JPS63222811A - Batch-type manufacture of polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain a polyurethane slab with flat top surface by providing the process in which the foaming stock solution of polyurethane is agitated and mixed, the process in which said foaming stock solution is poured into a foaming tank and the process in which the polyurethane foam slab with flat top surface is produced by the centrifugal force due to the rotation of the foaming tank. CONSTITUTION:An isocyanate component of a prescribed amount is charged in a mixing and agitating tank 25 from a raw material feeding pipe 32. Simultaneously, other raw materials such as polyol component and catalyst are charged in the agitating tank 25 from a pipe 34, and said materials are uniformly mixed by rotating an agitating wing 26. Then, the foaming stock solution prepared in the mixing and agitating tank 25 is poured into the foaming tank 11 through a discharging pipe 28 by opening an electromagnetic valve 29. Next, the foaming tank itself is rotated by way of a shaft 15 and a bar 13 by a motor 14, whereby the surface of the foaming stock solution rises even in the vicinity in contact with the foaming tank 1 almost same as the central part, and the polyurethane slab with flat top surface is obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing polyurethane foam.

[Prior Art] Conventionally, urethane foam slabs are urethane foam that is foam-molded into large blocks, which are then sliced to a desired thickness or cut into a desired shape to be used as interior materials for vehicles or for vehicles. Widely used as cushioning material.

By the way, as a method for producing polyurethane foam, as shown in FIG. 5, a polyurethane foam slab 2 is produced by injecting a polyurethane foam stock solution into a large container (foaming tank) 1, foaming it, and curing it. It has been known. In this case, the foaming operation is usually performed with the inner surface of the foaming tank 1 covered with release paper (not shown). This patch type manufacturing method has the feature that it can be carried out even in a relatively narrow space. Furthermore, this method has the advantage that by changing the shape of the foaming tank 1, slabs of arbitrary shapes can be manufactured.

[Problems to be Solved by the Invention] However, the conventional batch-type manufacturing method has the following problems.

That is, when the polyurethane foaming stock solution is stirred and poured into the foaming tank 1, the foaming reaction proceeds and the liquid level gradually rises. At this time, as the foaming reaction progresses, the viscosity of the rising stock solution also increases, so foaming is inhibited near the area where it contacts the foaming tank 1 due to frictional resistance with the inner surface of the foaming tank. For this reason, the polyurethane foam slab 2 after foaming has a shape that is high at the center and low at the periphery, as shown in FIGS. 6 and 7, and a flat top surface cannot be obtained.

As a result, as shown by the two-dot chain line in FIG. 6, the convex top of the obtained slab 2 must be cut off to a predetermined size, resulting in waste parts and an increase in the number of steps. There was a problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing urethane foam that can produce a slab with a flat top surface when manufacturing a polyurethane foam slab.

[Means for Solving the Problems] The present invention consists of a step of stirring and mixing a polyurethane foaming stock solution, a step of injecting this foaming stock solution into a foaming tank, and a step of rotating the foaming tank and applying centrifugal force to form a polyurethane foam with a flat top surface. The gist is to include a process of manufacturing a foam slab.

[Function] According to the present invention, polyurethane foam having a flat top surface is produced by pouring a polyurethane foam foaming stock solution mixed and stirred appropriately into a foaming tank, and then foaming while rotating the foaming tank itself at an appropriate speed. You can get slabs. Therefore, unlike the conventional method, the convex top portion is not cut into a predetermined shape, and unnecessary slabs are not generated and the cutting process can be omitted.

In the present invention, the rotational speed of the foaming tank is approximately 20 to 120 revolutions per minute, although it varies depending on the rise of foaming. here,
If the rotation speed is slower than the 20 rotation valve, sufficient centrifugal force cannot be obtained and the polyurethane foam slab cannot be sufficiently flattened. On the other hand, if the rotational speed exceeds 120 rpm, the centrifugal force will be too strong, inhibiting the foaming reaction and easily causing cracks.

In the present invention, the polyurethane foam foaming stock solution includes polyols such as polyether polyols and polyester polyols, organic isocyanates such as tolylene diisocyanate, amine catalysts, tin catalysts, blowing agents (water), foam stabilizers (silicone oil), and others. Pigments, fillers, etc. are used in appropriate combinations depending on the required properties.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4. Here, FIG. 1 is a polyurethane foam manufacturing apparatus according to the present invention, FIG. 2 is a plan view of a foaming tank according to the same apparatus, FIG. 3 is an explanatory diagram of a shaft according to the same IIT, and FIG. FIG. 3 is a rear view of the layer.

11 in the figure is a cylindrical foaming tank having an opening 11a at the top. A shaft receiving hole 1 is provided in the opening 11a.
A bar 13 with 2 is provided. A tip end 15a of a shaft 15 (shown in FIG. 3) connected to a motor 14 engages with this bar 13, and as the motor 14 rotates, the shaft 15. The foaming tank itself is rotated via the bar 13. Further, a foaming stock solution introduction port 11a is opened in the side wall of the foaming tank 11, and a door 16 that can be opened and closed is provided in the introduction port 11a. Furthermore, the foaming tank 11 is placed on a support stand 18 with casters 17 attached to its lower part via rollers 19.

A rail 20 is attached near the foaming tank 11. A trolley 22 having wheels 21 on its legs is placed on the rail 20, and can approach or retreat from the foaming tank 11 by expanding and contracting the extrusion cylinder 23. A rotating shaft 24 is stretched horizontally on the cart 22, and a cylindrical mixing and stirring tank 25 is pivotally fixed to the rotating shaft 24. The rotation shaft 24 is rotatably driven by a motor and an irregular gear (not shown), so that the mixing agitation tank 25 is rotated and tilted in the direction indicated by the arrow in the figure. . A stirring blade 26 is provided inside the mixing stirring tank 25 in the axial direction, and this stirring blade 2
6 is adapted to be rotationally driven by a motor 27 attached below the mixing and stirring tank 25. Further, at the lower end of the side surface of the mixing and stirring tank 25, a foaming liquid discharge pipe 28 is provided extending obliquely downward. This foaming stock solution discharge pipe 28 and the mixing agitation tank 25 are communicated with each other via a solenoid valve 29 provided at the boundary between the two.

Furthermore, a measuring tank 30 for the organic isocyanate component is arranged above the mixing and stirring tank 25, and the measuring tank 30 is connected to an organic isocyanate supply source via a pipe 31. A raw material supply pipe 32 is provided at the lower end of the measuring tank 30, and between the raw material supply pipe 32 and the measuring tank 30 there is an i! A magnetic valve 33 is provided. In addition, the raw material supply pipe 32
A pipe 34 for supplying polyurethane foam raw materials other than isocyanate components, such as polyols and catalysts, is connected to.

A cleaning solvent supply pipe 35 for polyurethane foam raw material is attached to the organic isocyanate component measuring tank 30, and this supply pipe 35 is connected to a cleaning solvent tank 36. Further, a cleaning solvent waste liquid receiver 37 is installed, and this waste liquid receiver 37 is connected to the cleaning solvent tank 3 through a pump 38.
is connected to.

Next, the operation of the manufacturing apparatus having the above structure will be explained.

First, the extrusion cylinder 23 is expanded and contracted, and the mixing stirring tank 25 is
The polyurethane foam foaming stock solution is adjusted in a state where the polyurethane foam is retreated from the foaming tank 11. That is, after the organic isocyanate component is supplied into the metering tank 30 from the pipe 31 and measured, by opening the electromagnetic valve 33, a predetermined amount of the isocyanate component is introduced into the mixing tank 25 from the raw material supply pipe 32. At the same time, other raw materials such as a polyol component and a catalyst are introduced into the mixing tank 25 from the pipe 34 .

Next, the stirring blade 26 is rotated to mix uniformly.

Next, by driving the extrusion cylinder 23 to extend, the mixing and stirring tank 25 is advanced to the illustrated position, and the foaming stock solution is discharged t! ! ! 28 is inserted into the foaming tank 11 through the foaming stock solution inlet 11a. At this time, the door 16 is pushed by the foaming stock solution discharge pipe 28 so that it can be easily opened. Subsequently, by opening the electromagnetic valve 29, the foaming stock solution adjusted in the mixing stirring tank 25 is injected into the foaming tank 11 through the discharge pipe 28. At that time, the rotating shaft 24 is rotated as necessary to tilt the mixing and stirring tank 25 forward to promote outflow of the foaming stock solution.

Thereafter, the extrusion cylinder 23 is driven to contract, thereby retracting the mixing tank 25 and closing 1116. Next, the foaming tank itself is rotated by the motor 14 via the shaft 15° bar 13. Here, the rotational speed of the foaming tank 11 varies depending on the rise of foaming, but is approximately 20 to 120 rpm.
minutes. As a result, a centrifugal force acts on the foaming solution in the foaming tank 11, and the surface of the foaming solution rises in the vicinity where it is in contact with the foaming tank 11, almost in the same way as in the center, resulting in a polyurethane foam slab with a flat top surface. can get.

On the other hand, while the polytan foam slab is being foam-molded in the foaming tank 11 as described above, the mixing stirring 1!28 and the isocyanate component measuring tank 30, which have been retreated from the foaming tank 11, perform the following operations. The polyurethane foaming solution adhering to the inner surface is cleaned. That is, pump 3
8 is driven, the cleaning solvent is supplied into the cleaning solvent tank 36, and the mixing and stirring tank 25 is further filled with the cleaning solvent. Next, by rotating the stirring blade 26, the mixing stirring tank 26
After dissolving the foaming stock solution adhering to the inner wall of the solenoid valve 2,
9 to drain the cleaning solvent. When the cleaning solvent is discharged, the foaming stock solution adhering to the inner wall of the discharge pipe 28 is also dissolved. The cleaning solvent thus discharged is stored in the waste liquid receiver 37, and then sent to the cleaning solvent tank 36 by the pump 38 and reused.

When the cleaning is completed, the next foaming material is prepared in the same manner as described. Further, the foaming tank 11 is pulled out by rotating a turntable (not shown), and another foaming tank is installed in its place at the position shown.

In this way, polyurethane foam slabs can be continuously manufactured by repeating the same operations as above.

According to the present invention, after the polyurethane foam stock solution is injected into the foaming tank 11 using a stirring table, the foaming tank itself is rotated at a predetermined speed by the motor 14.
Due to the centrifugal force, a polyurethane foam slab with a flat top surface (as shown in FIG. 8) can be obtained.

In the above embodiments, the shapes of the shaft connected to the motor and the bar of the foaming tank are not limited to the configurations described above. That is, since it is sufficient that the rotational force of the motor is transmitted to the foaming tank, various structures in which the shaft and the bar engage are conceivable.

Furthermore, the structure of the polyurethane foam manufacturing apparatus described in the above embodiments is of course not limited to the structure described above.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to obtain a polyurethane foam slab with a flat top compared to the conventional method, so that the convex top can be cut to a predetermined shape as in the conventional method. It is possible to provide a method for manufacturing polyurethane foam that can improve the yield of slabs and omit the cutting process without any problems.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a polyurethane foam manufacturing apparatus according to the present invention, FIG. 2 is a plan view of a foaming tank according to the same apparatus, and FIG.
FIG. 4 is a rear view of the foam layer, FIG. 5 is an explanatory diagram of the conventional batch manufacturing method, and FIG. 6 is a perspective view of a polyurethane foam slab obtained by the conventional method. 7 is a front view of FIG. 6, and FIG. 8 is a front view of a polyurethane foam slab obtained by the method of the present invention. 11... Foaming tank, 12... Shaft receiving hole, 13...
・Bar, 14.27...Motor, 15...Shaft, 16...Support, 20...Rail, 21...Wheel, 22...Dolly, 23... ... Extrusion cylinder, 24 ... Rotating shaft, 25 ... Mixing stirring tank,
26... Stirring blade, 28... A raw solution discharge pipe, 29
．． 33...Solenoid valve, 30...Measuring tank, 31...
- Piping, 32... Raw material supply pipe, 34... Raw material supply pipe, 35... Cleaning solvent supply pipe, 36... Cleaning solvent tank, 37... Cleaning solvent waste liquid receiver, 38... Pump . Applicant's agent Patent attorney Takehiko Suzue Figure 7 Figure 8

Claims (1)

[Claims] It is characterized by comprising a step of stirring and mixing a polyurethane foaming stock solution, a step of injecting this foaming stock solution into a foaming tank, and a step of rotating the foaming tank and producing a polyurethane foam slab with a flat top surface by centrifugal force. A method for producing polyurethane foam.