WO1995033094A1

WO1995033094A1 - Safety yarn and process for its manufacture

Info

Publication number: WO1995033094A1
Application number: PCT/IT1994/000073
Authority: WO
Inventors: Roberto Del Dotto; Marco Del Dotto
Original assignee: I.L.C. Del Dotto S.R.L.
Priority date: 1994-05-31
Filing date: 1994-05-31
Publication date: 1995-12-07
Also published as: EP0729529A1; EP0729529B1; DE69422828D1

Abstract

The yarn (F) will be passed, according to the process, through a homogeneous liquid mixture of pure pigments with solvents, so as to become luminescent and visible in a colour shade different from the optic one, if exposed to a Wood lamp.

Description

SAFETY YARN AND PROCESS FOR ITS MANUFACTURE

The present invention concerns a safety yarn that may be applied for preventing counterfeits and falsifications into the seams and decorations of documents, like passports and similar, and of leather goods and clothing, of the kind becoming luminescent if exposed to light sources like ultraviolet Wood lamps, and the realization process thereof.

It is well known that articles covered with luminescent substances, even if showing a conventional colouring when they are exposed to the optic spectrum, i.e. between 4,000 and 7,000 Angstrom wave length, when exposed to the ultraviolet rays of a Wood lamp show their luminescence with different colours and shades.

It is the aim of the present invention to exploit such feature for the realization of a new kind of yarn which, used on documents, leather goods and clothing, does not show at sight, on optic frequences, any difference to conventional yarns but that, if exposed to the Wood lamp, becomes luminescent, with colours and shades completely different from those visible to the naked eye. The aim is reached, according to the present invention, by means of a yarn of the synthetic kind like polyamide, polyester and similar, raw or dyed and lubricated with silicone mixtures, or by means of a yarn of a cotton-synthetic mixture, raw or dyed and polished, satined or glazed by means of flours, grease, wax, paraffin-oil, silicon so as to eliminate all down which is always present in cotton, which is passed, according to the process, through a liquid homogeneous mixture of pure pigment with solvents, so as to become luminescent and remarkable in a colour shade, if exposed to the Wood lamp, different from the optical one.

The main advantage of the yarn obtained by means of the process according to the present invention, consists in that the determined shade may be perfectly seen, under the Wood lamp, without any difference of shade in the chosen colour, so as to prevent any counterfeit to the documents and the goods to which it will be applied.

The present invention will be described more in detail hereinbelow referring to the enclosed drawing in which a vertical scheme is shown of the means used for the realization process of the yarn according to the present invention. The figure shows the means and the sequence of the realization phases for obtaining a safety yarn for preventing counterfeits and falsifications of documents and leather goods and clothing, characterized in:

- a plurality of means 1 for the controlled stretching of the yarn F coming from an initial twisting bobin R;

- a small basin 2 having the shape of a half cylinder, fed with constant quantities of a mixture of ink and solvent by means of a drop proportioning device 3 with adjustable flow, and containing an electrically operated first steel roll 4 under which passes said yarn F in its obliged way, getting completely immersed into said small basin 2;

- a second steel roll 5, kept pressed against said first roll 4 and covered with absorbent material that sucks the mixture and spreads it with extreme evennes onto said yarn F passing between the two rolls;

- a device 6 for keeping rolls 5 and 4 pushed one against the other, with a mechanical self-adjusting force, according to the thickness of the yarn F, for avoiding that said yarns carries along too much mixture;

- a pottery thread-guide 7, placed before the inlet of the yarn F into the small basin 2 and that may be horizontally adjusted for increasing the lasting of the absorbent material of roll 5 which, due to the sliding speed of yarn F, gets quickly worn, and for delaying the sliding between rolls 4 and 5, due to the considerable mechanic friction of said yarn F onto the absorbent material, which is the cause of its periodic replacement;

- a third steel roll 8, partially immersed into a basin 9 containing lubricant for providing yarn F, with which it gets into contact, with the flowability requested for sewing, by means of a second lubrication: infact, the first lubrication performed onto said yarn F before its immersion into the mixture is partially reduced by the imbibition;

- a plurality of thread-guides 10 placed before and behind roll 8;

- a Wood lamp placed between the outlet from said basin 9 and the final winding of yarn F, for the immediate visual control of the result;

- a winding means 11 for the yarn F.

The process will be completed by the electronic precision meter counter 12, by means of which the chosen length, according to the kind and thickness of the yarn F used, may be programmed, and by the controll 13 of the oil level in the operating machine.

Claims

1. A safety yarn for preventing counterfeits and falsifications onto documents, leather goods and clothing, characterized in that it passes, according to the process, through a homogeneous liquid mixture of pure pigment with solvents, so as to become luminescent and visible in a determined colour shade, if exposed to a Wood lamp.

2. A safety yarn according to claim 1, characterized in the realization process comprising:

- a plurality of means (1) for the controlled stretching of the yarn (F) coming from an initial twisting bobin (R);

- a small basin (2) having the shape of a half cylinder, fed with constant quantities of a mixture of ink and solvent by means of a drop proportioning device (3) with adjustable flow, and containing an electrically operated first steel roll (4) under which passes said yarn (F) in its obliged way, getting completely immersed into said small basin

(2);

- a second steel roll (5), kept pressed against said first roll (4) and covered with absorbent material that sucks the mixture and spreads it with extreme evennes onto said yarn (F) passing between the two rolls;

- a device (6) for keeping rolls (5) and (4) pushed one against the other, with a mechanical self- adjusting force, according to the thickness of the yarn (F), for avoiding that said yarns carries along too much mixture;

- a pottery thread-guide (7), placed before the inlet of the yarn (F) into the small basin (2) and that may be horizontally adjusted for increasing the lasting of the absorbent material of roll (5) which, due to the sliding speed of yarn (F), gets quickly worn, and for delaying the sliding between rolls (4) and (5), due to the considerable mechanic friction of said yarn (F) onto the absorbent material, which is the cause of its periodic replacement;

- a third steel roll (8), partially immersed into a basin (9) containing lubricant for providing yarn (F), with which it gets into contact, with the flowability requested for sewing, by means of a second lubrication: infact, the first lubrication performed onto said yarn (F) before its immersion into the mixture is partially reduced by the imbibition;

- a plurality of thread-guides (10) placed before and behind roll (8); - a Wood lamp placed between the outlet from said basin (9) and the final winding of yarn (F), for the immediate visual control of the result;

- a winding means (11) for the yarn (F).

3. A process for realizing the safety device according to claim 1, characterized in the presence of an electronic precision meter counter, for counting the chosen lengths of the yarn, according to the kind and the thickness thereof.