FR2503626A1 - METHOD AND APPARATUS FOR FASTENING A SEALING PIECE ON THE DISCHARGE HOLE OF A CLOSURE CAPSULE OR PLASTIC CONTAINER - Google Patents

Abstract

THE PRESENT INVENTION IS TO BE IMPLEMENTED IN CONJUNCTION WITH THE MOLDING BY INJECTION OF A CLOSING CAPSULE OR OF A CONTAINER. A CONTINUOUS SEALING STRIP 13 ADVANCED INTERMITTENTLY, THEN A MOBILE BACK-AND-BACK MOLDING BAND 15, WITH A SHARP EDGE AT ITS TIP, ADVANCES THROUGH STRIP 13 UNTIL A POSITION IN WHICH A FOOTPRINT 20 OF THE MOLD , DEFINING THE SPILL HOLE OF THE CAPSULE 21 OR OF THE CONTAINER 19, IS CLOSED BY A SEALING PIECE DETACHED BY PUNCHING OF THE TAPE 13, AND A THERMOPLASTIC RESIN IS THEN INJECTED IN THE ENCLOSURE. THUS, WE AVOID THE NEED TO PRECISELY POSITION THE CAPSULE OR CONTAINER TO APPLY THE SEALING PART AFTER MOLDING.

Description

The present invention relates to a method and apparatus

  for attaching a sealing part to the hole

  pouring a closure cap or a container

plastic material.

  It has been proposed to fix a sealing part on the

  spill hole of a closure cap or recipe

  to attest that the contents of the container have remained intact from the filling of the container until handed over to the user. The fixing of the sealing part is carried out while keeping the container or the capsule of

  plastic closure, placing the seal

  on the spill hole of the container or cap.

  sule or by welding this piece by heating or ultrasound.

  However, this sealing technique requires the setting

  container or capsule in a pre-positioned position.

  determined, which makes the automatic sealing machine complicated and expensive. It also makes it necessary to precisely adjust the operating conditions such as duration, temperature and sealing pressure to prevent the seal being too weak or too strong. Especially when the room

  must be slightly attached to the hole

  container or capsule to be detached, these operating conditions become critical and must be

  precisely the various sealing parameters.

  Accordingly, the present invention aims to provide:

  - a method and apparatus for fixing very easily

  capping a sealing piece on the spill hole

  of a capsule or plastic container without

  see the use of a special device for maintaining and

  after molding of the capsule or container;

  - a method and an apparatus for fixing

  detachable piece of seal on the hole for

  a capsule or plastic container without having to adjust the conditions

  as required by the conventional sealing technique.

rante.

  According to the present method, to fix a piece of seal

  on the discharge hole of a capsule or container.

  plastic, intermittently

  a continuous sealing strip on its inner face

  a layer of thermoplastic resin. A movable, reciprocating molding member having a sharp edge at its tip advances through the sealing strip by puncturing it to a position where the portion of the impression of the injection mold defining the pouring hole of the capsule or container is closed by the

  seal detached by punching the sealing strip.

  Then, a thermoplastic resin is injected into the cavity.

  te, so that the sealing piece is attached to the thermoplastic resin injected constituting the capsule or the

  container to close the spill hole.

  Preferably, the injected thermoplastic resin has chemical affinity for that of the sealing part, so that the thermoplastic resin of the sealing part partially melts and solidifies, solidifying, with the pouring hole of the capsule or molded container,

to close this hole.

  According to the present invention, the apparatus for attaching a sealing member to the pouring hole of a plastic capsule or container comprises an injection molding device having a mold imprint of the capsule or of the container. This footprint is

  open to a terminal section defining the

  capsule or container. A means is provided for

  the intermittent advance of a sealing strip

  continue in a direction normal to the axis of the hole

  ment. A movable, reciprocating molding member having a sharp edge at its tip extends along the axis of the discharge hole and the side of the seal strip opposite the impression. This molding member can move forward to detach

  by punching the sealing part of the sealing strip

  and bring it into the closed position of the

green imprint.

  Other purposes and features of the present invention

  will emerge from the detailed description that will now be

  to give some of the favorite achievements of the invention

  with reference to the accompanying drawings, in which: - Figures 1 to 3 are partially sectional views

  showing an apparatus according to the invention in different posi-

  active arrangements for attaching a sealing part to the pouring hole of a plastic capsule; FIGS. 4 to 6 illustrate in perspective a process in which a sealing part is detached by

  punching a continuous band and attached to the hole

  a plastic capsule; FIG. 7 is a perspective view with a section of

  the plastic capsule sealed by the seal

LEMENT;

  FIGS. 8 and 9 are sectional views of a caption

  plastic sule sealed by a seal of another type; and - Figure 10 is a front view with section of a tube

  made of plastic sealed by a sealing piece se-

  in a second embodiment of the invention.

  By considering the apparatus according to the invention shown in FIGS. 1 to 3, it can be seen that it comprises four molding blocks 1 to 4, the last three of which, 2 to 4, are designed to be movable in order to be able to move closer and to move apart. of the first molding block 1. This first molding block 1 supports a

  male mold section 5 of an injection molding device

  6. The male mold section 5 extends beyond the end face of the first mold block 1 to the second mold block 2 and has an open outlet section 7 at its protruding end. Inside the male mold section 5 is provided a core 8 arranged to be mobile next

  its axis. The second molding block 2 is traversed by a beam of

  transverse sage 9 large enough to lock the game without

  protruding portion of the male mold section 5, subject to its open outlet section 7. Accordingly, when the second molding block 2 comes enclose the mold section

  male 5, approaching the first block of

  1 to abut against the latter, the open outlet section 7 of the male mold section 5 exceeds even beyond

  of the end face of the second molding block 2. The third

  the third molding block 3 has, in its end face

  a recess 10 big enough to enclose the stump

  open outlet 7 of the male mold section 5, in

  with it a small annular gap, when the third molding block 3 is brought against the second molding block 2. The third molding block 3 also has a bore 11 which communicates with the recess 10 and extends to the outer end face of the block, along the axis of the open outlet section 7 of the mold section

  5. The fourth molding block 4 is arranged to

  placed in conjunction with the third molding block 3 and has a shallow groove 12 at the interface between the third and fourth molding blocks. This shallow groove 12 extends horizontally, perpendicular to

  the axis of the open outlet section 7. The shallow groove

  of 12 contains a sealing strip 13 which advances by

  termittence along the groove 12. The fourth block of

  molding 4 also has a horizontal bore 14 which

  with the shallow groove 12 and extends into the

  along the bore 11 of the third sealing block 3.

  In the horizontal bore 14 of the fourth molding block 4 extends without play a molding section 15, bar-shaped,

  moving back and forth along the bores 11 and 14 of the third

  sth and fourth molding blocks 3 and 4 respectively.

  As seen in Figures 4 and 6, these bores 11 and 14, and the mold section 15, each have, in section, a generally circular shape having on a portion of its periphery a projecting lobe outwardly. The section of

  bar-shaped molding 15 at its end

  a sharp, sharp peripheral edge 16, so that when the section 15 passes inwardly the interface between the third and fourth molding blocks, it detaches by punching the sealing strip 13 a

  sealing member 17 and pulls it inwards.

  It is made sure that once the second, third

  and fourth molding blocks completely close to the first

  first molding block to close the mold by bearing against each other, the core 8 and the molding section advance inwards until they collide with each other by their inner ends, which enclose then between them the sealing part 17. Their meeting point is very close to the open outlet section 7 of the

  5. According to the embodiment of the present invention,

  1 to 3, in the closed position of the mold where the core 8 and the molding section 15 are at the end of the inward advance stroke as indicated above, a frustoconical impression 18 of FIG. molding of a tubular container 19 is formed between the male mold part 5 and the frustoconical wall portion 8a of the core 8, and a double annular cavity 20 for molding a capsule 21 of

  closure of the tubular container 19 is provided between the

  Cylindrical terminal end 8b of the core 8, the opening section

  open section 7 of the male mold section 5, the inner face

  re of the recess 10 provided in the third molding block

  3 and the sealing member 17 located at the inner end

  in extension of the mold section 15. The two fingerprints

  18 and 20 are connected to each other by an annular channel

  22 very narrow. When the mold occupies this position

  of closure, a molten thermoplastic resin is injected

  in the footprints 18 and 20 through an injection port

  between these fingerprints, then is cooled by

  current situation. Because of this mode of injection of the resin

  thermoplastic, the sealing part 17 which delimits the

  preint 20 is closely attached to the hole

  After cooling of the injected resin, the mold is opened by removing the second, third and fourth molding blocks from the first molding block, and also by retracting the core 8 and the At this time, the molded capsule 21, to which the sealing part 17 is attached, is detached from the molded tubular container 19 at the

  the annular channel connecting the two moldings and tom-

  be below the mold as shown in Figure 3. Furthermore, the molded tubular container 19 is extracted from the mold

  at the same time as core 8. In order to take up

  pulled, the bar-shaped molding section 15 moves back through the punched sealing strip 13, as illustrated

  in Figure 6, then allows the latter to describe a movement

  prefixed to present a virgin stretch in

  face of the molding section 15 for the purpose of

  next step, as shown in Figure 4.

  The sealing strip 13 to be used according to the invention must comprise a layer of plastic material of

  to be melted, at least partially, by the heat of

  thermoplastic sine injected into the impression 20 and adhered

  to the material molded into the impression once this

  cooled. It is preferable that the plastic layer of the sealing strip 13 has chemical affinity for the injected thermoplastic resin for molding the tubular container and the capsule. In saying that there is a chemical affinity between the two resins, it is meant here that both contain polymer units

  derivatives of the same monomer. For example, when the thermal resin

  injected moplastic for molding the tubular container or

  capsule is polyethylene resin, the sealing tape

  It is also made of polyethylene resin or ionomeric resin. It is not necessary that the sealing tape

  either entirely of polyethylene resin or iono-

  aforementioned mother: it is sufficient that the inner side of the band

  sealing, which is attached to the plastic material

  lée, or in such a resin. Therefore, we can use

  a sealing tape with one or more

  on the polyethylene resin or the ionomeric resin, for example

  example formed of a laminate of polyethylene resin

  aluminum foil, polyethylene terephthalate resin polyethylene resin with or without adhesive agent,

  ionomer-polyethylene terephthalate resin with adhesive agent

  sif, or ionomer-"nylon" resin with adhesive agent. The

  Figures 8 and 9 illustrate an embodiment according to the-

  wherein the inner capsule 21 is made of polyethylene resin and the sealing member 17 is formed of two layers, polyethylene resin 17a and polyethylene terephthalate resin 17b. It is conceivable that the polyethylene resin

  17a of the sealing piece 17 is secured to the cap-

  sule 21, which is also made of polyethylene resin. As a result

  when pulling the capsule 21

  this sealing 17, the part thus secured 17a of the

  polyethylene resin of this piece remains on the perimeter

  capsule 21 and easily separates from the

  t3626 of polyethylene terephthalate resin 17b and the

  unsecured portion 17a 'of the polyethylene resin

by the sealing part.

  In the examples of sealing tape indicated

  above, it is preferable that the sealing strip has

  ionomer resin when it is desired to obtain a seal

  detachable material forming, for example, an easy-to-remove seal

  expensive on a container or on a container capsule. The molecular structure of the ionomeric resin comprises ethylene and a carboxylic acid group between which ionic bonds are established by a metal such as sodium

  or zinc. When the ionomer resin sealing

  When heated to a temperature above 110.degree. C., only the ethylene present in its molecular structure melts and is secured to a molded article of polyethylene resin, but without any adhesion of the carboxylic acid group. So, in

  keeping the temperature above 110 ° C, we can fix

  the ionomer resin sealant to the polyethylene resin molded article, but the attachment is not as strong as for a polyethylene resin sealer. Consequently, when one wishes to withdraw the

  fixed sealing part, it is easy to detach.

  For this reason, an ionomer resin seal

  is very suitable for sealing.

  The present invention is very advantageous when applied to the application of a seal to the pouring hole of a plastic container or capsule because

  it makes it possible to choose the material of the seal among various materials.

  such as laminated polyethylene film and

  thin metal sheet. In addition, it is possible to weaken

  Fixing the sealing part by reducing the degree of fusion of the plastic layer of the part

  sealing by the addition of organic or inorganic

  than at higher melting point.

  The sealing member 17 detached by punching the sealing strip 13 preferably has a tongue that can be grasped between the fingers to detach easily.

sealed.

  According to the embodiment of the invention illustrated in FIGS. 1 to 9, the sealing part 17 is fixed to the capsule 21. However, it goes without saying that by modifying the

  Injection mold cavity design can be

  the invention relates to the fixing of the sealing part to the discharge hole of a tubular container 19a as shown in FIG. 10. In general, the arrangements described are suitable for any modifications without

  to go beyond the scope of the invention.

Claims (8)

  1. Method of fixing a sealing part on the   spill hole of a closure cap or recipe   plastic die during the injection molding of this element, characterized in that it comprises intermittent feeding operations of a continuous sealing strip (13) comprising a layer of thermoplastic resin on its face   interior, advancement of a movable molding member to   and forth (15), having a sharp edge at its tip and which passes through said sealing strip by punching it, to a position in which a mold cavity (20) of the injection mold (6) which defines a discharge hole of said capsule (21) or said container (19) is closed by   a sealing member (17) detached by punching the   said sealing strip, and injection molding of a thermosetting resin   plastic in said molding impression, so that the   said sealing member is attached to said injected thermoplastic resin which forms said capsule or said   container, to close the spill hole.   2. Method according to claim 1, characterized in that the thermoplastic resin located on the inner face   of said sealing strip has chemical affinity vis-à-   injected to mold said capsule (21) or the said container (19).   3. Method according to claim 1 or 2, characterized in that said capsule (21) or said container (19) is in   polyethylene and that said sealing strip (13) comprises   has an inner layer of polyethylene and an outer layer of   Polyethylene terephthalate.   4. Method according to claim 1 or 2, characterized in that said capsule (21) or said container (19) is made of polyethylene and in that said sealing strip comprises   an inner layer of ionomeric resin.   5. Apparatus for attaching a sealing member to the pouring hole of a capsule or container   plastic material by means of an injection molding device   jection which has a mold impression of the capsule or container, characterized in that said apparatus comprises   means (12) for intermittently feeding a sealing strip   Continuously (13) in a direction normal to the axis of said cavity (20), said cavity being open to a terminal section which delimits a discharge hole of said capsule (21) or said container (19), and an organ molding (15) which has a sharp edge (16) at its tip and   is movable back and forth along the axis of said vent hole.   the said molding member being provided on the side of the   sealing strip opposite said impression and   cer, by punching off a sealing part (17)   of said sealing strip, to a position of iron   meture of the open end of said fingerprint; 6. Apparatus according to claim 5, characterized in that said sealing strip (13) is interposed between two molding blocks (3, 4) through which two bores (11, 14) are arranged in register for receiving without play and   guiding said movable molding member back and forth (15).   7. Apparatus according to claim 6, characterized in that the two aforesaid molding blocks (3, 4) are movable   towards said injection molding device (6).   8. Apparatus according to claim 6 or 7, characterized in that said bores (11, 14) of the two aforesaid blocks   moldings (3, 4) have a section of generally circular shape.   re on which a lobe 117) projects outwardly.