JPH04349967A - Stabilizing device for adhesive spread of cold extrusion coater - Google Patents

Abstract

PURPOSE:To save the comsumption of an adhesive by keeping up a high yield of spread and simultaneously making the quality of an end product uniform by continuing a stabilized spread in a long adhesive coating operation to last all day. CONSTITUTION:This apparatus is provided with coolers 6a and 6b a to retain a temperature slightly lower than ordinary temperature; a means of inhibiting the cooling of an adhesive mixture 7, comprising a chilling unit 9 and the like; a means of extrusion-coating the adhesive mixture 7, comprising an extrusion pump 10, an extrusion nozzle 11, a glue recovery box 12 and the like; a means of measuring the flow rate of the adhesive mixture 7, comprising a flowmeter 15 situated between the extrusion nozzle 11 and the extrusion pump 10; and a means of controlling the flow rate of the adhesive mixture 7 by comparing the values by measurement of the flowmeter 15 with a predetermined set value of flow rate and regulating the number of revolutions of a variable speed motor 17 to drive the extrusion pump 10.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applied to the production of building materials such as plywood and laminated veneer materials by keeping the upper surface of a plate-like material such as a plywood veneer that is continuously transported at a temperature slightly lower than room temperature. , cooling extrusion application of adhesive in which an adhesive mixture consisting of an adhesive and additives such as a curing agent and a crosslinking agent is extruded and applied in a horizontal line to suppress changes in viscosity due to chemical reactions as much as possible. The present invention relates to a coating amount stabilizing device applied to a machine.

0002

[Prior Art] Conventional adhesive applicators of this type are:
For example, in JP-A No. 2-235974, an automatic adhesive coating device is used that maintains the liquid temperature at a temperature slightly higher than room temperature, e.g.
A high-pressure pump pressurizes predetermined amounts of the adhesive and its curing agent, crosslinking agent, and other additives, which are maintained at 5°C or higher to reduce flow resistance and facilitate atomization.
While stirring and mixing with a static mixer etc.,
An adhesive mixture made by stirring and mixing the adhesive and additives can be sent to a spray gun and sprayed in a horizontal line on the upper surface of a plate-like object such as a veneer veneer that is continuously conveyed on a conveyor. There was a so-called two-liquid mixing heated spray type adhesive automatic coating device configured as follows.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned two-component mixing type heated spray adhesive automatic coating device, etc., the adhesive and its additives are kept at a temperature slightly higher than room temperature. Although it is possible to assist the atomization effect of the adhesive mixture with a spray gun, the flow path of the static mixer etc. may be blocked by the gelled substance of the adhesive mixture that occurs over time. Not only did this have problems such as frequent clogging of the spray gun and lack of stability, but also the method of applying the adhesive mixture to the plate-like object by spraying it with a spray gun was a so-called open method of application. This method had the disadvantage that a large amount of the adhesive mixture was scattered and the coating yield was extremely low.

[0004] Therefore, in order to eliminate the drawbacks of the above-mentioned conventional apparatus, the first object of the present invention is to create an adhesive mixture consisting of an adhesive and its additives, which is maintained at a slightly higher temperature than normal temperature by the above-mentioned conventional apparatus. We have fundamentally changed the heating spray application method using an open method onto a plate-shaped object, in which adhesive is sprayed in a horizontal line with a spray gun, and the adhesive mixture consisting of adhesive and its additives is heated to a temperature slightly lower than room temperature. The adhesive mixture is held in place to suppress changes in viscosity due to the gelling effect of the adhesive mixture during the application process, and the adhesive mixture is extruded horizontally in a straight line through an extrusion nozzle, and excess adhesive mixture is removed. The object of the present invention is to significantly improve the coating yield by improving the cooling extrusion coating method using a closed method on a plate-shaped body, in which the coating material is recovered and used again.

[0005] A second object of the present invention is that even if the adhesive mixture is cooled and applied at a temperature slightly lower than normal temperature, the gelling effect due to the chemical reaction of the adhesive mixture will not occur over time. The viscosity of the adhesive and the mixing ratio with additives cannot be avoided for each lot supplied, and as a result, the viscosity of the adhesive mixture changes. Because of the flow resistance caused by viscosity, the flow rate discharged from the extrusion nozzle also constantly fluctuates, causing uneven coating. The discharge flow rate is measured by a flow meter, and even if the adhesive mixture has a slight change in viscosity, the discharge flow rate of the extrusion pump is automatically controlled to be maintained at a constant value according to the measured value, The purpose of this invention is to significantly improve quality by stabilizing the amount of adhesive applied during long-term adhesive application work that lasts all day by preventing fluctuations in the flow rate due to changes in viscosity in the flow rate discharged from the extrusion nozzle.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a coating amount stabilizing device using an adhesive cooling extrusion coating machine, which relates to a so-called two-component mixing type cooling extrusion type adhesive automatic coating device. , has the following configuration requirements.

[0007] a) A cooler that maintains an adhesive mixture consisting of an adhesive and its curing agent, crosslinking agent, and other additives at a temperature slightly lower than room temperature to minimize changes in viscosity due to its gelling action. , cooling suppression means consisting of a chilling unit, etc.

b) The adhesive mixture kept at a temperature slightly lower than normal temperature is extruded in a horizontal straight line from an extrusion nozzle toward the glue collection box directly below while being slightly pressurized by an extrusion pump, and the veneer is conveyed by a conveyor. An extrusion coating means that can apply this to the upper surface of a plate-like object such as a veneer.

c) Flow rate measuring means, which is capable of measuring the flow rate of the adhesive mixture discharged from the extrusion nozzle by inserting a flowmeter between the extrusion nozzle and the extrusion pump.

d) Flow rate control means that transmits the measured value of the flow meter to a controller and compares it with a predetermined flow rate setting value to automatically control the rotation speed of a variable speed motor that drives the extrusion pump.

[0011]

[Function] The adhesive cooling extrusion coating machine of the present invention coats the adhesive and its curing agent, crosslinking agent, and other additives in an appropriate ratio, for example, 1.
An adhesive mixture prepared by mixing at a ratio of about 0:1,
The liquid temperature is maintained at a temperature slightly lower than room temperature, for example, when the air temperature is 10 to 20 degrees Celsius, the liquid temperature is kept at a low temperature of about 5 to 15 degrees Celsius, in order to suppress the progress of gelation due to its own chemical reaction as much as possible during the application process. By distributing various types of coolers in the distribution channels and storage tanks, and circulating refrigerant such as cold water produced by a chilling unit etc. into the coolers, the above-mentioned conditions can be reduced during long coating work that lasts all day long. First, a means for suppressing cooling of the adhesive mixture is constructed, which maintains the adhesive mixture at a temperature slightly lower than room temperature to suppress the progress of gelation due to its own chemical reaction as much as possible. Next, several kilograms of the adhesive mixture, which has been maintained at a temperature slightly lower than room temperature by the cooling suppressing means for the adhesive mixture, is pumped by an extrusion pump such as a gear pump or a mono pump.
The material is slightly pressurized to about /cm2 and fed to an extrusion nozzle consisting of a large number of nozzles and slits, and extruded horizontally in a straight line toward the glue collection can directly below the extrusion nozzle and the glue collection can. For example, 200 g/m
The extrusion coating means is configured to apply an adhesive mixture in a coating amount of about 2.2 mm, and the excess adhesive mixture other than that applied to the upper surface of the plate is returned to the storage tank. It is installed in a closed system so that it can be recovered and used again. Next, a flowmeter such as an electromagnetic flowmeter is inserted between the extrusion nozzle and the extrusion pump, and the flowmeter is, for example, 200 g/
10-20 liters/mi for a total application amount of about m2
In addition to measuring the discharge flow rate of the flowing adhesive mixture of about do,
In order to automatically maintain the discharge flow rate at a constant value even if there is a slight change in the viscosity of the adhesive mixture, the rotation speed of the variable speed motor is adjusted in comparison with a predetermined flow rate setting value for the required application amount. By configuring the adhesive admixture flow rate measuring means and flow rate controlling means to automatically control the adhesive mixture over the day by preventing fluctuations in the flow rate due to viscosity changes in the discharge flow rate from the extrusion nozzle. This is the first time that it has become possible to stabilize the coating amount during long-term coating operations.

0012

[Example] FIG. 1 shows an example of the arrangement of the present invention.
An adhesive supply pump 2 consisting of a gear pump, mono pump, etc. that supplies a fixed amount of adhesive such as urea resin stored in an adhesive tank 1; and an aqueous solution of ammonium chloride, for example, corresponding to the urea resin stored in an additive tank 3. The adhesive and additive are metered and flowed at a predetermined mixing ratio to a mixer 5 by an additive supply pump 4, which is a gear pump, mono pump, etc., which supplies a fixed amount of a curing agent such as the like. The outer periphery of the mixer 5, the outer periphery of the storage tank 8 that temporarily stores the adhesive mixture 7 stirred and mixed by the mixer 5, the periphery of other distribution channels for the adhesive mixture 7, and as the case may be. Cooling means such as coolers 6a and 6b are attached to the outer periphery of the adhesive tank 1, and refrigerant such as cold water from a chilling unit 9 for producing refrigerant is circulated and supplied to these cooling means. The adhesive mixture consisting of the adhesive and additives is heated at a liquid temperature of 5° C. at a temperature slightly lower than room temperature, for example, at an air temperature of 10 to 20° C.
First, a means for suppressing cooling of the adhesive mixture is constructed, which maintains the adhesive mixture at a low temperature of about 15 DEG C. and suppresses the progress of gelation due to chemical reaction as much as possible. Next, in the storage tank 8, the adhesive mixture 7, which has been kept at a temperature slightly lower than room temperature by the cooling suppressing means, is slightly pressurized to about several kg/cm2 by an extrusion pump 10 consisting of a gear pump, mono pump, etc. , the extrusion nozzle 11 consisting of a large number of nozzles and slits, etc.
For example, on the upper surface of a plate-shaped body 14 such as a veneer veneer, which is extruded in a horizontal line toward 2 and continuously conveyed by a conveyor 13 between the extrusion nozzle 11 and the glue collection box 12,
The adhesive mixture extrusion coating means applies the adhesive mixture in a coating amount of about 0.00 g/m2, and the excess flowing adhesive mixture 7 other than that applied to the upper surface of the plate-shaped body 14 is
A is installed in a closed system so that it can be collected again by gravity into the storage tank 8 or by an appropriate collection pump and used again. Next, a flow meter 15 such as an electromagnetic flow meter is inserted between the extrusion pump 10 and the extrusion nozzle 11, and the total amount of application is about 200 g/m2, for example, with respect to the total amount of application discharged from the extrusion nozzle 11. It is possible to measure the flow rate of the flowing adhesive mixture 7a at a rate of about 10 to 20 liters/min, and to maintain the discharge flow rate at a constant value by adjusting the rotation speed of the extrusion pump 10 based on the measured value of the flow meter 15. For example, a PID operation controller 16 or the like is inserted between the flowmeter 15 and the variable speed motor 17, such as an inverter control motor or AC servo motor that drives the extrusion pump 10, to mix the flowing adhesive. The rotation speed of the variable speed motor 17 is automatically controlled by comparing it with a predetermined flow rate setting value for the required coating amount so that the discharge flow rate is automatically maintained at a constant value even if there is a slight change in the viscosity of the object 7a. The adhesive mixture flow rate measuring means and flow rate control means are configured to do this.

[0013]

Effects of the Invention As explained above, the present invention includes a cooling suppressing means for suppressing changes in viscosity due to chemical reactions of an adhesive mixture as much as possible, and a method for extruding the adhesive mixture in a horizontal line to form a plate-shaped body. An extrusion coating means for coating, a flow rate measuring means for measuring the extrusion flow rate of the adhesive mixture, and automatically maintaining the discharge flow rate at a constant value even if the adhesive mixture has a slight change in viscosity; Since the device is a device for stabilizing the coating amount using a cooling extrusion coating machine for adhesive, which includes a control means, the present invention is capable of applying heated spraying of a two-component adhesive mixture using a conventional device using a spray gun using an open method. The clogging of the spray gun and low coating yield, which were the disadvantages of this method, have been overcome by the closed cooling extrusion coating method using the extrusion nozzle of the adhesive mixture maintained at a temperature slightly lower than room temperature, according to the present invention. In addition, the flowmeter of the present invention can be used to cope with the occurrence of coating spots caused by changes in flow resistance due to the viscosity of this type of two-component adhesive mixture, which is always subject to slight viscosity changes. All of these problems have been solved by a flow rate measurement control means using an extrusion pump, and in particular, the present invention is suitable for manufacturing building materials such as plywood and laminated veneer materials.
The implementation effect was that we were able to simultaneously achieve savings in adhesive consumption by maintaining a high coating yield and equalization of product quality by maintaining a stable coating amount, even during long adhesive coating operations that lasted all day long. This is extremely remarkable.

[Brief explanation of drawings]

FIG. 1 is a side view showing an example of arrangement.

[Explanation of symbols]

1 Adhesive tank 2 Adhesive supply pump 3 Additive tank 4 Additive supply pump 5 Mixer 6a, 6b Cooler 7 Adhesive mixture 7a Flowing adhesive mixture 8 Storage tank 9 Chilling unit 10 Extrusion pump 11 Extrusion nozzle 12 Glue collection box 13 Conveyor 14 Plate-shaped body 15 Flowmeter 16 Controller 17 Variable speed motor

Claims (1)

[Claims] [Claim 1] A cooler that maintains an adhesive mixture consisting of an adhesive and its curing agent, crosslinking agent, and other additives at a temperature slightly lower than room temperature to minimize changes in viscosity due to its gelling action. , cooling suppression means consisting of a chilling unit, etc.;
A board such as a veneer veneer that is kept at a slightly lower temperature than the room temperature and is extruded in a horizontal line from an extrusion nozzle toward a glue collection box directly below while applying slight pressure with an extrusion pump and is conveyed by a conveyor. An extrusion coating means capable of applying the adhesive mixture to the upper surface of a shaped body, and a flow rate measurement device capable of measuring the flow rate of the adhesive mixture discharged from the extrusion nozzle by inserting a flow meter between the extrusion nozzle and the extrusion pump. and a flow control means that transmits the measured value of the flow meter to a controller and compares it with a predetermined flow rate setting value to automatically control the rotation speed of a variable speed motor that drives the extrusion pump. A device for stabilizing the coating amount using an adhesive cooling extrusion coating machine, characterized by: