EP2024240B1 - Base for a packaging made from plastic - Google Patents

Abstract

The piece has an internal convex surface, an external concave surface and a peripheral soldering zone (4) which is fixed on an internal surface (5) of a lateral wall (2) of a package. The convex and concave surfaces comprise zones centered around an axis (3) and contacting with a tool utilized for fixing the piece to the lateral wall. A profile of a package`s base (1) is defined by a circular arc of radius greater than or equal to half of semi-diameter of the piece.

Description

Field of the invention

The invention is in the field of packaging comprising a side wall consisting of a laminated film and a bottom welded to said wall.

State of the art

There is packaging corresponding to the definition above.

By way of example, mention may be made of patent documents AT-B-293,944 , EP 1 362 797 and FR-A-1,593,395 .

In this type of object, the bottom must provide stability, strength and tightness of the package. In particular, it must offer good resistance to deformation when an effort is applied to its center.

General presentation of the invention

The problem that the present invention proposes to solve lies in improvements over the state of the art.

In the invention, the solution of the aforementioned problem consists of a plastic part as described in appended claim 1.

Particularly advantageous embodiments of the invention are described in the dependent claims.

• poids minimum
• volume perdu minimum
• pas ou peu de nervures
• faible déformation du fond sous 40N
• pas de rotation de la zone de soudure
• bonne tenue pression sous 3 bars .

Advantageously, the part according to the invention can have the following characteristics:

• minimum weight
• minimum lost volume
• no or few ribs
• low deformation of the bottom under 40N
• no rotation of the weld area
• good holding pressure under 3 bars.

Detailed exposition of the invention

• La figure 1 représente une partie d'emballage comprenant un fond selon l'invention
• La figure 2 illustre la face interne d'un fond selon l'invention
• La figure 3 illustre la face externe du fond de la figure 2.

The invention is described in more detail below by means of examples illustrated by the following figures:

• The figure 1 represents a packaging part comprising a bottom according to the invention
• The figure 2 illustrates the internal face of a bottom according to the invention
• The figure 3 illustrates the outer face of the bottom of the figure 2 .

List of numerical references used in the figures

1. 1) Background
2. 2) Side wall
3. 3) Axis
4. 4) Welding area
5. 5) Internal surface of the side wall
6. 6) Convex inner face
7. 7) Concave external face
8. 8) Cavity
9. 9) Bossage
10. 10) Inner face contact area
11. 11) Outside contact area
12. 12) Center of the room

The bottom 1 illustrated in the figures is circular and has an outside diameter of between 35 and 63.5 mm. Its height is generally less than 35mm.

Of course, the bottom may have a different shape, eg oval or polygonal.

The bottom 1 preferably has a profile whose curve is a circle of radius r between one and two times the outer radius of the bottom 1. Its height is generally between 10 and 25% of its diameter. This profile is truncated in its center and continued a flat area of diameter equal to 30 to 50% of its outer diameter so as to facilitate its handling from the inside. The bosses 9, if necessary, preferably represent 30 to 60% of its projected area. The outer gripping zone may be a central disk or a center ring of width approximately 0.5 mm and an inner radius of approximately 85 to 90% of the outer diameter of the bottom. The bottom thus defined has a characteristic thickness of the order of 0.8 to 1.5 mm according to its outside diameter and its height. The bosses 9 may be thinner, of the order of 20%. The angle α of welding is generally between 45 and 75 °

A bottom of outer diameter 49.1 mm, height 7.5 mm, weld angle α = 60 °, circular curvature radius r = 30 mm truncated by a central flat area of diameter 20 mm, a crown on its lower part of inner diameter 43.5 mm for a width of 0.5 mm and with bosses 9 on about 50% of its surface meets all the technical characteristics defined above. This bottom 1 has a general thickness of 1 mm and 0.8 mm in the bosses 9.

The bottom also has a flat area at its lower end to ensure the stability of the package. In the previous case, this stability is ensured by the crown which serves for the external gripping of the bottom 1.

The bottom 1 described above is generally manufactured by injection. It can also be produced by compression molding or thermoforming.

It is made of thermoplastic material, for example PE, PP or PET. It can also be multilayered so as to contribute to the overall barrier of the package.

It is attached to the film that makes up the body of the packaging by hot air and / or induction welding, depending on whether the film used for the body contains aluminum or not.

The resulting packaging has excellent stability. It has good static mechanical properties (held under a central load of 40N, pressure resistance) and shock (drop test). It also has the properties required for liquid or air sanitization.

Claims (15)

1. Rigid or semirigid plastic part designed to form the bottom (1) of a package whose side wall (2) consists of a laminated film, said part having a central axis (3) and comprising:

   a. a peripheral welding zone (4) designed to contact and be welded to the inside surface (5) of said side wall (2);

   b. a convex inside face (6) and a concave outside face (7);
   the inside face (6) and the outside face (7) each comprising a zone (10, 11) whose centre is on said axis (3) and which is designed to contact a tool used to attach the part to said side wall (2);
   characterized in that it also comprises:

   a profile at least partially defined by a curve, that is truncated at its centre and followed by a flat zone whose diameter is equal to 30 to 50% of its outside diameter to make it easy to handle from the inside.
2. Part according to the preceding claim whose profile is at least partially defined by an arc of a circle of radius (r) greater than or equal to half the semidiameter of the part.
3. Part according to Claim 1 or 2 comprising humps (9) on its outside face (7).
4. Part according to the preceding claim in which the humps (9) are distributed around an annular zone whose centre is on said axis (3).
5. Part according to the preceding claim comprising an odd number of humps (9).
6. Part according to the preceding claim in which the number of humps is 3, 5 or 7.
7. Part according to any one of Claims 3 to 6 in which the ratio of the area occupied by the humps (9) to the total area of the part is between 0 and 70%.
8. Part according to any one of the preceding claims possessing a stiffness that allows an at least partial transformation of the concave face into a convex face and vice versa in the direction of the force and/or pressure exerted on one of the faces.
9. Part according to any one of the preceding claims in which said welding zone (4) comprises a portion that forms an angle of from 5° to 150° with said axis (3).
10. Part according to any one of the preceding claims in which said zone of external contact is a planar annulus with a width of at least 0.3 mm.
11. Part according to any one of the preceding claims in which the inside face, in its portion which is intended to contact a product, has a curvature which is such that its derivative at any point is continuous.
12. Part according to any one of the preceding claims whose perimeter is circular.
13. Part according to any one of Claims 1 to 11 whose perimeter is oval.
14. Part according to any one of Claims 1 to 11 whose perimeter is polygonal.
15. Package comprising a side wall consisting of a wrapped laminated film and a bottom consisting of a part according to any one of the preceding claims.

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