Manufacturing apparatus and manufacturing method for resin molded products

Abstract

The present invention is characterized by comprising: a die head (2) which pushes out a parison (S) having a primary material layer (11) that is made of a plastic material, a barrier layer (13) that is made of a barrier material, a first adhesive layer (12) that bonds the primary material layer (11) and the barrier layer (13) together, a recycle layer (15) that is made of a recycled material, and a second adhesive layer (14) that bonds the recycle layer (15) and the barrier layer (13) together; and a molding die (3) in which a pair of multi-layer sheets formed from the parison (S) are molded so as to have a desired shape in a state such that a pair of recycle layers (15) are bonded inward of a pair of barrier layers (13).

Description

Technical Field

[0001] The present invention relates to an apparatus and a method for manufacturing a resin molded product.

Background Art

[0002] For the purpose of saving energy resources and reducing environmental impact, containers are manufactured using recycled materials such as recycled plastics. For example, Patent Document 1 discloses a resin molded product having a multilayer structure in which an innermost layer made of HDPE, an adhesive layer, a barrier layer made of EVOH, an adhesive layer, a recycled layer made of a recycled material, and an outermost layer made of HDPE are laminated from the inner surface toward the outer surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, when the recycled layer is formed of a recycled material obtained by crushing an unnecessary fuel tank or the like, the recycled material may be contaminated with odors from fuels or the like because the fuel tank or the like has been used for a long period of time. Therefore, when the recycled layer is disposed outside the barrier layer, there is a problem that the odor leaks to the outside.

[0005] The present invention has been made from such a perspective, and an object thereof is to provide an apparatus and a method for manufacturing a resin molded product that suppress leakage of odor from the recycled layer with a simple configuration.

Means for Solving the Problems

[0006] To solve the aforementioned problems, a die head for extruding a parison having a main material layer made of plastic, a barrier layer made of barrier material, a first adhesive layer for bonding the main material layer and the barrier layer, a recycled layer made of recycled material, and a second adhesive layer for bonding the recycled layer and the barrier layer, and a molding die for forming a desired shape from the parison, in which a pair of multilayer sheets are formed and the pair of recycled layers are bonded together so that they are on the inside of the pair of barrier layers, A transport unit that holds the pair of multilayer sheets formed from the parison, and inverts the pair of multilayer sheets so that the pair of recycled layers are on the inside of the pair of barrier layers, It is characterized by being equipped with [the following features].

[0007] Furthermore, the present invention includes a preparation step of preparing a pair of multilayer sheets comprising a main material layer made of plastic material, a barrier layer made of barrier material, a first adhesive layer for bonding the main material layer and the barrier layer, a recycled layer made of recycled material, and a second adhesive layer for bonding the recycled layer and the barrier layer. A placement step involves holding the pair of multilayer sheets, inverting the pair of multilayer sheets relative to each other, and arranging them so that the pair of recycling layers are inside the pair of barrier layers. The invention is characterized by comprising a molding step of bonding the multilayer sheets together in a mold with the pair of recycling layers placed inside the pair of barrier layers.

[0008] According to the present invention, by sandwiching a pair of recycling layers between a pair of barrier layers, it is possible to suppress the leakage of odors to the outside. Furthermore, the orientation of the multi-layer sheet can be easily changed.

[0009] Furthermore, it is preferable that the pair of multilayer sheets are formed by cutting the parison that is extruded into a cylindrical shape.

[0010] According to the present invention, multilayer sheets can be easily prepared. [Effects of the Invention]

[0013] According to the resin molded product manufacturing apparatus and manufacturing method of the present invention, it is possible to suppress the leakage of odor from the recycled layer to the outside with a simple configuration. [Brief explanation of the drawing]

[0014] [Figure 1]A schematic side view showing a manufacturing apparatus for resin molded articles according to an embodiment of the present invention. [Figure 2] This is a side cross-sectional view showing a multilayer sheet according to an embodiment of the present invention. [Figure 3] This is a schematic side view showing the operating status of the conveying device. [Figure 4] This is a side cross-sectional view showing the multilayer sheet after inversion. [Figure 5] This is a side view showing the press forming process. [Figure 6] This is a diagram of a modified example 1. [Figure 7] This figure shows a modified example 2. [Modes for carrying out the invention]

[0015] ≪Manufacturing apparatus for resin molded products according to an embodiment≫ As shown in Figure 1, the resin molded product manufacturing apparatus 1 comprises a die head 2, a molding die 3, and a pair of conveying units 4, 4. The resin molded product manufacturing apparatus 1 is used to manufacture plate-shaped resin molded products such as bumpers and body parts.

[0016] The die head 2 is positioned above the mold 3 and is a supply device that supplies the parison S to the mold 3. The parison S is composed of multiple types of molten resins layered together and is a precursor extruded from the die head 2. In this embodiment, the cylindrical parison S supplied from the die head 2 (see also Figure 5) is cut in the height direction to form the multilayer sheets 10, 10 described later.

[0017] The molding die 3 comprises a first molding die 3a and a second molding die 3b. The first molding die 3a and the second molding die 3b are positioned facing each other. The first molding die 3a has a molding portion 30a that is concave relative to the parison S. The second molding die 3b has a molding portion 30b that is convex relative to the parison S. The first molding die 3a and the second molding die 3b can be opened and closed by moving them in the left and right directions, and the supplied parison S can be molded into a desired shape by clamping and pressing it from the left and right directions.

[0018] The conveying unit 4 is a device that holds the multilayer sheet 10 by sandwiching it. A pair of conveying units 4, 4 are arranged on the left and right of the parison S. The conveying unit 4 can hold the multilayer sheet 10 and convey it to a predetermined position. Further, the conveying unit 4 can rotate around the vertical axis while holding the multilayer sheet 10.

[0019] ≪Multilayer Sheet According to Embodiment≫ Next, the multilayer sheet 10 of the present embodiment will be described. As described above, the multilayer sheet 10 is formed by cutting the tubular parison S at two positions in the height direction using a cutter device (not shown). The multilayer sheet 10 shown in FIG. 2 shows the state immediately after cutting. The multilayer sheet 10 has a rectangular plate shape (sheet shape). The multilayer sheets 10, 10 include a main material layer 11, a first adhesive layer 12, a barrier layer 13, a second adhesive layer 14, a recycling layer 15, and a main material layer 16 from the inner layer side to the outer layer side. That is, since the tubular parison S is cut in the height direction, the layer structure of the multilayer sheets 10, 10 is symmetric with respect to the vertical central axis.

[0020] The main material layer 11 is a layer that serves as a base material for the resin molded product to be molded, and is formed of a thermoplastic resin such as HDPE (high-density polyethylene) or PE (polyethylene).

[0021] The barrier layer 13 is a layer that prevents odor (gas) from permeating in the inner and outer directions of the resin molded product to be molded, and is formed of, for example, EVOH (ethylene-vinyl alcohol copolymer resin).

[0022] The recycling layer 15 is a layer composed of recycled products. The recycling layer 15 can, for example, collect unnecessary parts such as parison scraps and burrs, or pulverize and reuse used hollow plastic molded products (automobile fuel tank products, etc.).

[0023] The first adhesive layer 12 is a layer that adheres the main material layer 11 and the barrier layer 13, and is formed of, for example, modified PE (modified polyethylene), epoxy, etc.

[0024] The second adhesive layer 14 is a layer that adheres the barrier layer 13 and the recycling layer 15, and is formed of, for example, modified PE (modified polyethylene), epoxy, etc.

[0025] The main material layer 16 is a layer that serves as the base material for the molded resin product, and is formed of a thermoplastic resin such as HDPE (high-density polyethylene) or PE (polyethylene). The main material layer 16 may be omitted. In other words, the layer configuration may be set so that the recycled layer 15 is the outermost layer.

[0026] ≪Method for manufacturing resin molded products≫ Next, a method for manufacturing a resin molded product according to this embodiment will be described. The method for manufacturing a resin molded product according to this embodiment includes a preparation step, an arrangement step, and a molding step.

[0027] The preparation step involves preparing the multilayer sheets 10, 10. In the preparation step, as shown in Figure 1, the cylindrical parison S supplied from the die head 2 is cut in the height direction using a cutter device (not shown). This forms the multilayer sheets 10, 10 having the layer configuration shown in Figure 2. As shown in Figure 3, the multilayer sheets 10, 10 are held in the transport units 4, 4, respectively.

[0028] The placement process involves inverting the multilayer sheets 10, 10. In the placement process, the multilayer sheets 10, 10 are held by the transport units 4, 4 and inverted relative to each other. In other words, in the placement process, the transport unit 4 is rotated 180° with respect to the vertical axis. As a result, as shown in Figure 4, the main material layers 16, 16 of the multilayer sheets 10, 10 face each other, and the main material layers 11, 11 face outwards. If the main material layer 16 is omitted, the sheets are arranged so that the recycled layers 15 face each other.

[0029] The molding process involves clamping the mold 3 to form a resin molded product of the desired shape. As shown in Figure 5, the first mold 3a and the second mold 3b are moved toward each other to sandwich the multilayer sheets 10, 10. At this time, the multilayer sheets 10, 10 are bonded together with a pair of recycled layers 15 positioned inside a pair of barrier layers 13. After press molding, the product is cooled, and the resin molded product is removed from the first mold 3a and the second mold 3b to complete the resin molded product.

[0030] According to the embodiments described above, it is possible to mold a resin molded product in which the recycling layers 15, 15 are sandwiched from the outside by the barrier layers 13, 13. As a result, the odor of the recycling layer 15 is blocked by the barrier layers 13, 13 and prevented from leaking out to the outside.

[0031] Furthermore, according to the preparation process of this embodiment, the multilayer sheets 10, 10 can be formed simply by cutting the parison S that is extruded into a cylindrical shape.

[0032] Furthermore, according to the arrangement process of this embodiment, the recycled layers 15, 15 can be placed inside the barrier layers 13, 13 simply by inverting the multilayer sheets 10, 10 in the transport unit 4.

[0033] Here, the layer configuration shown in Figure 2 is the same as the configuration used when forming a hollow resin container such as a fuel tank. In other words, a barrier layer 13 is provided to prevent the fuel stored inside from permeating to the outside, and a recycling layer 15 and a main material layer 16 are provided on the outside of it. When forming the resin molded product of this embodiment, for example, the layer configuration of the parison S may be set to the layer configuration shown in Figure 4 at the stage of supplying resin to the die head 2. However, changing the position of each material supplied to the die head 2 is not easy because it requires design changes considering the viscosity of the material, the opening width of the flow path, etc. In other words, in practice, the layer configuration of the parison S cannot be changed frequently.

[0034] In this respect, according to this embodiment, the layer configuration can be easily changed by using the transport units 4,4 while keeping the conventional die head 2 in use (without changing the conventional layer configuration). In other words, the recycled layer 15,15 can be sandwiched between the barrier layers 13,13 by a simple method of inverting the multilayer sheets 10,10 in the transport units 4,4.

[0035] <Example 1> Figure 6 shows a modified example 1. In the resin molded product manufacturing apparatus (resin molded product manufacturing method) according to modified example 1, instead of a cylindrical parison, plate-shaped (sheet-shaped) multilayer sheets 10, 10 are prepared from the beginning.

[0036] In Modification 1, for example, two sheet-like multilayer sheets 10 are formed one by one using a co-extrusion multilayer T-die method. The multilayer sheets 10, 10 are held in the transport sections 4A, 4A while being bonded together so that they have the same layer structure as in Figure 4. When holding, heating from both sides with heaters H, H may be used. In the molding process, the bonded multilayer sheets 10, 10 are transported to the mold 3 by the transport sections 4A, 4A and molded.

[0037] <Modification 2> Figure 7 shows a modified example 2. In modified example 2, a mold 40 is used. The mold 40 forms the multilayer sheets 10,10 by vacuum evacuation. Thus, in the molding process, the resin molded product may be formed by vacuum evacuation.

[0038] Although embodiments and modifications of the present invention have been described above, the design can be modified as appropriate without violating the spirit of the present invention. For example, the layer configuration of the multilayer sheet 10 (type of resin, thickness of each layer, etc.) is not limited to those described above and can be set as appropriate. [Explanation of symbols]

[0039] 1. Manufacturing equipment for resin molded products 2 Die heads 3 Molding mold 3a 1st mold 3b 2nd mold 4. Conveying section 10 multilayer sheets 11 Main material layer 12 First adhesive layer 13 Barrier layer 14 Second adhesive layer 15 Recycling Layer 16 Main material layer S. Parison

Claims

1. A die head for extruding a parison having a main material layer made of plastic, a barrier layer made of barrier material, a first adhesive layer for bonding the main material layer and the barrier layer, a recycled layer made of recycled material, and a second adhesive layer for bonding the recycled layer and the barrier layer, A mold is used to form a desired shape by forming a pair of multilayer sheets from the parison and bonding the pair of recycled layers so that they are on the inside of the pair of barrier layers, A resin molded product manufacturing apparatus comprising: a conveying unit that holds the pair of multilayer sheets formed from the parison, and inverts the pair of multilayer sheets so that the pair of recycled layers are on the inside of the pair of barrier layers.

2. The apparatus for manufacturing resin molded products according to claim 1, characterized in that the pair of multilayer sheets are formed by cutting the parison which is extruded into a cylindrical shape.

3. A preparation step for preparing a pair of multilayer sheets comprising: a main material layer made of plastic material; a barrier layer made of barrier material; a first adhesive layer for bonding the main material layer and the barrier layer; a recycled material layer made of recycled material; and a second adhesive layer for bonding the recycled layer and the barrier layer. A placement step involves holding the pair of multilayer sheets, inverting the pair of multilayer sheets relative to each other, and arranging them so that the pair of recycling layers are inside the pair of barrier layers. A method for manufacturing a resin molded product, comprising a molding step of bonding the multilayer sheets together in a mold with the pair of recycling layers placed inside the pair of barrier layers.

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