EP0835212A1

EP0835212A1 - Cover ring with sealing coating for a press-in lid

Info

Publication number: EP0835212A1
Application number: EP97922869A
Authority: EP
Inventors: Norbert Bellingroehr
Original assignee: Schmalback Lubeca AG
Current assignee: Trivium Packaging Group Netherlands BV
Priority date: 1996-04-25
Filing date: 1997-04-24
Publication date: 1998-04-15
Anticipated expiration: 2017-04-24
Also published as: ES2245463T3; WO1997041043A1; DE19616528B4; DE59712379D1; EP0835212B1; ATE300480T1; DE19616528B8; DE19616528A1

Abstract

The invention relates to press-in lids for forming a snug sealing fit therebetween, the internal wall (20b) and a cover ring (30, 30a, 30b) which has two vertical wall sections pointing upwards. The object of the invention is to act against quick-leak filling fluids, paints or glazes by sealing means but that it should be possible to re-close the press-in lid so that the seal provided is just as efficient. It should also be possible to print on or coat the cover surface (20a) of the press-in lid (20, 20a, 20b), it being possible to dry or bake said print or coating at a high temperature to provide externally information identifying the container contents sealed by the lid. It is also proposed to provide a press-in lid which does not have a coating in the edge region thereof or only has a internal lacquer coating (22b, 22). A thin layer (32, 32a) protecting against leakage is only applied to sides of the cover ring on its vertical inner wall (30b). Said layer protecting against leakage consists, in particular, of polypropylene. The snug sealing fit is achieved between the vertical wall (20b) of the press-in lid and the thin layer protecting against leakage on the cover ring.

Description

COVER RING WITH SEALING COATING FOR A PRESSURE COVER

The technical field of the invention is the container for holding solvent-containing or low-solvent and thus creep-friendly filling fluids, 5 for example wood preservatives, and a related cover ring for the reclosable holding of a push-in cover (in short: ED cover).

Increasingly, low-solvent and low-creeping goods are filled into round cans (round containers) and resealable with an ED lid, which is pressed into a lid ring. The lid ring is connected to the can body with a seam. The fold seam is usually a double fold.

Through use, a state of the art has become accessible to the general public, in which an ED cover is provided with an internal lacquer coating and, in addition to the lacquer, a sealant is also applied in the sealing area between the cover ring and press-in cover (spot coating or ring rubber coating). Alternatively, it has also been proposed to replace the inside coating of the cover with a layer of polypropylene (PP). However, polypropylene is not in a position higher ₂ o withstand temperatures so that the lid panel of the lid as advertising space, a color code for the color of the paint in the container or wood preservative may not be used by the application. Also, the cover mirror, which is large per se, cannot be used for other technical and advertising information. Printing on the lid mirror or applying 25 colored varnish on it would require drying or a baking process which results in temperatures of more than 150 ° which damage or burn the polypropylene on the underside of the lid.

The technical problem facing the invention is accordingly a better sealing of the fit of the press-in lid with creep-friendly filling fluids and the creation of the possibility of visually designing the lid mirror without the fit being affected in its tightness.

This is accomplished when the press-in lid snug fit is-designed such that a ₃₅ Kriechschutzschicht is attached to the lid ring and the plug lid itself either none or only one inwardly facing lacquer coating carries at least in this area (claim 1). This is also achieved by a cover ring coated on the inside or on the underside for connection to a container Cover ring attached layer is a creep protection layer, in particular made of polypropylene (claim 8). Finally, a method is proposed for tightly closing crawling goods in a resealable container, the lid mirror remaining printable or coatable even in the outward-facing lid area (claim 12).

The press-in cover is therefore not coated with a PP material, but the cover ring, at least in the sealing area, but preferably on its entire inner surface, which on the one hand forms the fold seam for the fold and on the other hand fits inwards on the fuselage, which is designed from a vertical wall pretends.

The cover and cover ring are made of sheet metal.

It has been found that with this configuration a required contact pressure can be achieved in the sealing area of the snug fit, the cover can be painted or unpainted and an additional ring rubber coating, which is still required in the prior art, can be omitted as an additional creep protection seal. The push-in lid can still be used as an advertising space. It can be printed or painted at any time, since it is no longer provided with a polypropylene with a limited temperature.

Surprisingly, the cover ring coated with the thin creep protection layer, in particular polypropylene, provides the basis for eliminating the usual compound in the rebate area (the usual sealant), since the inside of the

Cover ring existing polypropylene layer for sealing between the cover ring and can body is sufficient. The extension of the creep protection layer in the sealing area thus also forms the new "compound" over one surface of the entire cover ring, which fulfills the sealing task in the fold.

The invention achieves required contact pressures of> 0.5 bar. The highest level of tightness is achieved for filling fluids which are easy to creep or penetrate, spot lacquers of the prior art can be dispensed with, as can ring rubbers. In addition, there is the possibility of providing the inside of the cover, which may have to be provided, and which can withstand higher temperatures, without forming PVC, which takes environmental aspects into account. Extensive tests have shown that with the above-mentioned fillings with standing, lying or upside down cans and at room temperature as well as in the incubator, a 50 μm layer of polypropylene in the snug fit area offers absolute filling safety.

However, the invention can not only be used for filling fluids which are easy to creep, it also has an application area which extends to dry and moisture-sensitive filling materials, that is to say the prevention of the ingress of moisture through the fit from the outside into the dry filling material. One such area of application is in the filling of dry milk, which must be closed securely after opening and without the risk of becoming damp.

The invention (s) are explained and supplemented below using several exemplary embodiments.

FIG. 1 is a section of the sealing area D of a press-in cover 20. Shown is a container body 10, a cover ring 30 arranged thereon via a fold area 40 and the press-in cover 20 with a cover mirror 20a fitted on a vertical wall 30b of the cover ring.

FIG. 2 is a detail from FIG. 1, which is concentrated on the sealing area D. Coatings 32a, 22 act in the sealing area D on the vertical

Wall 30b of the lid ring and the vertical wall 20b of the push-in lid together.

The reclosable container shown in the detail in FIG. 1 has an essentially round container body 10 which forms a double fold 40 with a cover ring 30 over an edge region 10a. The cover ring is contoured and carries a circumferential bead between its two vertical wall sections 30a, 30b, the latter two of which lie directly against the inner wall of the container body 10 and the other points essentially horizontally inwards.

A fit D for a press-in cover 20 is formed on the inward-facing inner surface of the vertical cover ring wall 30b. Starting from a cover mirror 20a, it has a vertical circumferential wall section 20b which interacts with the mentioned inner wall of the cover ring 30b.

The inner wall section 20b of the cover 20 runs between a support flange 20c and the cover mirror 20a, wherein the support flange 20c and cover mirror 20a run essentially parallel and perpendicular to the vertical wall 20b of the cover 20.

The vertical wall 20b of the push-in cover 20 is provided with a flat but wide indentation which is approximately matched in its extent to the vertical wall 30b of the cover ring. In this area, especially as can be seen from FIG. 2, the sealing fit D is formed, which does not allow the goods that are eager to crawl to pass. In addition, a seal between the support flange 20c and the outer region of an upwardly rolled roller 31 of the vertical cover ring wall 30b is possible, either purely mechanically or also caused by the extension of the thin creep protection layer 32a beyond the sealing region D, in

5 the curling 31.

The circumferential flat bead 20b in the vertical wall is transferred into the support flange 20c and the cover mirror 20a via two different depth sections. The two step sections are circumferential, as is the flat bead 20b; as

10 shallow depth system groove.

The thin anti-creep layer 32a shown specifically in FIG. 2 only in the sealing area D is made of polypropylene in the example. It is firm and with a thickness of the order of 50 μm attached to the vertical wall 30b of the cover ring 30 u. In the case of a prefabricated cover ring which is punched out of a metal sheet which is completely covered with a polypropylene layer, it can extend over the entire cover ring on one side, the polypropylene layer then being different on a different shape according to FIG Place inwards (in sealing area D), upwards (in rolling area 31), downwards

₂ ü (in the lid ring area between seal seat D and fold 40) and inwards and upwards (in the fold area 40). In all of these areas of the cover ring, the one-sided coating of the cover ring is sufficient to be able to perform a sealing function in each case.

25 The polypropylene layer takes on a sealing function in the area of the fold 40, instead of a sealing agent usually provided there, which can be omitted. The thin anti-creep layer is sufficient to perform 40 sealing functions in the rebate area as well.

30 In the area of the sealing seat according to FIG. 2, together with the

Push-in lid takes over the sealing task through the polypropylene layer. The lid has no additional sealing layer, it can only be provided with a coating that can withstand higher temperatures if the lid in its lid mirror 20a e.g. is provided with a varnish that is baked or at

35 high temperature is dried. This layer can be a color layer to identify the color of the container contents, it can also take on other information tasks. The thickness of the creep protection layer 32, which is designated 32a in the sealing area D, can vary, but remains small and is selected in the range between 30 and 200 μm, depending on the sheet thickness and the creep-resistant filling material, such as lacquers, paint or glaze.

If the lacquer coating, which was previously mentioned for the cover 20, is applied, care should be taken to ensure that the lacquer coating is essentially PVC-free; PVC sealing layers in the sealing area can be omitted anyway.

Claims

Expectations:

1. Push-fit fit for a reclosable container (10, 20) for filling with creep-friendly filling fluid, such as paint, paint, glaze or wood preservation primer, in which

(a) the sealing area (D; 20b, 30b) of the cover seat on the side (30b) of a cover ring (30) folded over at the upper edge (10a) of the container body (10) with a thin creep protection layer (32, 32a), in particular made of polypropylene (PP) is provided; (b) the sealing area (D; 20b, 30b) of the cover seat on the part of the

Push-in cover (20; 20a, 20b) has no coating or only a lacquer coating (22b, 22).

2. A snug fit according to claim 1, wherein the lacquer coating covers essentially the entire underside (22) of the press-in cover (20; 20a, 20b).

3. Fit according to one of the preceding claims, in which the creep protection layer (32, 32a) extends over the substantially entire underside of the cover ring (30), in particular up to the fold region (40) towards the container body (10).

4. Fit according to one of the claims mentioned, in which the creep protection layer (32, 32a) has a thickness between 30 μm (micrometer) and 200 μm, in particular 50 μm.

5. Fitting fit according to one of the mentioned claims, in which the lacquer coating (22, 22b) of the cover (20) is essentially, in particular completely PVC-free.

6. Fit according to one of the claims mentioned, in which no lacquer layer is provided on the underside of the cover ring (30) and in the sealing area (D) no additional ring of sealant layer (spot coating) is provided.

7. A fit according to one of the claims mentioned, in which no additional sealant (compound) is provided in the fold (40). 8. Coated cover ring (30; 30a, 30b) with a substantially vertically running radially inner wall section (30b) for a sealing fit on a container (10, 20) according to one of the claims mentioned, in which at least the (horizontal) underside and a sealing area (D) on the inside of the vertical wall section (30b) is covered with a thin creep protection layer (32, 32a).

9. Lid ring according to claim 8, in which

(a) the creep protection layer is considerably thinner than the sheet thickness of the cover ring (30), in particular in the range between 50 μm and 100 μm (micrometer); and or

(b) a vertical wall section (20b) of a cover (20) for the cover ring (30) is provided with a circumferential sealing bead (20b) which has only a shallow depth and a flat beading base in order to match the width of the beading base (20b) to correspond approximately to the axial height of the inner wall (30b) of the cover ring.

10. Lid ring according to claim 8 or 9, wherein the creep protection layer (32,32a) is essentially made of polypropylene (PP).

11. Lid ring according to one of claims 8 to 10, in which also in the area of

Cover ring (30), which forms the fold (40), one

12. A method for securely closing creeping contents in smaller containers, which are reclosable, in which method

(a) a cover ring (30) is covered with a creep protection layer (32, 32a) at least in the sealing area (D) or one with the creep protection layer

5 pre-coated sheet material is used to punch out a cover ring;

(b) the cover ring according to (a) is crimped (40) onto a container body (10);

(c) a press-in cover (20) is punched and shaped and its io cover mirror (20a) is coated on the outside, in particular printed or lacquered, and is subjected to a heat treatment above 100 ° C., its outer coating being dried, in particular baked.

13. The method according to claim 12, in which the creep protection layer is or is applied as a thin layer, in particular with a layer thickness below 200 μm.

14. The method according to one of the above method claims, in which the entire

20 The underside of the cover ring (30) is or will be covered with the thin creep protection layer (32, 32a).

15. The method according to one of the above method claims, in which the creep protection layer (32, 32a) is essentially made of polypropylene.

25

16. The method according to one of the above method claims, in which the shaping of the push-in cover (20; 20a, 20b) is the shaping of a circumferential, outwardly directed system groove in a core wall (20b) of the cover (20), directed and matched to the axial height of the Sealing area (D) of the cover ring comprises.

30th CHANGED REQUIREMENTS

[Received at the International Bureau on September 25, 1997 (September 25, 1997), original claim 11 amended; a l le further claims unchanged (3 pages)]

(a) the sealing area (D; 20b, 30b) of the cover seat on the side (30b) of a cover ring (30) folded over at the upper edge (10a) of the container body (10) with a thin creep protection layer (32, 32a), in particular made of polypropylene (PP) is provided;

(b) the sealing area (D; 20b, 30b) of the cover seat on the side of the press-in cover (20; 20a, 20b) has no coating or only a lacquer coating (22b, 22).

3. A snug fit according to one of the preceding claims, in which the creep protection layer (32, 32a) extends over the substantially entire underside of the Deckelriπgs (30), in particular up to the fold area (40) to the container body (10).

7. A fit according to one of the claims mentioned, in which no additional sealant (compound) is provided in the fold (40).

8. Coated cover ring (30; 30a, 30b) with a substantially vertically extending radially inner wall section (30b) for a sealing fit on a container (10, 20) according to one of the mentioned claims, in which at least the (horizontal) underside and a sealing area (D) on the inside of the vertical wall section (30b) is covered with a thin creep protection layer (32, 32a).

9. Lid ring according to claim 8, in which

11. Cover ring according to one of claims 8 to 10, in which also in the region of the cover ring (30) which forms the fold (40), a creep protection layer (32) made of polypropylene is applied to the sheet metal side of the cover ring pointing inwards in the fold .

(a) a cover ring (30) is covered with a creep protection layer (32, 32a) at least in the sealing area (D) or a sheet material pre-coated with the creep protection layer is used to punch out a cover ring;

(b) the cover ring according to (a) is crimped (40) onto a container body (10);

(c) a press-in cover (20) is punched and shaped and its cover mirror (20a) is coated on the outside, in particular printed or lacquered, and is subjected to a heat treatment above 100 ° C., its outer coating being dried, in particular baked.

13. The method according to claim 12, wherein the anti-creep layer is or is applied as a thin layer, in particular with a layer thickness below 200 μm.

14. The method according to one of the above method claims, in which the entire underside of the cover ring (30) is or becomes covered with the thin creep protection layer (32, 32a).