JP2017036111A - Conveyance belt for optical inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyance belt for optical inspection which can reduce a visual burden on an operator who visually inspects an object.SOLUTION: A conveyance belt for optical inspection 10 is for inspection of an object by placing an object on one surface, and transmitting light irradiated from the other surface, and includes a first elastic layer 12 formed of a translucent thermoplastic material, a core body canvas 14 arranged on the first elastic layer 12, and a second elastic layer 16 which is formed of the translucent thermoplastic material on the core body canvas 14 and on which the object is placed. At least one of the first elastic layer 12 and the second elastic layer 16 has irregular reflection surfaces 12a, 16a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical inspection conveyor belt.

  An object such as food, medicine or electronic component placed on the conveyor belt is irradiated with light from the back surface of the conveyor belt to inspect the appearance and the presence of foreign matter. For example, when performing an appearance inspection, a light-transmitting conveyor belt is used to brighten the belt and visually inspect abnormalities such as foreign matter contamination and product chipping.

  Focusing on the visibility when visually inspecting an object, a conveyor belt is proposed in which a surface cover layer formed of a transparent thermoplastic resin is provided on a core canvas having a high light transmittance of 90% or more. (For example, refer to Patent Document 1).

JP2015-67442A

  In the transport belt in which the transparent surface cover layer is provided on the core canvas having high light transmittance, the light irradiated from the back surface almost certainly passes through the transport belt. Such light is close to direct light and has a dazzling brightness, which is effective for inspection of an object. However, too bright light close to direct light is a visual burden for an operator who inspects an object and causes increased fatigue.

  Therefore, an object of the present invention is to provide an optical inspection transport belt that can reduce the visual burden on an operator who visually inspects an object.

  The conveyance belt for optical inspection according to the present invention is a conveyance belt for optical inspection for inspecting an object by placing the object on one side surface and transmitting light irradiated from the other side surface, A first elastic layer formed of a light-transmitting thermoplastic material, a core canvas provided on the first elastic layer, and formed of a light-transmitting thermoplastic material on the core canvas; A second elastic layer on which an object is placed, and at least one of the first elastic layer and the second elastic layer has an irregular reflection surface.

  According to the conveyance belt for optical inspection of the present invention, since the first elastic layer formed of the translucent thermoplastic material has the irregular reflection surface, the light irradiated on the irregular reflection surface is irregularly reflected. Since light is diffused by irregular reflection, glare of light passing through the second elastic layer on the core canvas through the core canvas on the first elastic layer is suppressed. Thereby, the visual burden on the operator who visually inspects the object placed on the second elastic body can be reduced.

  In addition, since the conveyance belt for optical inspection of the present invention is formed of a light-transmitting thermoplastic material in addition to the first elastic layer, it is inherently sufficiently light-transmitting. Therefore, when the glare of light passing through the optical inspection transport belt is suppressed by irregular reflection at the irregular reflection surface of the first elastic layer, the amount of light passing through the optical inspection transport belt is maintained, and the target There is no hindrance to the optical inspection of things.

It is explanatory drawing which shows the structure of the conveyance belt for optical inspection which concerns on this embodiment. It is a schematic diagram which shows the apparatus for a light transmittance measurement test which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. 1 is a first elastic layer (hereinafter referred to as a lower elastic layer) 12 formed of a light-transmitting thermoplastic material, a core canvas 14, and a light-transmitting material. It has a structure in which a second elastic layer (hereinafter referred to as an upper elastic layer) 16 formed of a thermoplastic material is sequentially laminated. In the conveyance belt 10 for optical inspection, the upper elastic layer 16 is the front surface (outer peripheral side), and the lower elastic layer 12 is the back surface (inner peripheral side). When inspecting an object using the optical inspection transport belt 10, the object is placed on the front surface, and light is irradiated from the back surface.

<Lower elastic layer>
Since the lower elastic layer 12 is provided on the inner peripheral side of the optical inspection conveyance belt 10, the lower elastic layer 12 is on the light source side when inspecting an object by irradiating light. At least a part of the lower surface of the lower elastic layer 12 is an irregular reflection surface 12a. In the present embodiment, a weighted surface formed by weighting is used as the irregular reflection surface 12a. It is preferable that the fabric weight processing surface has the unevenness | corrugation in which the recessed part and the convex part were provided by the vertical and horizontal alternately. In this case, the pitch of the unevenness is not particularly defined, but can be set to, for example, about 1.0 to 1.8 mm. Moreover, the height of the convex part in an unevenness | corrugation can be about 0.2-0.7 mm, for example.

  The thickness of the lower elastic layer 12 is 0.2 to 1.0 mm so as to ensure the translucency required for optical inspection and the strength and durability of the belt required for conveying the object. It is preferable that it is a grade.

  The lower elastic layer 12 is formed from a translucent thermoplastic material. Examples of the light-transmitting thermoplastic material include thermoplastic elastomers made of polyolefin such as polyurethane and polyethylene / polypropylene, and polyester. The thermoplastic elastomer forming the lower elastic layer 12 has a colorless and translucent appearance to ensure the desired translucency, and does not contain components such as pigments, dyes, and solid fillers that conceal light. Is desired. The thermoplastic elastomer forming the lower elastic layer 12 is a polyurethane elastomer excellent in processability and strength, and is preferably a non-yellowing type polyurethane elastomer. Furthermore, the thermoplastic elastomer forming the lower elastic layer 12 is preferably a non-yellowing polyurethane elastomer containing no phenyl group.

<Upper elastic layer>
The upper elastic layer 16 can basically be formed with the same thickness by using the same material as that of the lower elastic layer 12 described above. Also in the upper elastic layer 16, it is preferable that at least a part of the upper surface is an irregular reflection surface. In this embodiment, the upper surface of the upper elastic layer 16 uses a pear ground formed by pear finish as the irregular reflection surface 16a. The roughness of the pear ground can be about Ry = 30 to 90 μm.

<Core canvas>
It is desired that the core canvas 14 has a light transmittance that is moderately reduced without being too light transmissive. By using such a core canvas 14, the above-described effect of the irregular reflection surface 12a of the lower elastic layer 12 is further enhanced.

  The core canvas 14 is a woven fabric woven by crossing warps and wefts. As the core canvas 14, a plain woven fabric woven by crossing warp and weft at a substantially right angle can be used. The plain woven fabric is preferably woven with a warp density of 55 to 59 pieces / 25.4 mm and a weft density of 25 to 29 pieces / 25.4 mm.

  The thickness of the core canvas 14 is preferably about 0.45 to 0.65. The core canvas 14 having such a thickness can be provided with appropriate light transmission as well as the strength and durability of the belt necessary for conveying the object.

  If the warp and the weft constituting the core canvas 14 are too thin, the belt tension may be reduced, which may hinder the conveyance of the object. In addition, the core canvas 14 including warps and wefts that are too thin cannot easily control the light transmittance because light is easily transmitted therethrough. On the other hand, when the warp and the weft are too thick, there is a risk of excessively impeding the transmission of light. If the fineness of the warp (the thickness of the yarn) is about 770 to 1430 dtex and the fineness of the weft is about 460 to 860 dtex, both sufficient belt tension and moderately reduced light transmittance can be achieved. Here, dtex (decitex) is the mass of a 10,000 meter yarn expressed in grams.

  Examples of the material of the warp and the weft constituting the core canvas 14 include synthetic fibers such as polyester, vinylon, polylactic acid, and polyurethane. Such synthetic fibers preferably exhibit a transparent, translucent or white appearance.

  More specifically, as the core canvas 14, a polyester filament, a fiber having a fineness of 1100 dtex, a twist of 150 ± 10 S, and a fiber of 150 ± 10 Z are used as warps, and a polyester monofilament and a fiber of a fineness of 660 dtex (Φ0.25) are used as the weft. A plain woven fabric having a warp density of 55 to 59 yarns / 25.4 mm, a weft density of 25 to 29 yarns / 25.4 mm, and having warp yarns of S and Z alternately can be used. A spun yarn can be used as the fiber constituting the core canvas 14.

  An adhesive layer 15 made of a translucent thermoplastic material is formed on the core canvas 14 so as to be bonded to the lower elastic layer 12 and the upper elastic layer 16.

2. Manufacturing Method The optical inspection conveyance belt 10 may be any method as long as the lower elastic layer 12 and the core canvas 14 are fixed and the core canvas 14 and the upper elastic layer 16 are not fixed and peeled off. It can manufacture by the method of.

  The lower elastic layer 12 is prepared by applying a predetermined light-transmitting thermoplastic elastomer onto a predetermined fabric weight for fabric by, for example, calendaring or the like to produce a sheet-shaped material, and the obtained sheet-shaped material is a core body. It can be transferred and arranged on the lower surface of the canvas 14. In the present embodiment, examples of the fabric for fabric used in the production of the lower elastic layer 12 include plain woven fabric and weft-woven fabric, but plain woven fabric is preferable.

  The upper elastic layer 16 is made of a sheet-like material on a release paper using a light-transmitting thermoplastic elastomer similar to that of the lower elastic layer 12, and the obtained sheet-like material is formed on the upper surface of the core canvas 14. Can be transcribed and placed. The release paper used for producing the upper elastic layer 16 is not particularly limited, and general release paper can be used.

  An adhesive is applied to the core canvas 14 by coating to form an adhesive layer 15. The adhesive can be prepared by dissolving a translucent thermoplastic material as described for the lower elastic layer 12 and the upper elastic layer 16 in an organic solvent. As the adhesive, for example, a translucent non-yellowing polyurethane elastomer dissolved in a mixed solvent of methyl ethyl ketone / cyclohexane / tetrahydrofuran is used.

  In transferring the lower elastic layer 12 and the upper elastic layer 16, a sheet-like material is disposed on the upper and lower surfaces of the core canvas 14 to obtain a laminate. The upper surface of the laminate is a release paper, and the lower surface is a fabric for fabric weighting. This laminated body is heat-pressed and processed to a predetermined thickness. The thickness of the laminated body after thermocompression bonding can be, for example, about 1.1 ± 0.15 mm. By performing thermocompression bonding, the lower elastic layer 12 is fixed to the lower surface of the core canvas 14 and the upper elastic layer 16 is fixed to the upper surface of the core canvas 14.

  The release belt on the upper surface and the fabric canvas on the lower surface are peeled and the lower elastic layer 12, the core canvas 14 and the upper elastic layer 16 are sequentially laminated, and the conveyance belt 10 for optical inspection according to this embodiment. Is obtained. The lower surface of the lower elastic layer 12 of the optical inspection transport belt 10 of the present embodiment is an irregular reflection surface 12a made of a weighted surface that reflects the unevenness of the weighted fabric. In the present embodiment, the upper surface of the upper elastic layer 16 is an irregular reflection surface 16a made of a pear ground.

  The transport belt 10 for optical inspection thus obtained can have a desired size according to the device to be applied. For example, the width can be about 450 ± 5 mm and the length can be about 30 ± 5 m. The conveyance belt 10 for optical inspection of the present embodiment can be used for optical inspection of an object by joining both ends with finger joints and processing them into an endless shape.

3. Action and Effect In the optical inspection transport belt 10 according to this embodiment, the lower elastic layer 12 formed of a light-transmitting thermoplastic material has an irregular reflection surface 12a. When performing optical inspection, an object is placed on the upper elastic layer 16 of the optical inspection conveyance belt 10 and light is irradiated from the lower elastic layer 12 side. In the conveyance belt 10 for optical inspection of this embodiment, the irradiated light is irregularly reflected by the irregular reflection surface 12 a of the lower elastic layer 12.

  When light diffusely reflects on the irregular reflection surface 12a of the lower elastic layer 12, light entering in the thickness direction of the optical inspection transport belt 10 is diffused, so that the width of the brightness distribution is widened. The light passing through the upper elastic layer 16 on the core canvas 14 becomes soft light and dazzling is suppressed. As a result, the visual burden on the operator who visually inspects the object placed on the upper elastic layer 16 can be reduced. Since the lower elastic layer 12 and the upper elastic layer 16 are translucent, the amount of light that passes through the optical inspection transport belt 10 is maintained even when light is diffused, and light is suppressed even if glare is suppressed. The brightness required for inspection can be maintained.

  When irregular reflection occurs also on the upper surface of the upper elastic layer 16, the light is further diffused by the irregular reflection surface 16a, so that the glare of light reaching the operator can be further suppressed.

  When the core canvas 14 has a moderately reduced light transmittance, the amount of light reaching the worker can be reduced, so the visual burden on the worker who visually inspects the object is reduced. The effect is even higher.

4). Examples Hereinafter, the resin sheet will be described as specific examples, but the present invention is not limited to the following specific examples.

[Example 1]
A translucent non-yellowing polyurethane elastomer as a translucent thermoplastic material was applied in a sheet shape to a fabric for fabric weighting with a thickness of 0.3 mm by calendering, and a release paper was arranged on the surface. The fabric for basis weight used is a canvas (1) having the following specifications.

  The canvas (1) uses a polyester filament, a fiber having a fineness of 1100 dtex, a twist of 150 ± 10 S, and 150 ± 10 Z as a warp, and a polyester monofilament using a fiber of a fineness of 1100 dtex (Φ0.32) as a weft, and a warp density of 67 to 75. This is a plain woven fabric in which the warp is 50/50 mm, the weft density is 50 to 58/50 mm, and the warp is S and Z alternately.

  The sheet-like material sandwiched between the fabric for canvas and the release paper was solidified by a general method, and the fabric for fabric and the release paper were peeled off to obtain the resin sheet of Example 1.

  As a result of observing the resin sheet of Example 1 with a microscope, an irregular reflection surface composed of a weighted surface was confirmed on the lower surface of the resin sheet. On the basis weight processing surface, irregularities due to the traces of the texture of the peeled basis weight canvas were generated. The pitch of the unevenness was about 1.4 mm, and the height of the convex portion was about 0.25 mm. The upper surface of the resin sheet was an irregular reflection surface made of a satin surface, and the surface roughness was Ry = 49 μm.

[Example 2]
A resin sheet of Example 2 was obtained in the same manner as in Example 1 except that the release paper was changed to the canvas (1) and both sides of the sheet-like material were sandwiched between the fabrics for weighting. In the resin sheet of Example 2, irregular reflection surfaces composed of a weighted surface having the same unevenness as in Example 1 were confirmed on the upper surface and the lower surface.

[Example 3]
The light of Example 3 is the same as Example 1 except that the canvas (1) to which the translucent non-yellowing polyurethane elastomer is applied is changed to release paper, and both sides of the sheet-like material are sandwiched by the release paper. An inspection conveyor belt was obtained. In the resin sheet of Example 3, the upper surface and the lower surface were irregular reflection surfaces composed of a satin surface.

[Comparative example]
A light-transmitting non-yellowing polyurethane elastomer similar to that in Example 1 was used, and a fabric sheet for release and a release paper were used, and a resin sheet of a comparative example was produced by pressing. The surface of the resin sheet of the comparative example is a mirror surface.

  About each resin sheet of an Example and a comparative example, the following light transmittance measurement tests were done.

<Light transmittance measurement test>
In the light transmittance measurement test, each resin sheet 30 of the example and the comparative example was irradiated with light from a light source installed on the back surface of the resin sheet, and the transmittance of light passing through the resin sheet 30 was measured as light transmittance. .

Specifically, the light transmittance measurement test apparatus 20 shown in FIG. 2 is used to irradiate light from a light source 24 installed on the back surface of the sheet with the endless resin sheet 30 wound around the pulley 22. The illuminance on the surface of the resin sheet 30 was measured using the measuring device 26. As the light source 24, an LED panel (LEDXC120-W manufactured by MISUMI Corporation) was used, and as the measuring device 26, an illuminometer (LX1128SD manufactured by Mother Tool Co., Ltd.) was used. Using the illuminance E0 of the light source 24 and the illuminance E1 of the surface of the resin sheet 30 measured by the measuring device 26, the light transmittance T was calculated by the following formula.
Light transmittance T = (E1 / E0) × 100 (%)

  The measurement environment is a room temperature of 23 ° C., a relative humidity of 50%, and a room brightness of 760 lux. The light source 24 was adjusted to an illuminance of 4090 lux, and the distance between the resin sheet 30 and the measuring device 26 was 0 mm.

  In Example 1 in which the lower surface of the resin sheet is a weighted surface and the upper surface is a matte surface, the illuminance E1 on the surface of the resin sheet was 3910 lux, and the light transmittance T was 95.6%.

  On the other hand, in the case of the comparative example whose surface is a mirror surface, the illuminance E1 on the surface of the resin sheet was 4010 lux, and the light transmittance T exceeded 98%. Compared with this result, it can be seen that the light transmittance T of the resin sheet of Example 1 was lowered by setting the lower surface to the irregular reflection surface made of the weighted surface and the upper surface to the irregular reflection surface made of the matte surface.

  In the resin sheet of Example 2 in which both surfaces are irregular reflection surfaces composed of a weighted surface, the illuminance E1 of the resin sheet surface is 3840 lux, and the light transmittance T is 93.9%. Further, in the resin sheet of Example 3 in which both surfaces are irregular reflection surfaces made of a satin surface, the illuminance E1 on the resin sheet surface was 3970 lux, and the light transmittance T was 97.1%. In Example 2 and Example 3, as in Example 1, the light transmittance T was decreased.

  Thus, it was confirmed that the light that passed through the two irregular reflection surfaces of the lower surface and the upper surface of the resin sheet was diffused and the light transmittance of the surface was lowered. Even in the optical inspection transport belt 10 in which the core canvas 14 is sandwiched between the lower elastic layer 12 and the upper elastic layer 16, when the lower elastic layer 12 and the upper elastic layer 16 have irregular reflection surfaces, the belt is used. The light passing therethrough is diffused and the light transmittance on the belt surface is lowered. As a result, it is possible to reduce the burden on the operator who inspects the object on the conveyance belt 10 for optical inspection.

5). Modifications The present invention is not limited to the embodiments described herein, and can be modified as appropriate within the scope of the gist of the present invention.

  In the above embodiment, the case where the irregular reflection surface is formed on both the lower elastic layer 12 and the upper elastic layer 16 has been described. However, the irregular reflection surface may be formed only on either the upper elastic layer 16, for example. .

  In the above embodiment, the irregular reflection surface on the lower surface of the lower elastic layer 12 is a weighted surface formed using a fabric for weighting, but may be a satin surface formed using a release paper. Since irregular reflection should just arise, the formation method of irregular reflection surface 12a is not specifically limited. For example, after the lower surface of the lower elastic layer 12 is formed flat, the irregular reflection surface can be formed by performing a roughening treatment.

  When the irregular reflection surface is provided on the upper elastic layer 16, the irregular reflection surface may be a weighted surface formed by using a fabric for weighting in addition to a pear ground.

  Moreover, in the said embodiment, although the translucent thermoplastic elastomer was demonstrated as a translucent thermoplastic material for forming the lower elastic layer 12 and the upper elastic layer 16, using a translucent thermoplastic resin. You can also.

  Similarly, for the adhesive layer 15, a light-transmitting thermoplastic resin can be used as the light-transmitting thermoplastic material. The adhesive layer 15 may be formed by immersing the core canvas 14 in the adhesive in addition to applying the adhesive to the core canvas 14. In some cases, the region on the core canvas 14 side of the lower elastic layer 12 and the upper elastic layer 16 fixed to the core canvas 14 can also function as the adhesive layer 15.

  The core canvas 14 is not limited to a plain woven fabric, and a twill woven fabric or a satin woven fabric can also be used.

  Moreover, when making the conveyance belt 10 for optical inspection of this invention endless form, you may join both ends by a sky bar joint.

DESCRIPTION OF SYMBOLS 10 Optical inspection conveyance belt 12 Lower elastic layer 12a, 16a Diffuse reflection surface 14 Core body canvas 16 Upper elastic layer 20 Light transmittance measurement test device 22 Pulley 24 Light source 26 Measuring instrument 30 Resin sheet

Claims (3)

An inspection belt for inspecting an object by placing the object on one surface and transmitting the light irradiated from the other surface,
A first elastic layer formed of a translucent thermoplastic material;
A core canvas provided on the first elastic layer;
A second elastic layer that is formed of a light-transmitting thermoplastic material on the core canvas and on which the object is placed;
At least one of the first elastic layer and the second elastic layer has an irregular reflection surface.   The conveyance belt for optical inspection according to claim 1, wherein the irregular reflection surface has irregularities in which concave portions and convex portions are alternately provided in the vertical and horizontal directions.   The transport belt for optical inspection according to claim 1 or 2, wherein the core canvas has a warp fineness of 770 to 1430 dtex and a weft fineness of 460 to 860 dtex.

Images