciprocating cycle for the extrusion/blow molding of hollow bodies, of the type comprising:--a member for storing labels disposed above the open mold,--a vertically mobile jack, disposed above the open mold, associated with means adapted to grip a label in the storage member, then to lower this label into the open mold,--means adapted to maintain the deposited label against the walls of the mold during the path of transfer of this mold, wherein a jack adapted to generate a reciprocating vertical movement is associated with a vertical rigid rod bearing at its end a rigid member adapted to pivot about this end, this pivoting rigid member comprising two rigidly connected arms, one forming a pivot stop when its abuts on the upper part of the mold, the other, vertical, bearing at its other end the label to be deposited.

Abstract: A label transferring device for blow molding machines which includes a sliding mold insert with a plurality of label carrying segments which are shifted into an access aperture communicative with the mold cavity. As the insert is shifted, each label carrying segment cooperates with the mold to form the cavity. A label transfer arm assembly removes a label from a supply magazine and places the label on one exposed label carrying segment while another label carrying segment is within the mold cavity undergoing the molding and label attachment process.

Abstract: A method and an apparatus for producing double walled thermoplastic pipe with integral bells are disclosed. The pipe has corrugated outer wall that has the bells molded into it, and a smooth inner wall. The inner wall is removed from the bell after the pipe is formed and set. During production, the inner wall is punctured along the bell section to admit air into the chamber between the two walls. This prevents collapse of the outer wall due to reduced air pressure as the air in the chamber cools.

Abstract: An in-mold label dispenser (22) for a blow molding machine is disclosed as including a dispensing head (56) mounted for rectilinear movement along a first axis A between a label magazine (48) and an open mold (28) and having a label carrier (58) mounted on the dispensing head for rectilinear movement between retracted and extended positions along a second axis B transverse to the first axis A. Rectilinear movement of the dispensing head (56) along the first axis A and coordinated extending and retracting rectilinear movement of the label carrier (58) along axis B transfers a label (50) from the magazine (48) to the mold (28) in preparation for the blow molding operation. The label dispenser (22) has particular utility when provided with a pair of the label carriers (58) to simultaneously transfer a pair of labels (50) to the open mold (28) within the confined space limitations involved.

Abstract: An in-mold label dispenser (10) is disclosed for supplying labels to a multiple cavity blow molding machine (12) for an in-mold labeling process. Label dispenser (10) includes a dispensing head (24) mounted for movement between a withdrawn position free of the mold and an inserted position between mold sections in an open position of the mold. A plurality of label carriers (26) are mounted on the dispensing head (24) for movement between retracted and extended positions in order to receive labels (32) from magazines (28) and supply the labels to the mold. A drive mechanism (30) moves the dispensing head (24) and the label carriers (26) for the in-mold label dispensing. Preferably, the dispensing head (24) is mounted on a support (34) and is moved in a hesitating manner to receive labels. The dispensing head support (34) is preferably mounted on a frame (38) in a manner that conserves floor space and the frame is also mounted in order to permit access to the associated blow molding machine.

Abstract: In a process for making a filled and closed container of heat-sealable plastic hose, in one work operation, the hose is expanded to become a container body, the body is filled and the upper part of the container is shaped when the container is closed. After the filling process and before closing, the upper part of the container is closed by a rubber stopper. An apparatus to carry out the process includes a container-molding appliance having a lower and upper mold parts, with a mold holding fixture in each of the upper parts which can be displaced in the direction of movement of the upper mold part and be moved automatically opposite the upper mold part, and with a holding device inside the plastic hose which can be moved vertically. The holding device releasably holds the rubber stopper for insertion into the completed container body.

Abstract: A method for producing a hollow synthetic resin article, which comprises opening a split mold having an inner molding surface with a contour conforming to the configuration of the desired article, feeding a heated molding material of a thermoplastic synthetic resin in the form of a tube or two parallel-laid sheets into a space between the opposing mold members of the split mold, applying a negative pressure to vacuum suction holes provided in the molding surfaced and the parting surfaces of the split mold to vacuum-form the molding material, and while the negative pressure is being applied or after the application of the negative pressure is stopped, closing the mold to form the molding material into the final desired configuration.

Abstract: A process and a device for forming a tennis ball by the formation of two semispherical bowls in crude elastomeric material each having on its border a structural shape that is deformed by compression when the two semispherical bowls are pressed one against the other while a depressurization is effected in the joining zone of the two semispherical bowls on the outside of them.

Abstract: This relates to a labeller for applying labels to the cavities of mold halves of a rotating blow molding machine whereby when a parison is blow molded within each mold thereof to form a bottle or like hollow article, each such article will be provided with at least one and preferably two labels. The labeller is provided with pick-up heads to pick up labels from two opposed hoppers and then move the labels in between the paths of rotation of mold halves and with proper timing advance the labels into the mold half cavities and discharge them on the walls of the mold cavities. Control circuitry is provided for the automatic operation of the labeller whereby not only can the labeller operate without interference with the moving mold halves, but also accurately position the labels within the cavities. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

Abstract: Disclosed is a container for storing product and a process and apparatus for making the container. The container comprises a paperboard outer container and a plastic inner container which has been drawn and blow formed into the outer container. The container is characterized by plastic screw threads which extend from the plastic inner container around the upper portion of the outside of the paperboard outer container. The screw threads permit a cap to be screwed onto the container after product, e.g. food, is placed in the container. The screw threads are vacuum formed, preferably simultaneously with the blow forming of the plastic inner container.

Abstract: This relates to a transfer apparatus for transferring labels from a label stack into the cavity of a moving mold half. The transfer device includes a pivotally mounted arm which has mounted on its free end a transfer head which swings about the arm so that for a limited movement of the arm there can be a much greater movement of the transfer head. Thus, the transfer head may rapidly enter and rapidly depart from a mold cavity so that a label may be seated in the mold cavity very quickly without requiring any slowdown of the movement of the mold half. The transfer head is provided with vacuum heads which operate to effect a peeling of a label from its associated stack beginning along one edge portion of the label so as to assure that only a single label is picked up from the stack.

Abstract: A method of manufacturing a thin-walled article of synthetic resin, in particular a large-sized article, while using an inner and an outer template, the synthetic resin being supplied via one or more apertures in one of the two template portions and whereby a partial vacuum is maintained via one or more air discharge apertures downstream of the synthetic resin front.

Abstract: This relates to a transfer device for transferring labels from a stack into mold cavities without modifying the operation of the existing molding machine. The transfer device includes a pivotally mounted arm which is positioned and pivoted by a linear drive shaft positioned by a cam carried by an associated mold half. The transfer head is mounted on the arm for pivoting about the arm by way of an actuator which includes drive pulleys coupled by drive belts. The transfer head includes vacuum heads, one of which has associated with a suction cup thereof bellows for retracting the suction cup after the suction cup has sealed with the label to initiate peeling of the label from the stack. The suction cup is guidingly mounted so as to maintain its orientation at all times.

Abstract: A double-walled paper container produced by placing a preformed paper container in a shaping die set cavity of a vacuum draw shaping apparatus, positioning a single piece of synthetic resin film or sheet on the top of said paper container, holding the film at the peripheral edge thereof, heating the film to make the plastic film, stretching the film and applying negative pressure to the film to line said preformed paper container with the film is in water-tight fashion and wherein the lined paper container has a good shape holding ability and is hygienic for the user thereof.

Abstract: Apparatus for removably attaching inserts to articles by means of shrinkable plastic bands, comprising in combination:(1) means for feeding an opened band of shrinkable plastic film into vertical alignment with an article banding station,(2) means for (a) shaping an insert into generally cylindrical form, such that the diameter of said cylindrical shaped insert is less than the diameter of said opened plastic band, but greater than the article over which the insert is to be placed, and (b) feeding said cylindrical shaped insert into vertical alignment with said opened band at said article banding station, said means comprising: (i) a movable plate provided with at least one cylindrical aperture extending through said plate, said aperture communicating on its peripheral side with a slot extending to the edge of said plate and (ii) means for feeding said insert into said aperture and for conforming said insert to the cylindrical inner surface of said aperture,(3) means for telescopingly pushing said opened band

Abstract: The present invention is directed to an apparatus and method wherein bottom blanks for containers are severed from a web feed roll and subsequently transferred at a compatible speed and spacing to final forming mandrels on which finished containers are to be formed. The bottom blanks are tangentially transferred from a first transfer turret at a final velocity and spacing most desirable for cutting and minimizing scrap to a second transfer turret at a second velocity and spacing and thereafter tangentially transferred to the final forming mandrels. Subsequently, preprinted rectangular blanks of longitudinally stretch-oriented foam sheet material formed into cylinders are transferred onto the final forming mandrels. Thereafter, the bottom blanks the cylindrical blanks and the final forming mandrels are heated to shrink the cylindrical blanks so that they assume the shape of the final forming mandrels. The top curl on containers such as drinking cups and food tubs is formed after shrink forming.

Abstract: A surfboard having a central core of relatively soft and/or light material such as balsa wood or foamed plastic and a laminated outer skin construction is disclosed herein along with a method and apparatus for making the surfboard or a similar article. Both the method and apparatus utilize particular vacuum molding techniques which form the laminated outer skin constructions while at the same time accurately conforming this skin construction to the complex curvatures of the core.

Abstract: An apparatus for producing multi-walled thermoplastic tubing having a corrugated wall and a substantially smooth inner wall secured to the corrugated wall, there is incorporated two sets of endless flexible belts each of which is entrained around rotatable end rolls, the outer runs of the belts of one of the sets thereof alternating with the outer runs of the other of the sets thereof, with these outer runs of the various belts serving to urge the inner wall against the corrugations of the corrugated wall while the thermoplastic material of the walls is soft thereby to secure the walls together, and with an electrically energizeable heating coil being provided for softening the thermoplastic material of the corrugated wall to ensure satisfactory securement between the walls.

Abstract: Individual flanged trays are deposited on a conveyor belt. A continuous film is applied across the top surface of the trays. A heated flat plate is pressed into the film and causes the tray flanges to bend to a desired position. The plate heats the film throughout and bonds the film to the tray flanges. Directly thereafter and while at the same station, vacuum is applied which serves to deform the film into the interior of the trays. The formed film preferably has rounded corners and may be partially separated from the bottom wall and side walls of the tray by an air space. Thereafter, a heated plug preferably having insulated sides, heat seals the now deformed film to the bottom wall of the tray. A cutting device trims the excess film at the tray flanges. The excess film may be scavenged and recycled. The cutting device may be provided at the deforming station or the sealing station or at a trimming station downstream of either of these stations.

Abstract: A solar panel comprising first and second generally parallel, spaced sheets of plastic material and a corrugated sheet of plastic material sandwiched between and bonded to the first and second sheets, the spacing between adjacent corrugations in the corrugated sheet being considerably less than 50% of the distance between the first and second sheets and no greater than about 1/2 inch, the plastic material being light transmitting and characterized by resistance to ultraviolet deterioration.

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.