JPS60127114A - Manufacture of formed insulation panel - Google Patents

Abstract

PURPOSE:To prevent voids from developing by a method wherein stock liquid is cast in a contour frame, which is held at a temperature below the bumping temperature of foaming agent, and said temperature is kept on holding until the whole cast stock liquid starts on boaming and, after that, the stock liquid is covered by a jig in order to complete the foaming. CONSTITUTION:A contour frame 2, which is held at 25-30 deg.C or a temperature below the bumping temperature of foaming agent in advance, is installed on the upper end of a receiver 9, which is in the upper limit of its movement, in the atmosphere of temperature same as the temperature of the contour frame 2. A casting head 7 is shifted above the contour frame 2 under the state that the receiver 9 is fixed at its upper limit position in order to cast the stock liquid 3a of foamed insulation panel 3. When the case stock liquid 3a develops foaming due to the temperature of the contour frame 2, the receiver 9 is quickly lowered down to its lower limit position in order for the contour frame 2 to install in the lower cover 5 of a jig 4 so as to close its upper cover 6. Consequently, because no bumping of chlorofluoromethane in stock liquid occurs and no void is developed, the lowering of heat insulation performance, the deformation of contour frame and the like can be prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to foam insulation panels used in refrigerators and the like.

Structure of the conventional example and its problems FIGS. 1 to 3 show a conventional foam insulation panel and its manufacturing method. The configuration of this conventional example will be explained below with reference to FIGS. 1 to 3.

In the figure, reference numeral 1 designates a foam insulation panel consisting of a metal box-shaped outer frame 2 with an open top surface, and a foam insulation material 3 made of urethane or the like using trichlorofluoromethane as a foaming agent. Reference numeral 4 denotes an iron jig, which includes a concave lower lid 6 that can be mounted with the open surface of the outer frame 2 facing upward, and this lower lid 5.
It consists of a reverse-circuit-shaped upper lid 6 that is attached to and can be opened and closed. and,
When the upper and lower lids 6.6 are closed, a sealed space having the same shape as the foam insulation panel 1 is formed.

Further, 7 is an injection head for injecting the stock solution 3a of the foamed heat insulating material 3.

Next, the operation of the above conventional example will be explained.

First, the jig 4 is generally kept at a temperature of 4Q to 50° C., the jig 4 is opened, and the outer frame 2 is attached to the concave shape of the lower lid 6 (the state shown in FIG. 3A). Here, the temperature of jig 4 is 4
If it is below 0°C, the heat of reaction during foaming will be absorbed from the foamed heat insulating material 3, slowing down the reaction rate and prolonging the curing time; if it is above 60°C, the heat of reaction will accumulate and the reaction speed will increase.
As the expansion speed increases, the flow resistance between it and the facing material increases,
Filling performance at the end of the aging insulation layer decreases.

Next, an injection door is placed directly above the outer frame 2, and the stock solution 3a of the foamed heat insulating material 3 at a temperature of 20 to 25° C. is injected into the center of the outer frame 2 (the state shown in FIG. 3B). At temperatures below 20℃, use undiluted solution 3.
The viscosity of a increases, the fluidity of the liquid decreases, and the temperature decreases from 1 to 26℃.
In the above case, foaming starts at the same time as the injection due to the temperature of the jig 4, and since the liquid does not flow, the filling property of the end portion of the foamed insulation material is reduced 3, and the injection head 7 is moved immediately after injection, Close the top lid 6. After the injection starts, the injected stock solution 3a becomes foam in a few seconds due to the temperature of the jig 4, then expands and fills the closed space in the jig 4, and hardening is completed after several minutes. (Situation shown in Figure 3C). After the curing is completely completed, the upper lid 6 of the jig 4 is opened and the foam insulation panel 1 is taken out (the state shown in the third diagram).

The foam insulation panel 1 is made as described above, but
In the conventional example described above, since the outer corner frame 2 is attached to the lower cover 5 of the jig 4 maintained at 40 to 50 degrees Celsius, the metal outer frame 1 is heated to 40 to 60 degrees Celsius within a few seconds after being attached. The temperature was raised to ℃,
At the time when the stock solution 3a of the urethane heat insulating material 3 is injected, the temperature has completely risen to the temperature of the lower lid 6. Therefore, 20-2
When the undiluted solution 3a of the urethane insulation material 3 at 5°C is injected, the undiluted solution 3a flows over the outer frame 2 whose temperature has been raised to 40 to 50°C, so the undiluted solution 3a in contact with the outer frame 1 surface suddenly When the temperature rises to 35° C. or higher, trichlorofluoromethane, which is a blowing agent in the stock solution 3a, bumps, resulting in the formation of voids 8 between the urethane heat insulating material 3 and the outer frame 2.

These voids cause a decrease in the insulation performance of the foam insulation panel 1 and deformation of the surface of the outer frame 2 due to temperature changes in the pressure of trichlorofluoromethane in the voids 8.

Purpose of the Invention The present invention eliminates the drawbacks of the above-mentioned conventional examples, and prevents the trichlorofluoromethane in the urethane insulation material stock solution from bumping on the surface of the outer frame and the generation of voids. <This is to eliminate the deterioration of the insulation properties of the flannel and the deformation of the outer frame surface due to temperature changes in the pressure inside the void.

Structure of the Invention The present invention provides -] In order to achieve the second time, the temperature of the outer frame is maintained at 26 to 30 ° C. from the time when the urethane insulation paulownia raw solution is injected until the foaming starts, At the same time as foaming begins,
The outer frame is mounted on a jig at a temperature of 40 to 50°C to produce a foam insulation panel.

DESCRIPTION OF THE EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to FIGS. 4 to 6. Components that are the same as those of the prior art will be designated by the same numbers and will be described in detail. 9 is omitted. In the figure, 9 is a support that attaches to the lower lid 6 and is movable up and down. The upper end is bifurcated, and the outer frame 2 can be attached and held between them. Then, the receiver 9 is moved downward with the outer frame 2 attached thereto, and the outer frame 2 is attached to the lower lid. Also, when the bracket 9 is moved to the upper limit, one end of the bracket 9 protrudes more than 10 cm from the lower lid 5, and care must be taken to ensure that the temperature of the outer frame 2 does not rise due to the temperature of the lower lid 5. be.

Next, the operation of the above embodiment will be explained.

The outer frame 2, which has been heated to 25 to 30° C. in advance, is attached to the upper end of the support 9 which has been moved to the upper limit in an atmosphere with a temperature similar to that of the outer frame 2 (the state shown in FIG. 4A). Then, with the receiver 9 fixed at the upper limit, the injection head 7 is moved above the outer frame 2, and the stock solution 3a of the foamed heat insulating material 3 at 20 to 26° C. is injected (the state shown in FIG. 4B).

When the injected stock solution 3a foams 5 to 10 seconds after injection due to the temperature of the outer frame 2 of 26 to 30°C, the receiver 9 is quickly lowered to the lower limit and the temperature is increased to 4° to 50°C. The outer frame 2 is attached to the lower lid 5 of the jig 4, and the upper lid 6f is closed (state shown in FIG. 4C).

After a few minutes, the injected undiluted solution 3a of the foamed insulation material 3 fills,
After curing is completed, open the top lid 6 of the jig 4, move the receiver 9 upward, and take out the foamed insulation panel 1 that has been cured (the state shown in the fourth diagram).

In this embodiment, since the outer frame 2 is operated in an atmosphere having approximately the same temperature as the outer frame 2, the temperature of the outer frame 2 is maintained at 25 to 30°C until it is attached to the lower cover 5 of the jig 4. be done. Therefore, the temperature of the injected foam insulation third stock solution 3a is also 25% from the time it is injected until the outer frame 2 is attached.
The temperature is kept at ~30°C.

Here, from the temperature correlation diagram of the vapor pressure of trichlorofluoromethane (Figure 6), the vapor pressure of pure liquid trichlorofluoromethane increases as the liquid temperature rises and reaches 1 atm at 23.8°C (Fig. 6). In the case of the stock solution 3a containing trichlorofluoromethane (broken line in Figure 6), it can be seen that due to the effect of increasing the boiling point of the mixed liquid, the temperature does not reach 1 atm at 23.8°C, but reaches 1 atm at about 28°C (Figure 6). solid line). In addition, the temperature at which trichlorofluoromethane bumps from the stock solution 3a is even higher, 36°C or higher, so 25
Bumping of trichlorofluoromethane does not occur at all from the stock solution 3a in which ~30'CK is maintained. Therefore, the voids 8 on the surface of the outer frame 2, which are caused by conventional bumping, are not formed at all, resulting in a decrease in the insulation properties of the resulting foam insulation panel 1 and a reduction in the pressure of trichlorofluoromethane in the voids 8. This has the advantage that deformation of the surface of the outer frame 2 due to temperature changes can be prevented.

Note that during the period from when the stock solution 3a of the foam insulation material 3 is injected until it starts foaming, if the temperature of the stock solution 3a falls below 26°C, the amount of heat required for the reaction will be insufficient and the reaction will be extremely slow. As a result, a foamed heat insulating material 3 with low crosslinking density and low strength is produced, so the temperature of the outer frame 2 must be 26° C. or higher, and must be 30° C. or lower to prevent void formation.

Effects of the Invention The present invention has the above-mentioned configuration, in which the stock solution of the foam insulation material is injected into the outer frame maintained at a temperature at which the foaming agent does not bump, and the temperature of the outer frame is maintained until the stock solution all begins to foam. Since the foaming agent is kept at a temperature that does not cause bumping and is then covered with a jig to complete foaming, bumping of trichlorofluoromethane does not occur and voids are not generated, resulting in reduced insulation performance and deformation of the outer frame. It can be resolved.

[Brief explanation of drawings]

Fig. 1 shows a conventional foam insulation material 9Iφ'910m, Fig. 2 is a sectional view taken along the I-vi line in Fig. 1, Fig. 3 is a sectional view showing the installation process in Fig. 1, and Fig. 4 The figure is a cross-sectional view showing the manufacturing process of the foam insulation panel according to the present invention, Figure 6 is a cross-sectional view of the foam insulation old panel according to the present invention, and Figure 6 is a diagram of the liquid temperature change of the vapor pressure of 1-lichlorofluoromethane. It is. 1. Foam insulation moon panel 2. Box-shaped outer frame, 3.
Urethane insulation material, 3a Urethane insulation material stock solution, Injection head, 9... Receiver. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 (2) Figure 3 Figure 4

Claims (1)

[Claims] A foamed heat insulating material using trichlorofluoromethane as a foaming agent is injection molded into a box-shaped outer frame with an open top surface, and the temperature of the outer frame is controlled from the time when the stock solution of the foamed heat insulating material is injected until it becomes foamed. during which the blowing agent is maintained at a temperature that does not cause bumping;
Thereafter, the method for manufacturing a foam insulation panel includes molding the foam insulation material by placing it in a jig kept at a temperature that does not impair the filling properties and curing properties of the foam insulation material.