JPS60204473A - Cap for vessel cover and manufacture thereof - Google Patents

Abstract

A process for making a closure cap (2) provided with a gasket (5) from a polypropylene material for a container (1), said closure cap (2) comprising an end wall and a circumferential side wall (11), in which process the gasket (5) is formed in the closure cap via a melting and a cooling operation by applying in the closure cap an amount of plastisol which is shaped therein into a gasket configuration at an elevated temperature adjusted after the plastisol addition; causing the plastisol shaped into the gasket configuration to melt completely by further energy supply and then cooling same to form the gasket, whereby starting from an integral combination of the closure cap (2) with a sealing ring (13) which is connected with the closure cap by means of a number of frangible bridges (12) capable of being broken on the first opening of the container, and, to form the gasket (5), carrying out the melting operation by heating the closure cap after addition of the plastisol to a temperature of 50 to 110 DEG C and by exposing the resulting plastisol shaped into the gasket configuration subsequently, as is known per se, to microwave energy until the plastisol has been completely molten.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a method for manufacturing a container lid cap comprising a gasket and a ceiling wall and a circumferential wall from a polypropylene material, the method comprising: The plastisol is melted and cooled at a predetermined temperature and formed into a gasket shape, and then energy is supplied to the plastisol formed into the gasket shape to completely melt it and then cooled, so that the gasket becomes a container lid. Relating to a method formed within a cap.

PRIOR ART A process of this kind is known from Dutch patent application No. 80.03571. In this known method, the container cap is made by injection molding. manufactured from olefin polymers. As this olefin polymer, high melting point polypropylene having a melting point of about 1650 is preferably used.

That is, after the PVC blastisol is applied to the container, the melting point of the olefin polymer used, such as polypropylene, is 5
~65C1 Preferably preheated to a temperature of 5 to IFI' lower. For example at least 130C1 preferably 145-1
After preheating the cap to a temperature of 60C, preferably 300-500.0001kfEZ in a suitable oven.
This temperature is subsequently maintained by high frequency heating (which is not critical from a practical point of view). Plastisol formed into a gasket shape by high-frequency heating is instantly completely liquid, that is, completely cast, which means that the resin is dissolved in the plasticizer.

Preheating is suitably carried out in a hot air oven.

In this known process, it has generally been shown that conventional plastisols are unsuitable if the temperature of the container cap is more than 65'C below its melting point.

When using low melting point plastisols, the temperature of the cap can be kept even lower during the preheating process. However, in the case of a cap made of a low melting point olefin polymer, the temperature range of the cap to be maintained during preheating should be 5 to 15 C1, preferably 5 to 10 C lower than the melting point of the olefin polymer. Must. Therefore, when the cap is made of high-density polyethylene, for example, the temperature range of the cap during the preheating step is preferably 120 to 125C.

In fact, in this known process, for example, after the plastisol has been applied to a container cap, this cap is removed by 30 t.
Ill? , preferably in a hot air oven at an ambient temperature 20C lower. For example, when polyethylene is used as the olefin material, the preheating step is carried out for about 6 minutes at an ambient temperature of 165-160C for 11-10 minutes, e.g. 155C, followed by heat loss of the preheated container lid. The sample is kept in a microwave oven at a temperature sufficiently high to prevent this, for example an ambient temperature of at least 140C. The time allowed for microwaves depends on the energy to be supplied, but is not less than about 1 minute.

The process of forming the plastisol in the container lid cap is carried out by conventional means, preferably under a liquid or semi-liquid condition, until a gasket shape is obtained, with the plastisol facing upwards, i.e. with the top wall at the bottom wall. This is done by injecting the plastisol into the disposed cap, and then subjecting the cap to high speed rotation in step A to distribute the plastisol.

Preferably, the inside of the ceiling wall of the cap has an inner edge, and the plastisol is injected into the annular space between the inner edge and the side wall.

This known manufacturing method is suitable for various container lids; however, for bottles with a flared hem structure (d) and snap-on type lids, an anti-tamper evident member (not specifically specified) is required.
heft means), and usually,
The inner diameter is limited to approximately 25-32wn.

Various types of tamper-evident mechanisms are known to be used in combination with container lids, including Verpackinq-Rundrchau, 1Q, published in October 1986.
Pages 74 to 1093 "Verschlr't;zze
f'ir getranke-furcher L".

Of these, a type consisting of a sealing ring manufactured integrally with the container lid and connected to the side wall of the container lid through a number of narrow, frangible bridges which are broken when the container is first opened. cannot be used within the framework of known methods.

That is, during the preheating step, the container lid is held at a high temperature and heated by microwave energy to a temperature only 5 to 65 C below the melting point of the olefin polymer forming the cap, so that the bridge and seal are heated. The ring softens and deforms, making the structure unusable.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a container lid cap with a gasket made of polypropylene material, in particular a sealing ring of the type connected to its side wall via a number of bridges which are destroyed by the first opening of the container. The present invention provides a method for manufacturing a container cap.

A further object of the invention is a container formed from an olefin polymer, provided with a gasket of plastisol material, suitable for use in containers having a wide diameter of 90 mm and above, and provided with a sealing ring of the type described above. There is a cap on offer.

According to the present invention, there is provided a method for manufacturing a container lid cap comprising a ceiling wall and a circumferential side wall from a polypropylene material, which comprises applying a plastisol inside the container lid cap and applying the plastisol to a predetermined amount. A method in which a gasket is formed in a container lid cap by melting and cooling the plastisol at a temperature of , from the complete connection of the container lid cap and the sealing ring,
The sealing ring is connected to the cap by a number of flanges that are broken when the container is first opened, and then to form a gasket, the cap is heated to 50° to 110°C after application of plastisol and formed into a gasket shape. A method is provided which is characterized in that the plastisol produced is subjected to sufficient microwave heating, known per se, to completely cast the plastisol.

The invention further provides a container lid cap made of an olefin polymer, provided with a gasket formed by plastisol, and having a ceiling wall and a circumferential side wall, in which a locking collar is arranged around the container neck.
A sealing ring is provided for sealing the container in cooperation with the collar, the ring being fully connected to the side wall of the container cap via a flange-like bridge which is broken upon initial opening of the container. Additionally, there is provided a container lid cap characterized in that the ceiling wall of the cap is formed with a 20-50% thinner portion at the gasket forming position.

The present invention further provides a method for sealing a container, in which the temperature of the sealing ring is increased after the container is closed with a cap, and the sealing ring is deformed around the fastening collar in the direction of the container neck. After closing the container with the container cap described in Section 1, heat treatment is applied to the sealing ring and the bridge part to give sufficient plastic deformation to the polypropylene material, and then the sealing ring is placed on the fastening collar. There is provided a method for sealing a container characterized by mechanically pressing against the container neck and simultaneously spreading and flattening a bridging portion on the collar. Preferred Embodiments of the Invention Used in the Invention Plastisols are conventional ones, for example those containing vinyl acetate copolymer resins with 5% vinyl acetate and further containing one or more conventional additives such as stabilizers, plasticizers, viscosity reducers, torsion reducers, etc. is used.

Further, in the present invention, the ceiling wall of the container cap is provided with an annular space on the inside that is partitioned by two protrusions (Irndeγcut) provided below, and the outside of the annular space is substantially defined by the inner circumferential side wall of the cap. It is very advantageous for the annular space to be delimited and for the plastisol to be injected into this annular space by conventional means.

The starting point for the invention is preferably the top wall of the cap, which is 26 to 50 inches thinner at the location where the gasket is to be formed. At such a position, an annular space is defined by the above-described protrusion. This facilitates heat transfer to the plastisol in an oven such as a hot air oven with preheating. Furthermore, the higher flexibility of the ceiling wall in appropriate locations increases the self-ventilation of the container contents when they are sterilized.

Furthermore, in the method of the present invention, the operation of melting the plastisol placed in the legitimate position in the container cap involves preheating the combined cap and plastisol to a temperature of 50 to 110C, and then changing the resulting gasket shape to a temperature of 10 to 200C.
This is done by exposing Mlh to high frequency heating.

According to a preferred embodiment of the present invention, the melting operation is performed by applying the plastisol inside the cap and then heating the cap to 100C for 15 to 30 seconds to completely melt the plastisol formed into the gasket shape. .10-27. ．．
This is done by applying high frequency energy of 15 AHIz. This frequency can be used industrially throughout the world.

According to the manufacturing method of the present invention, a container lid cap consisting of a uniform gasket with an unbreakable and undeformable sealing ring is obtained, which cap can have an inner diameter suitable for wide-mouthed containers. be. For example, according to the present invention:
Caps with inner diameters of 90 mm or more can be obtained.

The invention includes, but is not limited to, the cap being fully connected to the sealing ring and the inner side wall of the cap engaging a corresponding member provided on the container neck to open the container by rotation of the cap; It is also particularly suitable for producing caps that are threaded so that they can be closed.

According to the invention, it also comprises a circumferential side wall and a ceiling wall made of an olefin polymer and provided with a gasket made of plastisol material, furthermore via a bridge which is broken during the first opening of the container. It is very advantageous that the cap is provided with a sealing ring that is completely connected to the circumferential side wall of the cap, that the ceiling wall is thinned by 20 to 50 inches at the gasket location, and that the inner diameter of the cap is within 100 mm. A container lid is provided.

A container lid cap suitable for the present invention has an annular space defined by two undercuts, and a gasket is accommodated within this space. In addition, the inner downward protrusion has a tapered cross section and is elastic, so that when the container is closed by applying the cap,
Preferably, the protrusion is wide enough to be partially located on the top surface of the container neck.

If the container lid cap is made of polypropylene material, the diameter of the sealing ring is sufficiently large so that the sealing ring and the bridge do not come into contact with the container after the container is closed by the cap.

When the sealing ring and bridge are heated during the sealing operation, contact as described below means that heat will be dissipated through the container and the retrograde deformation of the polypropylene material will be insufficient.

On the other hand, when sizing the sealing ring and the bridge in a cap made of polypropylene material, it is ensured that the bridge is tensioned and expanded during the sealing operation by means of a fastening collar provided on the neck of the container.

The invention also relates to a method for sealing a container which, after closing the container, comprises increasing the temperature of the sealing ring and deforming it around the fastening collar in the direction of the container neck.

When using the cap of the invention made of polypropylene material, the subsequent operations are, after closing the container with the cap, to heat-treat the sealing ring until the polypropylene material undergoes sufficient retrograde deformation, and to place the ring on the fastening collar. is mechanically pressed against the neck of the container, simultaneously tensioning and spreading the bridge over the collar.

For example, the heat treatment may be applied to the sealing ring and the bridge to a temperature of about 4DO1.
This is done by exposing it to air at a temperature of Z' for about 2 seconds. After mechanical binning, such as by clamping, a sealing ring is placed around the container under the fastening collar to tension and flatten the flange-like bridge. Therefore, although the polypropylene material has its own strength, the sealing ring easily separates at the flange-like bridge when the container is first opened.

That is, when the cap is first removed, the sealing ring separates from the container cap via the bridge, and after the cap is closed again, the cap always moves to open the container. It has become.

The container lid cap according to the invention has three combined properties:
impression-proof and vacuum
be able to close under m-fight conditions, (b
) After opening, the container can be closed again in a manner that completely isolates the container from the atmosphere; (C) Occlusion of the container after initial filling is an incomplete seal.

The fact that the cap according to the invention is made to have an internal diameter of up to 100 mm makes it possible to carry out food products, which are mainly filled in wide-mouthed containers, for example with a neck diameter of 90 mm, regardless of whether there is a partial vacuum or not. First, it provides the advantage that the container can be sealed so that it is provided to the consumer in a sealed condition that guarantees freshness.

This ensures that product warranties such as those provided on food containers are extremely reliable. In the case of lids that do not have a breakable seal, such dates are not actually true.

The present invention will be explained below based on specific examples shown in the accompanying drawings.

In FIG. 1, which shows an axial section through the cap closed by a lid cap, the neck wall of the container made of glass is designated by 1 and the polypropylene cap is designated by 2.

On the inside, the cap 2 has two circumferential cuts 6.
It has an annular space formed by 4. This annular space is made up of a gasket 5. The inner notch 6 is crescent-shaped and has elasticity because the thickness decreases toward the outside. This crescent-shaped structure allows the inner notch to rest on a portion of the neck edge of the container. As a result of this, a portion of the high unscrewing torsion of the gasket 5 is absorbed and reduced by this cutout. Furthermore, due to the crescent-shaped cut-out projection 3, during sterilization of the container contents, the expanded air generated in the process flows between the somewhat deflected elastic projection 6 and the neck. This deflected protrusion 6 therefore simultaneously creates an additional holding force on the gasket, holding it in place.

In FIGS. 2 to 5, a polypropylene cap 10 consists of a side wall 11 and a sealing ring 16, which are connected to each other via a flange-like bridge 12. The neck 14 of the container is formed with a fastening collar.

In the pre-sealing state (FIG. 2), the side wall 11 with the flange-shaped bridge 12 and the sealing ring 16 is separated from the container.

FIG. 4 shows the state in which the flange-shaped bridge 12 with the sealing ring 16 is gripped by the clamp 15 moving towards the container after being subjected to the action of 400 C hot air.

Next, the flange-shaped bridging portion 124-t and the fastening collar 17
The upper and lower sides are tensioned and flattened, and at the same time the sealing ring 16 is also flattened between the clamp 15 and the container neck 14.

In comparison with FIG. 6, FIG. 5 shows that as a result of the deformation occurring between the flange-like bridge 12 and the sealing ring 16, the diameter of the sealing ring 16 is smaller than the maximum diameter of the fastening collar 17. Show that.

When the cap is unscrewed, axial displacement of the cap 10 is prevented by the junction of the sealing ring 16 opposite the fastening collar 17. During subsequent unscrewing, the forces exerted by the sealing ring 13 and the fastening collar 17 on the flange bridge 12 increase, causing tension and flattening of the flange bridge 12 (itself made of strong polypropylene). ] is the dot-dashed line 1 in Figure 5.
It will be destroyed along the line shown by 6.

Of course, the present invention is not limited to the embodiments described above, and various modifications can be made within the framework of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of the container lid cap according to the present invention; Fig. 2 is a partially enlarged sectional view of the neck side wall of the container closed by the container lid cap at a stage before sealing processing; is a sectional view taken along the line ■-■ in FIG. 2, FIG. 4 is a cross-sectional view taken along the line ■-■ in FIG. 4, FIG. 1 is a cross-sectional view (excluding the clamp and container). 1 is the container, 2 is the cap, 6 is the inner protrusion, 4 is the outer protrusion, 5 is the gasket, 11 is the side wall of the cap, 12 is the bridge part, 16 is the A sealing ring, 14 a container neck, 15 a clamp, and 17 a fastening collar.

Claims (1)

[Claims] (1) A method for manufacturing a polypropylene container lid cap comprising a gasket and a ceiling wall and a circumferential side wall, the method comprising: applying plastisol in the container lid cap;
This is melted and cooled at a predetermined temperature and formed into a gasket shape, and then energy is further supplied to the plastisol formed into the gasket shape to completely melt it,
A gasket is then formed in the container lid cap by cooling, proceeding from a complete connection of the container lid cap with a sealing ring, which sealing ring has a number of flange-like protrusions that are broken upon initial opening of the container. connected to the cap by
Next, when forming the gasket, after applying the plastisol, the cap is heated to 50° to 110C, and the plastisol formed into the gasket shape is sufficiently subjected to microwave heating, which is known per se, to completely cast the plastisol. how to. (2) The method according to claim 1, wherein the ceiling wall of the cap is 20 to 50% thinner at the location where the gasket is formed. (3) In the melting process, after heating at 50° to 100°C, the plastisol formed into a gasket shape is
2. A method according to claim 1, which is carried out by applying microwave energy at 0 MHz. (4) The melting process is 100C1 after application of plastisol.
Heat the cap for 15 to 0 seconds and then heat the plastisol shaped into a gasket to 27.10 to 27.
．． 7. The method according to claim 6, wherein 15 J (Hzc7)v microwave energy is applied to completely melt the material. (5) In a container lid cap made of an olefin polymer, provided with a gasket formed by plastisol, and having a crown wall and a circumferential side wall, a locking collar (Lockin) disposed around the neck of the container is provided.
A sealing ring is provided which cooperates with the container to seal the container, the ring being fully connected to the side wall of the container cap via a flange-like bridge which is broken on the first opening of the container. The container lid cap is characterized in that the ceiling wall of the cap is formed with a 20 to 50% thinner portion at the gasket forming position. (6) The cap according to claim 5, wherein the inner diameter of the cap is 100 mm or less. (7) An annular space partitioned by two undercuts is formed inside the ceiling wall, and a gasket is housed in the space, and among the projections,
The inner protrusion has a tapered cross section and is elastic, and has a width such that when the cap is used on a container, the protrusion is placed on at least a portion of the upper surface of the neck of the container. A cap according to claim 5 or 6. (8) the sealing ring and bridge do not contact the container when the cap is applied to the container, but such that during the sealing operation the bridge is taut and stretched under the fastening collar;
8. A cap according to any one of claims 5 to 7, wherein the sealing ring is made of polypropylene material having a sufficiently large diameter. (9) A method for sealing a container in which, after closing the container with a cap, the temperature of the sealing ring is increased to cause the sealing ring to deform in the direction of the container neck around the fastening collar, as set forth in claim 8. Use a container cap,
After closing the container with the cap, the sealing ring and the bridge are heat-treated to give sufficient plastic deformation to the polypropylene material, and then the sealing ring is mechanically pressed against the container neck on the fastening collar. A method for sealing a container, characterized in that a bridging portion is simultaneously spread and flattened on the collar.