MXPA97008876A - Method for postmarking a handle to a plastic container oriented by tens - Google Patents

Abstract

The present invention relates to a method for the post-mold fixing of a handle to a plastic container (50), characterized in that it comprises the steps of: blow molding a body (51) of a plastic container oriented by tension with at least a recess (56, 58) for fixing the integral handle in a mold (40), removing the body (51) from the mold (40), providing a separate handle (71) having at least one projection (75, 76) and inserting the projection into the recess, wherein the recess (56, 58) is formed with a higher level of orientation than the adjacent portions of the body (51), and exposing the body (51) of the container to an elevated temperature in a time interval and a temperature sufficient to cause thermal shrinkage of the tension-oriented recess (56, 58) in close engagement with the projection (75, 76) to secure or secure the handle (71) to the body (51) of the container

Description

METHOD FOR POSTING A HANDLE TO A TENSION-ORIENTED PLASTIC CONTAINER Field of the Invention The present invention relates to a method for the post-mold fixation of a handle to a tension-oriented plastic container, and more specifically to a method that uses thermal shrinkage of a tension-oriented container body, to ensure engagement or contact of the handle and the container.

Background of the Invention Plastic containers that can be filled with hot liquids are designed for the packaging or packaging of liquids (eg juice) which must be placed in the container while hot to provide adequate sterilization. During filling, the container is subjected to elevated temperatures of the order of 82-85 ° C (180-185 ° F) (product temperature) and positive internal pressures of the order of 1400-3500 kg / m2 (2-5 lbs. / square inch) (the filling fluid pressure). The container is then capped and when the Ref. 026201 product is cooled, a negative internal pressure is formed in the sealed container. Biaxially oriented polyethylene terephthalate (PET) beverage bottles have been designed to receive a product for filling with a hot liquid with controlled thermal shrinkage and minimal distortion. Such a bottle is described in U.S. Pat. No. 4,863,046 entitled "Hot Filler Container", which was issued on September 5, 1989 in favor of Collette et al. The Collette container is provided with a plurality of vacuum panels recessed in the intermediate panel section of the container, which reduces the magnitude of the vacuum generated in the sealed container to prevent any large uncontrolled geometric distortion. When the product cools, the vacuum panels deform and move in at the same time. A label around the wrapping covers the panels under vacuum and is supported by portions of the central wall embossed in the vacuum panels, the posterior areas between the panels under vacuum, and the areas for placement of the horizontal sluice above and below. the vacuum panels. The vertical recessed flanges can be provided in the back areas and inside the vacuum panels to increase the longitudinal rigidity of the panel section.

Pasteurization is another method of sterilization which subjects a container to high internal temperatures and pressures. In this case, the container is filled with a cold liquid product (at room temperature or below it), which may or may not be carbonated, the container is sealed, and then the sealed container is sent through a chamber of pasteurization wherein both the product and the container are subjected to a high equilibrium temperature (i.e., up to about 70-75 ° C) for a period of time (eg, ten minutes) to effect sterilization. This period of prolonged exposure to high temperatures generates high internal pressures due to vaporization of the fluid. After pasteurization, the container must be cooled without significant distortion or being crushed by vacuum. There is a need to provide a thermally resistant container, such as a container that can be filled with hot or pasteurizable liquids, with a handle for easy transportation and controlled pouring. This is especially true with larger containers, for example, 1.9 liters (64 ounces), 3.8 liters (128 ounces) and larger, because the weight of the product and the size of the container make it difficult for the user to manipulate it. . An integral handle is difficult to form with materials that can be hardened by stress, such as polyester. A separately formed handle requires a secure locking mechanism, especially with larger containers (ie heavier). And as always, to be commercially successful, a container with handles must be capable of being manufactured at the lowest possible cost, which usually means a shorter cycle time on the high production manufacturing equipment and a minimum number of steps of additional manufacture. Numerous attempts have been made to effect fixation in the molding of a handle to a plastic container in a commercially viable manner. However, most of these attempts have not been successful because fixing the handle during molding involves: (a) more complex blow molding equipment to make it possible to insert a prefabricated handle into a mold for the blowing of the container in the correct position: (b) the time added for the insertion of the handle in the mold, which hinders the performance of the blow molding equipment: and (c) the difficulty in blow molding a form fixed to the complex handle, due to the stress hardening characteristics of polyesters and other plastics. Accordingly, the fixation of the handle in the molding has significant disadvantages. Another difficulty with the provision of handles for heat-resistant containers (for example, for filling with hot or pasteurizable liquids), whether done in molding or after molding, is that exposure to a high temperature can distort the container and / or the handle in such a way that there is no longer a secure coupling of the handle and the container. Accordingly, there have been few attempts to market a thermally resistant container having a separate handle, especially in larger containers. A juice container that can be filled with large-sized hot liquids (128 ounces or 3.8 liters) with a packing handle, sold by the Ocean Spray Company of Lakeland, Mass., Is shown in Figures 1-2. This stretch-blown PET container 2 has a cylindrical side wall panel 3 with six vacuum panels 4 placed symmetrically around the circumference to relieve or remedy the crushing by vacuum. Instead of trying to fix a handle to the side wall of the container (such side wall is subjected to increased pressure, thermal shrinkage, and crushing by vacuum during the filling process with a hot liquid), a handle of the packaging type 5 is snapped onto a projection 6 adjacent to the finish of the neck 7. The polyethylene handle 5 includes a ring portion 8 which can be stretched to make possible its insertion onto the shoulder 6 of the neck and the subsequent release to be kept under the ledge. An extended "U" -shaped element 9 extends from the ring which is intended to be held by a user's hand during transportation and pouring. It is necessary to use two hands during the pour, one fixed to the container and the other to raise the base of the container. It is somewhat difficult to pour from this container into small cups, due to the large size and weight of the container. A small cup should normally be carried very close to the opening of the container 10, to prevent spillage. This difficulty with controlled pouring into small cups is partly due to the large opening of the container in the neck finish, which is required by the characteristics of stretch blow molding of polyethylene terephthalate (PET), that is, to achieve the necessary level of axial expansion and the ring in the container, a preform having a relatively large opening is required to manufacture this large volume container. Accordingly, the present container that can be filled with hot, commercial liquids, with a packing or packaging handle has several limitations. WO 95/15250 by Collette et al., published June 8, 1995, discloses a method and apparatus for forming a tension-hardenable plastic container with deep recesses, to make it possible to secure the "post-mold" fixation of a handle. The container is formed in a modified blow mold, to form partial recesses in the container, and then the blades or blades are further extended to mechanically shape the deep recesses. The mechanical shaping operation exceeds the stretch limits imposed by the stress hardening of the plastic material during blow molding. GB 2255546 A to Parker, published on November 11, 1992, discloses a blow molded container which is formed separately and a handle subsequently fastened. The body of the container has two opposingly positioned handle securing portions, which receive the projections or depressions on the opposite ends of the handle. The handle is adjusted or snapped into the body of the container, and can be further secured by means of an adhesive or welding. WO 82/02370 to Thompson, published on July 22, 1982, discloses a blow molded container which is formed separately and a handle subsequently fastened. The container includes a recess in its side wall with upper and lower fixing projections, which receive the complementary fixing means on the opposite ends of the handle. The handle and the container can be fixed by means of interlock, welding, bonding or adhesives. European Patent Application 0650900 A1, published on May 3, 1995, discloses a separately formed blow molded container and a handle subsequently fastened. The handle is formed with a pair of mounting beam parts that have coupling projections on the internal sides thereof. The handle can additionally include to equip or adapt projections to prevent the fall of the handle.

Brief Description of the Invention This invention is directed to a method for post-mold fixing of a handle to a plastic container. A body of the plastic container oriented by tension is molded having at least one recess for fixing the integral handle. The body is removed from the mold and a separate handle is provided having a projection with complementary shape for insertion into the recesses. Then, before, during, or after filling the container body with a product, the container body is exposed to an elevated temperature in a time interval and at a temperature sufficient to cause thermal shrinkage of the container body oriented by the stress and of the fixing recess of the handle, such shrinking ensures the engagement of the recess around the projection. In one embodiment, a body of the polyester container that can be filled with hot liquids is stretch blow molded from a preform to tension the side wall of the container. A notch for receiving the large handle is formed in the side wall of the upper container, in the company of a pair of upper and lower opposed axial recesses, aligned with the vertical axis of the container. The axial elongation and orientation of the container body ensure that there will be thermal shrinkage in the axial direction during subsequent exposure to elevated temperatures. A separate handle is provided which fits or fits within the notch in the side wall of the container and includes opposite axial tabs to fit or fit within the recesses. The handle is formed of a thermoplastic which softens when heated, to make possible the folding of the handle to facilitate the insertion of the tabs in the recesses of the body of the container. Then, during filling with the hot liquid, the body of the hot container first expands and then shrinks when cooled in an axial direction, generating a compressive force which keeps the handle rigid and the container body in engagement. This container can be used to make a juice container that can be filled with hot, large-sized liquids (eg, 128 ounces or 3.8 liters). The handle makes it possible to carry out the spill in a controlled manner with one hand. Other embodiments that use alternative or additional elements for fixing the handle include: a protrusion in the shape of a dovetail; a neck ring; and / or a bubble molded into the side wall of the container which can be softened (by means of heat) and compressed above a ring on the handle, to fix or secure the handle in place. Still another embodiment uses a handle having studs which fit or fit within the walls of the column molded into the side wall of the container, and such studs may include spikes or metal elements (for induction heating) to ensure additionally the coupling. The induction heating of the studs and the localized heating of the bubble (for compression around the ring) are both heating steps (for fixing the handle) which occur prior to filling. Pasteurization is an example of a process where the heating step (for fixing the handle) occurs after filling the product. In various embodiments, the thermal shrinkage, which secures the coupling, may be in one or both of the axial and annular directions. Also, an adhesive can be used to ensure the fixation of the handle / container. In addition, a pouring nozzle can be attached to the finish of the neck of the container having a reduced area opening for control of the improved pouring operation. These and other advantages of the present invention will be described more particularly with respect to the following description and drawings of the selected modalities.

Brief Description of the Drawings Figure 1 is a front elevation view of a juice container that can be filled with hot liquids, of the prior art, having a packaging or packaging handle. Figure 2 is a top view of the packing or packaging handle of the prior art container of Figure 1. Figure 3 is a schematic cross-sectional view of a stretch blow molding apparatus for making a body of the container oriented by tension with a pair of handle fastening elements, in accordance with the present invention. Figure 3A is a fragmentary enlarged portion of the area of Figure 3 circled by arrows 3A, showing the lower molded recess. Figure 3B is a fragmentary enlarged portion similar to that of Figure 3A but of an alternative embodiment wherein the blow molded recess has been mechanically deepened by means of movable blades or blades in the mold for blow molding. Figure 4 is an exploded perspective view of a blow molded container made in accordance with a first embodiment of the invention, having recesses for fixing the handle, integrally molded, in the side wall of the container, and showing a handle that is going to be fixed to it. Figure 5 is a fragmentary perspective view of the handle fixing area of Figure 4 but with the handle snapped onto the side wall of the container. Figures 6-8 show a series of steps for fixing the handle according to the first embodiment; Figure 6 shows the separate handle with the arm of the handle being heated; Figure 7 shows the heated arm that is bent to make the fixation possible, and Figure 8 shows the handle fixed to the container. Figure 9 is a partial side elevational view of the container of Figures 4-5, showing the shrinkage forces during filling with a hot liquid, which ensure the coupling of the handle and the body of the container. Figure 10 is a fragmentary exploded perspective view of a second embodiment, showing a body of the molded container and the handle around which it is to be fixed.

Figure 11 shows the snap fit of the handle on the body of the container in the second embodiment. Figures 12-14 show a series of steps to fix the handle to the body of the container according to the second embodiment; Figure 12 shows the separate handle with the arm of the handle being heated; Figure 13 shows the heated arm that is bent to make the fixation possible; and Figure 14 shows the handle fixed to the container. Figure 15 shows the forces of shrinkage by filling with a hot liquid, which ensure the coupling of the handle and the container in the second embodiment. Figure 16 is a fragmentary exploded perspective view of a third embodiment with a bubble molded in the side wall of the container, and a handle around which it is to be fixed. Figure 17 shows the fit or fit of the handle on the body of the container in the third embodiment. Figures 18-20 show a series of steps for fixing the handle to the bubble in the third embodiment; Figure 18 shows the separate handle: Figure 19 shows the ring of the handle placed around the bubble and a hot iron that heats the bubble; and Figure 20 shows the compressed bubble that fixes or secures the handle on the container. Figure 21 shows the shrinkage forces during filling with a hot liquid, which fix or ensure the coupling of the handle to the container. Fig. 22 is a fragmentary exploded perspective view of a body of the molded container having a dovetail-shaped protrusion and a handle to be fixed thereto according to a fourth embodiment. Figure 23 is a perspective view of the container with the handle fixed (fourth embodiment). Figure 24 illustrates a mounting method (fourth embodiment). Figure 25 is a side elevational view of the mounted handle and the container (fourth embodiment). Figure 26 is a cross-sectional view of the connection of the dovetail / handle shaped protrusion, taken along the lines 26-26 of the section of figure 25. Figures 27-28 show a fifth embodiment wherein a handle has a pair of studs which fit or fit into the walls of the column in the side wall of the container; Figure 27 is a fragmentary exploded perspective view of the container and the handle to be affixed, and Figure 28 is a fragmentary perspective view of the container with the handle affixed. Figures 29-30 are cross-sectional views of a post / stud wall fixing mechanism; Fig. 29 is a cross-sectional view taken along line 29-29 of Fig. 28 showing a stud inserted into a wall of the column, and Fig. 30 shows the shrinkage of the walls of the column around of the stud. Figures 31-32 are cross-sectional views of a mechanism for fixing the wall of the column-stud. Figure 31 shows a stud with a metal blade inserted into a wall of the column, and Figure 32 shows the shrinkage of the walls of the column around the stud following induction heating. Figures 33-34 are cross-sectional views of a third mechanism for fixing the walls of the column / stud. Figure 33 shows a stud having a metal insert and barbs inserted into the wall of the column, and Figure 34 shows the shrinkage of the walls of the column around the stud, using both induction heating and mechanical coupling. middle of the barbs. Figures 35-37 show a pouring nozzle for fixing to a finish of the neck of the container, Figure 35 is an exploded perspective view of the pouring nozzle and finishing of the neck of the container, Figure 36 is a view in FIG. upper floor of the pouring nozzle, and Figure 37 is a cross-sectional view taken along line 37-37 of Figure 36, of the pouring nozzle attached or fixed to the finish of the neck.

Detailed description of the invention Figures 3-9 illustrate a method of manufacturing a container according to a first embodiment of the invention. The container is a beverage bottle that can be filled with hot 3.8-liter (128-ounce) polyethylene terephthalate (PET) liquids. The bottle (see Figure 3) has a total height A of about 320 mm, a height B of the panel section of about 125 mm, and a diameter C of about 155 mm. The thickness of the container in section B of the panel is of the order of 0.6 mm.

As shown in Figure 3, the bottle 50 is blow molded and stretched from an injection molded preform 21. The preform has a finish of the threaded neck 22, upper, and a forming portion of the lower body 23. The preform is heated to the glass transition temperature of the PET, and is retained in a blow-molding apparatus and stretched by a collar or ring 31 which engages the finish of the neck 22. A rod or stretching rod 32 is inserted into the preform and elongated axially to impart axial orientation to the forming portion of the body 23 of the preform below the finish of the neck. The axial extension in the section of the panel can be of the order of 2.7-2.9X. The tip 33 of the rod for axial stretching keeps the center of the base of the preform extended in its position in the center of the blow mold 40, so that the preform is securely centered during the radial (annular) expansion. Then, a fluid such as a gas (shown by arrows 41) is inserted into the interior of the preform for radial stretching of the preform in engagement with the internal mold walls 42, whereby the preform assumes the shape of the cavity for blow molding. The annular extension in the section of the panel can be of the order of 3.2 - 3.8X. The ratio of the planar stretch in the panel section (ie, the axial extension multiplied by the annular extension) can be of the order of 8-12: 1, and for a PET container that can be filled with hot liquids is preferably of the order of 9-10: 1. The body 51 of the container is formed with an enlarged upper projection 52 adjacent to the finish of the unexpanded neck 22, the projection increases in diameter in a direction away from the finish of the neck. However, one side of the projection is formed with a large notch 53, which projects inwardly towards the container body, which forms an area for fixing the handle and makes it possible to insert the user's fingers between the handle and container body (see figures 5 and 8). The projection includes a pair of recesses or grooves 56, 58, upper and lower, axially aligned, which form the fastening elements of the handle as described hereinafter. The large notch 53 includes a substantially vertical rear wall 54, a horizontal upper wall 55 shortened with an upper recess 56, and an elongated horizontal bottom wall 57, with the lower recess 58. Both recesses 56, 58 are formed adjacent to the rear wall 54. Beneath the projection 52, the body 51 of the container includes a substantially cylindrical panel section 59 (defined by the axis 70 of the vertical container) with six vacuum panels 60 positioned symmetrically around the section of the panel. The vacuum panels 60 each include a recessed inwardly concave portion 61, which is flexible to enable controlled contraction of the container when a vacuum is formed during cooling of the filled container with a hot, sealed liquid. A central embossed panel 62 includes a vertical overflow flange 63 to provide strength, to prevent curvature or warping of the panel. In addition, the vertical flanges 64 are provided in the walls of the post between the vacuum panels to provide rigidity. The base 65 of the container includes a vertical ring 66 surrounding a central upwardly pulling dome 67, the central dome includes a plurality of circumferentially distributed panels for reinforcing the base against inversion. Figure 4 again shows the container as it is molded, of the first embodiment, and a handle around which it is to be fixed. The narrow radius notches 56, 58 have undergone a fairly high level of tension orientation during the radial and axial expansion of the preform, because of its relatively small radius of curvature. These inserts will therefore have a relatively high level of orientation compared to other portions of the side wall, which will produce a higher level of thermal shrinkage as will be described hereinafter. In a mode shown in Figure 3a, the notch or recess 58 has been cast by stretching and blowing to a depth dx and a width wi where the ratio d?: W? it is preferably at least of the order of 2: 1 or greater. The lower part of the recess has a reduced thickness t2 which is preferably at least of the order of 50% less than the thickness of the wall of the portions t3 of the adjacent body. In a second embodiment shown in Figure 3B, the blow molded recess is mechanically depressed by movable blades or blades 401, 402 in the blow mold (see Figure 3), wherein the ratio of the depth d2 to the The width 2 of the recess is preferably at least on the order of 3: 1 or greater, and more preferably between 3: 1 and 4: 1. In any of the embodiments shown in Figures 3A and 3B, wherein the section of the panel is oriented in a planar stretching ratio of about 10: 1 for a filling application with a hot liquid, the recess is preferably oriented in a ratio of planar stretching of at least the order of 12: 1 or greater, and more preferably of at least 15: 1. The lower part of the recess will be at least 50% thinner than the rest of the side wall; therefore, for a panel section of 0.46 mm (0.018 inches) thick, the lower part of the recess will be of the order of 0.25-0.31 mm (0.010-0.012 inches) in thickness. The depth of the recess can be of the order of 5-10 mm (0.20 inches to 0.40 inches). To provide the deep recesses (notches) in the container body as shown in the preferred embodiment of Fig. 3B, the method and apparatus described in WO 95/15250 of Collette et al, published June 8, 1995 , and entitled "Method and Apparatus For Forming A Strain-Hardenable Plastic Container", can be used. In this application a method for blow molding a preform made of a thermoplastic stress-hardenable material is described, wherein the blow molding has at least one extendable projection (see blades or blades 401 and 402 in Figure 3) To form a partial recess in the container when the material is blow molded onto the projection, the depth of the partial recess is limited by the stress hardening of the thermoplastic material during blow molding. Subsequent to this, there is a mechanical extension of the depth of the partial recess by the extension of the projection further down into the recess to form a deep recess for fixing the handle.

Then, the projection is mechanically retracted to allow the removal of the molding container for blowing. A handle is subsequently fixed to the container. Figure 5 shows a handle 71 fixed to the container in the notch 53, according to the steps illustrated in Figures 6-8. The handle 71 is a separate injection molded body, preferably formed of a polyolefin. The handle includes a main arm 72 substantially vertical, to be held by the user, and upper and lower horizontal extensions 73, 74, which carry a pair of elements or tabs 75, 76 that couple the recess axially aligned. As shown in Figure 6, the main arm 72 is heated by a heater 80. This softens the main arm and makes it possible to be bent, bringing the upper and lower extensions closer together to facilitate the insertion of the upper and lower tabs. 75, 76 in the upper and lower recesses 56, 58 of the container. When the handle cools, it becomes rigid and is now properly placed on the container. Then, as illustrated in Figure 9, the container is filled with a hot liquid (see filling line 81) and sealed immediately with the lid 82. The hot liquid heats the body 51 of the container causing thermal expansion and then the shrinkage during cooling of the body 51 oriented by tension. The shrinkage is caused by the relaxation of the residual stress resulting from the blow molding operation. The axial shrinkage forces 83 which occur in the walls 55, 57 of the upper and lower recesses, particularly in the highly oriented and highly curved recesses 56, 58 of the upper and lower handle, because of the container body shrinks in closer engagement with the extensions of the upper and lower handle 73, 74 and the tabs 75, 76. Once the container has cooled, the handle 71 is held securely by the axial compressive forces within the arms. notches 53 of the container, to enable the pouring operation with one hand from the container. The recesses encapsulate and encircle the tabs to prevent the handle from detaching by pulling the container. Figures 10-15 show a second embodiment of the invention. Again, a 1.9 liter (64 lb.) PET container 150 is blow molded and stretched from a preform, as shown in FIG. 3. In this embodiment, the notch 153 in the projection 152 is modified to eliminate the wall of the upper recess. The notch includes a substantially vertical rear wall 154 and a horizontal bottom wall 157. A lower axial recess 158 is formed in the bottom wall, adjacent to the rear wall. Instead of providing an upper axial recess, a notch 156 is created under the protrusion 125, below the finish of the neck 122, such notch is formed during the injection molding of the preform. The handle 171 has a main vertical arm 172, a lower extension 174 with an axial tab 176 for insertion in the lower recess 158, and an upper extension 173 with an upwardly extending projection 175, which can be adjusted under pressure inside the notch 156 under the projection 125. Figures 12-14 illustrate the steps for fixing the handle to the container according to the second embodiment. Again, the main vertical arm 172 is heated to soften the same, the arm is bent to bring the closest extensions 173 and 174 together and to facilitate the insertion of the upper projection 175 into the notch 156 and the lower tab 176 within the lower recess 158. When the handle cools, it again becomes rigid and is fixed or secured in position. Figure 15 shows the container 150 filled with a hot, sealed liquid, wherein the shrinkage forces by filling with a hot liquid, axial, 183, fix or secure the coupling (axial compression) of the lower recess wall 157 and the extension of the lower handle 174, and the tab 176 in the recess 158. The device 175 of the upper handle, which is fits or fits into the groove 156, is not subjected to significant thermal shrinkage forces because the finish of the container neck is substantially not oriented and therefore does not shrink. Also, the finish of the neck 122 is a substantially thicker portion of the container, which increases the strength of the upper handle device. Figures 16-21 show a third embodiment of a container 250 for filling with a hot liquid, PET, using a mechanism for fixing the handle, bubble / ring. Figure 16 shows the projection 252 of the container having a notch 253 similar to that in the first embodiment, with a rear wall 254 and upper and lower walls 255, 257 having upper and lower recesses 256, 258. In this case, a outwardly extending bubble 265 is formed in the center of the rear wall 254. The bubble 265 has a substantially rectangular shape with rounded corners. The handle 271 has a main vertical arm 272 and upper and lower extensions 273, 274; in this embodiment the upper and lower extensions are connected by a second vertical arm 277. The arm 277 includes a ring 278, which is of a substantially rectangular shape and designed to fit around the bubble 265 on the container. As shown in Figs. 18-20, the handle is positioned in the recess 253, with the ring 278 around the bubble 265, and the upper and lower tabs 275, 276 in the upper and lower recesses 256, 258. The bottle it is preferably pressurized and the bubble is then heated, such as by applying a hot iron 280 against the bubble 265, to soften it. The softened bubble is then compressed into the container, causing the bubble to expand and extend over the ring 278 of the handle to secure or secure the ring to the container. Once cooled, the rigid handle will be immobilized or locked in the container. Again, as shown in Figure 21, thermal shrinkage forces 238 around the upper and lower walls 255, 257 and the recesses 256, 258, will further secure or secure the handle device. In an alternative embodiment, the tabs and recesses are removed and the ring / bubble used to fix or secure the handle and the container.

Figures 22-25 show a fourth embodiment of a container 350 having a dovetail-shaped protrusion 354. The projection 352 of the container is formed with a notch 353 having a substantially vertical dovetail-like protrusion 354. but inclined, which extends outwards, as shown in cross-section in figure 26. The handle has a complementary cavity 377 adapted to be slid over the projection in the form of a dovetail. The handle 371 includes a lower projection 376 which fits or engages within a notch 358 at the lower end of the protrusion, to prevent the handle from separating from the protrusion. Again, the thermal shrinkage forces will secure or secure the handle / container coupling. Figures 27-34 show a fifth embodiment of the invention, using a coupling mechanism of the column wall / stud bolt. Figure 27 shows a container 550 with a protrusion 552 having a notch 553 similar to that of the second embodiment, including a rear wall 554 and a bottom wall 557. Formed on the rear wall are a pair of walls 556, 558 of the column, upper and lower, aligned radially, which project internally towards the vertical axis of the container. The handle 571 includes a main vertical arm 572, upper and lower transverse extensions 573, 574, and a second vertical arm 577 that connects the upper and lower extensions. The second arm 577 includes a pair of radially extending upper and lower studs 578, 579 adapted to be adapted or fitted within the walls 556, 558 of the post, as shown in Figure 28. Figures 29 -34 show three versions of the wall coupling of the column / stud. In a first version, shown in Figures 29-30, a stud 578a includes a cylindrical post element 581a of a first diameter having an enlarged circumferential ring or head portion 582a of a second diameter (larger than the first diameter ) and which couples the wall 556 of the circumferential column. During thermal shrinkage, the wall of the post 556 is axially shrunk around the ring 582a (assuming the position of the shrinkage 556 ') to secure or secure the coupling of the handle. In a second version, shown in Figures 31-32, a sheet metal layer 583 is applied over the ring 582a, to make possible the induction heating of the wall 556 of the column to fix or additionally secure the wall of the column around stud 578a.

In a third version, shown in Figures 33-34, a metallic insert 584 of a steel spring forms the ring 582a on the stud 578a, and the tines 585 extend from the metal insert 584 to further secure or secure the joint or fixing between the stud and wall 556 of the column. In any of the above embodiments, a pour nozzle 600 (see Figures 35-37) can be added to the neck finish 22 to further improve the pouring capacity. The pouring nozzle has an upper surface 601 with an opening 602 of reduced area smaller than the opening 10 of the neck finish. A projection 603 extends downwardly from the top wall for engagement of the neck finish 22. The elongated and relatively narrow opening 602 of the pouring nozzle facilitates the controlled pouring operation from the relatively large opening 10 of the neck finish, especially for pouring into small cups. The container can be made from any of the known polymeric resins which provide good resistance at an elevated temperature, such as polyesters, polyolefins, polycarbonates, nitriles, and the copolymers of the above, as well as other high temperature polymers.

Phthalic acid polyesters based on terephthalic or isophthalic acid are commercially available and are convenient. The hydroxy compounds are typically ethylene glycol and 1,4-di- (hydroxymethyl) cyclohexane. The intrinsic viscosity for the phthalate polyesters is typically in the range of 0.6 to 1.2, and more particularly of 0.7 to 1.0 (for the O-chloro-phenol solvent). 0.6 corresponds approximately to a viscosity average molecular weight of 59,000, and 1.2 to an average viscosity molecular weight of 112,000. In general, the phthalate polyester can include polymer bonds, side chains, and end groups not related to the formal precursors of a simple phthalate polyester. Conveniently, at least 90 mole percent will be terephthalic acid and at least 45 mole percent of a glycol or aliphatic glycols, especially ethylene glycol. The bottle grade polyethylene terephthalate (PET) homopolymers and copolymers are commercially available from Eastman Chemical Co. of Kingsport, TN. Another useful polymer with physical properties similar to PET is polyethylene naphthalate (PEN). The PEN provides a 3X improvement in the oxygen barrier property (compared to PET), at some additional cost. The container may be either a single layer, or multiple layer construction, including layers of an oxygen barrier material such as ethylene vinyl alcohol or polyvinylidene chloride, and may include a layer of scratch material. reprocessed, such as recycled or post-consumer PTE. Although certain embodiments of the invention have been specifically illustrated and described herein, it is to be understood that variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following

Claims (36)

1. A method for the post-mold fixing of a handle to a plastic container (50), characterized in that it comprises the steps of: blow molding a body (51) of a plastic container oriented by tension with at least one recess (56, 58 ) of fixing the integral handle in a mold (40), removing the body (51) from the mold (40); providing a separate handle (71) having at least one projection (75, 76) and inserting the projection into the recess; wherein the recess (56, 58) is formed with a higher level of orientation than the adjacent portions of the body (51); and exposing the body (51) of the container to an elevated temperature in a time interval and at a temperature sufficient to cause thermal shrinkage of the recess (56, 58) oriented by tension in close engagement with the projection (75, 76) to fix or securing the handle (71) to the body (51) of the container.

2. The method according to claim 1, characterized in that: the step of the exposure includes presenting the body (51) of the container with a product and exposing the body of the filled container to an elevated temperature.

3. The method according to claim 1, characterized in that: the step of the exposure comprises filling the body (51) of the container with a hot liquid product.

4. The method according to claim 2, characterized in that: the exposure step comprises pasteurization.

5. The method according to claim 1, characterized in that: the body (51) of the container is polyester and at least one recess (56, 58) is tension-oriented at a planar stretching ratio of at least 12: 1.

6. The method according to claim 5, characterized in that: the at least one recess (56, 58) is oriented by tension at a planar stretch ratio of at least 15: 1.

7. The method according to claim 5, characterized in that: the body (51) of the container is axially stretched in the order of 2.7-2.9X.

8. The method according to claim 5, characterized in that: the container body includes a section (59) of the panel which is tension oriented at a planar stretch ratio of the order of 9: 1 to 11: 1.

9. The method according to claim 1, characterized in that: the stress orientation reduces the thickness of the wall of at least a portion of the at least one recess (56, 58) by at least 50%.

10. The method according to claim 1, characterized in that the body (51) of the container has a vertical axis (70) and: the at least one recess (56, 58) is aligned with the vertical axis (70); and the step of the exposure includes causing at least one recess (56, 58) to suffer axial shrinkage in a direction parallel to the vertical axis (70).

11. The method according to claim 10, characterized in that: the body (51) of the container is molded with a pair of opposed axial recesses (56, 58); and the step of the exposure includes causing the opposite axial recesses (56, 58) to suffer shrinkage along the vertical axis (70) from each other, to apply a compressive force to the handle (71).

12. The method according to claim 1, characterized in that it further comprises: mechanically deepening the at least one molded recess (56, 58).

13. The method according to claim 1, characterized in that: the handle (71) can be bent and the pitch of the fastener includes bending the handle to insert the projection in at least one recess.

14. The method according to claim 1, characterized in that: the handle (71) is formed of a thermoplastic material and during the passage of the fixation, the handle is exposed to an elevated temperature which softens the thermoplastic material to facilitate the insertion of the projection in at least one recess.

15. The method according to claim 1, characterized in that the body (150) of the container has an upper neck finish (122) and a side wall (152) and: the method further comprises molding a preform having a finish (122) of the neck and a notch (156) adjacent to the neck finish to form a first handle fastening element; and the preform is blow molded in the body of the container and the recess (158) is molded in the side wall to form a second handle fastening element.

16. The method according to claim 1, characterized in that the body (250) of the container has a side wall (252) and: the molding step includes forming a bubble (265) projecting outwardly from the body of the container to form a handle fastening element; the handle (271) is provided with a ring (278) shaped to surround the bubble; and the fixing step includes placing the ring (278) around the bubble (265), expose the bubble (265) to an elevated temperature to soften the bubble, and compress the softened bubble (265) around the ring (278) to secure or secure the bubble and the ring.

17. The method according to claim 1, characterized in that: the molding step includes the formation of a projection (354) in the form of a dovetail on the body (350) of the container; the handle (371) is provided with a cavity (377) slidable on the projection in the shape of a dovetail; and the fixing step includes the sliding of the cavity (377) on the projection (354) in the shape of a dovetail.

18. The method according to claim 17, characterized in that: the step of the molding includes the formation of the recess (358) adjacent to the projection (354) in the form of a dovetail in such a way that the projection (376) and the recess ( 358) prevent the cavity (377) from being slid off from the protrusion (354) in the shape of a dovetail.

19. The method according to claim 1, characterized in that: the molding step includes the formation of a pair of walls (556, 558) of the column; the handle (571) is provided with a pair of projections (578, 579), each projection comprising a rod (581a) with an enlarged head portion (582a) to fit or fit within one of the walls of the column; and the step of the exposure includes causing thermal shrinkage of the walls (556, 558) of the column around the portions of the enlarged head (582a).

20. The method according to claim 19, characterized in that: the portions of the enlarged head (582a) are provided with metal (583); and the step of the exposure includes the induction heating of the metal (583) to cause thermal shrinkage of the walls (556, 558) of the column around the portions of the enlarged head (582a).

21. The method according to claim 19, characterized in that: the projections (578, 579) are provided with tines (585); and the step of the exposure includes the shrinkage of the walls (556, 558) of the column around the tines (585).

22. The method according to claim 1, characterized in that: the step of the fixation includes adhesively coupling the recess (56, 58) and the projection (75, 76).

23. The method according to claim 1, characterized in that: the step of molding includes the molding by blowing and stretching the body (51) of the polyester container.

24. The method according to claim 1, characterized in that: the step of the molding includes the molding by blowing and stretching a body (51) of the container substantially of polyethylene terephthalate (PET).

25. The method according to claim 1, characterized in that it further comprises: during the blow molding, forming the body (250) of the plastic container with an integral bubble (265) projecting outwardly from the body of the container to form a handle fastening element; the handle (271) has a ring (278) shaped to surround the bubble (265); and place the ring (278) around the bubble (265), expose the bubble at an elevated temperature to soften the bubble (265), and compress the softened bubble (265) around the ring (278) to secure or secure the bubble and the ring.

26. The method according to claim 1, characterized in that the at least one projection (578, 579) of the handle is provided with metal (583), and the exposure step includes the induction heating of the metal (583) to cause the thermal shrinkage of the at least one recess (556, 558) around at least one projection (579, 579).

27. The method according to claim 1, characterized in that the at least one recess (58) has a depth di and a width i where the relation d?: W? is at least of the order of 2: 1 or greater.

28. The method according to claim 27, characterized in that the ratio d?: W? is at least of the order of 3: 1 or greater.

29. The method according to claim 27, characterized in that the at least one recess (56, 58) has a lower wall having a reduced thickness t2 of the order of at least 50% less than the thickness of the wall t3 of the portions of the body adjacent to the recess.

30. The method according to claim 29, characterized in that the body (51) of the container is polyester.

31. The method according to claim 30, characterized in that the polyester is substantially polyethylene terephthalate.

32. The method according to claim 27, characterized in that the polyester is substantially polyethylene terephthalate and the at least one recess (56, 58) is oriented at a planar stretching ratio of at least of the order of 12: 1 or greater.

33. The method according to claim 32, characterized in that the at least one recess (56, 58) is oriented to a planar stretching ratio of at least of the order of 15: 1 or greater.

34. The method according to claim 32, characterized in that the body (51) of the container has a section (59) of the panel which is oriented to a planar stretching ratio of the order of 8-12: 1.

35. The method according to claim 34, characterized in that the section (59) of the panel has a planar stretching ratio of the order of 9-10: 1.

36. The method according to claim 1, characterized in that the body (51) of the container is substantially of polyethylene terephthalate, the body has a portion of upper protrusion (52) having a notch (53) which forms an area for the fixing the handle and making it possible to insert the fingers of the user between the handle (71) and the body (51) of the container, the notch (53) includes a rear wall (54) substantially vertically between the upper and lower walls ( 55, 57), and at least one recess includes upper and lower recesses (56, 58) formed respectively on the upper and lower walls (55, 57) adjacent to the rear wall (54), wherein each recess (56, 58) ) has a depth di and a width wi where the relation d?: w? is at least of the order of 2: 1 or greater, and each recess (56, 58) has an upper wall having a reduced thickness t2 which is at least of the order of 50% less than a thickness t3 of the wall of the portions of the body adjacent to the recess, the body (51) of the container also has a section of the panel (59) having a planar stretch ratio of the order of 9-10: 1, and each recess (56, 58) which is oriented at a planar stretch ratio of at least the order of 12: 1 or greater.