ITBO20130201A1 - SYNTHETIC SKIN AND CORRESPONDENTS METHOD AND PRODUCTION PLANT - Google Patents

Description

DESCRIPTION

â € œ SYNTHETIC LEATHER AND CORRESPONDING METHOD AND PRODUCTION PLANTâ €

TECHNIQUE SECTOR

The present invention relates to a synthetic leather and corresponding production method and plant.

ANTERIOR ART

Synthetic leather has been in production for many years, a plastic material that mimics the look and feel of natural leather (or real leather).

A known synthetic leather normally comprises: an upper layer in colored plastic material presenting an external surface on which a relief design is imprinted that reproduces the appearance of natural leather; a support fabric on which the upper layer is glued; and an adhesive layer which is interposed between the top layer and the support fabric to establish a stable mechanical connection between the top layer and the support fabric.

DESCRIPTION OF THE INVENTION

The purpose of the present invention is to produce a synthetic leather and corresponding production method and plant, which allow to obtain a more â € œroundâ € softness and hand, offer greater elasticity for the same quality of coated paste and elastic fabric of support used (ie at the same production cost), and at the same time are easy and economical to produce.

According to the present invention, a synthetic leather and corresponding production method and plant are made, according to what is claimed by the attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the attached drawings, which illustrate a non-limiting example of embodiment, in which:

â € ¢ Figure 1 is a schematic and cross-sectional view of a synthetic leather made in accordance with the present invention;

â € ¢ Figure 2 is a schematic and plan view of an adhesive layer of the synthetic leather of Figure 1; and â € ¢ Figure 3 is a schematic and side view of a gumming station in which the adhesive layer of Figure 2 is applied.

PREFERRED FORMS OF IMPLEMENTATION OF THE INVENTION

In figure 1, the number 1 indicates a synthetic leather as a whole.

The synthetic leather 1 comprises an upper layer 2 in colored plastic material presenting an external surface 3 on which a relief design and a possible colored print reproducing the appearance of the natural leather is imprinted. Furthermore, the synthetic leather 1 comprises an intermediate layer 4 made of plastic material, generally of a neutral color, which is arranged immediately below the upper layer 2. Finally, the synthetic leather 1 comprises an elastic support fabric 5 on which the layers 2 and 4 are glued by means of the interposition of an adhesive layer 6; in other words, the adhesive layer 6 is interposed between the layers 2 and 4 and the elastic support fabric 5 to establish a stable mechanical connection between the layers 2 and 4 and the elastic support fabric 5.

As an example, the upper layer 2 can be based on a hydrocarbon-based plasticizer to which it is added: a UV stabilizer that protects the material from sunlight, a flame retardant solution that confers flame retardant properties, a dye, and calcium carbonate as an inert filler. The intermediate layer 4 has a composition similar to the upper layer 2, from which it differs in the presence of expanding substances which swell during cooking, giving it softness and thickness.

The elastic support fabric 5 is generally made of 100% Nylon and is of the â € œinterlockâ € type, normally thermo-set at 190-200 ° C to present good shape and dimensional stability even at high temperatures.

According to a preferred embodiment, the adhesive layer 5 comprises a plurality of empty spaces 7 which separate a series of points 8 of adhesive material from one another. According to what is better illustrated in Figure 3, the adhesive layer 6 is shaped like a checkerboard showing a cyclic alternation of points 8 of adhesive material and empty spaces 7. Preferably, the empty spaces 7 each have an area similar to the points 8 of adhesive material so that the proportion between the volume occupied by the empty spaces 7 and the volume occupied by the points 8 of adhesive material is close to 1: 1; in other words, the volume of the empty spaces 7 occupies approximately 50% of the total volume of the adhesive layer 6 (more generally, the volume of the empty spaces 7 occupies approximately 40% -60% of the total volume of the adhesive layer 6).

The presence of empty spaces 7 in the adhesive layer 6 allows to give a greater softness to the touch to the synthetic leather 1 to the advantage of the perceived quality of the synthetic leather 1 itself, as well as a better elasticity of the material for the same quality of the coating paste used ; in other words, the presence of the empty spaces 7 in the adhesive layer 6 allows a considerable elastic deformability of the adhesive layer 6 which, in turn, allows the synthetic leather 1 to be softer to the touch.

According to a preferred embodiment, the relief pattern of the outer surface 3 of the upper layer 2 has an opaque embossing. In this way, the external surface 3 has a lower reflection of light and therefore offers an overall appearance more similar to natural leather (ie less â € œplasticâ €).

According to a preferred embodiment, the outer surface 3 of the upper layer 2 is covered with a protective finish 9 containing a percentage of wax comprised between 5% and 10%. The presence of wax in the protective finishing 9 affects the reflection of light from the external surface 3, giving the external surface 3 an appearance more similar to natural leather (ie less â € œplasticyâ €); moreover, the presence of the wax in the protective finish 9 also gives the upper layer 2 a more pleasant and natural hand (ie less â € œplasticyâ €). According to a preferred embodiment, the protective finishing 9 contains polyurethane microspheres inside. The presence of the polyurethane microspheres in the protective finish 9 makes the upper layer 2 more similar to natural leather, as it avoids the so-called â € œwriting effectâ €, that is, it allows to avoid that passing the hand on the external surface 3 remains a â € œaloneâ € in correspondence of the areas where the hand has passed. On the contrary, a normal opaque finish, which contains particles of mica flakes, is subject to the writing effect: passing the hand on the external surface 3 orient the mica particles that leave an imprint (i.e. a halo), like microfiber fabrics.

As previously mentioned, the elastic support fabric 5 is made of 100% Nylon and is of the â € œinterlockâ € type; the â € œinterlockâ € construction is particularly advantageous as it gives, with the same material used, greater elasticity. According to a preferred embodiment, the elastic support fabric 5 has a weight of approximately 60 grams per square meter (approximately ± 5%) and a thickness of approximately 0.45 mm (approximately ± 5%); this combination of weight and thickness is particularly advantageous as it gives an optimal sensation of softness to the touch (ie when a user touches the synthetic leather 1 he feels a particularly pleasant and therefore appreciated tactile sensation of softness). Finally, the elastic support fabric 5 has an elongation (measured according to what is established by the UNI EN ISO standards) both in the sense of the weft and in the sense of the warp and applying a load of 5 kg greater than 140%. These characteristics of elasticity of the elastic support fabric 5 improve the workability of the synthetic leather 1 and, at the same time, give the synthetic leather 1 a consistency more appreciated by users (as it is easier to work during the saddling phase because it does not have unsightly creases even in the presence of accentuated undercuts or elbows to be covered).

A production method of the synthetic leather 1 described above is described below.

Initially, a web of embossed paper is unwound from a reel on which, in a spreading machine, the upper layer 2 of colored plastic material (having the consistency of a dense liquid) is coldly spread in such a way that an external surface 3 of the upper layer 2 is in contact with the embossed paper tape to imprint on the external surface 3 a relief design that reproduces the appearance of the leather.

Subsequently, the paper web carrying the upper layer 2 is passed into a cooking oven to cook the upper layer 2 so as to gel the upper layer 2 itself (ie to obtain the transformation of the resin from the liquid state to the rubbery state).

After the first passage in the cooking oven, on the upper layer 2, in a spreading machine, the intermediate layer 4 in plastic material (having the consistency of a thick liquid) is coldly spread. Subsequently, the paper ribbon carrying also the intermediate layer 4 is again passed into a cooking oven to cook the intermediate layer 4 so as to gel the intermediate layer 4 itself (i.e. to obtain the transformation of the resin from the liquid state to the rubbery state) .

After the second passage in the baking oven, the adhesive layer 6 is applied on the intermediate layer 4 (and therefore, indirectly, on the upper layer 2) in a gumming station 10 (schematically illustrated in Figure 3). Downstream of the gumming station 10, the elastic support fabric 5 is placed on the adhesive layer 6 to establish a stable mechanical connection between the layers 2 and 4 and the elastic support fabric 5 by means of the interposition of the adhesive layer 6.

Finally, the production of synthetic leather 1 ends with the removal of the paper tape which can be reused for the creation of a new production batch.

As shown in Figure 3, the gumming station 10 comprises an applicator roller 11 which applies the points 8 of adhesive material on the layers 2 and 4. The lateral surface of the applicator roller 11 has a plurality of recesses 12 reproducing the final pattern of the points. 8 of adhesive material. Coupled to the applicator roller 11 is an upper hopper 13 containing a mass 14 of adhesive material which transfers the adhesive material inside the recesses 12; downstream of the hopper 13 there is a doctor blade 14 to equalize and uniformly distribute the adhesive material inside the recesses 12.

The synthetic leather 1 described above has numerous advantages.

In the first place, the synthetic leather 1 described above has physical characteristics very similar to the characteristics of natural leather; in particular, the synthetic leather 1 described above has an appearance very similar to natural leather, a consistency and softness very similar to natural leather, and a more pleasant and soft hand.

Furthermore, the synthetic leather 1 described above is simple and inexpensive to manufacture, since its total production cost is completely similar to the total production cost of traditional synthetic leather.

Finally, the synthetic leather 1 described above is more easily workable during the saddling phase; in fact, thanks to a similar good elasticity in the weft and in the warp, the synthetic leather 1 described above does not have unsightly creases even in the presence of accentuated undercuts or elbows to be covered.

Claims (14)

R I V E N D I C A Z I O N I 1) Synthetic leather (1) comprising: an upper layer (2) in colored plastic material presenting an external surface (3) on which a relief design is imprinted that reproduces the appearance of natural leather; an elastic support fabric (5) on which the upper layer (2) is glued; and an adhesive layer (6) which is interposed between the upper layer (2) and the elastic supporting fabric (5) to establish a stable mechanical connection between the upper layer (2) and the elastic supporting fabric (5); the synthetic leather (1) is characterized by the fact that the adhesive layer (6) comprises a plurality of empty spaces (7) which separate a series of points (8) of adhesive material from one another. 2) Synthetic leather (1) according to claim 1, wherein the adhesive layer (6) is shaped like a checkerboard presenting a cyclic alternation of points (8) of adhesive material and empty spaces (7). 3) Synthetic leather (1) according to claim 1 or 2, wherein the empty spaces (7) each have an area similar to the points (8) of adhesive material. 4) Synthetic leather (1) according to claim 1, 2 or 3, wherein the relief pattern of the outer surface (3) of the upper layer (2) has an opaque embossing. 5) Synthetic leather (1) according to one of claims 1 to 4, wherein: the support elastic fabric (5) is of the â € œinterlockâ € type; the elastic supporting fabric (5) has a weight of about 60 grams per square meter and a thickness of about 0.45 mm; and the support elastic fabric (5) has an elongation both in the sense of the weft and in the sense of the warp and applying a load of 5 kg greater than 140%. 6) Synthetic leather (1) according to one of claims 1 to 5, wherein the outer surface (3) of the upper layer (2) is covered with a protective finish (9) containing 5% wax and 10%. 7) Synthetic leather (1) according to one of claims 1 to 6, wherein the outer surface (3) of the upper layer (2) is covered with a protective finish (9) containing polyurethane microspheres inside. 8) Synthetic leather (1) comprising: an upper layer (2) in colored plastic material presenting an external surface (3) on which a relief design is imprinted that reproduces the appearance of the leather; an elastic support fabric (5) on which the upper layer (2) is glued; and an adhesive layer (6) which is interposed between the upper layer (2) and the elastic supporting fabric (5) to establish a stable mechanical connection between the upper layer (2) and the elastic supporting fabric (5); the synthetic leather (1) is characterized by the fact that the relief design of the external surface (3) of the upper layer (2) has an opaque embossing. 9) Synthetic leather (1) comprising: an upper layer (2) in colored plastic material presenting an external surface (3) on which a relief design is imprinted that reproduces the appearance of the leather; an elastic support fabric (5) on which the upper layer (2) is glued; and an adhesive layer (6) which is interposed between the upper layer (2) and the elastic supporting fabric (5) to establish a stable mechanical connection between the upper layer (2) and the elastic supporting fabric (5); the synthetic leather (1) is characterized by the fact that: the elastic support fabric (5) is of the â € œinterlockâ € type; the elastic supporting fabric (5) has a weight of about 60 grams per square meter and a thickness of about 0.45 mm; and the support elastic fabric (5) has an elongation both in the sense of the weft and in the sense of the warp and applying a load of 5 kg greater than 140%. 10) Synthetic leather (1) comprising: an upper layer (2) in colored plastic material presenting an external surface (3) on which a relief design is imprinted that reproduces the appearance of the leather; an elastic support fabric (5) on which the upper layer (2) is glued; and an adhesive layer (6) which is interposed between the upper layer (2) and the elastic supporting fabric (5) to establish a stable mechanical connection between the upper layer (2) and the elastic supporting fabric (5); the synthetic leather (1) is characterized by the fact that the external surface (3) of the upper layer (2) is covered with a protective finishing (9) containing a percentage of wax between 5% and 10%. 11) Synthetic leather (1) comprising: an upper layer (2) in colored plastic material presenting an external surface (3) on which a relief design is imprinted that reproduces the appearance of the leather; an elastic support fabric (5) on which the upper layer (2) is glued; and an adhesive layer (6) which is interposed between the upper layer (2) and the elastic supporting fabric (5) to establish a stable mechanical connection between the upper layer (2) and the elastic supporting fabric (5); the synthetic leather (1) is characterized by the fact that the external surface (3) of the upper layer (2) is covered with a protective finish (9) containing polyurethane microspheres. 12) Method of production of a synthetic leather (1); the production method includes the steps of: spread an upper layer (2) of colored plastic material on an embossed paper tape so that an outer surface (3) of the upper layer (2) is in contact with the embossed paper tape to impress on the outer surface (3) itself a relief design that reproduces the appearance of the leather; baking the paper tape provided with the upper layer (2) in the oven to gel the upper layer (2) itself; applying an adhesive layer (6) to the upper layer (2); placing an elastic support fabric (5) on top of the adhesive layer (6) to establish a stable mechanical connection between the upper layer (2) and the elastic support fabric (5) by interposing the adhesive layer (6); the production method is characterized by the fact that the adhesive layer (6) comprises a plurality of empty spaces (7) which separate a series of points (8) of adhesive material from one another. 13) Production method according to claim 12, in which the adhesive layer (6) is applied by means of an applicator roller (11), the lateral surface of which has a plurality of recesses (12) reproducing the final design of the points (8) of adhesive material. 14) Production plant of a synthetic leather (1); the production plant includes: a spreading machine for spreading an upper layer (2) of colored plastic material on an embossed paper web so that an external surface (3) of the upper layer (2) is in contact with the embossed paper web to imprint on the surface (3) the exterior itself is a relief design that reproduces the appearance of the leather; a cooking oven for cooking the paper web provided with the upper layer (2) so as to gel the upper layer (2) itself; a gumming station (10) for applying an adhesive layer (6) to the upper layer (2); an application station for placing an elastic support fabric (5) on top of the adhesive layer (6) so as to establish a stable mechanical connection between the upper layer (2) and the elastic support fabric (5) by means of interposition of the adhesive layer (6); the production plant is characterized by the fact that the gumming station (10) is able to apply the adhesive layer (6) in such a way that the adhesive layer (6) comprises a plurality of empty spaces (7) which they separate a series of points (8) of adhesive material from one another.