Method for making a colored relief strip by etching

Abstract: The invention relates to a method for making a relief strip, comprising the steps of etching the strip, causing the etched strip to pass through a coloring line, a silicone solution metering unit, to meter a silicone solution on the strip etched portion, introducing the strip into a mold having a plurality of mold cavities of different cross-sections and spacings, therefrom a vacuum metered ink amount is ejected and caused to enter the recess of the material, and causing the strip to further pass through an infrared oven, and finally brushing the strip.

Description: BACKGROUND OF THE INVENTION The present invention relates to a method for making a relief colored strip. In particular, a prior art method for making relief colored strips comprises the following operating steps. At first, is carried out an etching step by using a 20/30 ton eccentric press, on a polypropylene support having a size of 9.5 millimeters and a thickness of 400 µm (microns), or on a polyamide support having the same size. The eccentric press is provided with a mold holder, supporting a mold having a plurality of inside modular letter-shaped recesses each having a length of 4.5 millimeters and a pointed tip. The composition of a letter array will define a text to be reproduced by the machine. Then, the etching pressure is adjusted, and the etching thickness is controlled preferably to 80/90 microns. The etched material is conveyed to a coloring line, or system, which is conventionally called "COLORING MACHINE". The strip is caused to pass under a liquid colored resin delivery device, using as a base a colored chlorosulphonated polyethylene, and brought into a solution in a rate of 20% of dry extract, with an aromatic solvent. Suitable rubbing blades remove on the flat portion of the strip the exceeding ink and the strip is then caused to pass through an infrared oven and is brought to a dry condition. A rotary brush assembly at the outlet of the oven will fully clean residual materials of the strip, more specifically of the flat portion of the strip. Then, as an end result, we will have an inked portion in the letter recesses, and a remaining perfectly clear portion. The colored mass is constituted by: Chloro-sulphonated polyethylene base 618 p CACO 3 163.5 p Titanium dioxide 94 p Pigment 63 p Catalyzer 1.5 p Aromatic solvent 60 p Total 1000 p To 1 Kg of the above base material there are added 500 g of an aromatic solvent. The colored paste base comprises: Chloro-sulphonated polyethylene 251 p 200 magnesium oxide 37 p PE 200 7.7 p PolAC 616 4.9 p Tinuvin 0.6 p Aromatic solvent 698.8 p Total 1000 p However, the above disclosed method has the disadvantageous effect that the ink also adheres to undesired portions of the strip being processed. SUMMARY OF THE INVENTION The aim of the present invention is to provide a method for making a relief colored strip in which the ink material is prevented from adhering to undesired portions of the strip, by using a releasing type of process. Within the scope of the above mentioned aim, a main object of the present invention is to provide a specifically designed ink having very high anti-abrading strength, as well as a very high anti-ageing strength against the atmospheric agents and ultraviolet radiation. The above mentioned aim and objects, as well as yet other objects are achieved by the present invention which specifically relates to a method for making a colored relief strip comprising a first etching step in which said strip is etched, said method further comprising the steps of causing said etched strip to pass through a coloring line and a releasing solution metering unit, provided for metering said solution on said strip etched portion, introducing said strip into a mold provided with a plurality of different cross-section and spacing cavities, and causing the ink to exit said cavities under vacuum and in a properly metered condition, to allow said ink to enter the material recess, conveying the strip through an infrared oven and brushing the strip. Further details and advantages as well as important features of the present invention will become more apparent hereinafter from the following detailed exemplary disclosure of a preferred embodiment of the inventive method, which has been given by way of a merely indicative example for illustrating several possible variations of the invention. More specifically, the inventive method comprises a strip etching step, in which the strip is etched by using a 20-30 ton press, on a polypropylene support having a 9.5 millimeter size and a thickness of 400 µm (microns) or by using a polyamide support having the same size. The eccentric press comprises a mold holder, thereon a mold is set, said mold having in its inside a plurality of modular letters having a length of 4.5 millimeters and a pointed tip. The composition of a letter array will define a text to be reproduced by the machine. Thus the etching pressure is adjusted, and the etching thickness is controlled, preferably, to 80/90 µm (microns). After having etched the strip by the above disclosed system, the strip is caused to pass through a coloring line, in which a releasing solution is metered on the etched portion of the strip. This operation is adapted to meter on said strip a primer amount corresponding to a thickness of a µm (micron) through the overall flat region of the polypropylene or polyamide material. This processing step is performed in order to prevent the ink mass from attaching to the flat surface. Then, the strip is introduced into a mold provided with a plurality of different cross-section and spacing cavities, therefrom the ink is caused to be ejected under vacuum and as suitably metered to enter the material recess. The mold comprises moreover an ink recovering nozzle, for recovering the excess ink and causing it to be sent again to the under-vacuum vessel. Thus, in such a closed loop operation, the viscosity of the ink will be held unaltered. Then, the strip is conveyed to an infrared radiation oven and, at the outlet of said oven, the strip is processed through the two sides thereof by a brushing system. The colored mass comprises: 1 Chloro-sulphonated polyethylene base 523 p 2 WN3 43.8 p 3 Gem resin 17.7 p 4 Titanium dioxide 100 p 5 828 Resin 17.7 p 6 Pigment 77 p 7 Aromatic solvent 220.8 p Total 1000 p To 1 kg of the above base material 1/2 kg aromatic solvent is added. The colored paste base comprises 1 Chloro-sulphonated polyethylene 848 p 2 Ci8 Resin 50.5 p 3 PolAC 616 27 p 4 Titanium 70.3 p 5 Irganox 2.1 p 6 Tinovin P 2.1 p Total 1000 p To 285 gr of said base 715 gr of aromatic solvent are added. It should be pointed out that a first important advantage of the present invention consists of the releasing process, which is performed in order to prevent the ink material from adhering to undesired portions of the strips. A further advantage derives from the construction of the automatic metering head, of the vacuum continuous jet type with a recycle, and of the cleaning system performing the cleaning operation on both sides. Finally, it should be pointed out that the chemical composition of the ink will provide a greater resistance against abrading, ageing, atmospheric agents and UV radiation.

Claims: A method for making a colored relief strip comprising: a) a first etching step in which said strip is etched by using a press so as to form recesses in the strip, b) a step of causing said etched strip to pass through a coloring line, in which a releasing solution is metered through a releasing solution metering unit on said etched strip in order to prevent ink from attaching to the flat surface of said etched strip, c) introducing said strip into a mold provided with a plurality of cavities having different cross-sections and spacings, d) causing ink to exit said cavities under vacuum condition and under properly metered condition, such that said ink enters said recesses, e) conveying the strip through an infrared oven, and f) brushing the strip. A method according to Claim 1, characterized in that said mold is provided with an excess ink recovering nozzle, for recovering the excess ink and converging the recovered ink to a vacuum vessel. A method according to Claim 1, characterized in that said releasing solution is coated on the overall flat portion of the strip with a primer amount corresponding to a thickness of one µm (micron). A method according to Claim 1, characterized in that said brushing step is carried out on the two sides of said strip. A method according to Claim 1, characterized in that said colored mass comprises: a chlorosulphonated polyethylene base 523 parts; WN3 43.8 parts; Gem resin 17.7 parts; Titanium dioxide 100 parts; Resin 828 17.7 parts; Pigment 77 parts; Aromatic solvent 220.8 parts, to a total of 1000 parts. A method according to Claim 5, characterized in that to each Kg of said base 1/2 Kg of an aromatic solvent is added. A method according to Claim 1, characterized in that the colored paste base comprises: Chlorosulphonated polyethylene 848 parts; Resin Ci8 50.5 parts; Pol AC 616 27 parts; Titanium 70.3 parts; Irganox 2.1 parts; Tinovin P 2.1 parts, to a total of 1000 parts. A method according to Claim 7, characterized in that to each 285 grams of said base 715 grams of aromatic solvent are added.

Inventors: FERRO MARIO, FERRO, MARIO
Applicants: VENETA DECALCOGOMME S R L, VENETA DECALCOGOMME S.R.L
Application year: 1999
Main classification: B41M1
IPC codes: B41M3, B41M1