LOW DENSITY SEMIFINISHED PRODUCT FOR MANUFACTURING BUOYANT PRODUCTS

Abstract: Low density semifinished product for manufacturing buoyant products, comprising a plurality of layers (3) of closed-cell expanded material, having a specific gravity lower than that of water, the said layers (3) being flexible and elastic and being joined together by quilting (4, 5) spaced so as to define between them pockets of air, characerised in that the said quilting (4, 5) is preferably distributed in closed patterns.

Description: LOW DENSITY SEMIFINISHED PRODUCT FOR MANUFACTURING BUOYANT PRODUCTS TECHNICAL FIELD The invention concerns a low density semifinished product for manufacturing buoyant products, comprising a plurality of layers of closed-cell expanded material, having a specific gravity lower than that of water, the said layers being flexible and elastic and being joined together by means of consecutive quilting spaced so as to define pockets of air between them to increase buoyancy. BACKGROUND ART Such a semifinished product, classified in the category of "non-woven fabric", is employed mainly for manufacturing items of clothing, such as jackets, overalls, items of clothing for specific uses, for fishing, sailing, or other activities, particularly for use in marine or aquatic environments in general, and for manufacturing objects aiding in natatorial activities, as well as bags, or holders in general for use in proximity to these environments and which require protection against the risk of sinking. Conventional items of clothing that enable a person to remain afloat are most uncomfortable and do not allow the degree of agility of movement that would be preferable when carrying out working activities, or sporting activities, or other types of activities . Furthermore, when manufacturing buoyant products in general, to obtain holders, covers, bags, or other items, a limitation has been found consisting of the fact that it is necessary to adopt special manufacturing processes which entail considerable costs. Also, the products obtained with these processes turn out to be rigid and difficult to handle. Such prior art may be subject to further improvements with a view to eliminating the said drawbacks. From the foregoing emerges the need to solve the technical problem of inventing a semifinished product that is suitable for manufacturing, in an extremely simple manner, buoyant products or that assist buoyancy, such as items of clothing, that are soft and easy to handle; in the case of clothing, these have to offer an adequate degree of buoyancy without excessively limiting freedom of movement. DISCLOSURE OF THE INVENTION The invention solves the said technical problem by adopting a semifinished product of the type mentioned in the preamble characterised in that the quilting is preferably arranged in closed patterns. This considerably improves the buoyancy in water of objects made with the semifinished product, in that it creates a series of pockets in which air is - so say - trapped, providing a more stable and long-lasting aid to buoyancy . The closed patterns may also be obtained with cross quilting; in this case, the items of clothing manufactured with such a semifinished product have an improved wearability and are more comfortable. The cross quilting also confers a particular resistance to mechanical stresses to the semifinished product, especially during processing, in that it keeps the layers securely joined together. As a resul of this invention it is possible to manufacture buoyant products of pleasant appearance, substantially without imposing limitations on the creative impulse of fashion designers, in that the semifinished product may substantially be processed like a fabric and may be inserted in any type of item of clothing, or accessory, without compromising the look and/or the practicality of said item. BRIEF DESCRIPTION OF THE DRAWINGS Some embodiments of the invention are illustrated, merely by way of non-limitative examples, in the accompanying drawings and wherein: Figure 1 is a perspective view of a roll of material in superimposed quilted layers, partially unwound, constituting the semifinished product; Figure 2 is a perspective view of a portion of semifinished product partially inserted in a lining in the form of a pocket; Figure 3 is a view as in Figure 1, but with the semifinished product inserted between a pair of net elements to assist the quilting; Figure 4 is section IV-IV, partial and enlarged, of Figure 3 ; Figures 5 to 25 show some examples of products manufactured using the semifinished product according to the invention, and show in order: Fig. 5 a handbag, Fig. 6 a tennis racket cover, Fig. 7 a belt bag, Fig. 8 a glasses case, Fig. 9 an envelope, Fig. 10 a wallet, Fig. 11 a fishing rod case, Fig. 12 a camera bag, Fig. 13 a vanity case, Fig. 14 a shoulder bag, Fig. 15 a bag with handles, Fig. 16 a travel bag, Fig. 17 a rucksack, Fig. 18 a sleeveless jacket, for going fishing, Fig. 19 a waistcoat, Fig. 20 a jacket with integrated hood, Fig. 21 a jacket with removable hood, Fig. 22 a life jacket, Fig. 23 a jacket for learning to swim, Fig. 24 a short single-piece jacket for surfers; Fig. 25 a jacket and trousers combination. WAYS OF CARRYING OUT THE INVENTION The material for manufacturing buoyant products, in the form of non-woven fabric 1, wound onto a roll 2, comprises a plurality of layers 3, joined together, preferably by means of quilting, in a longitudinal direction 4 extending in the direction of the length of each layer 3 and in a traverse direction 5 perpendicular to the previous direction. Each layer 3 is made of a material with a specific gravity lower than that of water, preferably an expanded material with closed compartments which, overall, is soft and very flexible; the thickness of each layer is approximately 1 mm. Optimum results have been achieved with closed-cell expanded polyethylene. The quilting 4, 5 joins two superimposed layers and define in the material 1 a plurality of closed areas, for example, squared, in which air is partially trapped for buoyancy and operating also as structural reinforcement. Cross-quilting prevents the material for becoming excessively stiff. The material 1 may also be provided with a lining, particularly but not exclusively when manufacturing clothes. Figure 2 shows how the material may also be inserted, in the direction indicated by arrow Fl, through an open side 7 of a lining 6 in the form of a pocket, so as to act as padding for the said lining. This makes the manufacture of elements making up items of clothing and objects of various types and functions particularly simple to manufacture. In general, the semifinished product may therefore act as padding in the manufacture of any type of object. As shown in figure 3, the set of layers 3 may be sandwiched between a pair of net elements 8, joined to the sheets 3 by means of the same quilting 4, 5 that interconnects the sheets 3. The adoption of at least one flat net element 8 renders the semifinished product easier to work, in that the sheets are considerably easier to pull under the heads of the sewing machines. Also, the net element prevents one or more of the sheets, that are made of a very soft material, from being cut by the thread used for the quilting. To this end, the net element 8 has to be very strong, but of reduced thickness, to prevent the product from becoming excessively rigid. Experimental results have shown that items of clothing made with the semifinished product 1 are able to meet the most exacting safety regulations for nautical equipment. It has also been found that the items of clothing made with this product provide excellent protection against wind, cold and atmospheric agents in general, in that they provide a high degree of thermal insulation. The material can therefore be used as padding for jackets, overalls, boots, in particular ski-boots. In practice the materials, dimensions and details of execution may be different from, but technically equivalent to those described without departing from the scope of the present invention. For example, the type of stitching used for the quilting may vary in function of manufacturing requirements.

Claims: CLAIMS 1. Low density semifinished product for manufacturing buoyant products, comprising a plurality of layers (3) of closed-cell expanded material, having a specific gravity lower than that of water, the said layers (3) being flexible and elastic and being joined together by quilting (4, 5) spaced so as to define between them pockets of air, characterised in that the said quilting (4, 5) is preferably distributed in closed patterns. 2. Semifinished product as claimed in claim 1, characterised in that the said quilting (4, 5) is distributed so that they cross over each other and cover substantially the entire surface of the semifinished product. 3. Semifinished product as claimed in one of the preceding claims, characterised in that at least the external layers (3) are each externally associated with a respective net element (8). 4. Semifinished product as claimed in one of the preceding claims, characterised in that each layer (3) is obtained from a closed-cell expanded material and has a thickness of preferably approximately 1 mm. 5. Semifinished product as claimed in claim 4, characterised in that the said expanded material is based on closed-cell expanded polyethylene. 6. Semifinished product as claimed in one of the preceding claims, characterised in that the number and the thickness of the said layers (3) is such that it confers to the ensemble a workabiility which is analogous to that of a fabric. 7. Semifinished product as claimed in one of the preceding claims, characterised in that it is inserted as padding in the manufacture of objects. 8. Containers characterised in that it is manufactured using a semifinished product as in one or more of the preceding claims. 9. Items of clothing characterised in that it is manufactured using a semifinished product as in one or more of the preceding claims.

Inventors: SARDI GIANLUCA, SARDI, GIANLUCA
Applicants: FLOAT S R L, SARDI GIANLUCA, FLOAT S.R.L., SARDI, GIANLUCA
Application year: 1997
Main classification: A41D13
IPC codes: A41D13, A41D31, B32B5, D05B11