JPS6325929B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for centrifugal molding of a laminate comprising a foam layer and a resin layer. Conventionally, there is a centrifugal molding method as an example of a method for producing a laminate consisting of a foam layer and a resin layer. That is, as shown in FIGS. 1 and 2, a resin liquid is first poured into the mold 2 while rotating the mold 2 supported by a plurality of rings 1, and then centrifugal molding is performed. Thereafter, the resin layer 3 is formed by heating and curing the resin liquid. Next, a large-sized foaming agent is introduced into the resin layer 3 and centrifugal molding is performed, and the large-sized foaming agent is heated and foamed to form a large-sized foamed layer 4. Next, a small-sized foaming agent is introduced into the large-sized foam layer 4 and centrifugal molding is performed, and the small-sized foaming agent is heated and foamed to form a small-sized foamed layer 5. Thereafter, the large foam layer 4 and the small foam layer 5 are laminated as required, and finally the resin layer 3 is laminated. According to such conventional centrifugal molding methods, material must be added, centrifugally molded, and heated and hardened (foamed) for each layer, so a long molding time is required to obtain one laminate. As a result, efficient molding cannot be performed, and since the temperature for curing and foaming differs for each layer, temperature control becomes complicated. Further, in the laminate obtained by the conventional method, each layer has a perfect circular shape, and it is not possible to obtain a laminate that is deformed, such as making some of the internal layers wavy. The object of the present invention is to centrifugally mold a laminate consisting of a foam layer and a resin layer, which can be centrifugally molded in a short time and efficiently, can easily control temperature, and can even produce deformed laminates. The point is that it provides a molding method. In order to achieve the above object, the method of centrifugal molding of a laminate consisting of a foam layer and a resin layer in the present invention is as follows:
A mixture is made of a large specific gravity resin liquid, a small specific gravity resin liquid, and multiple types of blowing agents with different specific gravity between the specific gravity values of both resin liquids, and this mixture has a difference in the curing temperature of both resin liquids. At the same time, the foaming temperature of each foaming agent is set differently, this mixture is put into a mold, and the mold is rotated to centrifugally form a layer due to the difference in specific gravity.In this state, the heating temperature is gradually increased. and reacting in each layer in turn. According to the method of the present invention, the following effects can be expected. That is, by putting the mixture into a mold, centrifugally molding layers based on the difference in specific gravity, and then heating, as the heating temperature increases, it is possible to cause each layer to react sequentially and harden or foam. As a result, the centrifugal molding of the laminate can be carried out efficiently in a short time, and the temperature can be easily controlled. Furthermore, during centrifugal molding of layers based on specific gravity differences, by randomizing the position of curing or foaming by heating in the layer thickness direction, for example, the next curing or foaming can be performed inside or outside of the hardened or foamed layer. The layer molded in the previous step can be deformed by the curing or foaming force (moving force) at that time, and a laminate in which the intermediate layer is deformed can be obtained. An embodiment of the present invention will be described below based on FIGS. 3 to 7. First, as shown in FIGS. 3 and 4, a mixture 12 is put into a mold 11 supported by a plurality of rings 10. This mixture 12 is composed of a high specific gravity resin liquid, a low specific gravity resin liquid, and three types (multiple types) of blowing agents whose specific gravity is different between the specific gravity values of both resin liquids. Therefore, it is centrifugally formed into layers due to the difference in specific gravity. That is, as shown in FIG. 5, a large specific gravity resin liquid A, a large specific gravity large particle blowing agent B, a large specific gravity small particle blowing agent C, a medium specific gravity large particle blowing agent D, a small specific gravity small particle blowing agent E, and a small specific gravity The large foaming agent F and the small specific gravity resin liquid G are placed in the mold 1.
Centrifugal molding is performed in this order starting from the inner surface of 1. At this time, the curing temperature of both resin liquids A and G and each blowing agent B to F
For example, as shown in Table 1, there is a temperature difference between the foaming temperature and the foaming temperature.

【table】

[Table] Therefore, when heating is performed after centrifugal molding, as the temperature rises, the high specific gravity resin liquid A first hardens to form a resin layer 13 on the inner surface of the mold 11.
Next, as shown in FIG. 6, the large-sized foaming agent B reacts to form a large-sized foaming agent 14 on the resin layer 13. Then, as the temperature rises, the blowing agents C to F react sequentially, and as shown in FIG. A resin layer 19 is laminated and molded on the inside. Cylindrical laminate 2 obtained by such molding
0 is removed from the mold 11, divided at appropriate positions in the circumferential direction, and then unfolded into a plate shape, which is then used as a seating part of a sofa. In the above embodiment, the reaction was performed sequentially from the inner surface of the mold 11 under the temperature conditions shown in Table 1, but the reaction position (order) may be random.
That is, as shown in FIG. 8, first, the inner and outer resin layers 13 and 19 are molded, and then the middle small foam layer 1
By reacting the large-sized foam layers 14 and 18 after molding the small-sized foam layer 15, the small-sized foam layer 15 can be deformed into a wave shape by the foaming pressure. Note that wave forming can be more easily performed by changing the number of revolutions of the mold 11 each time each layer is formed. Large particles and small particles in the foam layer can be arbitrarily combined.

[Brief explanation of the drawing]

1 and 2 show a conventional example, FIG. 1 is a vertical front view, FIG. 2 is a sectional view of the main part, FIGS. 3 to 7 show an embodiment of the present invention, and FIG. The figure is a longitudinal side view, FIGS. 4 to 7 are longitudinal front views, and FIG. 8 is a sectional view of main parts showing another embodiment. DESCRIPTION OF SYMBOLS 10... Ring body, 11... Molding mold, 12... Mixture, 13, 19... Resin layer, 14, 16, 18...
...Large foam layer, 15, 17...Small foam layer, 20
...Laminated body.

Claims (1)

[Claims] 1. A mixture of a large specific gravity resin liquid, a small specific gravity resin liquid, and multiple types of blowing agents with different specific gravities between the specific gravity values of both resin liquids is made. At the same time, the foaming temperature of each blowing agent is set at different temperatures, this mixture is put into a mold, and the mold is rotated to centrifugally form a layer due to the difference in specific gravity. A centrifugal molding method for a laminate consisting of a foam layer and a resin layer, which is characterized by gradually raising the temperature and reacting each layer in sequence.