FR2788254A1 - Making plastic screw cap with anti-tampering ring for bottle, comprises injection over-molding and precutting line of separation separately - Google Patents

Abstract

The blank is injected with no partially pre-cut line (7). In a later stage, this cutting line is established mechanically. An Independent claim is included for the cap made as described.

Description

The present invention relates to a method for manufacturing

  a plastic cap for a container such as a bottle.

  Plastic plugs are already known comprising a shell, provided with a bottom and a side skirt, as well as a tamper-evident ring extending said side skirt and connected by a circular precut line at the open end, opposite said bottom, of said

side skirt.

  Such plugs are particularly, although not exclusive,

  intended to be mounted on the neck of bottles made of plastic or glass and containing mineral or aerated waters,

  fruity drinks, sodas, wines, etc ...

  Said shell may include an internal thread intended to cooperate

  rer with an external thread provided on the neck of said bottles.

  Such known stoppers are produced by injection molding so that said precut line comes directly from molding,

  which is favorable with regard to the production rate.

  However, in some cases it may result, for the mold

  injection, complications such as this are prohibitively expensive.

tif.

  The object of the present invention is to remedy this drawback

  deny, by making it possible to simplify said mold and reduce the cost thereof.

  To this end, according to the invention, the method for producing by injection a plastic plug comprising a shell, provided with a bottom and a side skirt, as well as a tamper-evident ring extending

  said side skirt on the side opposite to said bottom and connected to the rest of said bou-

  chon by a pre-cut line, is remarkable in that: - we begin by making by injection a blank of said plug without any pre-cut line; and - in a subsequent step, an operation is carried out on said blank

  mechanical cutting to form said precut line.

  We can thus greatly simplify the structure of the mold and therefore

reduce the cost.

  The implementation of the process according to the present invention is particularly advantageous when, in order to be able to obtain a shell and a tamper-evident ring having mechanical characteristics optimized for their respective functions, said plug is made of at least two pieces of different plastics , one of which is molded into the other, as has already been proposed by the applicant in its patent FR-A-2 752 560 and in its French patent application No. 98 15030 filed on November 30, 1998. Indeed, molding such a plug into several pieces then requires a complex mold, which

  it is advantageous to be able to simplify.

  In such a case where said plug is made of at least two injected parts, one of which is overmolded to the other, it is advantageous for the simplicity of the mold, according to the invention, that said blank consists of said two injected parts. , with one overmolded to the other, and that, in said blank, that of said parts which carries said ring

  inviolability is achieved without any precut line.

  If, in accordance with the aforementioned French patent application, the process consists of

  - make, by injection molding, two pieces which correspond to

  pectively to said shell and to an annular crown carrying said tamper-evident ring, an annular support shoulder being formed in at least one of said parts; and - overmolding, by injection, one of said parts onto the other, so that they are secured to each other at said annular support shoulder, then it is advantageous, in accordance with the present invention , that, in said blank, said annular ring carrying said tamper-evident ring is produced without any precut line and that, in said subsequent step, said precut line is produced which defines, in said annular crown, two annular parts one of which forms said tamper-evident ring and the other of which connects said tamper-evident ring to said

  shell through said precut line and said shoulder-

annular support.

  As a variant, as described in the aforementioned French patent, the process can consist of

  - make, by injection molding, two pieces which correspond to

  pectively to said hull and to another hull, the bottom of which is suitable

  to completely cover the bottom of said shell, while the skirt of the

  said other shell is able to only partially cover the skirt of the

  said shell while leaving uncovered, on the side opposite to said bottoms, an annular crown of the skirt of said shell; and - overmolding by injection, one of said parts on the other, so as to

  that they are integral with one another in their overlapping position

really.

  In the latter case, in said blank, said annular crown

  the discovered area is carried out in accordance with the invention without any

  pre-cut gene and, in said subsequent step, said pre-cut line is produced which defines, in said exposed annular crown, an annular part forming said tamper-evident ring and connected to said shell

  through said precut line.

  Of course, the present invention also relates to a bou-

  chon of plastic material of the type described above, wherein said li-

  Pre-cutting is obtained by a mechanical cutting operation.

  The figures of the appended drawing will make it clear how the invention can be carried out. In these figures, identical references

  denote similar elements.

  Figures 1 and 2 illustrate, respectively, the roughing and the bou-

  chon an exemplary embodiment of the present invention.

  Figures 3 and 4 illustrate, respectively, the roughing and the bou-

  chon of an alternative embodiment of the present invention.

  The plastic cap blank 1, shown by the figure

  gure 1, comprises: - a part 2, injection molded, having the shape of a shell provided with a bottom 3 and a side skirt 4; - another part 5, also injection molded, intended to carry

  a tamper-evident ring and extending said lateral skirt 4, at the end

  open half of it, opposite the bottom 3.

  As can be seen in Figure 1, said parts 2 and 5, one of which is overmolded on the other, are secured to each other along

  an annular support shoulder 6.

  The plastic materials making up parts 2 and 5 can

  be different and / or have different colors.

  Along the shoulder 6, parts 2 and 5 can be returned

  joined together by chemical adhesion of their materials

  titutative or by mechanical adhesion. In the latter case, we can pre-

  see protrusions and / or hooking recesses on said shoulder 6 (not shown).

  The blank 1 can be produced in the manner described in the description

  French patent application no. 98 15030, with the exception that, upon leaving

  of the injection mold (not shown), said blank 1 is such that

  presented in Figure 1, that is to say that it does not have any pre-cut line to individualize the tamper-evident ring with respect to the rest

of said part 5.

  To obtain the plug 8 shown in Figure 2 from the blank 1 of Figure 1, is carried out in recovery, after ejection of this

  roughing out of said mold, an additional peri-cutting operation

  spherical, by slitting in the thickness, to form a line of prede-

  section 7 dividing said part 5 into an annular part 5A, secured to the shell 2 at the shoulder 6, and into an annular part 5B,

  constituting the tamper evident ring itself.

  Of course, the precut line 7, which is only shown

  schematically in Figure 2, can - as is usual - be form-

  fry braces, but it can also present any other

  appropriate configuration. In addition, it can be found at any desired level.

  re of part 5: it can in particular pass, if appropriate, through

one of the edges of the shoulder 6.

  In the alternative embodiment of FIGS. 3 and 4, the blank 10 of plastic plug comprises: - a first part 11, injection molded, having the shape of a shell provided with a bottom 12 and a skirt lateral 13; a second part 14, injection molded, also having the

  shape of a shell provided with a bottom 15 and a side skirt 16.

  Said parts 11 and 14 are secured to each other by overmolding, said second part 14 being fitted onto the first part 1 1 with its bottom 15 completely covering the bottom 12 and its side skirt 16 partially covering the side skirt 13, to leave, on the side of the open end of said first part 11, opposite the bottoms 12 and 15, an annular ring 17 thereof not covered by

said second part 14.

  Again, the materials of parts 1 1 and 14 can

  be different and / or have different colors.

  The blank 10 can be produced in the manner described in the French patent FR-A-2 752 560, except that, at the outlet of the ejection mold (not shown), said blank 10 is such that represented

  in FIG. 3, that is to say that it does not have any prede-

  cut to individualize a tamper-evident ring with respect to the rest of the

plug.

  Also, to obtain the plug 18 shown in Figure 4 from

  shot of the blank 10 of FIG. 3, a peripheral cutting operation is carried out, after ejection from said mold, by slitting through the thickness, to form a pre-cut line 19 separating from the rest of the part 11 , at least a portion 17A of the uncovered annular crown 17. Of course, it is this portion 17A which constitutes

  then the tamper evident ring itself.

  Here again, the precut line 19 may present any confi-

appropriate guration.

Claims (5)

  1. Method for producing a plastic plug by injection   tick (8, 18) comprising a shell (2, 11), provided with a bottom (3, 12) and a side skirt (4, 13), as well as a tamper-evident ring (5B, 17A) extending said side skirt on the side opposite to said bottom and connected to the rest of said plug by a pre-cut line (7, 19), characterized in that:   - We start by making by injection a blank (1, 10) of said bou-   chon (8, 18) without any precut line; and - in a subsequent step, a mechanical cutting operation is performed on said blank (1, 10) to form said pre-cut line (7, 19).   2. Method according to claim 1, according to which said plug is made of at least two injected parts (2, 5 - 11, 14), one of which is molded over to the other, characterized in that said blank (1, 10) consists of said two injected parts, with one overmolded to the other, and in that, in said blank, that of said parts (5, 11) which carries said tamper-evident ring   is performed without any precut line.   3. Method according to claim 2, according to which   - Two parts (2, 5) are produced by injection molding which correspond   tooth respectively to said shell and to an annular ring carrying said tamper-evident ring, an annular support shoulder (6) being formed in at least one of said parts; and - one of the parts is overmolded by injection onto the other, so that they are secured to one another at the level of said annular support shoulder (6), characterized in that, in said blank (1), said annular ring (5) carrying said tamper-evident ring is produced without any pre-cut line and in that, in said subsequent step, said pre-cut line (7) is produced which defines, in said ring annular (5),   two annular parts (5A, 5B), one of which (5B) forms said information ring   violability and the other (5A) connecting said tamper-evident ring (5B) to said shell (2) via said pre-cut line (7) and said annular support shoulder (6).   4. Method according to claim 2, according to which   - Two parts (11, 14) are produced by injection molding which correspond   lay respectively on said shell and on another shell, the bottom (15) of which is capable of completely covering the bottom (12) of said shell (11), while the skirt (16) of said other shell (14) is suitable only partially covering the skirt (13) of said shell (11) leaving   remain uncovered, on the side opposite said funds (12, 15), a   annular ring (17) of the skirt (13) of said shell (11); and - one of the said parts is overmolded by injection, so as to   that they are integral with one another in their overlapping position   clearly characterized in that, in said blank (10), said uncovered annular crown (17) is produced without any pre-cut line and, in   said subsequent step, said precut line (19) is made which defines   nit, in said uncovered annular crown (17), an annular part (17A) forming said tamper-evident ring and connected to said shell (11) by   through said precut line (19).   5. Plastic plug (8, 18) comprising a shell (2, 11), provided with a bottom (3, 12) and a side skirt (4, 13), as well as a tamper-evident ring (5B, 17A) extending said side skirt from the side   opposite to said bottom and connected to the rest of said plug by a line of pre-   cutout (7, 19), characterized in that said precut line (7, 19) is obtained by a mechanical cutting operation.