JP2967227B2 - Production method and press mold for consolidation material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention uses a press to produce a composite material mainly composed of a material such as plastic or metal that can be subjected to plastic working such as injection molding or press working. It relates to the method and the press die used for its processing. (Prior art) The conventional method for manufacturing composite materials employs a method of manufacturing at once with a very high pressure, such as rolling or extrusion.
It required huge equipment and the shape of the product was limited.
In addition, when molding using a press, multiple dies were required, which increased the cost of the dies and was uneconomical. In addition, bubbles are likely to be generated at the joint boundary of the composite material, and improvement of the quality has been desired. (Object of the Invention) It is a first object of the present invention to provide a method for producing a composite material by using a set of press dies. It is a second object of the present invention to provide a method of manufacturing a composite material in which bubbles at the bonding boundary of the composite material are reduced and the quality is improved. A third object is to provide a concrete press die for achieving the above object. (Means and Actions for Solving the Problems) FIGS. 1 to 3 are conceptual diagrams illustrating the steps of the present invention and the structure of the press die. In the present invention, a massive, granular, plate-like or net-like core material 3 is inserted between the press dies 1 and 2, and the press dies
The core material 3 is formed almost in the same manner as a press mold by bringing the pieces 1 and 2 closer. If there is no gap between the core material 3 and the press dies 1 and 2 at this stage, the gap between the press dies 1 and 2 is widened to a position where the target semi-finished product thickness can be obtained, and a flow channel for skin material press-fitting is created. If there is a gap here and the gap between the press dies 1 and 2 is already at the position where the thickness of the semi-finished product can be obtained, the skin material is directly pressed into this gap. Pressing of the skin material at this time can be performed simultaneously on both sides of the core material, but in this case, the thickness of the skin material tends to fluctuate. The following steps are taken to reduce the thickness fluctuation of the skin material. That is, following the step of forming the core material 3 into a target size and shape as shown in FIG. 1, the press die is opened at a distance corresponding to the thickness of the skin material on one side as shown in FIG.
The skin material is press-fitted from the nozzle 4 to form the skin material 5. Next, as shown in FIG. 3, the interval of the press die is opened by a distance corresponding to the thickness of the other skin material, and the skin material 7 is formed by press-fitting the material of the skin material from the nozzle 6. When the skin material is made into a multilayer, the steps of FIG. 2 and FIG. 3 are sequentially repeated.
In this case, the type of skin material can be changed sequentially.
The number of nozzles 4 and 6 can be plural. In order to further improve the thickness variation of the skin material and suppress the generation of air bubbles, press the dies together after the skin material is pressed in, reduce the distance between them, and compress the material. The bubble volume is inversely proportional to the molding pressure, and becomes smaller as the molding pressure increases. The bonding strength between the core material and the skin material and between the skin material and the skin material also increase with the increase of the molding pressure. Bubbles tend to remain when the core material is porous or reticulated, and for such a core material, the technique of pressing the press die after skin material injection molding is effective in reducing bubbles. It is preferable to reduce the pressure of the space to be injected before injecting the skin material in order to reduce the formation of bubbles inside the composite material. For this purpose, as shown in FIGS. 1 to 3, a dike 8 surrounding the press dies 1 and 2 to prevent material leakage.
And a press mold provided with an elastic body 9 surrounding the outer periphery of the bank and in contact with the press molds 1 and 2 to make the space between the press molds airtight, and depressurize the inside of the elastic body. At that time, the material between the press dies is prevented from leaking at the ridge 8, but the gas is
The pressure is reduced by suction through the gap between the dies 8 and the elastic body 9 through the gap between the dies 8 and the press mold 2. The embankment 8 is engaged with the groove as shown in FIGS. The elastic body 9 may be any structure as long as it can simultaneously contact the press dies 1 and 2 during depressurization in the press dies to make the press dies airtight, for example, an O ring. In addition, it is desirable that the press die has a device that keeps the heat at a temperature slightly lower than the freezing point of the skin material in order to improve the flow of the skin material. It is easiest and cheapest to apply these heats from the outside of the press mold. (Embodiment 1) The core material is a 10-mesh steel wire mesh having a wire diameter of 0.6 mm, and is formed into a bowl having a diameter of about 100 mm and a depth of about 40 mm as shown in FIG. At this time, the interval between the press dies is set to 1.5 mm, and the polyethylene heated to 180 ° C. is press-fitted from the nozzle 4 as shown in FIG. At this time, polyethylene as a skin material penetrates the mesh of the core material in addition to the gap between the wire mesh surface as the core material and the press die and fills the inside of the press die. Subsequently, as shown in FIG. 3, the polyethylene having a different color from the first skin material heated at 170.degree. Wire mesh as the core material,
Polyethylene as a skin material adheres well to each other to form a good composite material. (Embodiment 2) The difference from Embodiment 1 is that the pressure is reduced from the nozzle 10 using a rotary pump in the steps of FIGS. 2 and 3. Among the causes of air bubbles in the first embodiment, air and moisture-induced air bubbles in the press die can be reduced by reducing the pressure between the press dies prior to press-fitting the skin material. (Embodiment 3) A plastic waste material containing polyethylene as a main component is cut into a diameter of about 1 mm, and this is heated to about 170 ° C. and pressed into a thickness of, for example, 2 mm as shown in FIG. 1 to obtain a core material. . The core material here may or may not be melted, but it is better to solidify it by the time of injecting the skin material or set it to a temperature that is less likely to flow than the skin material. Then, as shown in FIG.
Press the polyethylene heated to 170 ° C from the nozzle 4 with a 1 mm opening. Subsequently, as shown in FIG. 3, the interval between the press dies is opened by 1 mm, and polyethylene heated to 160 ° C. is press-fitted from the nozzle 6. The cut plastic waste is completely covered by the skin material and becomes a 4 mm thick composite material. (Effect of the Invention) A sound composite material can be easily produced by the method using one set of press dies of the present invention. In addition, by continuously pressing the press mold after injection molding, or by reducing the pressure between the press dies prior to pressurizing the skin material, it is possible to reduce bubbles at the joint boundary, strengthen the joint boundary, and improve the quality of the composite material. it can. Further, the method for producing a composite material according to the present invention can be realized by a simple apparatus equipped with a press die as described above, which is equipped with a vacuum pump or a vacuum device utilizing a suction effect of a high-speed fluid, or a known press and press device. In the present invention, inexpensive materials such as waste materials can also be used as the core material.
In addition, the number of times the material is removed from the press mold during the manufacturing process is small, so the efficiency can be improved compared to the conventional method. (Application Field of the Invention) The method of the present invention can be applied not only to plastics and metal materials, but also to any other materials having plastic workability to the extent that they can be press-formed, and can expand the types of composite materials at once.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 3 are conceptual diagrams illustrating the steps of the present invention and the structure of a press die. 1,2 ... Press mold 3 ... Core material 4,6 ... Skin material press-in nozzle 5,7 ... Skin material 8 ... Material leakage prevention embankment 9 ... Airtight elastic body 10 ... Pressure reducing nozzle

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 45/00-45/84 B29C 43/00-43/58 B29C 33/00-33/76

Claims (1)

(57) [Claims] Insert a block, granule, plate, or mesh core between the press dies, move the press dies closer together to form this core, and then increase the gap between the press dies to fill the gap between the core and the press dies. A composite material characterized by press-fitting the skin material, then pressing the press mold closer to compress the material, and then successively increasing the gap between the press dies and forcing the skin material into the gap between the material and the press mold. Manufacturing method.