JPH04164601A - Spread-stabilizing device in automatic coater of adhesive - Google Patents

Abstract

PURPOSE:To keep the spread of adhesive mixture always uniformly by a method in which the flow amount of the adhesive mixture fed to an extruding nozzle from an accumulator is measured by a measuring device, and the speed of the variable speed-motor which drives a conveyer by measurement signal is proportionally controlled by a proportional control board. CONSTITUTION:Pressurized gas 15 is fed to an accumulator 6 with the regulation of pressure through a pressure-regulating valve 16, and the adhesive mixture 22 of the set discharging amount corresponding to necessary spread is extruded on the upper surface of the object 10 to be coated which is transferred on a conveyer 9 from an extruding nozzle 8. The measurement signal of a flow meter 11 is transmitted to the proportional-control board of the variable speed- motor 12 which drives the transferring conveyer of the object 10 to be coated so that the spread of the adhesive mixture 22 with which the upper surface of said object 10 is coated is always kept uniformly. By proportionally controlling the speed of the variable speed-motor 12 by the proportional-control board 13, the spread of the adhesive mixture 22 with which the upper surface of said object is coated, is always kept uniformly.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention applies adhesives to the upper surface of objects to be coated, such as veneer veneers, which are continuously conveyed when manufacturing building materials such as plywood and laminated veneer materials. The present invention relates to a coating amount stabilizing device installed in an automatic adhesive coating machine that extrudes and applies adhesive mixtures such as curing agents and crosslinking agents.

(Prior Art) A push pump for supplying an adhesive mixture to an extrusion nozzle, which is used in a conventional automatic adhesive applicator using this kind of two-component adhesive paste, is as illustrated in Fig. 2. A so-called quantitative supply type gear pump, in which a pair of gears 78, 7b are housed in a housing 7C, was used alone, or a gear pump with an accumulator for pressurized gas was used. Also, the conveyance speed of the object to be coated is several tens of meters.
The coating operation was performed at a relatively low speed of 1 n or less.

(Problem to be solved by the invention) In recent years, the speed of adhesive application has significantly increased in the manufacturing process of building materials. Since the amount of discharge pulsates, causing uneven coating, an accumulator with a constant pressurized gas was used in order to eliminate the pulsation. However, even if a constant pressure gas accumulator is used, in the case of a two-component adhesive mixture, as shown in Figure 3, the adhesive and the hardening agent,
The viscosity increases as the chemical reaction of the cross-linking agent progresses, and the viscosity of the adhesive mixture changes over time due to fluctuations in liquid temperature due to changes in temperature, etc., so the amount of adhesive to be discharged can vary widely. There was a serious drawback in that the coating was variable and resulted in significant coating unevenness.

The present invention is an automatic two-component adhesive applicator that uses the above-mentioned car pump as a push pump into an aracumulator, and responds to fluctuations in the discharge amount due to changes in the viscosity of the adhesive mixture discharged from the araccumulator. By proportionally controlling the conveyance speed of the object to be coated conveyed on the conveyor immediately below, the amount of the adhesive mixture applied to the upper surface of the object to be coated can be maintained uniformly from beginning to end. The purpose of this is to eliminate the occurrence of uneven coating due to changes in viscosity.

(Means for Solving the Problems) In order to achieve the above object, the coating amount stabilizing device of the present invention has the following features:
A main agent supply pump that supplies a fixed amount of adhesive stored in a main agent tank, an additive supply pump that supplies a fixed amount of curing agent, crosslinking agent, etc. stored in an additive tank, and a fixed amount of supply from the main agent and additive supply pump. a mixer that stirs and mixes the adhesive, its curing agent, crosslinking agent, etc.; and a push pump that supplies the adhesive mixture, such as the adhesive, its curing agent, crosslinking agent, etc., stirred and mixed by the mixer to the araccumulator. This is a two-component mixing type in which the adhesive mixture discharged from the aluminizer is supplied to an extrusion nozzle, and then extruded and applied onto the upper surface of the object to be coated, such as a veneer veneer, which is continuously conveyed by a conveyor. This is a coating amount stabilizing device for an automatic adhesive coating machine that has the following structural requirements.

a) Measuring the flow rate of the adhesive mixture supplied from the araccumulator to the extrusion nozzle with a flowmeter,
The speed of the variable speed motor that drives the conveyor is proportionally controlled by a proportional control panel based on the measurement signal of the flowmeter.

b) The accumulator is equipped with an adhesive mixture level controller to control the forced pump on and off.

C) The pressure of the pressurized gas supplied to the accumulator is made variable by a pressure regulating valve.

5. Effect] Since the coating amount stabilizing device in the two-component mixing type adhesive automatic coating machine of the present invention is configured as described above, even if the car pump is used as the push pump of the accumulator, it will not work. The pulsation in the discharge amount due to the tooth shape of the carrier can be completely eliminated by the pressurizing action of the pressurized gas by the accumulator, and the viscosity of the adhesive mixture discharged from the extrusion nozzle over time can be completely eliminated. Maintaining an even coating amount of the adhesive mixture applied to the upper surface of the object to be coated in response to changes can be achieved by inserting a flow meter between the accumulator and the extrusion nozzle, and by A proportional control panel is attached to a variable speed motor attached to a conveyor, and the variable speed motor is proportionally controlled via the proportional control panel 61 based on the measurement signal of the flow meter, thereby controlling the adhesive mixture over time. Stabilization control is achieved to maintain a uniform coating amount on the upper surface of the object from beginning to end regardless of viscosity changes.

That is, the two-component adhesive automatic applicator used in the present invention applies urea resin adhesive, for example, to the upper surface of an object to be coated, such as a veneer veneer, which is continuously conveyed by a conveyor such as a ring roll. A veneer veneer sheet conveyed at a high speed of, for example, 80171/min, in which an adhesive mixture of about 10:1 of adhesive and its curing agent is extruded from an extrusion nozzle in the shape of noodles and applied in multiple lines. Discharge ports with a diameter of about 5mm are drilled in a staggered manner at intervals of about 3 shoes, so that the adhesive mixture can be applied in a multi-line manner at a required coating amount of about 200 g/m on the upper surface of the object to be coated. An extrusion nozzle is installed on the conveyor, and the noodle-shaped adhesive mixture, which is constantly being extruded from the extrusion nozzle at a set discharge amount commensurate with the required application amount, is transferred to a receiver facing below the conveyor. The system is constructed in a closed loop in which the urea resin adhesive and its curing agent are then circulated and recovered into the mixer where the urea resin adhesive and its curing agent are stirred and mixed.

Further, in this case, the set discharge amount corresponding to the required application amount by the accumulator of the adhesive mixture constantly discharged from the extrusion nozzle is determined by the conveyance speed of the object to be coated, such as the veneer veneer, and the It is determined by the required application amount of the adhesive mixture to the object to be applied, for example, 80u/min.
In the case of a transport speed of about 100 kg/mjn and a required coating amount of about 200 g/m, the discharge rate must be stably maintained at a set discharge rate of about 15 to 20 kg/mjn. However, in reality, the viscosity of two-component adhesive mixtures may change over time due to chemical reactions even during their pot life, and the setting from the extrusion nozzle using a constant-pressure accumulator is difficult. Since the discharge amount fluctuates widely, the present invention involves inserting a flowmeter, such as an electromagnetic flowmeter or an ultrasonic flowmeter, between the alumulator and the extrusion nozzle. By using a proportional control panel to proportionally control a variable speed motor attached to a conveyor that conveys the object to be coated, such as various servo motors or inverter-controlled motors, based on measurement signals from a flowmeter, the upper surface of the object to be coated can be The actual amount of the adhesive mixture to be applied is maintained evenly from beginning to end; in other words, in this case, the proportional control by the flow meter, proportional control panel, and variable speed motor controls the amount of adhesive mixture applied. If the viscosity of the adhesive increases and the discharge rate from the extrusion nozzle decreases, the conveyor speed is lowered to maintain a constant coating amount per unit length. When the viscosity decreases and the discharge amount from the extrusion nozzle increases, the conveyor speed is increased to maintain a constant coating amount per unit length.
The speed of the variable-speed motor is controlled proportionally to maintain stable constant application throughout.

In addition, in the automatic application process using a two-component mixture type adhesive such as the adhesive and its curing agent, crosslinking agent, etc. as in the present invention, it is necessary to In order to prolong the use time and eliminate problems due to premature gelation, the adhesive and the adhesive mixture, such as the adhesive and its curing agent, crosslinking agent, etc., are heated in their flow path to the required temperature, e.g.
The first cooler is inserted into the supply process to cool down the adhesive, which is supplied in an overwhelmingly large quantity by the main agent supply pump, to delay the chemical reaction by cooling the adhesive to about A second cooler is also attached to the mixer that stirs and mixes the mixture, and the first and second coolers are cooled by a refrigerator or the like.
Connected to a chilling unit that uses cold water at around °C as a refrigerant, the adhesive and the adhesive mixture, such as the adhesive, curing agent, crosslinking agent, etc., are constantly cooled and maintained at the required temperature of around 5 °C. The device is designed to extend the pot life and suppress excessive changes in viscosity beyond the controllable range.

In this case, for example, even if a fast-curing, high-productivity adhesive mixture containing a urea resin adhesive and its curing agent at a mixing ratio of about 10:1 is used, it will gel in about 10 minutes at room temperature. The onset time of gelation can be delayed by several hours, and even in an all-day application operation, e.g., lasting up to 8 hours, the adhesive admixture typically has a
2C) ONg is consumed at a time and the blending time is updated sequentially, so the actual usable life of the adhesive mixture is delayed even further than the gelation start time due to the above blending, and lasts for well over a day. The safety and stability of the coating work can be ensured, and the discharge amount from the extrusion nozzle can be freely set according to the required coating amount by adjusting the pressure of the accumulator. be.

(Example) Fig. 1 shows an example of the implementation of the present invention, in which an adhesive such as urea resin stored in a main agent tank is supplied in a fixed amount, for example, at a rate of about 9/n to 15 to 20. A main agent supply pump 2 consisting of a car pump, a mono pump, etc., which supplies a constant amount of supply commensurate with the amount of adhesive consumed, and a curing agent, such as an aqueous ammonium chloride solution, corresponding to the urea resin stored in an additive tank 3. Supply a fixed amount of agent, e.g. 1.5
~2K9/min The additive HO agent supply pump 4, which is composed of a diaphragm pump, mono pump, etc., supplies a constant supply amount commensurate with the consumption of the curing agent at a rate of 10:1.
The adhesive and its curing agent are flowed toward the mixer 5 at a mixing ratio of about 100 ml.

A first cooler 17 is inserted into the flow path between the adhesive main agent supply pump 2 and the mixer 5 to cool the adhesive to a required temperature during the supply process. A second cooler 18 is attached to the wall surface or an appropriate location thereof, and the adhesive and its curing agent are newly supplied by a stirring propeller 19 installed in the container, and the recovered adhesive is The adhesive mixture 20 consisting of the adhesive, its curing agent, etc. is made to flow and is cooled to a required temperature during the process of stirring, mixing, supplying and recovering.

Note that the first and second coolers 17 and 18 are supplied with a refrigerant such as cold water produced by a chilling unit 21 for refrigerant production in a circulating manner, and the circulation path and attached equipment are normally covered with heat insulating material. Usually, the cooling means on the hardening agent side is omitted because the amount is small, but if necessary, the refrigerant from the chilling unit 21 can be applied to the circulation paths of these or the walls of attached equipment. It is also possible to supply and cool it. Next, the adhesive mixture 2o, which has been cooled to a required temperature in the mixer 5, and its curing agent, crosslinking agent, etc., is pumped to a pressure of 1 to 5 Ky by an appropriate force pump 7, such as a car pump or a centrifugal pump. It is pressurized and supplied into the accumulator 6 under a constant pressure of about .

In this case, the retention level of the adhesive mixture in the accumulator 6 is detected by a level controller 14 consisting of an ultrasonic sensor, etc., and the push pump 7 is controlled on/off so that the appropriate amount can be replenished at the right time. It is something that is installed. Further, pressurized gas 15 such as compressed air is regulated and supplied to the accumulator 6 at a pressure of about 1 to 5 K9/cit through a pressure regulating valve 16 such as a Guyafram type, and is supplied from the extrusion nozzle 8 as required. The adhesive mixture 22 in a set discharge amount commensurate with the applied amount is extruded in the form of noodles onto the upper surface of the object II being conveyed on the conveyor 9. Furthermore, a flow meter 11 such as an electromagnetic flow meter or an ultrasonic flow meter is inserted between the accumulator 6 and the extrusion nozzle 8, so that even if the flow rate measured by the flow meter 11 fluctuates, , so that the amount of the adhesive mixture 22 applied in multiple lines on the upper surface of the object 10 to be applied is maintained evenly from beginning to end.
The measurement signal from the flow meter 11 is transmitted to the proportional control panel 13 of the variable speed motor 12, such as various servo motors or inverter-controlled motors, which drives the conveyor 9 for conveying the object 10, and the proportional control panel 13 variable speed motor 1
By proportionally controlling the speed of
The apparatus is designed to maintain a substantially uniform amount of the adhesive mixture 22 applied to the upper surface of the 0 from beginning to end. Furthermore, when the adhesive mixture 22 is extruded in the form of noodles from a large number of discharge ports 23 provided in a staggered manner on the bottom surface of the extrusion nozzle 8, when the object 10 to be coated is being conveyed directly below, the adhesive mixture 22 is placed on the upper surface of the object 10 being conveyed. is applied in a multi-line manner, and when the object 10 to be coated is not being conveyed, it is applied to the receiver immediately below.
After putting the receiver into the container of 24, the mixed dust, wood chips, etc. are filtered through a filter such as a wire mesh, and an appropriate collection pump 25 is used.
It is constructed in a closed loop in which it is collected again into the mixer 5 and used for circulation. The adhesive mixture 22, which is extruded from the extrusion nozzle 8 in the form of noodles and applied in multiple lines on the upper surface of the object to be coated 10, is applied by cold pressing with the laminated objects to be coated in a subsequent step. The adhesive mixture 22 is applied by the extrusion nozzle 8 in such a manner that the multi-linear coating form is laterally spread out by a pressing operation using a hot press or the like and applied to the road surface. The extrusion means is not limited to the noodle-like extrusion means from a large number of staggered discharge ports 23 in the embodiment, but may also be, for example, a poultice-like extrusion means from horizontal linear slits, or even foaming. Of course, it is also possible to add other means.

(Effects of the Invention) As explained above, the present invention uses a car pump of an automatic coating machine that mixes two components of this type of adhesive, its curing agent, crosslinking agent, etc., as a push pump into an accumulator. In this method, the conveyance speed of the object to be coated conveyed on the conveyor immediately below is proportionally controlled in accordance with the variation in the coating amount due to the change in viscosity over time of the adhesive mixture discharged from the aracumulator. In order to maintain an even coating amount of the adhesive mixture applied to the upper surface of the coating body from beginning to end and to prevent the occurrence of uneven coating due to changes in viscosity, the adhesive mixture is supplied from the aracumulator to the extrusion nozzle. The flow rate of the adhesive mixture is measured by a flow meter, and the speed of the variable speed motor that drives the conveyor is proportionally controlled by a proportional control WJ board based on the measurement signal of the flow meter, so that the substantial amount of the adhesive mixture is Since the amount of coating is maintained evenly from start to finish, the present invention completely prevents the occurrence of coating spots caused by pulsating discharge that occurs in conventional devices and coating spots caused by changes in viscosity over time. Not only was it possible to safely and reliably provide a product with uniform adhesive strength, but it was also able to prevent unexpected changes in viscosity over time that exist in this type of two-component adhesive mixture. This is a very remarkable implementation effect, as it was possible to perform timely and accurate automatic coating work without any human supervision or adjustment by workers.

[Brief explanation of the drawing]

Fig. 1 is a layout diagram showing an embodiment of an automatic coating machine for two-component adhesive of the present invention, Fig. 2 is a vertical side view showing an embodiment of a push pump, and Fig. 3 is a layout diagram showing an embodiment of an automatic coating machine for adhesive mixtures of the present invention. This is an example of the change in viscosity during use. 1... Main agent tank, 2... Main agent supply pump, 3...
・Additive tank, 4... Additive supply pump, 5...
Mixer, 6... Accumulator, 7... Push pump, 8... Extrusion nozzle, 9... Conveyor, 1o
... object to be coated, 11 ... flowmeter, 12 ... variable speed motor, 13 ... proportional control m board, 14 ... level controller, 15 ... pressurized gas, 16 ... Pressure control valve. Patent applicant: Hashimoto Electric Industry Co., Ltd. Figure 2 Figure 3 Working time

Claims (1)

[Claims] 1. A main agent supply pump (2) that supplies a fixed amount of adhesive stored in a main agent tank (1), and a fixed amount of curing agent, crosslinking agent, etc. stored in an additive tank (3). the additive supply pump (4), and the base and additive supply pumps (2, 4).
) A mixer (5) that stirs and mixes the adhesive, its curing agent, crosslinking agent, etc. supplied in a fixed amount from the mixer (5), and a mixer (5) that stirs and mixes the adhesive, its curing agent, crosslinking agent, etc. A push pump (7) supplies the material to the accumulator (6), and the adhesive mixture discharged from the accumulator (6) is supplied to the extrusion nozzle (8) and is continuously conveyed by the conveyor (9). In an automatic two-component adhesive coating machine that extrudes and applies adhesive onto the upper surface of a conveyed object (10) such as a plywood veneer, the adhesive is applied from the accumulator (6) to the extrusion nozzle (8). The flow rate of the supplied adhesive mixture is measured by a flow meter (11), and the speed of the variable speed motor (12) that drives the conveyor (9) is controlled by a proportional control panel ( 1
3) A coating amount stabilizing device in an automatic adhesive coating machine that performs proportional control. 2. The automatic adhesive applicator according to claim 1, wherein said accumulator (6) is equipped with an adhesive mixture level controller (14) to control on/off of said push pump (7). Application amount stabilizing device. 3. The coating amount stabilizing device for an automatic adhesive coating machine according to claim 1, wherein the pressure of the pressurized gas (15) supplied to the accumulator (6) is made variable by a pressure regulating valve (16). .