FR2539107A1 - THREE-PART CONTAINER AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Abstract

The present invention relates to a three-part container and its manufacturing method. A container 101 intended for the packaging of food products is composed of three separate parts, the upper part 103 and the lower part 104 being obtained by injection molding or by thermoforming of a thermoplastic plastic material, and the cylindrical central part 102 being obtained by extrusion of a polymer compatible with the first mentioned, the lower and upper parts being welded by rotation to the central part. The container according to the invention can, for example, be used as a drink bottle. (CF DRAWING IN BOPI)

Description

The present invention relates to a container of polymeric materials

thermoplastics and its

  In particular, the present invention

  tion concerns multi-part containers which are

  welded to each other by rotation to form the

final neur.

  Conventional container manufacturing methods typically involve shaping metals, glass, or other paper-based composites into container shapes. Other Conventional Container Making Techniques

  also include thermoforming of plastics

  The present invention relates more particularly to

  plastic containers, in particular

  those based on polyesters or polyolefins

  manufactured in accordance with the process of the invention

  Advantageously, those manufactured by the usual techniques of thermoforming plastics, as well as those produced by shaping glass, metals or papers. In conventional methods of manufacturing plastic bottles, these can be formed of one or more methods. One of these methods consists in forming a preform usually called a parison, by injection molding a molten plastic material into a mold. parison, and allowing the molded object to solidify This parison is then placed in an extrusion blow molding apparatus o by the combined effect of heat, air pressure, and mechanical stretching devices, it expanse This process in two or three steps is slow and expensive, it requires high investments and requires a great expenditure of energy. Indeed, the fusion of the polymer to mold the parison by injection,

  the cooling that follows and afterwards the warming

  required for extrusion blow molding require a

great heat input.

  Another method of manufacturing plasticized resin containers in direct injection molding in which a molten liquid polymer is directly injected into a mold having the shape of the desired bottle. This method, although it eliminates the double contribution of heat of the parison process, does not allow to obtain an orientation of the polymer and therefore the resulting bottle has a very weak structure 'Moreover, because of the lack of orientation of the polymer, there is only one very low barrier to oxygen penetration

and the exhaust of C 02-

  A third method for forming containers

  thermoplastic material consists in extruding a

  tubular, which is enclosed in a mold, and

  As it is still in the molten state, an extrusion blow is performed to bring it to the final shape of the

  bottle This method also presents as a disadvantage

  to give very little orientation to the plastic of the bottle, but in addition the bottle has a zone of low resistance, in this case the bottom, o the

  solder is formed during extrusion blow molding.

  The present invention aims to avoid the

  various disadvantages mentioned above.

  The subject of the present invention is a container made of thermoplastic material, formed of separate parts that can each be obtained by thermoforming, method

more economical.

  The present invention also relates to a method for assembling the different parts of the

  container by welding them to each other by friction.

  The thermoplastic container of the invention, intended for the packaging of food products, food and beverages, and having a low gas permeability at least on a part, is characterized in that it comprises: an upper part formed from a first polymer having a closure device above, and on the base a U-shaped flange peripherally disposed around this portion; a lower portion formed from a second polymer having at the top a U-shaped flange peripherally disposed around this portion; a central portion comprising a tubular member

  cylindrical, formed from a third comparable polymer

tible with the first two;

  the lower and upper hermetic-

  welded to the central part by a method of

rotational welding.

  The present invention also relates to a method of manufacturing such a container, which method comprises thermoforming an upper part with a threaded mouth, and a cylindrical wall; thermoforming a lower portion having nesting characteristics; extruding a central cylindrical portion on which is welded by rotation the upper and lower parts. The present invention is also described by way of the accompanying drawings in which: Figure 1 shows a sectional sectional view of a container according to the present invention; Figure 2 is a sectional side view, on a larger scale, of the upper part of the container, shown in Figure 1; Figure 3 shows a sectional view, on a larger scale, of the lower part of the container shown in Figure 1; Figure 4 shows an enlarged plan sectional view of the conductive ring with lugs of the upper part of the container described in Figure 2; Figure 5 shows a sectional side view of the lower part of the container fitted on the cap of the upper part of another container; Figure 6 is a sectional elevational view of

  the thickness of the three-layer wall of the container.

  Referring to Figure 1, there is shown a partial sectional view of a bottle 101 The bottle 101 generally comprises a central cylindrical portion 102 in the form of a tube, which is welded to the upper portion 103

  and at the lower portion 104 of the bottle.

  The upper part 103 generally consists of a slightly frustoconical cylindrical section 105, a shoulder section 106, the whole surmounted by a part

  cylindrical threaded 107 or neck whose helicoidal threads

  The annular portion 109 surrounds the neck 107 and extends radially outwardly. This annular portion 109 allows the bottle to be suspended from the filling machine while the bottle is being filled. in addition, the annular portion 109 also has a series of lugs located peripherally to allow engagement of the upper section in the mandrel of a device

rotary welding.

  The central portion 102 of the bottle 101 is generally a cylindrical tubular portion formed by extrusion or coextrusion. The cylinder is cut to length by means of a hot blade or laser to form

  bottles of the desired capacity Although the mode of execution

  1 shows that the wall of the central portion 102 is made of a single layer of a polymer, it is understood that this part may be a cylinder obtained by coextrusion and may have several layers of polymers, as illustrated. in Figure 6 These layers of

  polymers can be 3 or 5, and poly-

  mothers forming the inner and outer layers must comply with the standards in force for plastics in

  contact with food products, while poly-

  The mother forming the intermediate layer is a polymer having barrier properties such as ethylene-vinyl alcohol copolymer (hereinafter EVAL) to avoid the ingress of oxygen and the escape of C 02, through the wall of the container. can further add additional layers between the barrier polymer and the outer and inner layers, such as layers of adhesive products such as CXA (product manufactured by

  Pont de Nemours) to bind the other layers.

  The lower portion 104 comprises a circular diaphragm type closure having a relatively flexible central portion 110, a flange 111 and the whole surrounded by a flange 112 for rotational welding,

  turned up, circling the bottle.

  It should also be noted that the upper portion 105 has a similar flange 113 rotational welding, rotated

  down and placed at the foot of Part 104.

  U-shaped 112 and 113 are dimensioned to receive in a well-fitting manner the cylindrical portion 102 of the container.

  little clearance between the flanges 112, 113 and the cylindrical portion

  102, which will give some heat release when all these elements will be welded together by a rotational welding process As already mentioned, we can manufacture the container 101 from

  of a polymer selected from polyesters and polyole-

  In one embodiment, the container is manufactured from polyethylene terephthalate (hereinafter PET).

  polymer which can be brought into contact with foodstuffs

  tary, and having the advantage of being transparent, of being resistant and of having barrier effect properties. Moreover, the resistance of PET is particularly dependent on the orientation mode of its structure.

  obtained by drawing the polymer at the temperature of

  The central part of the container 101 is preferably

  A tube formed of a solid PET layer or a tube having a plurality of coextruded layers obtained from a circular coextrusion die. According to a preferred embodiment, five layers of polymer can be coextruded with the formation of a cylindrical tube There is an outer layer PET, then a layer of adhesive,

  then a layer of a barrier polymer followed by a

  These polymers can be extruded simultaneously into a single multi-layer cylindrical tube using a die without braces such as that described in US Pat. No. 4,249,875 of the Applicant. Referring to Figure 4, which shows a sectional view along the line 4-4 of the upper portion of the container 101 depicted in Figure 1, to show the structure of the ribbed annular portion 109 in this Figure 4, shows the threaded neck 107 in section, to which is integrally attached the annular peripheral portion 109, which projects radially out of the surface of the neck 107 to a certain distance is placed a series of rotational welding pins 114 arranged

  symmetrically around the periphery of the annular portion 109.

  These lugs 114 are adapted to be engaged on a rotational welding mandrel intended to give a movement of

  rotation at the top 105.

  Referring again to FIG. 1, it will be seen that a notch 116 has been cut in the wall of the flange 112 at the lower end of the portion 102. This notch is cut into the bottom edge of the container and serves as a marker for printing a label on this container and for also marking so that the preferred surface of this label is in a direction facing outside when the container is placed in a secondary packaging, for example in one package per group of six This is of particular interest to beverage sellers who request that the brand of their products be visible to customers when the containers are placed in a supermarket. It is also possible to place a lug in the upper part 103 rather than to cut a notch 116 in the flange 112. It is also possible to place a lug on the rim 111 of the lower part 104, which would therefore not be visible on the side or the top of the container 101 The slot location mode 116 represents the preferred mode

  execution for secondary packaging reasons.

  The notch 116 allows orientation of the bottle, as well as additional support for the

  container if one passes a rod in the slot 116.

  FIG. 2 shows a view of the upper part before being welded to the central part 102. This view shows that these upper parts 105 can fit into each other. In this FIG. 2, a second part has been drawn in dotted lines. This fact is very important when large-scale containers are manufactured because many containers are manufactured in one place and must be transported to another location for filling. one or two liters, these are made in one piece

  and transported empty to the Normal filling

  a truck or wagon, filled to capacity

  with these bottles, will only carry about a twenty

  of the normal load, since it carries empty bottles. The carrier is therefore paid to transport air. According to the present invention, nested bottles are transported, as indicated in FIGS.

  Figures 2 and 3, which increases the efficiency of transport.

  Figure 3 also shows the interlocking of the lower parts 104, a second nested part 104 being drawn in dotted line. Figure 2 shows the space saving resulting from the technique of the present invention, considering the distance over which the upper part 105, drawn in dashed lines, emerges from another part 105, in solid lines, in which it is nested, it is seen that the nested part occupies an additional space which is about one-third of the original space of this part Then we can

  carry a larger number of parts

  and save two-thirds of the cost of transport.

  8 - In addition to the savings thus achieved, it is necessary to

  not mention the one resulting from the use of

  a coextruded cylinder for the central part of the container which can be manufactured at the filling location.

  This only requires an appro-

  viewing in polymer granules, these being

  easily processed by extrusion into cylindrical tubes.

  Therefore, the design of the containers according to the present invention allows a significant saving of the transport costs of the empty containers as well as an improvement of certain characteristics, in particular the resistance, of the empty container coming from the technique.

  manufacturing by rotational welding.

  FIG. 5 shows another version of the lower part of the container. In this FIG. 5, a bottom portion 204 is formed having a U-shaped peripheral flange 212 for the rotational welding, and a reentrant flexible portion 211. rising cylindrical portion 210 which serves as a receptacle and which is adapted to receive the upper neck 107 of another container Screws a plug 115 on the neck 107 The lower shoulder 213 of the receptacle is sized to come into contact with the annular portion 109 of the bottle situated below and on which the lower part 204 is fixed The receptacle 210 formed in the lower part 204 makes it possible to stack the filled bottles on the storage shelf or in a display, this stack being stable and making it possible to present

products in an attractive way.

  A disadvantage of prior containers such as glass bottles and parison-type plastic bottles is that they are not very stable and can not be stacked without having to have a board or sheet between them. Thus, when the retailer and the supermarket owner want to have several rows of products, he has to spend time and money putting sheets between

each row.

  According to the present invention, and thanks to the use

  bottles having a cylindrical receptacle 210, disposed at the bottom of each of the bottles, the neck 107 having a plug 115 can penetrate into this receptacle 210 of a filled container, whose weight is supported by the strong annular portion 109 of

container just below.

  Although the upper parts 103 and the lower parts 104 and 204 can be formed by the conventional injection molding processes, it is possible to use other methods for producing them, and in particular that described in the French patent application No. 8214925 filed in name of the Applicant and which has several advantages over prior methods In this patent application, it is taught that a sheet which can comprise one or more layers of polymers at a temperature above that of orientation while applying a pressure is heated. of air on this sheet, which causes the sheet to penetrate down into a pre-forming mold for

  to form a bribery There is a certain cooling

  the preform and the temperature of the polymer falls back into the orientation range. At this point, a high air pressure is applied to the pre-form, which causes the sheet to go back to a final mold where it takes its place. final stretch configuration, which gives it a biaxial orientation that can not be achieved with injection molding processes. The use of this apparatus provides the upper and lower portions of the container of the present invention with

  sufficient orientation to obtain

  This barrier effect can also be improved by using a coextruded sheet to make upper and lower container parts having an intermediate layer of a polymer having barrier properties. In a normal operation, a beverage container is formed using the three parts depicted in FIGS. 2 through 5. Generally, the upper portion 105 formed by injection or thermoforming, and having a flange

  113 of downward directed welding, is

  The cylindrical portion 102, formed by extrusion or extrusion blow molding, is placed in the central mandrel

  of the rotational welding apparatus The lower part

  104 or 204 with flange 112 facing up

  is placed in the lower mandrel of the welding apparatus

  Preferably, the central mandrel is static while

  other chucks are rotated

  After placing the three container parts at their respective locations, the lower and upper chucks are rotated very rapidly relative to the central mandrel. Although the upper and lower chucks may rotate in the same direction, it is preferable that they rotate. in opposite directions to eliminate the twisting of one with respect to the other After reaching a predetermined rotational speed which is

  chosen according to the polymer used and the interplay of

  In the rotational welding flanges 112 and 113, the lower and upper portions are brought into contact with the central portion which is inserted into the U-shaped portion of the flange causing a temporary melting of the flange.

  plastic and allowing the welding of the different parts.

  This forms a tight and persistent hermetic seal in

112 and 113.

  The strapping resistance, obtained by the rotationally welded seals 112 and 113, contributes to increasing the overall strength of the container. Further, the shoulders of these flanges 112 and 113 extending radially outward define a protected area. to place a label on the finished container When a label is glued or printed on the central portion 102 of the container, the annular flanges 112 and 113 come into contact with each other.

  adjacent bottles and this avoids any rubbing

  the risk of erasure of the label, which is very

important for the trader.

  Among the advantages of the containers of this

  invention, one can cite in particular the faculty of se-

  easily accommodate for their transport, the faculty of the

  stack easily in displays, their good resistance

  this by strapping thanks to the joints welded by rotation, as well as the faculty to place decorative marks

that we erase with difficulty.

  Another particular advantage of the invention lies in the fact that it allows the manufacture of the various components of the container by various methods to obtain the best characteristics for each of the constituents. This is why the upper and lower parts are manufactured for obtain the best barrier and resistance properties, while the central part is manufactured by another method to improve the orientation properties and the barrier properties However, certain other characteristics can still be improved; thus, thanks to the rotational welding of the lower and upper parts on the central part, or increases the strength of the entire container, by a strapping, while providing protection to the decorative mark thanks to the created edges. providing an elongated central portion provides a maximum area for placing a decorative mark relating to food

  or to the drink contained in the container -

  In addition, the technique of the present invention

  makes it possible to manufacture containers with external surface

  To receive the printed and / or painted label, for example, when the central cylindrical portion 102 12 -

  is obtained by coextrusion, it can be arranged as the last

  re layer, that is to say the outer layer, a layer of a semi-porous opaque material, such as polystyrene, impact resistant or not, polyvinyl chloride or polypropylene, the surface then particularly suitable for printing with colors

alive by usual methods.

  It is possible to form the upper part 103 of the bottle in a transparent and resistant material such as polyethylene terephthalate (PET) which allows the customer to see the product in the bottle.

  we can choose an inexpensive material such as poly-

  styrene or shock polystyrene to make the lower part The choice of different materials depends

  obviously of their competence when welding by

  For example, the contact surfaces in the flanges of the upper 103 and lower 104 portions must be compatible with the inner and outer surfaces of the central portion 102, so as to be able to weld these surfaces by rotation. The compatibility of the various materials which may be used is good

known to those skilled in the art.

  The description given above concerns the

  production of bottles according to the technique of the present invention, but this technique can be used to make beverage or food cans, these boxes being used only once In this case, instead of a part upper with neck 103, the container has a circular upper, relatively flat, closing the box This upper part has a clip that can easily be lifted and pulled to open

  the box The upper part can be welded by rotation

  to the cylindrical central portion 102, instead of the upper portion 103 shown in the accompanying figures. Modifications and improvements can be made to the execution modes described above without

  depart from the scope of the present invention.

14 -

Claims (1)

Claims: 1 thermophilic container for the packaging of food products, food and beverages, having a low gas permeability at least on a part, characterized in that it comprises: an upper part formed from a first polymer, having a closure device above and at the base of a U-shaped flange arranged peripherally around this upper part; a lower portion formed from a second polymer having at the top a U-shaped flange peripherally disposed around this portion; a central portion comprising a cylindrical tubular member formed from a third polymer compatible with the first two; the lower and upper parts being hermetically welded to the central part by a rotational welding process. Thermoplastic container according to Claim 1, characterized in that the upper part comprises a threaded cylindrical neck, a filling ring extending all around the neck and having pins for rotational welding, a shoulder part and a part cylindrical extending downwardly and having at its base a flange for rotational welding. A catenary according to claim 1, characterized in that the upper portion comprises a relatively planar surface having an opening device, this portion being surrounded by a downwardly extending flange for rotational welding. Container according to claim 1, characterized in that the central tubular part comprises a multilayer cylinder having an inner layer and an outer layer of a strong polymer, and an intermediate layer having characteristics of low gas permeability. Container according to claim 1, characterized in that it also comprises a mark for placing the con- tainer in a predetermined position in a second package for presenting a well-defined part to the outside. Container according to claim 5, characterized in that the marker consists of a slot formed in the lowest part of the container. Container according to any one of the claims   1 to 6 characterized in that the lower portion comprises a device for stacking the containers and adapted to receive in an adjusted manner the top of a second container. 8 Method of manufacturing the container described in   any of claims 1 to 7, characterized   in that it consists in thermoforming an upper part with a threaded mouth and a cylindrical wall; thermoforming a lower part; extruding a central cylindrical portion on which is welded by rotation the upper part and the lower part.