JPS599544A - Device for testing abrasion resistance of film - Google Patents

Abstract

PURPOSE:To facilitate the measurement and to prevent the production of measuring errors, by providing an optical sensor in a device for testing abrasion resistance of a film, and judging the time when the substrate of a test piece begins to appear to be observed by an electric circuit instead of visual observation. CONSTITUTION:A test piece 2 is fixed to a turntable 1, and an abrasion wheel 3 is set thereon. A switch 6 is closed and the turntable 1 is rotated. At the same time, a counter 5 is started. When the painted surface of the test piece 2 is abraded by the abrasion wheel 3, the painted film is gradually peeled off, and a part where the substrate can be seen, appears. At this time, an optical sensor 7 detects the part. A comparator circuit 9 compares the output voltage from the optical sensor 7 with a reference voltage. When a difference is generated between both voltages, an output is generated from the comparator circuit 9. Then, an energized relay winding 15 actuates the switch 6 and a power source is cut off. The number of rotation of the turntable indicated by the couner 5 becomes the data for the abrasion resistance. Thus the measurement is facilitated and the measuring errors can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for testing the abrasion strength of coatings such as paints deposited on materials.

BACKGROUND TECHNOLOGY AND PROBLEMS Conventionally, there is a tipper tester as an apparatus for testing the abrasion strength of painted surfaces. This testing machine requires a worker to stay by the side from the time the test piece is set in the test machine to the end of the measurement.
It is extremely inefficient to have to keep an eye on the current situation. In addition, it is difficult to visually detect the point of wear when the base of the material begins to become visible, and since it is a sensory evaluation, there is a drawback in that it involves measurement inaccuracies.

OBJECTS OF THE INVENTION In view of the above-mentioned current situation, it is an object of the present invention to provide a glaze abrasion strength testing device that is easy to measure, efficient, and has few errors.

Summary of the Invention The present invention incorporates an optical sensor into an abrasion strength testing device such as a conventional tipper tester, and uses an electric circuit to automatically determine the point at which the base of the test piece begins to be visible, instead of human vision. 1. EMBODIMENT FIG. 1 is an external view showing an embodiment of the present invention. In the figure, (1) is a turntable with a test piece (
2) Fix. The test piece (2) is, for example, a painted plastic plate, and is placed with the painted side facing up. (3
) is a pair of wear wheels, which are arranged so as to abut against the painted surface of the test piece (2) with a constant load applied thereto.

When the turntable (11) rotates, the test piece (2) also rotates, and the wear ring (3) rotates around the axis and rubs the painted surface of the test piece (2). This is a suction port for sucking in dust generated from the (5
) is the rotational speed of the turntable (1), that is, the wear wheel (
3) and the test piece (2).

(6) indicates a switch for starting and stopping the turntable (1) and the counter (5).

The above-mentioned configuration is not much different from the conventional tipper tester, but in the present invention, the optical sensor or its light source (7) is mounted near the suction port (4), and the detection circuit described below is provided inside. This is different. When using a reflective sensor in which a light source and a light receiving sensor are integrated into the optical sensor, 17) in the figure is an optical sensor, which is attached to the downstream side of the suction port (4). The means for attachment may be adhesive tape, but is not limited thereto. Also, if the material of the test piece is translucent, a direct-light sensor can be used as the optical sensor, but in this case, (7) in the figure is the light source, which is composed of, for example, a light emitting diode and an optical fiber. Attach the suction port (4) K. Then, a light receiving sensor such as a phototransistor is attached to the turntable side.

FIG. 2 is a plan view showing an example of the turntable in this case. In the figure, (11 is a turntable, (2
) is a virtual test piece, (Il) is the N rotation axis of the turntable, and (12) is a hole in which a light receiving sensor is embedded. In the illustrated example, there are four holes (12), but the number is not limited thereto.

The light receiving sensor embedded in the hole (12) is electrically connected by suitable means.

In addition, the light receiving sensor V- can be stationary and fixed further below the turntable (not 11). In that case,
Instead of the hole (12), the turntable (11) may be provided with a through hole, or the turntable (11) may be made of a transparent material.

To use the test apparatus configured as described above, first, the test piece (2) is fixed on the turntable (1), and the wear ring (3) is set on it. Turn on the switch (6), rotate the turntable +1) and start the counter (5) at the same time. The painted surface of test piece (2) is a wear ring (
When rubbed with step 3), the paint film gradually peels off, revealing areas where the base material is visible. Then, the optical sensor detects this, and a detection circuit, which will be described later, is activated, and the switch (6) or another switch (not shown) is activated to turn off the power.

Therefore, the turntable +1) and the counter (5) stop, and the indicated value of the counter (5) at that time is read as the wear count. This number of times of abrasion becomes data representing the abrasion strength of the coating surface.

FIG. 3 is a plan view showing a test piece with the coating peeled off to reveal the base. In the figure, (21) is the painted surface, (
22) is the part rubbed by the wear ring (3), (23)
(24) shows the hole for setting the turntable. Since there is a clear difference in the output voltage of the optical sensor between the area where the paint film has peeled off (23) and the area where it has not, this is used for detection.

However, the manner in which the output voltage changes varies depending on the type of material and the type of paint.

According to the results of the experiment, when 10 to 15 microns of silver paint was applied on ABS resin, the initial output voltage from the reflective sensor was 60.5 mV, and the output voltage at the peeled part was 26.6 mV, a difference of 33 mV. It was .9 mV (reduction). In addition, when approximately 10 to 15 microns of black paint is applied on ABS resin, the initial output voltage is 4.7 mV, and the output voltage at the peeled part is a, 7 mV, and the difference is 2.0 mV.
(increase).

FIG. 4 is a block diagram showing an example of a detection circuit used in the present invention. In the figure, (force is the original sensor, (71)
is a light source consisting of a light emitting diode, etc. (7g) is a photo source
If the light sensor is a direct light sensor such as a transistor, (71) corresponds to (7) in FIG. (8)
is a constant current circuit for keeping the light amount of the light source (71) constant;
(9) is a comparison circuit that compares the output voltage of the optical sensor (that is, phototransistor (72)) with a reference voltage, and generates an output when there is a difference between the two voltages. Using the above-mentioned initial output voltage, which is known in advance as a voltage, before testing, adjust it with a variable resistor to set a predetermined reference voltage. A Schmitt switching circuit that produces an output of
A constant voltage circuit is used to supply a constant voltage to υ, a9 is a relay winding, and G is a ground terminal. Relay * m (151
When energized, it operates a contact (not shown) to turn off the power. With this circuit configuration, the turntable (1) and the counter (5) can be stopped by detecting the point in time when the base begins to be visible on the test piece (2). Although not shown, an integrating circuit is interposed between the optical sensor (7) and the comparison circuit (9) to integrate and smooth the pulse-like output voltage of the optical sensor (force). With such a detection circuit, even if the color of the paint changes to red, blue, green, etc., if there is a voltage difference between the initial output voltage and the output voltage of the peeled part, the comparator circuit (9) is activated using that difference. It can be made to work.

APPLICATION EXAMPLES In the above embodiments, a device suitable for abrasion strength testing of paint films was described based on a conventional tipper tester. Also applicable to strength testing equipment for vapor deposited films or printed surfaces.
It is flexible and can be modified and changed in various ways depending on the purpose. For example, the movement of the test piece is not limited to rotation, but may also be reciprocating. Effects of the Invention According to the present invention, since the electric circuit makes the determination instead of human senses, the measurement error is small and accurate.

There is no need for a worker to be by the side until the measurement is completed, and the measurement is done automatically, making it extremely easy and efficient.

[Brief explanation of the drawing]

Stripe 1 is an external view showing an embodiment of the present invention, FIG. 2 is a plan view showing an example of a turntable when using a direct light sensor, and FIG. 3 is a plan view showing a test piece with the underlying layer exposed. FIG. 4 is a block diagram showing an example of a detection circuit. (1)...Table, (2)...Test piece,
(2t)...Coating, (3)...Abrasion means, (5)...Counter, (7)...Light sensor, (9-15)... ...Detection circuit. −; call

Claims (1)

[Claims] A table on which a test piece is placed and fixed and moves repeatedly; an abrasion means that generates friction by coming into contact with the coating of the test piece; a counter that counts the number of movements of the table; an optical sensor that receives the reflected light or transmitted light, and detects a change in the output voltage of the optical sensor that occurs when the coating of the test piece peels off due to abrasion and the underlying layer is exposed, and detects the movement of the table and the counter. A coating abrasion strength testing device comprising: a detection circuit for stopping counting, and reading the indicated value of the counter at the time of stopping.