JP2018122520A - Pretreatment liquid coating drying device and printing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pretreatment liquid coating / drying apparatus capable of reducing the amount of waste paper generated at the start of printing of a printing system. SOLUTION: A pretreatment liquid coating unit capable of applying a pretreatment liquid to both sides or one of long surfaces of an object to be transported, and a heating means arranged downstream of the transport path of the pretreatment liquid coating unit. In the pretreatment liquid application drying device provided with the web drying unit for drying the transported object, the drying path length of the web drying unit is variably configured. [Selection diagram] Fig. 2

Description

  The present invention relates to a pretreatment liquid coating and drying apparatus and a printing system.

  2. Description of the Related Art As an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a multifunction machine having these functions, for example, an ink jet recording apparatus using a recording head that discharges ink droplets (droplets) is known. Inkjet image recording methods have problems related to image robustness, such as water resistance and weather resistance, in addition to initial quality problems such as bleeding, density, color tone, and show-through when recording materials other than dedicated paper are used. Yes.

  In order to solve these problems, there is a printing system in which a pretreatment liquid having a function of aggregating ink is applied to a recording material and dried on the upstream side before the ink droplets are attached by the printing apparatus. Known (for example, Patent Document 1).

  Normally, when printing of a printing system is started, a portion of paper as a recording material in a raw roll portion mounted on a paper feeding device connected further upstream of the pretreatment liquid coating / drying device becomes a print head portion of the printing device. Printing is not performed until it arrives, and the portion of the paper in the meantime becomes waste paper. This is because, when the paper is stopped, the guide rolls on the paper transport path generate winding gussets, causing gap fluctuation and meandering when the paper passes the print head during the next printing. This is because the print quality deteriorates.

  However, in the case of conventional printing systems including the system disclosed in Patent Document 1, even when using dedicated paper that does not require pretreatment liquid, it passes through the drying path of the pretreatment liquid coating and drying apparatus, so printing Wasted paper is generated when the system starts printing. In addition, even when the pretreatment liquid needs to be applied and dried using paper other than special paper, even when the required drying path is relatively short, such as when the paper basis weight is low or in the low speed mode, etc. In addition, since it passes through the entire drying path of the pretreatment liquid coating and drying apparatus, there has been a problem in that unnecessary paper loss occurs at the start of printing in the printing system.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a pretreatment liquid coating and drying apparatus that can reduce the amount of lost paper generated when printing of a printing system is started.

  The object is to provide a pretreatment liquid application unit capable of applying the pretreatment liquid to both surfaces or any one surface of a long object to be conveyed, and a heating means arranged on the downstream side of the conveyance path of the pretreatment liquid application unit. In the pretreatment liquid coating and drying apparatus provided with a web drying unit for drying the object to be conveyed, the problem is solved by the variable length of the drying path length of the web drying unit.

  According to the present invention, since the drying path length of the web drying unit is configured to be variable, it is possible to reduce the amount of paper loss that occurs when the printing system starts printing.

1 is a schematic diagram illustrating a configuration of a printing system according to an embodiment of the present invention. It is the schematic which shows the structure of the pre-processing liquid application | coating drying apparatus which concerns on embodiment of this invention, and has shown the state which closed the web drying unit. It is the schematic which shows the structure of the pre-processing liquid application | coating drying apparatus which concerns on embodiment of this invention, and has shown the state which open | released the web drying unit. It is the schematic which shows the structure of the pre-processing liquid application | coating drying apparatus which concerns on embodiment of this invention, and has shown the state which closed the web drying unit. It is the schematic which looked at the web drying unit provided in the pretreatment liquid application drying apparatus from the paper conveyance direction. It is the schematic which shows the structure of the web drying unit which concerns on different embodiment, and has shown the state which closed the web drying unit. It is a conceptual diagram which shows the different state of opening and closing of an individual unit frame, (A) is a full open state, (B) is a state in the case of 1/3 or less of maximum drying capacity, (C) is 2 of maximum drying capacity. The state in the case of / 3 or less, (D) shows the closed state when the maximum drying capacity is required.

  Hereinafter, embodiments of the present invention will be described in detail. First, as shown in FIG. 1, the printing system includes a paper feeding device 100, a pretreatment liquid coating / drying device 101, and a printing device 102. The paper feeding device 100 supplies a web W of a recording material, such as a roll-like continuous continuous paper, to a pretreatment liquid coating / drying device 101 provided on the downstream side of the web conveyance path. As will be described later, the pretreatment liquid coating and drying apparatus 101 records a pretreatment liquid that suppresses bleeding and show-through of inkjet ink printed on a recording material by a pretreatment liquid coating unit composed of coating means 13r and 13f. The recording material coated with the pretreatment liquid is dried by the web drying unit 80, and the recording material between the pretreatment liquid coating and drying apparatus 101 and the printing apparatus 102 is dancer unit 16. The amount of buffer is secured. The printing apparatus 102 is an ink jet recording apparatus that forms a desired image by ejecting ink droplets on at least one side of a recording material to which a pretreatment liquid has been applied in the pretreatment liquid coating and drying apparatus 101. Each includes first and second ink jet printer units and reversing units for ejecting ink droplets. In FIG. 1, for the sake of simplicity, only the recording head 105 that ejects ink droplets on one side of the recording material is shown. Further, a post-drying device may be provided in the printing apparatus 102 or on the downstream side of the conveyance path of the printing apparatus 102, and a winding device or a cutter device for cutting and stacking the web may be further arranged on the downstream side.

  Normally, when printing of the printing system is started, the paper portion (A portion) stopped on the original roll portion of the paper as the recording material loaded in the paper feeding device 100 reaches the recording head 105 of the printing device 102. Will be used as waste paper without printing. This is because, when the paper is stopped, the winding roll is generated by each guide roll on the paper conveyance path, so that gap fluctuation or meandering occurs when the paper passes the area of the recording head 105 during the next printing. This is because the print quality is deteriorated. The length of the waste paper generated every time the printing is started (ordinary amount of paper loss) varies depending on the system configuration. For example, it is about 15 m, of which the drying path path of the pretreatment liquid coating and drying apparatus 101 is 1 About 5m.

  2 to 4 show a schematic configuration of a pretreatment liquid coating / drying apparatus 101 having a pretreatment liquid coating unit, a web drying unit, and a dancer unit 16 including coating means 13r and 13f, and FIG. 2 shows the web drying unit closed. FIG. 3 shows a state where the web drying unit is opened, and FIG. 4 shows a state where the web drying unit is partially closed. In the pretreatment liquid coating / drying apparatus 101, a plurality of guide rollers 1 rotatably supported ensure a conveyance path for a web of paper that is a long object to be conveyed. When the web W is drawn from the paper feeding device connected to the upstream side and the inkjet dedicated paper is not used, pretreatment is performed on one side (back side) by the back side application unit 13r provided with the squeeze roller, the application roller, and the pressure roller. The liquid is applied. And the web W which passed the back surface application means 13r is apply | coated a pre-processing liquid on the other surface (surface) by the surface application means 13f provided with the squeeze roller, the application roller, and the pressurization roller. Both the back coating means 13r and the surface coating means 13f are selectively operated, and the web is coated with the pretreatment liquid on either the front surface or the back surface or on both surfaces.

  The web W on which the pretreatment liquid has been applied is a roller-shaped heating means 40r, 40f, 50r, 50f, 60r, 60f with a built-in heater of the web drying unit in which the drying unit upper frame 70f and the drying unit lower frame 70r are closed. Pass between. Each heating means 40r, 40f, 50r, 50f, 60r, 60f is arranged in a staggered manner, and a web-shaped portion is wound around to secure a bellows-like drying path length. The length of the drying path at this time is set so as to satisfy the maximum drying capacity defined in the apparatus specification of the pretreatment liquid coating / drying apparatus 101. Conditions for increasing the required drying capacity are a large basis weight of the web, a wide web width, a large amount of pretreatment liquid applied, a high printing speed, and the like. Note that the number of heating means that can come into surface contact with the web is not limited to three pairs for front surface heating and back surface heating, for a total of six, and may be two pairs, four pairs, or more. . Further, the drying unit upper frame 70f and the drying unit lower frame 70r have a plurality of steam exhaust fans for producing steam and temperature detection for measuring the temperature of each heating means 40r, 40f, 50r, 50f, 60r, 60f. Means may be provided.

  The web W that has passed through the web drying unit is conveyed by the feed roller 10 and the feed nip roller 9 and fed into the dancer unit 16. The dancer unit 16 has a buffer function that absorbs the difference in paper transport speed between the upstream and downstream sides, and a function that applies tension to the web W by the unit's own weight, and rotates to a movable frame that includes a weight and is movable in the direction of gravity. It has two guide rollers 15a and 15b that are freely attached, and the web W is wound in a W shape between the dancer unit 16 and the three guide rollers 1 arranged above the unit. ing. By adjusting the vertical position of the movable frame of the dancer unit 16, the buffer amount of the web W between the pretreatment liquid coating and drying apparatus 101 and the printing apparatus 102 is ensured.

  As shown in FIG. 5, each of the drying unit upper frame 70f and the drying unit lower frame 70r is hung between a pair of pulleys 77 arranged on both outer sides in the width direction (direction orthogonal to the paper surface of FIG. 1). The belt 78 is attached to the belt 78 via attachment arms 79f and 79r, and the web drying unit is closed or opened as the frames move toward or away from each other as the belt moves. Instead of such a configuration, for example, the drying unit upper frame 70f and the drying unit lower frame 70r are configured to move along the rail shaft so that each of them can be manually opened and closed, or driving for opening and closing. It is also possible to provide a motor and operate from the operation panel.

  The relative position states of the drying unit upper frame 70f and the drying unit lower frame 70r are detected by the drying unit position sensors 81 to 83 by the opening / closing mechanism shown in FIG. The drying unit position sensors 81 to 83 detect that the web drying unit is in the state shown in FIGS. Although the drying unit frame is provided with a filler and detected using a transmission type photo sensor, various known configurations such as a method of detecting the drying unit frame with a reflection type photo sensor can be used instead.

  Detection values of the drying unit position sensors 81 to 83 are taken into a control board 90 including a CPU and other electronic circuits. It is constructed so that information on printing conditions (web basis weight, web width, pretreatment liquid application amount, printing speed) is also taken into the control board 90. According to printing conditions (web basis weight, web width, coating amount of pretreatment liquid, printing speed) shown in Table 1 to be described later, the optimal heating means state determined in advance and the drying unit position sensors 81 to 83 Comparing the detected actual heating means status, if the results do not match, construct a control so that an error is generated and the printing operation is not performed, or an alarm is issued to the operator and the status of the heating means is the current status The control is constructed so as to confirm whether the printing operation can be started as it is.

  In the case shown in FIG. 2, when the ink jet dedicated paper is not used, the coating function of the pretreatment liquid coating unit is turned on, and the drying function of the web drying unit is also turned on. On the other hand, when the ink jet dedicated paper is used, the application of the pretreatment liquid is unnecessary, and the application function of the pretreatment liquid application unit is turned off. Specifically, the web is sandwiched from above and below, and the contact of the roller for applying the pretreatment liquid is released. Since the pretreatment liquid is not applied, the function of drying the pretreatment liquid becomes unnecessary. Therefore, the drying unit upper frame 70f carrying the heating means 40f to 60f and the drying unit lower frame 70r carrying the heating means 40r to 60r are separated from each other, and the heating means 40f, 40r, 50f, 50r, 60f, 60r are not used. A route. Although FIG. 3 shows a state where only the web drying unit is opened, it should be understood that the roller of the pretreatment liquid application unit is also released.

Here, the length of the drying path through which the web W passes through the heating means 40f, 40r, 50f, 50r, 60f, 60r shown in FIG. When the diameter of the heating means 40f, 40r, 50f, 50r, 60f, 60r is φ100 mm, the winding angle is 180 degrees, and the path length between the heating means is 100 mm, the drying path length from the inlet to the outlet of the web drying unit is As shown below, it is about 1500 mm.
(100 mm × π ÷ 2 + 100 mm) × 6≈1542 mm

On the other hand, as shown in FIG. 3, when the web drying unit is opened, the length of the drying path from the inlet to the outlet of the web drying unit is the diameter of each heating means × the number, which is about 600 mm. That is, by using the special paper that does not require the application of the pretreatment liquid, the web drying unit is opened to reduce the paper loss at the start of printing by 900 mm (0.9 m).
About 1500 mm (Fig. 2)-about 600 mm (Fig. 3) ≒ 900 mm (reduced paper loss)

  In the case of using the ink jet dedicated paper, the pretreatment liquid application is not necessary, and it is not necessary to pass the pretreatment liquid application / drying apparatus 101 itself. Therefore, the web W does not pass through the pretreatment liquid application / drying apparatus 101 at all. Obviously, it is possible to reduce the amount of waste paper by changing the path. However, in order to change the path route, a corresponding work is required, which increases machine downtime. That is, “cut the web W”, “remove the web in the pretreatment liquid coating / drying apparatus”, “change to a path path that does not pass through the pretreatment liquid coating / drying apparatus”, “tape etc. Such as “connecting by” and “sending the tape connecting part to a place that does not affect the next printing”. Needless to say, the tape connection part becomes a waste paper, but the posture of the web W changes due to the change of the path route, so that the meandering of the web W is generated at the initial stage of the next printing, and is stabilized. Therefore, the print quality is deteriorated. Therefore, it is necessary to print after feeding a certain amount of the web W until the conveyance is stabilized, and the amount of paper is also lost. In addition, since the downstream printing apparatus 102 has an inkjet head unit that ejects ink droplets onto the web W and a drying unit that dries the ink to create an image, the web W is cut once and the path path is changed. When the connected tape connecting part passes through the drying part in a heated state, the glue of the tape melts and the roller and the web W adhere to each other, causing jamming. Standby time is required and machine downtime increases. In addition, the next printing cannot be performed until the tape connecting portion is sent to the most downstream side (winding device) of the printing system, resulting in a loss of several tens of meters corresponding to the path path length of the system. There's a problem. That is, when the frequency of switching between jobs that use inkjet special paper and jobs that use non-exclusive paper is high, the path length of the drying path is shortened while the web W passes through the pretreatment liquid coating and drying apparatus 101. The switching configuration is superior.

  In the case of printing conditions such as a small basis weight of the web, a narrow web width, a small amount of pretreatment liquid applied, and a low printing speed, the maximum drying capacity of the pretreatment liquid application drying apparatus 101 Therefore, it is not necessary to secure the length of the drying path so as to exhibit the above, but if the maximum length of the drying path is maintained, unnecessary waste paper is generated. Therefore, adjustment is made so that the drying capacity is low under printing conditions that do not require the maximum drying capacity.

FIG. 4 shows a state in which the drying unit upper frame 70f and the drying unit lower frame 70r are opened up and down to reduce the amount of web winding (abutting range) around the heating means 40f, 40r, 50f, 50r, 60f, and 60r. ing. In FIG. 2, each heating unit is wound approximately 180 degrees, but in FIG. 4, for example, the winding angle around each heating unit is approximately 120 degrees. The drying unit upper frame 70f and the drying unit lower frame 70r are fixed at predetermined positions using the frame contact / separation configuration described with reference to FIG. When the diameter of the heating means 40f, 40r, 50f, 50r, 60f, 60r is φ100 mm, the winding angle is 120 degrees, and the path length between the heating means is 30 mm, the drying path length from the inlet to the outlet of the web drying unit is It is about 800 mm.
(100mm × π ÷ 2 + 30mm) × 6 ≒ 808mm
In other words, by partially closing the web drying unit under printing conditions that do not require the maximum drying path length, it is possible to reduce the waste paper at the start of printing by 700 mm (0.7 m).
About 1500 mm (Fig. 2)-About 800 mm (Fig. 4) ≒ 700 mm (reduced paper loss)

  In the case of FIG. 4, the path length in contact with the heating means 40f, 40r, 50f, 50r, 60f, 60r is 2/3 of the case of FIG. 2, so the drying function is also about 2/3. Depending on the printing conditions (web basis weight, web width, coating amount of pretreatment liquid, printing speed) that do not require the maximum drying capacity defined in the apparatus specifications of the pretreatment liquid coating and drying apparatus 101, the necessary drying capacity is low. Therefore, such use is possible.

Table 1 shows an example of the state of the heating means according to the printing conditions (web basis weight, web width, amount of application of pretreatment liquid, printing speed) for the pretreatment liquid coating / drying apparatus 101. The maximum specifications of each item are, for example, a web basis weight of 250 g / m ² , a web width of 20.5 inches (52.07 cm), and a printing speed of 50 m / min. When the printing conditions are all on the side where the required amount of drying heat is large, the web drying unit is used in the closed state shown in FIG. 2, but when the amount of drying heat required for each item is 2/3 or less, the portion shown in FIG. Use in closed state. When ink jet paper is used, the pretreatment liquid is not applied and drying is not necessary. Therefore, the paper is used in the open state shown in FIG. 1 regardless of other items. By doing so, it is possible to provide a pretreatment liquid coating / drying apparatus capable of reducing the amount of paper loss generated at the start of printing of the printing system.

  Table 1 shows an example in which the state of the heating means is divided into the three stages of FIGS. 2 to 4, but the amount of wrapping around each heating means is the maximum (state of FIG. 2) to the minimum (state of FIG. 3). As the number of divisions up to is further subdivided, the amount of waste paper at the start of printing can be reduced by using the configuration with the smallest amount of wrapping around the heating means among the necessary amount of drying heat according to the printing conditions Needless to say. Further, the boundary condition for switching the winding amount of the heating means for each item shown in Table 1 is an example, and is determined and determined by experiment, evaluation, or calculation. Although it switched to the required drying heat amount for every item, it can be considered that the necessary drying heat amount is classified by a combination of conditions of a plurality of items.

  FIG. 6 shows a schematic configuration of a web drying unit according to a different embodiment, which can be substituted for the web drying unit of the pretreatment liquid coating and drying apparatus 101 shown in FIGS. In this web drying unit, heating means 60f such as a first lower frame 71 equipped with a roller-shaped heating means 40r incorporating a heater and a first upper frame 72 equipped with a roller-shaped heating means 40f incorporating a heater are used. Are divided into individual unit frames each equipped with heating means, and can be opened and closed vertically and fixed in position. The first lower frame 71 and the first upper frame 72 form a pair, and their approach / separation is performed by the same opening / closing mechanism as shown in FIG. 5, and the contact / separation state is detected by the first position sensor 81. Similarly, the second position sensor 82 determines whether the second lower frame 73 and the second upper frame 74 that are paired are in contact with or separated from each other, and the state that the third lower frame 75 and the third upper frame 76 that are paired are third. Is detected by the position sensor 83. With this configuration, it is possible to switch to an optimum drying path length according to the printing conditions, and it is possible to provide a pretreatment liquid coating and drying apparatus that can reduce the waste paper generated when the printing system starts printing.

  FIG. 7 shows different states of opening and closing of individual unit frames. When ink-jet paper is used, no pretreatment liquid is applied and drying is not required. Therefore, the maximum drying capacity defined in the apparatus specifications of the pretreatment liquid application / drying apparatus 101 is shown in FIG. When the printing conditions require the drying unit, the drying unit is used in the closed state shown in FIG. Depending on the printing conditions (web basis weight, web width, amount of pretreatment liquid applied, printing speed), it is used as the optimum state of the heating means including FIG. 7 (B) and FIG. 7 (C). An example is shown in Table 2.

Table 2 is an example showing the state of the heating means according to the printing conditions (web basis weight, web width, coating amount of pretreatment liquid, printing speed) for the pretreatment liquid coating and drying apparatus 101. The maximum specifications are, for example, a web basis weight of 250 g / m ² , a web width of 20.5 inches (52.07 cm), and a printing speed of 50 m / min. When the drying heat amount required for each item is 2/3 or less of FIG. 7D, the drying heat amount required for each item is 1/3 or less of FIG. 7D in the state shown in FIG. 7C. In the case of the above, or when the required amount of drying heat is 1/3 or less of FIG. 7D due to a combination of a plurality of items, it is used in the state of FIG. For example, when used in the state shown in FIG. 7B, the heating means 50r, 50f, 60r, and 60f are not used. Therefore, it is not necessary to turn on the heater in the heating means, and the life of the parts can be extended and the parts need to be replaced. This has the effect of reducing machine downtime. Further, since the heating means 50r, 50f, 60r, and 60f do not rotate, the life of each bearing and the parts that slide and wear during rotation can be extended, and the machine downtime required for parts replacement can be reduced.

  This makes it possible to provide a pretreatment liquid coating and drying device that can reduce the amount of paper loss that occurs at the start of printing in the printing system. Further, the machine that extends the life of parts of the heater in the heating means that is not used and requires replacement of parts. Downtime can be reduced.

  Note that the number of heating means mounted on each individual unit frame is not limited to one, and the number of individual unit frames is not limited to three for front surface heating and back surface heating, for a total of six. Further, each of the individual unit frames can be provided with a temperature detecting means for measuring the temperature of a steam exhaust fan or a heating means for producing steam. The boundary condition for switching the number of heating means used for each printing condition shown in Table 2 is also an example, and is determined and determined by experiment, evaluation, or calculation.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited to specific embodiment, In the range of the summary of this invention described in the claim, various deformation | transformation and change Is possible.

  Note that an “inkjet recording apparatus” ejects ink droplets from a nozzle of a recording head onto a recording material to form an image (recording, printing, printing, printing is also synonymous, and images having meanings such as characters and figures). Including not only the application to the medium but also the action of applying an image having no meaning such as a pattern to the medium (simply referred to as droplet ejection or liquid ejection for causing a droplet to land on the medium) 2 3D images (stereoscopic images) as well as 3D images can be targeted). Further, in the present application, the material of the “recording material” is not limited to paper, and includes a fabric, leather, metal, plastic, glass, wood, ceramics, etc. The term “recording material” is used as a general term including what is called recording paper or the like. The “liquid” of the liquid droplets ejected from the recording head is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, but the viscosity is 30 mPa under normal temperature and normal pressure, or by heating and cooling. -It is preferable that it is less than s. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, etc., which include, for example, inkjet inks, surface treatment liquids, components of electronic elements and light emitting elements, and electronic circuit resist patterns It can be used in applications such as forming liquids and three-dimensional modeling material liquids.

1 Guide roller 9 Feed nip roller 10 Feed roller 13f, 13r Application means 15f, 15r Guide roller 16 Dancer unit 40f, 40r, 50f, 50r, 60f, 60r Heating means 70f Drying unit upper frame 70r Drying unit lower frame 81, 82, 83 Drying unit position sensor 90 Control board 101 Pretreatment liquid coating and drying device

JP 2014-159130 A

Claims (7)

A pretreatment liquid application unit capable of applying the pretreatment liquid to both surfaces or one of the surfaces of the long object to be conveyed, and the object to be conveyed by the heating means disposed on the downstream side of the conveyance path of the pretreatment liquid application unit. In a pretreatment liquid coating / drying apparatus comprising a web drying unit for drying an object,
A pretreatment liquid coating and drying apparatus, wherein a drying path length of the web drying unit is configured to be variable.   2. The front according to claim 1, wherein the heating unit of the web drying unit is movable in position, and the drying path length is changed by changing a range where the heating unit of the web drying unit comes into contact with the object to be conveyed. Treatment liquid coating and drying equipment.   The web drying unit has two frames approaching or separating from each other and a plurality of roller-shaped heating means provided in each frame, and the heating means is moved toward and away from the two frames by approaching and separating the two frames. The pretreatment liquid coating and drying apparatus according to claim 1, wherein the drying path length is changed by changing a winding amount of an object to be conveyed.   The web drying unit has a plurality of pairs of frames approaching or separating from each other, and each pair of frames is provided with a roller-shaped heating means, and each pair of frames is provided with a roller-like heating means. The pretreatment liquid coating and drying apparatus according to claim 1, wherein the drying path length is changed by changing a winding amount of the conveyed object.   5. The pretreatment liquid coating / drying apparatus according to any one of claims 1 to 4, and an inkjet recording that forms an image on a long object to be transported disposed downstream of a transport path of the pretreatment liquid coating / drying apparatus. And a printing system that changes a drying path length of a web drying unit of the pretreatment liquid coating and drying apparatus according to printing conditions.   A printing apparatus comprising: the pretreatment liquid coating / drying apparatus according to claim 3; and an ink jet recording apparatus disposed on the downstream side of the conveyance path of the pretreatment liquid coating / drying apparatus to form an image on a long object to be conveyed. In the system, the pretreatment liquid coating / drying apparatus is provided with a sensor for detecting the position of the frame, and the position state detected by the sensor is compared with a state determined in advance according to the printing conditions. A printing system that does not perform a printing operation in the case of mismatch.   A printing apparatus comprising: the pretreatment liquid coating and drying apparatus according to claim 4; and an ink jet recording apparatus that is disposed on the downstream side of the conveyance path of the pretreatment liquid coating and drying apparatus and forms an image on a long object to be conveyed. In the system, each of the pretreatment liquid coating and drying devices is provided with a sensor for detecting the position of a pair of frames, and the position state detected by the sensor is compared with a state determined in advance according to printing conditions. A printing system characterized by not performing a printing operation when the results do not match.

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