Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material, by deep-drawing operations performed on sheet material
  • B65D1/02—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents
  • B65D1/0223—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents characterised by shape
  • B65D1/0261—Bottom construction
  • B65D1/0284—Bottom construction having a discontinuous contact surface, e.g. discrete feet

Definitions

• the invention relates to the manufacture of containers, in particular bottles, obtained by blow molding or stretch blow molding from preforms or intermediate containers of thermoplastic material.
• a container generally comprises an open neck, through which the contents (usually a liquid or paste), a body, which gives the container its volume, and a bottom, which closes the body opposite the neck and forms a base for holding and maintaining the container when it rests on a surface.
• contents usually a liquid or paste
• body which gives the container its volume
• bottom which closes the body opposite the neck and forms a base for holding and maintaining the container when it rests on a surface.
• this temperature possibly being greater than the glass transition temperature of the constituent material of the container (for example, many PET containers, whose glass transition temperature is approximately 80 ° C, may be filled with liquids having a temperature approaching or exceeding 90 ° C);
• some carbonated liquids can be filled hot, or undergo pasteurization which increases both the temperature (and therefore the volume) of the liquid and the pressure of the dissolved gas heated.
• nitrogenous HR is introduced into the container, after filling but before capping, a drop of liquid nitrogen intended, after vaporization, to maintain under pressure the dead volume (located in the neck , above the liquid) and thus avoid excessive shrinkage of the container during cooling of the liquid.
• the bottom must be particularly resistant mechanically, and one generally uses a petaloid form: the bottom comprises feet projecting, in the form of petals, separated by convex wall portions, called valleys or valleys, which extend radially from the center of the bottom.
• the feet are intended to maintain the container placed on a surface; valleys are intended to absorb the forces (thermal, mechanical) exerted by the content, especially during filling.
• the petaloid bottoms significantly improve the mechanical performance of the containers, they nevertheless cause manufacturing difficulties, because of their tormented shape which can hinder the expansion of the material during blowing (called “blowing" the capacity of the container to be formed by blowing). Indeed, the material has a tendency to freeze as soon as it is in contact with the mold at the footprints of the valleys, which are reached first. The subsequent expansion of the material in the footprints is then slowed down, and in the end we notice undesired variations in material thickness between the valleys and the feet. In some cases, there is overtreatment in the feet, which results in whitening of the material.
• An object of the invention is therefore to provide a new container whose bottom satisfactorily satisfies the conflicting constraints of rigidity and blowing.
• the invention proposes a container made of thermoplastic material obtained by blow molding or stretch blow molding from a blank, this container comprising a petaloid bottom provided with projecting feet, separated by recessed valleys which extend radially to from a central area of the bottom, each foot having two flanks each bordering a valley laterally, each foot being provided on each of its flanks with a cheek which protrudes laterally on the side of the valley.
• the cheeks help to verticalize the feet on either side of the valleys, which increases the rigidity of the bottom and makes it more mechanically resistant to thermal and / or mechanical stresses exerted by the contents, for example on the occasion of a hot filling, or when the content is a carbonated liquid.
• each cheek is substantially flat and forms a small angle with a median radial plane of the valley. More specifically, the cheek forms, for example with this median plane an angle between 10 ° and 20 °, and preferably about 15 °.
• Each flank is also inclined with respect to a median plane of the valley, the cheek forming with the flank an angle greater than 0 ° and less than 20 °.
• Each flank and projecting cheek thereof preferably have a common edge extending at the junction with the valley.
• the cheek for example, has a substantially triangular outline; on at least one edge, it is connected to the side by a double curvature leave.
• the bottom comprises, in the valleys, stiffeners in the form of outwardly projecting radial ribs, which reinforce the bottom and which extend for example from a neighborhood of a zone. center of the bottom until near the periphery of it.
• Figure 1 is a perspective view from below of a container according to the invention.
• Figure 2 is an enlarged view of the bottom of the container of Figure 1;
• Figure 3 is a bottom plan view of the bottom of Figure 2;
• Figures 4, 5 and 6 are sectional views of the bottom, respectively along the lines IV-IV, V-V and VI-VI of Figure 3; for clarity the background lines inside the background have been erased.
• Figure 1 is shown, in perspective, the lower part of a container 1 - in this case a bottle - obtained by blow molding or stretch blow molding from a thermoplastic preform, for example polyethylene terephthalate (PET) .
• a thermoplastic preform for example polyethylene terephthalate (PET) .
• the container 1 extends along a main axis X and comprises a lateral wall 2 called body, and a bottom 3 which closes the body 2 at a lower end thereof.
• the bottom 3 is petaloid, and comprises a series of feet 4 formed by outward protrusions protruding outwardly of the container 1, and which extend from a central zone 3 of the pellet-shaped bottom 3, where the material has remained substantially amorphous, towards the periphery of the bottom 3.
• the most protruding part or top 6 of the feet 4 which is at the same time the widest and forms a seat for the container 1, by which it can rest on a flat surface (for example a table), is in the vicinity of the periphery of the bottom 3.
• Each foot 4 has an end face 7 which extends gently and sloping from the top 6 to the central zone 5 of the bottom 3, so that the foot 4 has in radial section a substantially triangular profile (Figure 4).
• the feet 4 are separated by valleys 8 formed by narrow strips of material which extend radially in a star shape from the central zone 5 of the bottom 3 to the periphery of this one.
• the valleys 8 are convex outwards in radial section (see left in FIG. 4) and slightly concave outwards in cross-section (that is to say along a plane perpendicular to the radial direction, cf. Figure 5).
• FIGS. 1 to 3 show that the feet 4 are equal in number to the valleys 8.
• the bottom 3 comprises five feet 4 and five valleys 8, regularly alternated and distributed in a star. This number is a good compromise; it could however be less (but greater than or equal to three), or greater (but preferably less than or equal to seven).
• Each foot 4 has two substantially planar flanks 9 which each border a valley 8 laterally. More precisely, the flanks 9 of the same foot 4 are turned back to back, in opposition to each other, while a same valley 8 is bordered laterally by two flanks 9 opposite two adjacent feet 4.
• Each flank 9 follows the general outline of the foot 4 (in this case triangular) and extends from a curvilinear upper edge 10, along which the flank 9 connects to the valley 8 by a fillet 11 of substantially circular section (FIG. 5), to a vertex 12 located in the vicinity of the top 6 of the foot 4.
• the side 9 is delimited by two edges substantially at right angles, namely an outer edge 13, substantially parallel to the body 2 of the container 1 and which extends from an outer end 14 of the upper edge 10 to the top 12, and an inner edge 15, substantially parallel to the end face 7 of the foot 4 and extending from an inner end 16 of the upper edge to at the top 12.
• the sidewalls 9 are not vertical (because the bottom 3 would be difficult or impossible to blow), but inclined opening from the valley 8 to the top 12, so that each foot 4 has, in section in a transverse plane (see Figure 6), a V-shaped profile with rounded or, in other words, U-shaped with flared branches.
• Each flank 9 is inclined with respect to a radial plane P intersecting the valley 8 along a center line in two identical parts, and has relatively large angular aperture A between 20 ° and 30 ° with respect to this plane P. .
• this angular aperture A is approximately 25 °.
• Each flank 9 connects to the end face 7 of the foot 4 by fillet-shaped connections 17 having a large radius.
• each leg 4 is provided on each of its flanks 9, a cheek 18 which projects laterally on the side of the valley 8.
• the cheek 18 is substantially flat and has a contour (in this case triangular) similar to that of the sidewall 9 which it projects.
• the cheek 18 extends from a curvilinear upper edge, coinciding with the upper edge of the flank, to a vertex 19 situated in the vicinity of the vertex 12 of the sidewall 9. It can be seen in FIGS. 4 and 6 that the outline of FIG. the flange 18 is substantially homothetic to that of the flank 9, the surface of the flange 18 being smaller than that of the flank 9.
• the flange 18 is delimited by two edges substantially at right angles, namely an outer edge 20 and an inner edge 21 , which meet at the apex 19 and are substantially parallel respectively to the outer edge 13 and to the inner edge of the sidewall 9 being shifted therefrom towards the inside of the cheek 18.
• the cheek 18 does not extend in a plane parallel to the sidewall 9 from which it projects, but inclined with respect thereto. More specifically, the cheek 18 has, relative to the radial plane P, a small angular aperture B, less than 20 ° and preferably between 10 ° and 20 °. In the example illustrated in FIG. 5, the angular aperture B is approximately 15 °. In other words, assuming, as described above, the sidewall 9 is inclined at an angle of between 20 ° and 30 ° with respect to the plane P, the flange 18 is inclined, relative to on the flank 9 itself, with an angle AB greater than 0 ° but less than 20 °.
• the outer edge 20 and the inner edge 21 of the cheek 18 are connected to the corresponding edges 13, 15 of the sidewall 9 by fillets 22 with an inverted double curvature (or double radius), which has been materialized in the figures (so clearly visible in FIGS. 2 and 6) by S-profile lines.
• the steep slope of the flanks 9 allows the material, during blowing, to easily reach the bottom of the footprint 4 (corresponding to the vertices 6), to the benefit of the bottom blowing 3.
• the presence of the cheeks 18 promotes the blowing of the bottom 3 because the latter, by their particular shape, dig the cavity of the mold at the flanks 9 and therefore have the effect of delaying the contact of the material with the mold at the cheeks 18 when blowing the container. Consequently, the other parts of the bottom 3 (in particular the junction between the valleys 8 and the flanks 9) can develop more easily than on the known petaloid bottoms.
• the presence of the cheeks 18 makes it possible to prevent this good blowing ability from being obtained to the detriment of the rigidity of the bottom 3.
• the cheeks 18 have the function of vertically locating the feet 4 on either side of the cheeks. valleys 8 and therefore oppose the collapse of the bottom 3 under the effect of mechanical and / or thermal stresses exerted on the container 1 (for example during a hot filling or in the case of a carbonated liquid ).
• the double inverted double curvature fillets 22 contribute dynamically to this function. Indeed, under the effect of mechanical and / or thermal stresses, the leaves 22 tend to flute and expand by flattening, which causes a deployment (in other words a verticalization) of the cheek 18 towards the valley 8.
• each stiffener 23 extends along a median line of a valley, from the central zone (or nearby) to the periphery (or near) of the bottom 3.
• Each stiffener 23 has in plan ( Figure 3) a spindle shape that widens from the central zone 5 to the periphery; in radial section ( Figure 4), the stiffener follows the convex arcuate contour of the valley 8; in cross section ( Figures 5 and 6), the stiffener has a curved profile towards the outside of the container.
• the stiffeners 23 serve to stiffen the bottom 3. Under the effect of mechanical and / or thermal stresses exerted on the container (for example during a hot filling or in the case of a carbonated liquid), the stiffeners 23 tend to flow dilating and flattening, which causes an enlargement of the valleys 8 and, consequently, a verticalization of the feet 4 which opposes, as indicated above, the subsidence of the bottom 3 .
• the stiffeners 23 occupy transversely the entire width of the valleys 8. It is sufficient that the stiffeners 23 occupy only part of the width of the valleys 8. Thus, according to a preferred embodiment shown in the figures and more particularly visible in FIG. 3, the stiffeners 23 extend transversely about a third of the width of the valleys 8.
• valleys 8 are not necessarily all provided with stiffeners 23: it could be expected on only part of them (for example one in two when the bottom 3 comprises an even number of valleys 8).

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• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Mechanical Engineering (AREA)
• Containers Having Bodies Formed In One Piece (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2010
  • 2010-04-21 FR FR1001704A patent/FR2959214B1/fr not_active Expired - Fee Related
• 2011
  • 2011-04-15 US US13/581,667 patent/US9428296B2/en active Active
  • 2011-04-15 EP EP11730382.6A patent/EP2560887B1/de active Active
  • 2011-04-15 CN CN201180014864.3A patent/CN102803081B/zh active Active
  • 2011-04-15 WO PCT/FR2011/050872 patent/WO2011131893A1/fr active Application Filing
  • 2011-04-15 JP JP2013505521A patent/JP2013525212A/ja not_active Ceased

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