GB2080412A - Connecting device of synthetic material incorporating interengaging profiled strips - Google Patents

Abstract

A connecting device of synthetic material comprises two strips 1a, 1b with profiles 2a, 3b of complementary shape engaging one in the other, with on at least one face of each strip a zone covered with a layer of heat- reactivatable synthetic adhesive 3a, 3b extending in a direction generally parallel to the corresponding profile. Such a device can be utilized to constitute a closure device for two parts 6a, 6b of a garment or camping tent. The adhesive may be continuous or discontinuous and laid down in one or more bands on each strip. <IMAGE>

Description

SPECIFICATION Connecting device of synthetic material incorporating interengaging profiled strips This invention relates to a connecting device of synthetic material of the type comprising two strips having profiled portions of complementary shape engaging one in the other, that is to say, the profiled portions, by interengaging, can ensure interconnection between the two strips which carry them. The profiled portions and the strips of which they form an integral part are usually of synthetic material and can be made, in a continuous manner and in great lengths, by extrusion, and then cut to the desired length according to their ultimate purpose. One use for such connecting devices is in the closure of bags of plastics material, each of the strips carrying a connecting profile being joined, for example by heat-sealing or adhesion, to an edge of the opening of the bag.If required, the connecting device can be completed by a slider which enables interengagement of the profiles to be facilitated.

As the synthetic material for such Strips, use can be made in particular of readily-extrudable materials such as polyethylene, polyurethane, polypropylene, polyesters, PVC and their analogues.

Generally, it is the manufacturer of such profiles who, in part by reason of the special tools needed, particularly when the interconnection is carried out by adhesion, iocates them on the walls of the bags or other products to be equipped with such profiled connecting strips, the production also being continuous advantageously.

It should also be noted that it can seem at first more rationai and more economical to effect location of the profiled connecting strips on the end product in the factory itself where they are made, because their location on the product in question can occur continuously at the outlet from the extruder, which allows a saving to be made of the operation of having to wind the profiled strip on a reel, an operation which is necessary if the strip has to be fitted to the product away from the site where the product is manufactured.

For whatever cause, what leaves the factory is not, in principle, a profiled strip which is freely locatable by the user on any product, but a strip aiready located in a definitive manner on this product, the intended use of which has consequently already been fixed.

There is thus a certain lack of flexibility in such a mode of manufacture and this constitutes a disadvantage which operates against the economy of the fabrication carried out.

This disadvantage appears particularly clearly if consideration is given to the number of products, other than bags or the like, on which profiled strips may play a part as devices for closure or interconnection between two elements. This applies particularly to all those products which, unlike bags, are not susceptible of manufacture by a continuous process permitting continuous unwinding and location of the profiled strip on the product. This also concerns in particular all products which are not capable of being heatsealed to the synthetic material constituting the profiled strips, as is the case with textiles, paper, board, etc. and, among synthetic materials, polyethers, neoprene and other materials which in general terms have an incompatibility with heatsealing to such strips.

It is thus difficult to envisage users, particularly if they have a production on a small scale, being able to absorb the cost of special supplementary equipment suitable for locating the strips on their products.

Among the products which, for this reason, avoid an interesting application of the profiled strips in question, one can include garments, camping tents, etc., and, in a general manner, all non-extrudable products which require a closure device or other means for bringing together two panels or other elements.

Thus, a very important part of the potential market for profiled strips of the kind in question is lost in fact, and, as can be seen, this is because of the current non-adaptation of these strips for convenient fitting at low cost to a whole range of varied and widely-used products.

It is an object of the present invention to remedy these disadvantages. In accordance with the invention there is provided as an article of manufacture, a strip of synthetic material having a profiled portion extending lengthwise thereof, with on at least one face of the strip a zone extending generally parallel to the profiled portion and at least partially covered with a layer of heatreactivatable adhesive.

There also is provided in accordance with the invention a connecting device of synthetic material comprising two strips having profiled portions of complementary shape engageable one in the other, in which each strip has on at least one of its faces a zone at least partially covered with a layer of heat-reactivatable synthetic adhesive, the zone extending in a direction generally parallel to the profiled portion of the respective strip.

Advantageously, the adhesive can be distributed as at least one continous band, for example a single continuous band of adhesive.

Alternatively, the adhesive can be distributed discontinuously. In this case, it can be a single discontinuous band of adhesive or, as may be preferable, several continuous parallel bands of adhesive.

As regards the adhesive, clearly it can advantageously be deposited continuously, at the outlet from the extrusion head producing the profiled connecting strips of synthetic material.

This heat-reactivatable adhesive, referred to as a "hot-melt" adhesive, will naturally be selected in dependence on the material of which the strip is made and the material to which the strip is intended to be affixed.

It will be seen that the present invention, in a very simple way, remedies the considerable disadvantages mentioned above of connecting devices of the prior art. In fact, a manufacturer of garments or other products will now receive, from the manufacturer of profiled connecting strips, directly-usable strips which, by means of any very simple and inexpensive heating device for reactivating the "hot-melt" or reactivatable adhesive of the Strips, can then be affixed, by an application under pressure, to those parts of the product intended to be provided with them. Such equipment can include, for example, heating and pressing jaws analogous to the heat-seal jaws utilized at the present time to weld strips to the edges of the openings of bags of synthetic material or the like.

The present invention also relates to products fitted with such strips in accordance with the invention, and thus includes in a general manner all products including a connecting device in accordance with the invention, that is to say where the profiled strips have at least one zone at least partially covered with a layer of synthetic reactivatable or "hot-melt" adhesive.

It can relate particularly to garments carrying such connecting devices, which then constitute closure devices replacing the usual buttons or even standard metallic or synthetic sliding fasteners. This replacement is particularly advantageous, because the profiled connecting strips, due to their intrinsic continuity, allow excellent sealing to be obtained at the junction of the two elements or parts of the garment to which they are connected.

A number of embodiments of the invention will now be described by way of example and with reference to the accompanying drawing, in which: Figs. 1 to 3 respectively are plan views of first, second and third embodiments of profiled strip of synthetic material adapted to form part of a connecting device according to the invention; and Fig. 4 is a transverse section through such a connecting device located on any form of product, for example a garment.

In Figs. 1 to 3, a strip of synthetic material, for example polyethylene, is indicated generally at 1.

A connecting profile extruded in a continuous manner at the same time as the strip is indicated at 2 and can be of any known type, for example a double bead as represented in Fig. 4 by the profiles 2a and 2b which, as can be seen, have complementary shapes permitting their interengagement and mutual connection by elastic deformation in known manner.

The strips 1 have on one of their faces a zone provided with a layer of a heat-reactivatable or "hot-melt" synthetic adhesive, the zone extending in a direction generally parallel to the corresponding profile 2. In the case of Fig. 1, the layer is continuous and is constituted by a single continuous band 3 of adhesive. In the case of Figs.

2 and 3, the adhesive layer is discontinuous; in the case of Fig. 2, it is constituted by a plurality of bands 4 separated by spaces without adhesive, and, in the case of Fig. 3, the adhesive layer is constituted by two continuous parallel bands 5 of adhesive, separated by an intermediate area which is free from adhesive. Any variation or combination of these configurations can be provided without exceeding the scope of the t invention.

To locate such strips 1 on any desired product, it is sufficient to present to the product the parts dt the strips covered by adhesive and to cause reactivation of the adhesive by heating, for example with the aid of heating jaws capable at the same time of pressing the strip against the product for the time necessary to effect adhesion.

In Fig. 4, two connecting strips 1 a and 1 b are shown, similar to the strips 1 described above, located respectively on two parts 6a, 6b which are elements of any desired product, the interconnection between strips and product parts being ensured by bands of adhesive 3a and 3b respectively. For example, these product parts can be two panels of a garment of cloth, where the connecting device 1 of the invention thus constitutes a closure.

The product parts indicated at 6a and 6b can clearly relate to any product and can be of any other material, for example polypropylene and, in general, of any other material which is heatsealable or non-heat-sealable to the material of which the strips are made.

The present invention is particularly advantageous when the connecting device is used for products which are not capable of being manufactured continuously, but it should be understood that the use of such devices, also advantageously, is not excluded with products, such as bags, which are manufactured continuously.

A supplementary advantage resides in the fact that the profiled strips made according to the invention can be rolled up, stored and transported as such, without it being necessary to cover the activatable adhesive by a removable protective strip. Such an adhesive in effect is not capable of adhering in the cold to the surface of an adjacent strip or another object. This allows an important saving to be achieved, because protective strips usually utilised to mask provisionally a band of adhesive which does not need to be reactivated in order to be operational are relatively expensive.

Claims (10)

1. As an article of manufacture, a strip of synthetic material having a profiled portion extending lengthwise thereof, with on at least one face of the strip a zone extending generally parallel to the profiled portion and at least partially covered with a layer of heat-reactivatable adhesive.

2. A connecting device of synthetic material comprising two strips having profiled portions of complementary shape engageable one in the other, in which each strip has on at least one of its faces a zone at least partially covered with a layer of heat-reactivatable synthetic adhesive, the zone extending in a direction generally parallel to the profiled portion of the respective strip.

3. A device according to claim 2, in which the adhesive is distributed as at least one continuous band.

4. A device according to claim 2, in which the adhesive is distributed discontinuously.

5. A device according to claim 3 or 4, in which the adhesive is distributed as a plurality of continuous parallel bands.

6. An article or device according to any preceding claim, in which the strip or strips is/are of extruded material.

7. A device according to any of claims 2 to 6, in which the interengageable profiles constitute the only coupling between the strips.

8. A strip substantially as hereinbefore described with reference to any one of the Figures of the accompanying drawing.

9. A connecting device substantially as hereinbefore described with reference to any one of the Figures of the accompanying drawing.

10. A product fitted with a connecting device as claimed in any of claims 2 to 7 or 9 constituting a closure for two parts of the product.