JPH01123671A - Dot marking method - Google Patents

Abstract

PURPOSE:To attach dot marks which have good visibility and do not exfoliate to article having low lightness and to prevent nozzle clogging by primer-coating a coating having high lightness on one surface of the article surface region having low lightness, then subjecting said region to dot marking with ink or coating having low lightness. CONSTITUTION:The paint (for example, coating contg. a white pigment and binder) which has the high adhesion to the articles having low lightness and has a high hiding power is primer-coated on one face of the surfaces of said articles. The surface is then subjected to the dot marking by, for example, the black ink or coating having low lightness so that this ink or coating is penetrated or fixed and is strongly bonded on the primarily-coated coating. As a result, the marks which have the good visibility and do not exfoliate are attached to the black or other articles having low lightness without causing the nozzle clogging.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a marking method, and more particularly to a method for dot marking objects of low brightness, such as black.

(Prior Art) It is widely practiced to mark various types of manufacturing information on intermediate materials such as steel pipes, steel plates, plastic pipes, and plastic plates, as well as products made from them. In recent years, this kind of marking has been done by dot marking, where ink is sprayed in dots and information is represented by a collection of multiple dots.

Many types of inkjet printers are known.

The ink used in Infusiera 1 to printers is usually black, but if the article to be marked is black, naturally white ink must be used. However, when marking with regular white ink on a black background, the mark is difficult to read because the black of the base cannot be hidden sufficiently, so the mark must be read by looking at the reflected light from an angle instead of looking at it from the front. Often there isn't. Therefore, in order to improve visibility, it is a good idea to use white ink with high hiding power, but then the nozzle of the Infusiera I printer is likely to clog due to the high pigment mK in the white ink. Previous efforts have been made to develop white inks that have high hiding power and do not cause nozzle clogging.

Further, unlike paper and wood, when dots or marks are made on metal or plastic, there is a problem that the marks may peel off due to friction or the like because the adhesion of the ink is weak. (Problems to be Solved by the Invention) The present invention provides a method for attaching a mark that is highly visible and does not peel off to objects of low brightness such as black, and that does not cause operational problems such as nozzle clogging. The purpose is to

[Means to solve the problem]

The object of the present invention is to provide a method for dot marking a low-brightness article, in which the surface area of the article to be marked is coated with a high-brightness paint, and then dot marking is performed with a low-brightness ink or paint. The problem is solved by a method characterized by

It is desirable that the high-brightness paint used for the base coat has high hiding power and strong adhesion to the article. For the curved shape, a paint containing a white pigment and a binder is used.

Since marking is performed after the base coat, it is preferable that the paint be quick-drying. The method of applying the base coat of paint is not particularly limited, but a method of spraying is preferred. For example, it is possible to use a device that blows air out from around a nozzle and uses the resulting negative pressure to suck out paint from the tip of the nozzle and spray it in the form of mist. The area over which the paint is sprayed can be determined by changing the injection angle by positioning the needles arranged concentrically within the nozzle;
It can be selected as appropriate by changing the distance between the nozzle and the article. For this purpose, for example the shot marker S-
10 (trademark, Special Paint Co., Ltd.) can be used. Alternatively, a spray method can be used in which the paint itself is ejected under high pressure.

After basecoating, dot marking is performed with a low-brightness, eg, black, ink or paint. Dot marking can be performed using a known inkjet printer. For example, an inkjet printer in which seven marking guns are arranged in a row as described in Japanese Utility Model Application Publication No. 58-t2aesa is preferred. Commercially available inks or paints can be used as appropriate. As this ink or paint, an ink or paint that is compatible with the film of Bain 1 to which the base coating is applied is used. The dot-applied ink or pane I then penetrates or adheres to the base paint film, creating a strong bond.

When performing dot marking, it is desirable that the base paint is at least partially dry. Otherwise, the boundary between the dot periphery and the base paint will be blurred and the mark will be untidy.

Between the base coat and dot marking, there should be at least 0.5
It is preferable to leave an interval of at least 2 seconds, especially at least 2 seconds.

One embodiment of the present invention will be described. A moving device for moving the black plastic tube to be marked at a constant speed, a fixed photoelectric means or switch for detecting when the end of the plastic tube has passed a fixed position, and air sucking out the white paint in the form of a mist. A fixed paint jetting device for base coating that can spray air and the flow path of the air and paint can be opened and closed by a solenoid valve. The installation consists primarily of an inkjet printer having a dot matrix of seven inkjet nozzles arranged in a row at right angles. The plastic tube is moved by a moving device at a speed of, for example, 120 TrL/min, and when the tip of the plastic tube at the point to be marked comes to a position facing the primer paint spraying device, the solenoid valve is opened and white paint is applied. Spray continuously for a period of time to apply the base coat to a predetermined width and length. When the tip of the base-coated area faces an inkjet printer located at a distance of, for example, 2 meters from the paint ejecting device, that is, 1 second from the start of ejecting white paint, the inkjet printer is appropriately controlled to print black paint. The desired mark is drawn on the white paint film by squirting ink in dots.

Although the article to be marked is moved in the above example, the article may be left still and the white paint jetting device and the inkjet printer may be moved, or both may be moved. In short, it is sufficient to appropriately move the two relative to each other.

The material of the article to be marked according to the present invention is not particularly limited, and examples include articles made of metals such as steel, and articles made of plastics such as tubes and plates, which generally have poor adhesion of ink or paint in the shape of a small drum.

As described above, the present invention provides good visibility for low brightness articles,
Moreover, it is possible to apply dot marks that do not peel off, and in this case, it is possible to perform dot marking without causing problems such as nozzle clogging.

Claims (1)

[Claims] 1. In a method of dot marking an article with low brightness, the surface area of the article to be marked is coated with high brightness paint, and then dot marking is performed with low brightness ink or paint. A method characterized by: 2. The method according to claim 1, wherein the high brightness ink is a white pigment paint and the low brightness ink is a black ink. 3. The method according to claim 1 or 2, wherein the base coating is performed using a spray nozzle and the dot marking is performed using an inkjet printer. 4. The method according to any one of claims 1 to 3, wherein the article is a black or nearly black metal article or plastic article.