JPH11247354A - Light-weight cellular concrete and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy of bar code printing in the production line of ALC, for which bar code printing is automated. SOLUTION: When light-weight cellular concrete A is conveyed by a conveying means, an ink jet printer 20 printing bar codes C on the light-weight cellular concrete A is arranged while being disposed to face a conveying passage. The bar codes C having line width Cy larger than the diameter By of the bubble B of a background in the printing surface of the light-weight cellular concrete A are printed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing a bar code for identification on lightweight cellular concrete used for exterior materials of buildings and the like, and a lightweight cellular concrete produced by the method.

[0002]

2. Description of the Related Art In the prior art for attaching an identification code such as a bar code to lightweight cellular concrete, there are means for attaching a label bearing the identification code and means for directly printing. As means for attaching a label, for example, JP-A-9-9087
No. 3 "Concrete product with label". According to this, there is an effect that the peeling of the label is prevented by the action of the adhesive having remarkable adhesiveness. However, even if the fear of peeling is neglected, problems such as reduced assembly accuracy of lightweight cellular concrete due to the thickness of the label, consumption of time required for drying the adhesive, and burden of expenses required for manufacturing the label, etc. There is a point.

On the other hand, as a means for direct printing, a method of spraying ink onto lightweight cellular concrete to perform printing is useful. Such a technique is disclosed, for example, in Japanese Patent Publication No. 53-1.
1965 "Automatic marking device for concrete products"
And JP-A-52-32920 "Concrete block marking device" and JP-A-4-325253 "Automatic marking device". According to these,
There is an advantage that automation of barcode printing in the production line of lightweight cellular concrete is achieved. However, the method of directly applying ink to lightweight cellular concrete has the following problems caused by the characteristics of lightweight cellular concrete. 1) Since lightweight cellular concrete contains bubbles,
The printing surface is not smooth. As a result, the print becomes unclear,
It is difficult to print accurate barcodes. Accompanying this, reading of the printed barcode may also be hindered. 2) Light-weight cellular concrete has high ink absorbency and diffusivity. Therefore, the printed barcode is easily blurred. Therefore, this property may also interfere with reading the printed barcode. 3) Light aerated concrete has a different color tone depending on the water content. As a result, the reflectance of light is liable to change, and the reading of the printed barcode tends to be inaccurate.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to provide a bar code printing automated bar code production line for lightweight cellular concrete. The purpose is to improve printing accuracy.

[0005]

In order to achieve the above object, a lightweight cellular concrete according to the present invention is a lightweight cellular concrete on which a bar code is printed, wherein the line width of the bar of the bar code has a background air bubble. It is characterized by being larger than the diameter of. To manufacture this lightweight aerated concrete, when transporting the lightweight aerated concrete by the transport means, an ink jet printer for printing a barcode on the lightweight aerated concrete is arranged facing the transport path, and the lightweight aerated concrete is printed on the printing surface. Print a barcode with a line width larger than the diameter of the background bubble. The lightweight cellular concrete is formed by injecting a mortar into a mold, semi-curing, cutting it into a desired shape with a piano wire or the like, and curing it by autoclaving.

[0006] Here, a cleaning means is disposed on the transport path upstream of the ink jet printer to clean the bar code printing surface of the lightweight cellular concrete, and to remove the dust or the like adhering to the lightweight cellular concrete but to the lightweight cellular concrete body. You may make it contribute to reliable printing.

[0007] Further, an air supply means may be provided around the nozzle of the ink jet printer, and air purging may be performed on the nozzle to contribute to prevention of adhesion of dust and moisture to the nozzle and ink.

[0008] A bar code reader is arranged in a transport path downstream of the ink jet printer, and the printing normality of the bar code is inspected, and the bleeding of the bar code due to the absorbability and diffusion of the ink to the lightweight cellular concrete. ,
It may contribute to prevention of misreading due to a difference in water content.

If the bar code reader is provided with a linear scanning means for scanning in a bar linear direction, in addition to the conventionally known scanning means, if a normal bar portion is detected at any position in the bar linear direction. Alternatively, a configuration may be adopted in which it is determined that the bar exists, thereby contributing to an improvement in reading efficiency.

[0010] From the lightweight cellular concrete on which the barcode is printed, the barcode may be read and post-processed or subjected to a physical distribution process so as to contribute to the convenience of the subsequent process.

[0011]

Embodiments of the present invention will be described with reference to the drawings. The present invention can be applied to wood and paper boxes in addition to lightweight cellular concrete of various shapes. In the following, as a preferred embodiment, a panel used for an exterior material of a building or the like will be described. The description will be given by taking a lightweight lightweight cellular concrete. The configuration of the present invention can be appropriately changed in design without departing from the gist thereof.

FIG. 1 is a schematic perspective view showing a mode in which mortar is injected into a mold (K) and semi-cured. For lightweight cellular concrete, mortar containing a foaming agent such as aluminum powder is injected into a mold (K), semi-cured, cut into a desired shape with a piano wire, etc., and fully cured by autoclave training, etc. Made by. Here, the fluid mortar is injected to a predetermined height of the mold (K) and semi-cured. However, in the semi-cured state where the mortar is taken out of the mold (K) and cured to the next step, a large number of mortars are formed. Bubble (B) remains. If air bubbles (B) are present on the barcode printing surface of the lightweight cellular concrete (A), due to voids in the air bubbles (B) or irregularities in the cross section of the broken air bubbles (B),
The printing surface cannot maintain uniformity. For this reason, the adhesion and diffusion of the ink vary, and a shadow due to unevenness occurs, so that the barcode becomes unclear.

By the way, a bar code is composed of a combination of four types of bars: a thick black line, a thin black line, a thick white line, and a thin white line. Usually, a black line is printed with black ink, and a gap between the plurality of black lines forms a white line. However, if the printing surface is black, such as when a black filler is applied to improve the flatness of the printing surface,
Print white lines with white ink. Usually, to read a barcode, a laser beam is irradiated and its reflected light is measured, so that reflection from a white line is detected as an ON signal. The detection of a thin white line involves the most error.

Therefore, in the present invention, the line width of the bar code is adjusted in consideration of the size of the bubble (B). That is, at least the line width of the thin white line in the bar constituting the barcode is substantially larger than the diameter of the background bubble (B) on the printing surface. Then, the influence of shading or the like due to unevenness due to the presence of the bubble (B) is reduced, a clear bar code is obtained, and misreading is prevented. Here, the bubble diameter of the background is such that the diameter of the majority of the bubbles (B) on the printing surface of the lightweight cellular concrete (A) which is hardened while containing many bubbles (B) is equal to or less than that value. Means diameter. For example, in ALC, bubbles (B) having a diameter of 1 mm or less occupy about 75 to 95%, so that the line width of the thin white line is preferably 1 mm or more. In addition, one of the few diameters 1mm
Even if a thin white line is positioned in the bubble (B), accurate reading is compensated by, for example, a linear direction scanning unit described later.

FIG. 10 shows a line width (C) of a bar code (C).
y) and the diameter (By) of the bubble (B),
It is explanatory drawing which showed the relative positional relationship between the head (21) of the inkjet printer (20) and the barcode (C) at the time of printing a barcode (C) on lightweight cellular concrete (A). The positional relationship between the printer head (21) and the barcode (C) in this figure will be described later. In the barcodes that are currently in widespread use, the width of a thin white line is often larger than that of a thin black line, as shown in the figure. Therefore, the line width (Cy) of the thin black line may be larger than the diameter (By) of the background bubble (B). Then, the variation in the adhesion and diffusion of the ink due to the presence of the bubble (B) is suppressed, and a clearer bar code (C) is obtained.

In the following, an example in which a bar code (C) is printed on the end (A10) located on the bottom (K10) side of the mold (K) when the mortar is semi-cured in FIG. 1 will be described. Note that a vertical broken line (Aa) in FIG.
Means a boundary surface when the semi-cured mortar is removed from the mold and cut into a desired shape with a piano wire or the like. FIG.
FIG. 3 is a front view showing an end portion of the lightweight cellular concrete (A) on which the barcode (C) is printed. FIG. 3 shows an inkjet printer (20) when the lightweight cellular concrete (A) is transported by the transport means. FIG. 7 is a schematic side view showing a state in which a barcode (C) is printed in ()). A step is provided at the end of the lightweight cellular concrete (A) in this example. The bar code (C) is printed in the recess (A11) formed by the step. Since the printing portion is the concave portion (A11), contact with the transporting member or the like is suppressed. For this reason, it is possible to prevent the bar code (C) from being blurred due to abrasion and hindering reading. In addition, the structure of a conveyance means, such as a conveyance roller (31), and an inkjet printer (20) is mentioned later.

FIG. 4 is a front view showing an end of the lightweight cellular concrete (A) having a shape different from that of the lightweight cellular concrete shown in FIG. 2, and FIG. 5 is similar to FIG. FIG. 4 is a conceptual side view showing a mode in which a barcode (C) is printed by an inkjet printer (20) when (A) is conveyed by a conveying means. Two steps are also provided at the end of the lightweight cellular concrete (A) in this example, and the protrusion (A1) formed by one of the steps is provided.
The barcode (C) is printed toward 2). Although printing may be performed on the concave portion (A11) between the two convex portions (A12) and (A12), priority is given to convenience such as the form of use of the product due to fear of wear of the barcode (C). In this case, printing is performed on the convex portion (A12). In any of the above cases, since barcode printing is performed on the end surface of the plate-shaped article having a small area, there is an advantage that printing can be performed by a common device even on a surface having a large area, that is, a wide variety of product sizes.

Before printing the barcode (C),
The printing surface may be coated with a filler to flatten the surface to contribute to printing stability and sharpness. In addition, the printing surface is shaved in advance and recessed to reduce contact of an article with the printed barcode (C), thereby reducing the barcode (C).
May contribute to the prevention of wear. After printing, the printed surface is coated with a light-transmitting coating agent, and the printed barcode (C) is printed.
May contribute to protection.

FIGS. 6 and 7 are an explanatory front view and an explanatory plan view, respectively, showing the outline of the bar code print reading apparatus. Lightweight cellular concrete (A) molded into a predetermined panel shape
It is placed on a group of transport rollers (31) of the transport device with its large surface substantially horizontal. Transport roller (3
1) forms a transport path by being installed in a plurality in a substantially horizontal posture on a gantry (30). The reason why the transport path is constituted by the roller (31) is to suppress pulsation and to achieve stable transport.

A plurality of guide rollers (32) having a substantially vertical posture are provided on one side edge of the upper part of the gantry (30) in the transport direction of the lightweight cellular concrete (A). The transport roller (31) is slightly inclined downward in the direction in which the guide roller (32) stands. Therefore, as clearly shown in FIG. 7, the lightweight cellular concrete (A) moves toward the guide roller (32) side on the transport roller (31), and the both rollers (31) (3)
It is transported while touching 2). The part where the bar code (C) is printed, that is, the bottom (K)
10) The end (A10) of the lightweight cellular concrete (A) located on the side is disposed near the guide roller (32) and transported. According to this configuration, the position where the lightweight cellular concrete (A) is conveyed is kept constant. In addition, if the standing position of the guide roller (32) is changed, the lightweight cellular concrete (A) and the ink jet printer (20) are changed. )
And the distance to the bar code reader (50) can be adjusted.

Ink jet printer (2
0) upstream of the two guide rollers (32)
Between (32), a cleaning means for cleaning the barcode printing surface (A10) of the lightweight cellular concrete (A) is provided. The cleaning means includes a scraper (41), a brush (42), and an air nozzle (43) from upstream to downstream of the transport path. The printing surface (A10) of the lightweight cellular concrete (A) facing the guide roller (32) is rubbed by the scraper (41) and the brush (42), and the cutting powder adhering thereto is jetted from the air nozzle (43). Removed by air. By this, not the dust attached to the lightweight cellular concrete (A),
Barcode printing on the lightweight cellular concrete (A) body is reliably performed.

The transport distance and speed of the lightweight cellular concrete (A) from which the cutting powder has been removed are detected by an encoder (33) connected to a transport roller (31), and the position thereof is detected by a printer position sensor (34). Is done. By providing the encoder (33), even if the transport speed of the lightweight cellular concrete (A) changes, the transport position can be accurately detected. The encoder (33) and the transport roller (3) are so arranged that the lightweight cellular concrete (A) directly contacts the encoder (33).
The height of 1) may be equal, or the transport rollers (3
The rotation of 1) may be transmitted to the encoder (33). If a proximity sensor is used as the sensor (34), it is possible to prevent misreading due to steam flowing from the lightweight cellular concrete (A).

Next, the light-weight cellular concrete (A) whose transport position is detected is printed with a barcode (C) by an ink jet printer (20). Since the guide roller (32a) immediately downstream of the ink jet printer (20) is installed with the portion in contact with the lightweight cellular concrete (A) raised, the lower part of the printing surface (A10) of the lightweight cellular concrete (A) is installed. Do not touch. This is to prevent ink bleeding caused by touching the bar code (C) just printed.

The lightweight cellular concrete (A) on which the barcode (C) is printed is subsequently replaced with a barcode reader (5).
The printed barcode (C) is read according to 0), and it is checked whether the barcode (C) has been printed normally. Immediately after printing, whether or not printing has been performed normally is inspected, so that inspection can be performed while printing is clear. This prevents misreading due to the characteristics of the lightweight cellular concrete (A), in which the color tone varies depending on the water content and the light reflectance tends to change, and the bar code (C) is accurately read and inspected. Becomes possible. Further, if there is an abnormality in printing, it can be dealt with at an early stage, which contributes to an improvement in productivity. A position sensor (35) for reader similar to the position sensor (34) for printer at the time of barcode printing is arranged upstream of the barcode reader (50).

With such an apparatus, a bar code (C) is printed and read at a predetermined portion of the lightweight cellular concrete (A) as follows. FIG. 8 is a block diagram of the printing process. The identification information of lightweight cellular concrete (A) input from an input unit such as a keyboard is CP
Via U, it is transmitted to the product code transmitter. The product code transmitter is synchronized with the transport speed of the lightweight cellular concrete (A) detected by the synchronization sensor (36),
The product code of lightweight cellular concrete (A) is transmitted to the inkjet printer controller and reading detector. The inkjet printer controller converts the transmitted product code into a print code and records it. Then, the conveyed lightweight cellular concrete (A) is transferred to the encoder (3).
3) and detecting by the printer position sensor (34), and transmitting the print code to the inkjet printer (20).

The lightweight cellular concrete (A) on which the bar code (C) is printed is detected by a bar code reader sensor (35), and the bar code reader (5) is detected.
0). The read barcode (C) is converted into a product code and transmitted to the reading detector. Then, the product code obtained by this reading is compared with the product code transmitted from the product code transmitter and recorded. If they match, a message that the printing has been performed normally is displayed on the display of the output unit. If they do not match, a message that the printing has not been performed properly is displayed.

Also, if the signal value read by the bar code reader (50) is abnormal in terms of density or the like, a message to that effect is displayed. For example, the barcode (C) generally tends to become thinner as time passes immediately after printing due to ink penetration and drying. Therefore, it is necessary to print at a density to which a compensation value that allows for a reduced density has been added so that a predetermined density can be maintained even when sufficiently dried. It is preferable that such a print density management function is also included in the print normality inspection item.

FIG. 9 is a block diagram of the reading process. The product code detected by the reading detector is transmitted to the reading counting device. The reading counting device is connected to the CPU, and contributes to reading normality inspection and production management. The reading detector is connected to a processing machine / distribution machine via a processing / distribution controller. In accordance with the detected product code, logistics such as post-processing such as cutting and cutting, and product transport control are controlled, thereby contributing to improved production efficiency and more efficient logistics.

FIG. 10 shows the relative positional relationship between the head (21) of the ink jet printer (20) and the barcode (C) when printing the barcode (C) on the lightweight cellular concrete (A). As shown, the rows of nozzles (22) of the printer head (21) are inclined at a predetermined angle (θ) with respect to the bar code length direction (y). This inclination angle (θ) is used when adjusting the density of the barcode (C) to be printed. If the inclination angle (θ) is increased, a barcode (C) having a large height (x1) can be printed, but the ink is dispersed more than that, so that the print density decreases. In order to print a barcode (C) having a high SN ratio, it is desirable to set the inclination angle (θ) small.

The bar code (C) is a check digit (C4) in addition to the quiet zone (C1), start code (C2), data code (C3), stop code (C5), and quiet zone (C6). Is added to prevent misreading.

In order to incline the rows of nozzles (22) of the printer head (21) with respect to the length direction (y) of the barcode, an ink jet printer (2) is used.
0) is provided with a head tilting means. 11 and 12 are a front view and a side view showing an installation mode of the ink jet printer (20). The ink jet printer (20) is installed on a support member (25) via an interval adjusting plate (24). The gap adjusting plate (24) is provided with a connecting means for freely moving and installing the ink jet printer (20) in a direction which is horizontal and perpendicular to the conveying direction of the lightweight cellular concrete (A). Thereby, the distance between the printer head (21) and the lightweight cellular concrete (A) is adjusted.

The support member (25) is provided with a rotation center screw (2).
7) and is connected to an altitude adjusting rod (28). The altitude adjusting rod (28) is fixed to the gantry (30) and holds the support member (25). Since the altitude adjusting rod (28) is provided with the long hole (28a),
The height of the inkjet printer (20) with respect to 0) can be appropriately adjusted.

The center screw 27 between the height adjusting rod 28 and the supporting member 25 has an axis which is horizontal and parallel to the direction of transport of the lightweight cellular concrete A. Therefore, the ink jet printer (20) turns around the turning center screw (27) as shown by the arrow (z) in a plane that is vertical and parallel to the transport direction of the lightweight cellular concrete (A). Thereby, the nozzle (2) of the printer head (21) in the bar code length direction (y) is
2) The row tilt angle (θ) is adjusted. When adjusting the inclination angle (θ), the operation is performed by loosening and tightening the set screw (26).

As the ink jet printer (20), a conventionally known ink jet printer can be appropriately used. However, in order to print a high-resolution barcode (C) at a high speed, it is preferable that the nozzle (22) be controlled at a high speed by a piezo element or the like. When an ink jet printer (20) that ejects ink in a slightly diffused manner is used, the distance between the nozzle (22) and the lightweight aerated concrete printing surface (A10) is reduced so that the barcode (C) does not become unclear. It is preferable to configure as follows.

FIGS. 13 and 14 are a front view and a side sectional view, respectively, of the ink jet printer (20). The ink jet printer (20) is housed in a box-shaped case (20a). According to the shape and position of the printer head (21), an opening (20b) is formed in the case (20a).
Is provided. An air supply pipe (29) led from an air supply means (not shown) is connected to the case (20a). Since the air from the air supply pipe (29) is discharged from the case opening (20b), the nozzle (22)
Is sent around. Therefore, the nozzle (22) is air-purged, thereby preventing dust and moisture from adhering to the nozzle (22) and the ink. At the same time, the air supply reaches the bar code (C) printed on the lightweight cellular concrete (A), and therefore, its drying is promoted. This prevents ink bleeding due to the characteristics of the lightweight cellular concrete (A), which has high ink absorption and diffusion properties.

FIG. 15 is a conceptual diagram showing the operation principle of the bar code reader (50). The bar code (C) is read and transmitted as follows. Laser tube (5
The laser beam emitted from 1) is converted into a lens (5
2) and mirror (53), polyhedral rotating mirror (5
4) The bar code (C) is irradiated via the plane swinging mirror (55). Since the polygon mirror (54) is rotating, the barcode (C) is scanned periodically. The bar code (C) is scanned in the bar line direction (x) by the reciprocating swing of the plane swing mirror (55). By providing such a linear scanning means,
If a normal bar portion is detected at any position in the line direction (x) of the bar, it can be determined that the bar exists. Therefore, erroneous reading due to partial white spot printing or the like is prevented, and the reading rate is improved.

The laser beam irradiated and reflected on the bar code (C) is reflected on a plane swinging mirror (55), a polygon rotating mirror (54), a mirror (53), and a lens (5).
Via 6) to the photodiode (57). Then, after being converted into an electric signal by the photodiode (57), it is amplified by the amplifier (58), digitized by the digitizer (59), and converted into product identification information by the decoder (60). The identification information is output to the interface (61) and the display (62).

The bar code reader (50) includes:
It is preferable to provide a barcode reconstruction function for reconstructing a barcode (C) that does not enter in parallel with the bar length direction (y) by dividing the barcode (C) into plural times. With this function, it is possible to prevent misreading due to angular deviation of the lightweight cellular concrete (A) during transportation.

The bar code reader (50) includes:
Based on the interval between the start bar (C2) and the stop bar (C5) of the barcode (C), a bar (C3) between them
It is preferable that a bar code length correction function for correcting the interval (C4) to be read is provided. With this function, it is possible to prevent erroneous reading due to a change in the length (y1) of the barcode.

[0040]

The lightweight cellular concrete of the present invention and the method for producing the same have the following effects due to the above constitution. According to the lightweight cellular concrete according to claim 1,
Since the line width of the bar of the barcode is larger than the diameter of the bubbles in the background, the influence of the bubbles on the barcode is suppressed. Therefore, the printing becomes clear and an accurate bar code can be obtained. According to the method for manufacturing lightweight cellular concrete according to the second aspect, a barcode having a line width larger than the diameter of the cells can be efficiently printed.

According to the third aspect of the present invention, since the bar code printing surface of the lightweight cellular concrete is cleaned in advance, it is possible to reliably print on the lightweight cellular concrete body. According to the method described in claim 4, since the nozzles are air-purged, dust and moisture are prevented from adhering to the nozzles and the ink. According to the method of claim 5,
Immediately after the barcode is printed, the print normality is checked.
Barcode bleeding due to the absorbability and diffusibility of the ink in the lightweight cellular concrete and erroneous reading due to the difference in water content are prevented. According to the method of the sixth aspect, since the bar is also scanned in the line direction, the barcode reading efficiency is improved. According to the method described in claim 7, the read barcode is transmitted to the step of performing the post-processing or the physical distribution process, so that the production efficiency is improved and the physical distribution is improved.

[Brief description of the drawings]

FIG. 1 is a conceptual perspective view showing a mode in which mortar is injected into a mold and semi-cured.

FIG. 2 is a front view showing an end of the lightweight cellular concrete.

FIG. 3 is a schematic side view showing a state in which a bar code is printed on the edge of the lightweight cellular concrete in FIG. 2;

FIG. 4 is a front view showing an end of a lightweight cellular concrete of another example different from FIG. 2;

FIG. 5 is a conceptual side view showing a state in which a barcode is printed on the edge of the lightweight cellular concrete in FIG. 4;

FIG. 6 is an explanatory front view showing an outline of a barcode print reading apparatus.

FIG. 7 is an explanatory plan view of the same.

FIG. 8 is a block diagram of a printing process.

FIG. 9 is a block diagram of a reading process.

FIG. 10 is an explanatory diagram showing a relationship between a line width of a barcode and a diameter of a bubble, and a relative positional relationship between a head of an inkjet printer and a barcode.

FIG. 11 is a front view showing an installation state of the inkjet printer.

FIG. 12 is a side view of the same.

FIG. 13 is a front view of the ink jet printer.

FIG. 14 is a side sectional view of the same.

FIG. 15 is a conceptual diagram showing the operation principle of a barcode reader.

[Explanation of symbols]

 A Lightweight cellular concrete Aa Cutting boundary of ALC A10 Bottom of ALC A11 Concave part A12 Convex part B Bubble By Bubble diameter C Bar code Cy Thin bar line width C1, C6 Quiet zone C2 Start code C3 Data code C4 Check digit C5 Stop Code K Formwork K10 Bottom of formwork θ Printer head tilt angle x Barcode bar line direction x1 Barcode height y Barcode bar length direction y1 Barcode length z Inkjet printer rotation direction 20 Inkjet printer 20a Inkjet printer case 20b Case opening 21 Printer head 22 Nozzle 23 Ink tank 24 Interval adjustment plate 25 Support member 26 Set screw 27 Rotation center screw 28 Altitude adjustment rod 28a Slot 29 Send Tube 30 gantry 31 transport roller 32 guide roller 32a guide roller immediately after printing 33 encoder 34 printer position sensor 35 barcode reader sensor 36 synchronization sensor 41 scraper 42 brush 43 air nozzle 50 barcode reader 51 laser tube 52, 56 lens 53 mirror 54 Polyhedral rotating mirror 55 Planar swing mirror 57 Photodiode 58 Amplifier 59 Digitizer 60 Decoder 61 Interface 62 Display

Claims (7)

[Claims] 1. A lightweight cellular concrete (A) on which a barcode (C) is printed, wherein the line width (Cy) of the bar of the barcode (C) is the diameter (By) of the background bubble (B). ) Larger lightweight aerated concrete. 2. When the lightweight cellular concrete (A) is transported by the transport means, the lightweight cellular concrete (A) is used.
An ink jet printer (20) for printing a bar code (C) is placed facing the transport path, and has a line width larger than the diameter (By) of the background bubble (B) on the printing surface of the lightweight cellular concrete (A). A method for producing lightweight cellular concrete by printing the bar code (C) of (Cy). 3. The method for producing lightweight cellular concrete according to claim 2, wherein a cleaning means is disposed on a transport path upstream of the inkjet printer (20) to clean the barcode printed surface of the lightweight cellular concrete (A). 4. An ink jet printer (20), wherein an air supply means (29) is provided around the nozzle (22), and the nozzle (22) is purged with air.
2. The method for producing lightweight cellular concrete according to item 1. 5. A bar code reader (50) is disposed on a transport path downstream of the ink jet printer (20) to check the printing normality of the bar code (C).
5. The method for producing lightweight cellular concrete according to any one of items 4 to 4. 6. A bar code reader (50) for scanning in a bar line direction (x) in a line direction scanning means (5).
The method for producing lightweight cellular concrete according to claim 5, further comprising the step of (5), wherein when a normal bar portion is detected at any position in the line direction (x) of the bar, the bar is determined to be present. 7. A lightweight method in which a bar code (C) is read from a lightweight cellular concrete (A) on which a bar code (C) is printed by the method according to any one of claims 2 to 6, and post-processing or distribution process is performed. Manufacturing method of cellular concrete.