MXPA97000691A - Offset printing process on a substrate of plastic material, and the product obtained with me - Google Patents

Abstract

The present invention relates to an offset printing process on a substrate of plastic material, of the type comprising the steps of preparing the metal sheet containing the inked image to be reproduced, followed by a step of preparing the rotary printing press, to finally indirectly reproduce the image on the surface of a substrate, wherein the offset printing process includes at least one drying step each time the image is recorded, and, the step of preparing the metal sheet comprises incorporating the image to be played back

Description

"PROCESS OF TMPRESTON OFFSET ON A PLASTIC PE MRTFRTßl SUBSTRATE AND THE PRODUCT OBTAINED WITH THE SAME" FIELD OF THE INVENTION The present invention relates to the technique for the reproduction of images on flat surfaces and, more particularly is related to an offset printing process on a substrate of plastic material, and the product obtained with the same.

BACKGROUND PE INVENTION In order to reproduce images on flat surfaces, such as paper, metal, glass, etc., five general printing processes are currently known, namely: relief printing, planographic printing, bas-relief printing, screen printing and electrostatic printing. The printing process that has been used for many years in commercial lithography, is the process of offset printing or indirect printing, which is a planographic process that uses thin metal sheets and inked that contain the image that is going to To reproduce, said image, which has been inked, is first transferred to a repeating roll or cylinder covered with rubber (rubber or rubber), to later print the image on the paper. The offset printing process has had a great application, being used over other printing processes due to the advantages it provides, among which we can cite the convenience for the preparation and assembly of the metal sheets where the image is located to reproduce, the possibility of obtaining good impressions on papers of not very good quality, as well as the speed with which the printing process is carried out, etc. The basic principle of color printing in all printing processes, is based on the use of only three primary colors that create the illusion of finding in the reproduction, the hundreds of colors that the oo can differentiate with respect to the figure original, so the printing processes are carried out using -thin with these three primary colors, these being yellow, rnagen + ay cían, being the ideal complementary blue, green and ro or, respectively, besides using in almost all commercial color printing processes, a fourth color, which is black. The process of color offset printing currently used for the reproduction of images on paper, basically comprises a first stage of preparation of the metal sheet containing the inked image to be reproduced, which has been previously coated on one of its faces with an emulsion layer sensitive to any type of light, which serves to sensitize the surface where the image is to be recorded, by transferring said image from the negative film to the metal sheet, it is recorded in a positive way (the right of the image is on the right), this transfer is done through a photomechanical process using a quartz lamp. The number of sheets that are prepared depends on the rotary press design that will be used, since there are presses that print the image to several inks in a single step, so that they can use from one sheet to eight metal sheets; subsequently, the rotary printing press is prepared by placing the rolled lantern (s) on a cylinder, giving it the necessary tension, and then adjusting the color tones; and, finally, the image is reproduced indirectly on the paper, obtaining the desired printed and colored figure. Prior to the present invention, to protect the images obtained on paper by means of offse4 printing, the already printed paper is coated with a substrate of transparent plastic material, using for this a suitable adhesive; however, the final product obtained has deficiencies in the union of both substrates, in addition to the presence of lumps caused by the adhesive used in the union of said paper and plastic substrates. On the other hand, in the current technique to be able to print on a plastic material, it is necessary to use some other printing process, as it is the case of the sepgrafia; However, this process has the disadvantage of not allowing the printing of images, since it only allows the printing of logos or letters. There is also the process of printing by mesh, in which to print images on a substrate of plastic material, the ink is brushed or roasted through an image of a template or stencil copper a very fine mesh placed on the substrate in where it will be printed. If the printing is in black and white, the process is ideal, but if the printing is to be done in color, the process becomes too slow, since each color is applied separately and must be allowed to dry before applying the next color, which makes it an expensive process. As a consequence of the foregoing, it has been sought to eliminate the drawbacks of current printing processes and provide an offset printing process on a substrate of plastic material, which in addition to eliminating the disadvantages previously established, allows obtaining an economical product of excellent quality .

OBJECTS OF THE INVENTION Taking into account the shortcomings of the prior art, it is an object of the present invention to provide an offset printing process on a substrate of plastic material, which is simple, practical and economical, and yet high efficiency par- to allow the reproduction of images on a substrate of plastic material. It is a further object of the present invention to provide an offset printing process on a plastic material substrate, which allows to eliminate sophisticated printing processes for the reproduction of images on plastic surfaces. It is still an object of the present invention to provide an offset printing process on a substrate of plastic material, which allows to obtain a final product of excellent quality, similar to the images of a photograph. The above objects, as well as other objects and advantages of the invention, are achieved by an offset printing process of the type comprising the steps of preparing them. Metal sheets containing the image to be reproduced; prepare the rotary printing press, winding each of the metal sheets on the corresponding cylinder, to subsequently adjust the color tones; and, reproducing the image on at least one of the faces of a substrate, wherein the offset printing process of the present invention includes the preparation of the metal sheet incorporating the image to be reproduced in reverse, ie the actual right of the image remaining on the left, in addition to including at least one drying stage.

BRFVF DESCRIPTION OF THE DRAWINGS The novel aspects that are considered characteristic of the present invention will be established with particularity in the appended claims. However, the invention itself, both by its organization and its method of operation, together with other objects and advantages thereof, will be better understood in the following descriptions of certain modalities, when read in conjunction with the accompanying drawings, in which: Figure 1 is a rear elevation view of a substrate of transparent plastic material, wherein an image printed upside down on the rear face of said transparent plastic substrate, obtained in accordance with a preferred embodiment of the process, is shown. Offset printing of the present invention. Figure 2 is a front elevational view of the transparent plastic material substrate of Figure 1, where the same image seen by the front face of said substrate is shown. Figure 3 is a top perspective view of a pad for deploying a computer mouse (rnouse pad), wherein the substrate of transparent plastic material bonded to a base material, constructed in accordance with the process < and offset printing of the present invention. nFSCR DETAILED < He has managed to reproduce images directly on surfaces of plastic material by means of offset printing, first modifying the engraving of the image on the metal sheet and later incorporating additional drying steps during the offset printing process. The modification of the engraving of the image and the incorporation of the drying stages, allow the possibility of obtaining a final product of excellent quality, where the reproduced image does not lose its sharpness, nor is it worn away by the use as time goes by. In this way, the offset printing process of the present invention allows the elimination of slow and expensive printing processes, as well as the elimination of adhesive materials that are detrimental to the quality of the final product. As already mentioned in the previous art chapter, the offset printing process currently used for the reproduction of images on a paper substrate, basically comprises a first step of preparing the metal sheet that will contain the image to be reproduced , which has been previously coated on one of its faces with an emulsion layer sensitive to any type of light, which serves to sensitize the surface where the image will be recorded.

When transferring the image to be reproduced from the negative film towards the metal sheet, it is recorded in a positive way, that is, the right of the image is to the right of the sheet, the image transfer being carried out by means of a photomechanical process, for which a table lamp is used. The rotary printing press is then prepared by placing the roll (s) over a cylinder, giving it the necessary tension, and then adjusting the color tones; and, finally, indirectly reproduce the image on paper, obtaining in this way the desired figure, printed and in full color. Referring to FIGS. 1 and 2, a substrate 100 is preferably shown in transparent plastic material, to which an image 101 has been etched onto its back face 102 using the innovative methodology of the present invention, which comprises In general terms, the reproduction backwards of said image 101 on the rear face of the substrate 100. It is important to mention that in the current technique, the reproduction of the image is done to the right and on the front face of a paper substrate or of any other material To carry out the process of the present invention, it is first prepared by at least one metal sheet, transferring the image of a negative film to the metal sheet, so that the image is turned upside down (the actual right of the image is to the left of the sheet). The metal sheet has previously been coated on at least one of its faces with an emulsion sensitive to any type of light, which serves to sensitize the surface where the image to be reproduced will be recorded. Once in the metal sheet, the image is inked and transferred in the offset machine first to a repeat cylinder covered with rubber, in which the image to be engraved is on the right, and this, in turn, transfers it. print on the back side of the transparent plastic substrate, in such a way that it is upside down. This operation of printing the image 101 upside down on the back face J02 of the substrate J00 of transparent plastic material, allows said image 101 to see it on the front face 103 of the substrate 100 of transparent pLastic material, to be seen to the right (the actual right of the image is on the right), as shown in Figure 2. On the other hand, as mentioned above, the offset printing process of the present invention, also includes the incorporation of at least one stage of drying. In the embodiment described, a first drying step is applied after the application of the first two primary colors, namely magenta and cyan, and a second drying step after the application of the third primary color, namely color yellow and the color black. It is important to mention that the application of the three primary colors and the black color, can be done in machines that allow to apply the four colors at once, for which a single drying step will be required. Returning to the modality described, once the substrate of plastic material has been printed the image, applying the first two primary colors (magenta and cyan), it is subjected to the first stage of drying at a temperature that is located between about 130 ° C and 190 ° C, preferably 170 ° C, for which a drying oven is used, which in the embodiment described, is preferably an electric resistance oven having a central drying chamber of approximately one meter in length The drying oven uses a conveyor belt to support and transport the substrates of plastic material, passing them through the central drying chamber. Once the image has been printed on the substrate of plastic material, to which the second two colors (yellow and black) were applied., this is subjected to the second drying step, which is carried out at a temperature which is between approximately 130 ° C and 190 ° C, preferably 170 ° C, in the same drying oven used in the first stage of drying. drying Finally, a layer of white ink is applied to the printed product, so that when said substrate is joined to a dark background, the clarity and sharpness of the printed image is not lost, so which application of said layer of white ink is carried out in the same rotary press. The substrate of plastic material used must be a transparent flexible plastic material, which is selected from the group consisting of polyvinyl chloride (PVC), styrene, polyethylene, polypropylene and l_exanR, preferably being used in the manner described Lexan. , which is a thermoplastic polycarbonate. It is important to mention that the substrate of transparent plastic material must present on at least one of its faces, a completely L sa surface, in order to adequately reproduce the inked image in color. The final product obtained with the offset printing process of the present invention will be more clearly illustrated by means of the following example, which is presented solely for illustrative and non-limiting purposes.

EJEUELO For the purpose of exemplifying the novel features of the present invention, a rotary two-color press was used, for which purpose it was proceeded to prepare metal sheets previously coated on at least one of its faces with an emulsion sensitive to any type of light, to sensitize the surface where the image will be recorded. Then the image to be recorded from a negative film was transferred to the metal sheet so that the image was reversed (the actual right of the image was left of the sheet). The image of the metal sheet, once inked is transferred to a repeat cylinder covered with rubber, in which the image to be engraved is to the right, and this, in turn, prints the image on the back surface of the plastic substrate so that it is the other way around. The transfer of the image of the negative film to said metallic sheets was carried out using a quartz lamp of 1,500 watts. The machine was prepared by placing two metal sheets with the same image to be reproduced, rolling them over the corresponding cylinder, in such a way that the image was printed on a substrate of transparent plastic material (LexanR), applying firstly the primary colors magenta and cyan. The product obtained was then subjected to a first drying step at a temperature of 170 ° C, for which an electric resistance drying oven was used, the four having a central drying chamber of approximately one meter in length. Once the product dried, the image was printed again on the previously printed image, but now applying the primary color yellow and the color black. Next, the product was subjected to a second drying step at a temperature of 170 ° C, using the same drying oven. Finally, a layer of white ink was applied on the image already printed, in order to obtain a product of plastic material that can be attached to another substrate of any color, without the sharpness and coloring of the image being lost. The final product made by the offset printing process of the present invention, was joined to a base of soft and soft poly-acrylic material, by means of a suitable adhesive, thus obtaining a computer mouse pad (mouse pad) , which is attractive to the eyes of the users. The mouse pad that was obtained is shown in Figure 3, which comprises a base substrate 104 and a substrate of transparent plastic material 100 to which an image 101 has been etched on its back face. The base substrate 104 and the transparent plastic material substrate 100 are bonded together by a suitable adhesive. In accordance with the foregoing description, it may be noted that the process in question has been devised so that by means of the modification in the way of recording the image to be reproduced on the metal sheet, as well as the incorporation of at least two additional drying steps. to the printing process, a practical and functional solution is offered to the problems that have to be able to reproduce images directly on surfaces of plastic materials, besides offering a product of excellent quality, lasting and that is attractive to the sight, which is can give you other uses, besides the one mentioned above, and at the same time eliminate too sophisticated processes. When certain embodiments of the invention have been illustrated and described, it should be emphasized that numerous modifications to them are possible. The present invention, therefore, should not be considered as restricted, except for what is required by the prior art and by the spirit of the appended claims.

Claims (8)

NOVELTY OF THE INVENTION CLAIMS

1. - An offset printing process on a substrate of plastic material, of the type comprising the steps of preparing the metal sheet containing the inked image to be reproduced, followed by a step of preparing the rotary printing press, placing said metallic sheet winding on a cylinder and adjusting the color tones, to finally indirectly reproduce the image on the surface of a substrate to be used, characterized in that the offset printing process includes at least one drying step each time the image is recorded in the substratum; and, the stage of preparation of the metal sheet compresses the incorporation of the image to be reproduced backwards by transferring the image of a negative film to the metal sheet, where the real right of the image is left of the sheet.

2. An offset printing process on a substrate of plastic material, according to claim 1, further characterized in that the preparation of the metal sheet comprises covering at least one of its faces with an emulsion sensitive to any type of light, which serves to sensitize the surface where the image to be reproduced will be recorded, once it is recorded on the metal sheet, the image is inked and transferred in the offset machine first to an IR repetition cylinder covered with rubber, in which the image to be engraved remains to the right, and this, in turn, transfers it and prints on the back side of a substrate of transparent plastic material, in such a way that it is reversed, the operation of printing the image upside down on the back side of the substrate of transparent plastic material, allowing said image to see it on the front face of the transparent plastic material substrate to be seen to the right, that is, the real right of the image is a the right.

3. An offset printing process on a substrate of plastic material, according to claim 1, further characterized in that said printing process includes two stages of drying, a first stage of drying after printing the image with both first primary colors, and a second drying stage at the end of the printing process.

4. An offset printing process on a substrate of plastic material, according to claim 3, further characterized in that the first and second drying steps are carried out at a temperature of between about 130 ° C to about 190 °. C, preferably being carried out at a temperature of 170 ° C.

5. An offset printing process on a substrate of plastic material, according to claim 1, further characterized in that the substrate used in the printing process is preferably a substrate of transparent plastic material L.

6. An offset printing process on a substrate of plastic material, according to claim 5, further characterized in that the substrate of transparent plastic material is selected from the group consisting of polyvinyl chloride (PVC), styrene, polyethylene, polypropylene and Lexan®, preferably using Lexan®.

7. A final product obtained with the offset printing process of the previous clauses, characterized in that it comprises a base substrate and a substrate of transparent plastic material to which an image has been recorded upside down on its back face, both substrates being joined by a suitable adhesive.

8. A final product according to claim 7, further characterized in that said final product is a pad for moving a computer mouse (rnouse pad).