IT202100030059A1 - “METHOD OF FINISHING LEATHER THROUGH THE DIRECT APPLICATION ON IT OF ACRYLIC, POLYURETHANE PRODUCTS, WAXES, THICKENING PRODUCTS, RELEASE PRODUCTS AND SIMILAR PRODUCTS” - Google Patents

Description

DESCRIPTION

Description of the invention with TITLE:

?Method of finishing leather through the direct application on it of acrylic, polyurethane, wax, thickeners, release agents and similar products, through the use of embossed release papers? on behalf

Summary and scope

The invention has its field of application in the leather processing industry, in particular in the finishing of leather surfaces, through coloring, application of release papers, elimination of defects from the surface.

The invention consists in placing the finishing products directly on the leather, by creating a film or surface layer of acrylic products, polyurethanes, waxes, thickeners, release agents and similar products without having to apply such products first on the paper, and then transfer them onto the leather. The process allows for the elimination of some phases compared to traditional processing, which normally involves the application of finishing products on paper, and then transferring them from this to the leather. The procedure found instead avoids the application of the products on paper with a whole series of consequent advantages in terms of time saving and space reduction, as it avoids the use of in-line machines connected to each other, while maintaining the same result in terms of quality? of the finished product.

State of the art

The finishing of the leather? the set of all those operations that are carried out on dry hides, after the wet phases carried out in the drum (and/or reel, tank, etc.) after drying. The purpose of the finishing? to give the necessary appearance and characteristics to the leather, based on the final articles requested (in the footwear, leather goods, clothing, furniture, car interiors, etc.) sectors, bringing the colors in tone, uniform, bright or opaque depending on the requests.

Very often the leathers present, on the grain side, a series of defects, the most sometimes natural, pre-existing that is? on the skins themselves, more? rarely caused by manufacturing accidents. In these cases ? the finishing which must remedy by eliminating or at least making these defects less visible, so as to allow the best use of the leather in question.

The finishing consists in the application, on the surface of the leather, of substances of various chemical nature, which form a thicker film. or less thin, transparent, elastic or hard, depending on the type of finishing and leather. This film must bond to the surface of the leather, so that it becomes one with it.

The traditional finishing methods are spraying, manual dabbing, coating and veiling.

Market needs in recent years have directed leather producers to seek alternative finishing methods by looking around in similar sectors (fabrics and imitation leather) to try to obtain more refined leathers. uniform in order to reduce waste to a minimum. Alternative systems to the traditional ones were therefore born which made it possible to improve the selection of leather by carrying out a qualitative transformation of the production from defective leathers having the capacity to ?mask the defects?.

Current systems for masking defects involve spreading the products on paper and then transferring them onto the skin. This happens in two ways:

1- In line system: once the spreading and drying of the products on the paper and leather has been completed, the paper is placed directly in contact with the leather, transferring the products themselves (product film) and the desired effect.

2- Paper ready to apply: are there already papers on the market? treated and worked on which are already? the products have been applied in the factory. These papers can be purchased in reels of various sizes and only in black and white colours. However, these cards must also be disposed of after the first use. Even in this case the hides must be spread and/or sprayed with finishing products and then put them in contact with these papers.

Problems of traditional applications

The systems currently used present the following problems: 1) the systems are generally complex, made up of one or more? coaters and dryers arranged in line and connected. There? involves high construction costs and the need? of large spaces for the dislocation of machinery, with dimensions exceeding 100 metres. 2) Are systems of this type suitable for large-scale production? high for colors, such as black and white. These systems are not suitable for small and medium productions of other colours, since they are every color change involves cleaning the systems and machine downtime. 3) Often the entire surface of the paper does not come into contact with the skin, as the latter has natural shapes of irregular sizes and shapes. The surfaces of the paper not coupled with the leather, before reusing the paper, must be cleaned with large reels of scotch tape which remove the film of products remaining on it, generating large quantities of of refusal. The card has a short duration of approximately 5? 10 cycles. 4) Generally the papers ready to apply are prepared with white or black colored products. When other colors need to be created, white paper is used and then the leather is colored using traditional methods. This procedure involves the duplication of costs and production times because? the color must be changed each time. Furthermore, every restart of the system, whether due to the reel running out or the color change of the papers ready for use, involves the loss of meters of paper, as well as a quantity? considerable amount of waste.

Detailed description of the invention and improvement of the state of the art

This innovative method consists in applying the finishing products: acrylics, polyurethanes, waxes, release agents, thickeners and others, directly onto the hides with traditional machinery in the tanning sector such as: coating machines (such as the ?Gemata? brand), glazing machines, spray and/or pad , without first applying them to the paper.

This procedure avoids the time-consuming step of applying the products first on paper and then on leather, which requires machinery that works in line and uses large quantities. of paper, as well as speeding up processing by eliminating a step.

It allows you to apply neutral release papers (papers on which a decorative relief design is normally imprinted which is released). without finishing products, using normal presses (such as Mostardini and Rotopress) which are normally used to iron leather. All finishing products are instead applied to the leather and not to the paper. Release papers without finishing products transfer their designs/prints onto the film of products previously applied to leather, facilitating, simplifying and economizing the process compared to traditional methods. The paper also has a much longer reuse life. long not being treated.

The process found allows a design to be given only to the film of products applied directly to the leather, thus not altering the softness and natural characteristics of the leather, as the latter is not engraved by the presses.

PROCEDURE STEPS:

1) Application phase of the products on the leather: in the first phase the finishing products are applied by spraying or equivalent method directly onto the leather; 2) Drying phase: the leather is dried inside an oven, blowing hot air or LED lamps;

3) Coating phase: the leather is passed through a machine equipped with a roller (of the "Gemata" brand type) in order to adhere, spread and apply further finishing products on the leather in a uniform manner;

4) Drying phase: the leather is dried again;

5) Printing phase with paper: the leather is coupled with neutral and dry paper, not treated with finishing materials and passed through a press in order to transfer the design from the paper to the leather.

Advantages of the procedure

The advantages of our system are: 1) avoiding the use of in-line and connected machinery, saving space and time;

2) avoid paper waste; in fact, the process does not have the limit of having to process a minimum quantity of leather and paper: in the classic system, paper is stretched on a belt and must be sprayed with the product, then the paper must be cleaned of the finishing product to allow it to be reused; 3) our invention does not involve spraying on paper, therefore it avoids cleaning it as happens in the traditional method, consequently allowing the paper to last longer and reusing it more quickly. times; 4) in the traditional system? It is necessary to wait for both the paper and the leather to dry while in the procedure described? Only the skin needs to be dried. From there? further advantages arise from this: 5) savings in investments for the creation of expensive systems both for sequential coating and for the production of paper/polypropylene with applied films; 6) energy saving due to the reduced use of machinery as the products are applied directly to the leather; 7) reduction of polluting factors, eliminating waste of both unapplied film and used paper; 8) versatility? and speed? of carrying out the finishing process in all colours; 9) this process? usable on all types of leather: bovine, sheep, goat, full grain, buffed and split, maintaining the standards required by the market.

The invention, ultimately, allows a finishing with color and/or design to be carried out directly on the leather through the application of untreated papers and the direct application of the finishing products with machinery and ironing presses (such as Mostardini and Rotopress), avoiding all the laborious and expensive processes normally used.

Detailed description of an embodiment of the invention

Taking into account the steps described above and the claims, according to one embodiment the raw leather is placed directly on the spraying machine which will spread it. finishing products on it (acrylics, polyurethanes, waxes, thickeners, release agents and similar products) creating a surface film on the leather itself.

In order to make this surface layer or film of products well adhered and joined to the leather, it is dried in an industrial oven.

What's leather like? treated is then placed on a roller coating machine and done so? pass inside the rollers which release further finishing products.

After having spread this second layer of finishing products, the leather will be subjected to a second drying inside an industrial oven. This drying allows the adhesion of the second layer of finishes to the first layer.

To leather like this? treated, the dry, untreated embossed paper is laminated, i.e. without any product applied on it. Leather and paper like this? coupled, they are placed on a hydraulic press of the type used for printing and ironing. By activating the press, the workmanship or design present on the paper is transferred and imprinted on the layers of products adhered to the leather in an indelible and permanent way, thus creating? the finished product.

Claims (1)

1) Process of leather processing through the direct application on it of one or more layers of acrylic, polyurethane, waxes, paints, thickeners, release agents and similar products on which to directly carry out finishing, colouring, printing and engraving using untreated n? processed, characterized by the fact that it includes the phases of: - (a) application of finishing products and/or paints directly onto leather; - (b) drying of finishes on the leather; - (c) spreading of further finishing products; - (d) second drying; - (e) printing and finishing of the leather through pressure lamination with untreated and dry paper; 2) process according to claim 1 characterized by the fact that the film or surface layer of acrylic, polyurethane, wax, paint, thickeners, release agents and similar products is applied (a) solely and directly to the leather using spray and/or roller machines of an industrial or similar type; 3) procedure according to one or more? preceding claims characterized by the fact that the drying phases (b-d) are carried out using hot air blowing ovens and/or LED lamps; 4) procedure according to one or more? preceding claims characterized by the fact that further finishing products are spread and made to adhere to the previous film of products applied (a) on the leather by passing the latter through releasing and applying roller machinery (c) said products and/or paints of various colors; 5) procedure according to one or more? preceding claims characterized by the fact that said paper is dry and free of treatments? release type, embossed, or similar; 6) procedure according to one or more? preceding claims characterized by the fact that said paper is placed on and coupled to the leather treated with the finishing agents (a-b-c-d) and passed through hydraulic presses which are activated (e); 7) procedure according to one or more? preceding claims characterized by the fact that said pressure (e) transfers the processing and/or embossing and/or design from the paper to the film of products previously applied (a-b-c-d) on the leather; 8) procedure according to one or more? preceding claims characterized by the fact that said paper, without treatment with finishes and/or paints, is reused more? times for further processing such as that referred to in the previous claims.