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1. (WO2018087661) SELF-ADHESIVE GASKET AND METHOD FOR MANUFACTURING THEREOF
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SELF-ADHESIVE GASKET AND METHOD FOR MANUFACTURING THEREOF

DESCRIPTION

Field of application

The present invention regards a ring-shaped self-adhesive gasket that can for example be used on flanges for connection between pumps and manifolds or on connections between ducts in systems of any type, industrial or civil, for example of the water, loading and unloading, heating, cooling, oil transportation, gas transportation, heating plants type or the like.

The invention also regards a method for obtaining such self-adhesive gasket.

State of the Art

As known, gaskets are usually interposed between two elements of a system, such as for example between two flanges, so as to provide fluidic sealing between them.

The most frequently used gaskets have a rectangular cross-section, with two opposite flat surfaces, and they are made of elastically or plastically deformable material so as to facilitate perfect adhesion thereof to the surfaces of the mechanical parts to be connected.

In order to provide reliable sealing free of fluid leakage, it is extremely important that the gasket be correctly positioned before assembling and that it remains in its position even during coupling and fastening between the surfaces to be connected, which must be perfectly matching.

For example, conventional gaskets tend to move between the flanges during the positioning thereof upon fastening the surfaces of the flanges together.

Furthermore, it is desirable that the hands of the operator be free when assembling the elements of the aforementioned system. It is clear that this is impossible to attain with conventional gaskets given that the operator must hold the gasket in position while working.

The above is inevitable in cases where the operator is called upon to work in narrow spaces, in particular if the operator is alone and/or if the elements to be connected are difficult to reach, cumbersome and/or are particularly challenging.

Furthermore, in case of maintenance there arises the need to replace the gasket after disassembling the components, thus increasing the aforementioned difficulties especially if the elements are found in narrow spaces.

As a matter of fact, the operator has to slightly separate the elements, two flanges for example, remove the worn out gasket and introduce the new one under challenging conditions.

Besides being disadvantageous for the operator the above also increases the system installation and maintenance costs.

Presentation of the invention

An object of the present invention is to at least partly overcome the aforementioned drawbacks, by providing a self-adhesive gasket that is highly functional and inexpensive.

Another object of the present invention is to provide a self-adhesive gasket that can be easily positioned on the surfaces of mechanical components to be connected.

Another object of the present invention is to provide a self-adhesive gasket that can remain in position even when fastening the surfaces to be coupled so as to avoid leakage in case of erroneous positioning.

Another object of the present invention is to provide a self-adhesive gasket that can be easily removed from the surface on which it is positioned, for example for replacement or in case of erroneous positioning.

Another object of the present invention is to provide a self-adhesive gasket that can be produced by means of a simple, economic and rapid process.

These and other objects to be further clarified hereinafter, are attained by a self-adhesive gasket and/or by a method for obtaining the same having one or more of the characteristics described, illustrated and/or claimed herein.

The dependent claims describe advantageous embodiments of the invention.

Brief description of the drawings

Further characteristics and advantages of the invention will be more apparent in light of the detailed description of a preferred but non-exclusive embodiment of the invention, illustrated by way of non-limiting example with reference to the attached drawings, wherein:

FIG. 1 is a schematic view of a system I in which the gasket is used 1;

FIG. 2 is a front schematic view of an embodiment of the gasket 1;

FIG. 3 is a schematic view of an embodiment of the production line 200 of the gasket 1;

FIG. 4 is a schematic view of a configuration example of the laminar element 10, in which each area 20 thereof includes a single dot-like adhesive portion 2;

FIG. 4a is an enlarged view of some details of FIG. 4a.

Detailed description of some preferred embodiments

With reference to the aforementioned figures, herein described is a self-adhesive gasket 1, which is designed to remain interposed between any two elements of a system I, for example between two flanges El, E2.

It is clear that the system I may be of any type, civil or industrial, for example of the water, loading and unloading, heating, cooling, oil transportation, gas transportation, heating plant type or the like.

Even though in the present description hereinafter reference will be made to two flanges for the sake of simplicity, it is clear that the gasket 1 may be interposed between any two elements of a system without departing from the scope of protection of the attached claims.

The gasket 1 may have a support structure , which may preferably be ring-shaped, for example with rectangular cross-section. In a preferred but non-exclusive embodiment, the support structure 1' may include one or more through holes 9, for example for allowing the screws for fastening the flanges or similar elements to pass through.

The support structure may have substantially flat and parallel surfaces 2', 3' mutually opposite to come into contact with the flange El and the flange E2 respectively.

The surface 2' may comprise one or more adhesive portions 2, which may be preferably covered by a removable protection layer 8.

Thus, an operator may fix the gasket 1 on one of the flanges, for example the flange El, preventing it from detaching therefrom by gravity, so as to have both hands free to perform the flange E2 and El fastening operation.

This enables facilitating the positioning of the gasket. As a matter of fact, after removing the protection layer the operator can easily install the gasket in the correct assembling position. The adhesive portions 2 ensure that the position is held even when coupling and fastening the flanges E2, El.

In a preferred but non-exclusive embodiment, the operator may detach the gasket 1 from the flange El and reposition it thereon using only one hand, for example in case of erroneous positioning or when performing maintenance operations.

The above may be enabled by an appropriate choice of adhesive material that the adhesive portions 2 are made of, as well as by the distribution, number and dimension of the latter.

To this end, the support structure may have several adhesive portions 2, which may advantageously be substantially dot-like.

Furthermore, the adhesive portions 2 may be suitably equally distributed on the surface 2'.

The adhesive portions 2 may have an extension smaller than 80% of the area of the surface 2', preferably smaller than 50% and even more preferably smaller than 30% thereof.

The adhesive material that the adhesive portions 2 are made of may have characteristics such to guarantee the aforementioned function.

For example, such adhesive material may have viscosity comprised between 1000 mPa s and 6000 mPa s at 160 °C and an operating temperature comprised between 140 °C and 170 °C.

Furthermore, the adhesive material may advantageously have properties such to enable the removal thereof from the gasket through a mechanical action imparted by the finger of the operator.

The adhesive material may preferably be Technomelt® DM 6540 sold by Henkel®. The support structure 1' may suitably be made of graphite possibly reinforced with metal, for example Flexgraf® sold by FMI SpA, or made of non-asbestos materials, for example non-asbestos cellulose, aramid or inorganic fibres compressed and bound using NBR/SBR rubber.

For example, the non-asbestos material may be Flexseals® sold by FMI SpA.

In a particularly preferred but non-exclusive embodiment of the gasket 1 , the adhesive portions 2 may be mutually sufficiently spaced to enable the operator to interpose at least one finger with a hand protected by working gloves between two consecutive adhesive portions 2.

Thus, it will be extremely simple to hold and handle the gasket 1, even wearing working gloves and in narrow spaces.

Furthermore, the removable protection layer 8 covering the surface 2' may advantageously be substantially coextensive with respect thereto.

Such characteristic is particularly advantageous in terms of obtaining the gasket 1, as explained hereinafter. Furthermore, the suitable distribution of the adhesive portions 2 enables an easy removal of the protection layer 8 even under challenging operating conditions.

The material that the protection layer 8 is made of may be per se known, for example silicone coated paper.

The gasket 1 may be obtained in a simple and economic manner through the method described hereinafter.

In its simplest form, such method may provide for preparing one or more laminar elements 10 and cutting the same so as to simultaneously obtain a plurality of self-adhesive gaskets 1.

In this text, the expression "preparation" and its derivatives is used to indicate the preparation of a component of interest in a process step of interest, thus including any preventive treatment aimed at the optimal execution of the step of interest, from simple picking and storage if required to heat and/or chemical and/or physical treatments and the like.

Thus, this enables obtaining a high number of gaskets 1 in a single operation, with clear advantage from an economic standpoint and ease of execution.

Each laminar element 10 may have a face 11 with a plurality of areas 20 each comprising the aforementioned adhesive portions 2, preferably dot-like.

In a first embodiment, for example illustrated in FIG. 3, the cutting may be carried out in each area 20, so as to obtain one or more gaskets 1 from each of the latter.

However, it is clear that each area 20 may include one or more adhesive portions 2, and that cutting may be carried out at several adjacent areas.

For example, in the embodiment of FIG. 4, each area 20 includes a single dot-like adhesive portion 2. As illustrated in FIG. 4a, the subsequent cutting step may act on a plurality of adjacent areas 20, for example four areas, for each gasket 1.

Thus, suitably dimensioning the areas 20 and/or the distance between the dot-like adhesive portions 2 enables obtaining a range of gaskets 1 with different diameter from a single configuration of the laminar element 10 . The cutting station 100 must be suitably set to this end.

Regardless of the above, the face 11 of each laminar element 10 may be covered by a removable protection sheet 80, so that gaskets 1 covered by a portion of the removable protection sheet 80, designated to define the aforementioned protection layer 8, are obtained upon cutting the laminar element 10 .

The materials may be the ones mentioned above. Thus, each laminar element 10 may be made of graphite possibly reinforced or made of non-asbestos material, while the removable protection sheet 80 may be made of silicone coated paper.

It is clear that in order to obtain the laminar element 10 of the desired dimensions, one may start from a larger laminar element and cut it to the desired size prior to, for example, applying the protection sheet 80, and prior to supplying the laminar elements 10 to the machining station 100 in any case.

Furthermore, it is clear that the laminar elements 10 can be cut in two or more steps, for example a first step in which the laminar elements 10 are cut into smaller laminar elements and a subsequent step in which the gaskets 1 are obtained from the latter.

However, the cutting of each laminar element 10 may preferably be carried out so as to simultaneously act on all sheets.

The cutting operation may preferably be carried out through the water-cutting method. On the other hand, cutting may be carried out using a blade.

In order to act on all areas 20 it is preferably advisable to use a multi-head machining station 100 with a machining head 110 for each area 20.

In case of simultaneous cutting of several laminar elements 10 the aforementioned laminar elements may be suitably mutually superimposed, each having the face 11 covered by the respective protection sheet 80 facing the face 12 of the subsequent laminar element.

The superimposition may be advantageously carried out in a manner such that the adhesive portions 2 of each area 20 of each of the laminar elements 10 are mutually matching.

Thus, by acting on the respective area 20 of the upper laminar element 10, each machining head 110 will also act on the areas 20 of the underlying laminar elements 10, so as to obtain a number of gaskets 1 equivalent to the number of the superimposed sheets for each area 20. Each gasket 1 will include a portion of the protection sheet 80 defining a protection layer 8 substantially coextensive with the surface 2'.

The above will enable producing a high number of gaskets 1 provided with the respective protection layer 8 in a single cutting operation.

If necessary, the machining heads 110 may also be used to drill through-holes 9.

The laminar elements 10 with the adhesive portions 2 and the protection sheet 80 may be supplied already suitably superimposed from a storage site and thus supplied to the machining station 100.

Alternatively, they may be picked in any number, superimposed in any suitable number and thus supplied to the machining station 100.

However, in another embodiment of the invention, the operation for obtaining the adhesive portions 2 on the laminar elements 10 may be obtained through a machining line 200 that firstly obtains the same adhesive portions 2 for each laminar element and then performs the cutting to obtain the gaskets 1.

A machining station 120 arranged upstream of the machining station 100 may be used to this end. The machining station 120 may be supplied by one or more laminar elements 10, and the adhesive material may be distributed on each one of them at the areas 20 to obtain the adhesive portions 2.

Thus, the machining station 120 may be of the multi-head type, one for each area 20 of each laminar element 10.

Furthermore, in order to obtain the substantially dot-like adhesive portions, each machining head 130 may pour one or more substantially dot-like adhesive portions in liquid state.

Preferably, as it for example occurs using the aforementioned adhesive material, the adhesive material may be in solid state at room temperature and pressure, for example in form of polygonal elements, and subsequently molten during the aforementioned pouring step.

For example, the adhesive material may have a melting temperature comprised between 80 °C and 120 °C.

When producing the adhesive portions 2 in line, at the exit of the machining station 120 there may be a machining station 140 in which the removable protection sheet 80 is applied on the face 11 of each laminar element 10. Such step may be carried out manually or mechanically.

One or more accumulation reservoirs may be possibly provided upstream of the machining station 120 and/or between the machining station 120 and the machining station 100 and/or at the exit of the machining station 100.

In light of the above, it is clear that the invention attains the pre-set objectives.

The invention is susceptible to numerous modifications and variants. All details can be replaced by other technically equivalent elements, and the materials can be different depending on the technical needs, without departing from the scope of protection defined by the attached claims.

For example, the gasket may be differently shaped with respect to the annular shape. The adhesive material may also be any adhesive material suitable for the purpose in cases where particular pressure and/or temperature resistance requirements must be met. Similarly, the protection sheet may also be made of different materials with respect to the indicated material and it may be of shape and size suitable to ensure the covering of the portions provided with adhesive material alone.