JP2023079576A - Insert blow-molded article and method of manufacturing the same - Google Patents

Abstract

To provide an insert blow-molded article which can be used for a pressure vessel or the like, has an excellent peeling strength between an inner resin layer and an outer FRP layer, and has an excellent recyclability even after being used, and a method of efficiently manufacturing the same.SOLUTION: There is provided an insert blow-molded article that is integrally provided with an FRP reinforcing layer consisting of an insert component on an outside of a main body resin layer. The insert blow-molded article is configured in that: the FRP reinforcing layer is formed by binding a filament group having directionality with a matrix resin; a thermoplastic resin having a mutual solubility is used for the matrix resin of the FRP reinforcing layer and a main material of the main resin layer; and the main body resin layer and the FRP reinforcing layer are integrated by thermal fusion.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an insert blow molded article that is blow molded by inserting an insert part, and a method for manufacturing the same.

In the past, metal containers were used for pressure vessels such as high-pressure hydrogen containers, but in recent years, resin containers (liners) with outer shells made of FRP such as carbon fiber are used. . As a method for forming an outer shell made of FRP, carbon fibers are wound around the outer circumference of an injection-molded or blow-molded resin container by a filament winding method, and a group of filaments such as the wound carbon fibers is impregnated with a resin. methods are commonly employed (see, for example, Patent Documents 1 to 3).

However, in the above-mentioned conventional pressure vessel consisting of a resin container and an outer shell, while a thermoplastic resin is used for the material of the resin container, a thermosetting resin is used for the matrix resin of the FRP. It was not possible to heat-seal the outer shell consisting of Moreover, the use of a thermosetting resin for FRP causes a difference in the coefficient of thermal expansion, and there is a drawback that delamination easily occurs between the container body and the FRP reinforcing layer.

Furthermore, in the above-mentioned conventional pressure vessel, since the used vessel is often disposed of as industrial waste without being recycled, there is a serious environmental problem. There is also a method of incinerating the pressure vessel at a high temperature and extracting only the carbon fiber for reuse. It was expensive and not economically viable.

In addition, in the method of forming the outer shell using the filament winding method, not only is the container body required to have considerable strength to wind the filament under tension, but also the position can be adjusted for containers of various shapes. It was difficult to manufacture with high precision and efficiency because a technique for winding the filament was required.

JP 2019-183935 A JP 2021-171978 A Japanese Patent No. 6490976

The present invention aims to solve the above-mentioned problems of the prior art. To provide an insert blow molded article which is excellent in recyclability even when it becomes old, and an efficient manufacturing method thereof.

As a means for solving the above problems, the present inventor has provided an FRP reinforcing layer composed of insert parts integrally on the outside of the main body resin layer, and the FRP reinforcing layer is formed of a group of filaments with directionality in a matrix resin. The main resin layer and the FRP reinforcing layer are heat-sealed by using thermoplastic resins compatible with the matrix resin of the FRP reinforcing layer and the main material of the main resin layer, respectively. An insert blow molded body was constructed by integrating them.

Further, in the present invention, the filament group of the FRP reinforcing layer is helically wound, parallel wound, in-plane wound, or polar wound with respect to the main body resin layer, thereby enhancing the reinforcing effect of the main body resin layer. can.

Further, in the present invention, the FRP reinforcing layer is a UD tape or UD sheet in which a group of filaments are arranged in one direction and impregnated with a resin, a laminate of chopped sheets obtained by cutting the UD tape into a predetermined length, or a filament. The reinforcement effect of the main body resin layer can be enhanced by forming the woven fabric sheet in which the strands bundled in the same group direction are woven and impregnated with resin.

Further, in the present invention, the FRP reinforcing layer is formed by arranging a plurality of insert parts adjacently, and by forming the main body resin layer across the boundary between the adjacent insert parts, the material and shape differ depending on the part. An FRP reinforcing layer can be integrally formed.

In the present invention, the peel strength can be further increased by using thermoplastic resins of the same type with the same melting point and coefficient of thermal expansion as the main materials of the matrix resin of the FRP reinforcing layer and the main resin layer.

Further, in the present invention, as an efficient method for manufacturing the above-mentioned insert blow molded article, after placing an FRP preform having a thermoplastic resin as a matrix resin in a mold as an insert part, the matrix resin of the preform A parison made of a thermoplastic resin compatible with is expanded in a mold to form a main resin layer, and the main resin layer and the preform are integrated by thermal fusion to form an FRP reinforcing layer. method can be adopted.

Since the insert blow molded article of the present invention uses a thermoplastic resin having compatibility with the matrix resin of the inner main resin layer and the outer FRP reinforcing layer, the heat fusion between the main resin layer and the FRP reinforcing layer can be increased to improve the peel strength. Moreover, by using thermoplastic resins with similar or the same coefficient of thermal expansion, the main resin layer and the FRP reinforcing layer can be made difficult to separate even when used in an environment with large temperature changes.

In addition, the insert blow molded product of the present invention uses thermoplastic resin for both the main resin layer and the FRP reinforcing layer, so even if the pressure vessel or the like is used, the container (fiber) can be finely pulverized. By melting the resin, it can be reused as FRP pellets, and can be recycled at low cost.

In addition, the insert blow-molded article of the present invention can be efficiently manufactured because the insert part of the FRP reinforcing layer is placed in a mold and blow-molded. Furthermore, since the insert part of the FRP reinforcing layer can be preformed using a mandrel or the like, the strength (thickness) of the main resin layer, which is required by the filament winding method, is not required.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an overall perspective view showing a cylindrical insert blow molded body of a first embodiment of the present invention; 1 is an enlarged sectional view showing a longitudinal section of a tubular insert blow molded article according to a first embodiment of the present invention; FIG. It is process explanatory drawing which shows the manufacturing method of the insert blow molding of 1st embodiment in this invention. FIG. 2 is an overall perspective view showing a container-shaped insert blow molded article of a second embodiment of the present invention. FIG. 2 is an overall cross-sectional view showing a vertical cross-section of a container-shaped insert blow-molded product of a second embodiment of the present invention. It is process explanatory drawing which shows the manufacturing method of the insert blow molding of 2nd embodiment in this invention.

"First Embodiment"
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. In the figure, the reference numeral 1 denotes an insert blow molding, and the reference numeral 11 denotes a main body resin layer. Also indicated by reference numeral 12 is the FRP reinforcing layer. In the present specification, the term "filament" refers to long fibers or continuous fibers having a fiber length of 100 mm or more, or those obtained by cutting them. tow, etc.). A "UD tape" means a tape-like arrangement of filaments aligned in the longitudinal direction, and a "UD sheet" means a sheet-like arrangement of filaments aligned in one direction.

"Composition and application of insert blow molding"
[1] Basic Configuration The basic configuration of the insert blow molded article 1 of the present embodiment will be described. In this embodiment, as shown in FIGS. 1 and 2, an FRP reinforcing layer 11 is formed on the outer side of a main resin layer 11 to form a pipe-shaped insert blow molded body 1 as a two-layer laminate. Also, compatible thermoplastic resins are used as main materials for the main resin layer 11 and the FRP reinforcing layer 12, respectively, and the main resin layer 11 and the FRP reinforcing layer 12 are integrated by thermal fusion. The FRP reinforcing layer 11 is formed from an insert part that is inserted into a mold during blow molding (details will be described later), and is formed by bonding filament groups with directionality with a matrix resin. As a result, an insert blow molded body 1 having excellent peel strength and recyclability can be constructed.

[2] Main body resin layer
[2-1] Materials Next, each component of the insert blow molded body 1 will be described. First, regarding the material of the main body resin layer 11, polycarbonate is used as the main material in this embodiment, but other materials may be selected as long as they are thermoplastic resins compatible with the matrix resin of the FRP reinforcing layer 12. For example, polyethylene, polyethylene terephthalate, polypropylene, ABS resin, AS resin, polyamide resin, acrylic resin, vinyl chloride resin, or a polymer alloy containing these as main materials can be used. Further, in the present embodiment, the main body resin layer 11 has a single layer structure, but from the viewpoint of strength and functionality (for example, gas barrier property, chemical resistance, gas barrier property), it may have a laminated structure. can combine resin layers of different materials. From the standpoint of peel strength and recyclability between the main body resin layer 11 and the FRP reinforcing layer 12, it is preferable to use a thermoplastic resin of the same kind as the matrix resin of the FRP reinforcing layer 12 and having the same melting point and coefficient of thermal expansion as the main material.

[2-2] Shape Regarding the shape of the main body resin layer 11, in this embodiment, it is cylindrical corresponding to the shape of the FRP reinforcing layer 12 which is an insert part. It can be changed arbitrarily. The thickness (thickness) of the main body resin layer 11 can be arbitrarily changed according to the application of the cylindrical (pipe-shaped) insert blow molded body 1 and the required strength. It is desirable to suppress the thickness), but it is also possible to intentionally form the thickness unevenly (to make the thickness uneven). Further, in the present embodiment, it is formed in a cylindrical shape without a bottom, but it can also be formed in a cylindrical shape with a bottom.

[3] FRP reinforcement layer
[3-1] Filament material As for the fibrous material of the FRP reinforcing layer 12, carbon fiber is used in this embodiment. synthetic fibers, chemical fibers, natural fibers, etc. can be used. In this embodiment, the carbon fiber UD tape is helically wound around the mandrel by the tape winding method to form the cylindrical insert part which is the preform of the FRP reinforcing layer 12. ) can be wound around a mandrel by a filament winding method. Such a structure in which a group of filaments is wound can be suitably employed as a reinforcing structure for the cylinder body of the insert blow molded article 1 in particular.

The orientation of the filament group of the FRP reinforcing layer 12 is helical winding orientation with respect to the main body resin layer 11 in this embodiment, but parallel winding, in-plane winding, or polar winding orientation can also be used. . "Helical winding" means a method of winding spirally at an angle of ±θ with respect to the axis of the cylinder, and "parallel winding" means a method of winding in a direction that is almost perpendicular to the axis of the cylinder. "In-plane winding" means a method of winding in the axial direction of a cylinder, and "polar winding" means a method of winding in the meridian direction of a sphere.

In addition, as the FRP reinforcing layer 12, a laminate of a UD tape or UD sheet in which a group of filaments is oriented in one direction and impregnated with a resin, or a chopped sheet obtained by cutting a UD tape or UD sheet into a predetermined length. Alternatively, it can be formed from a laminate of chopped strands obtained by cutting the strands bundled with the direction of the filament groups aligned and cut to a predetermined length, or from a woven fabric sheet obtained by weaving a plurality of strands and impregnating them with resin.

When using a UD sheet as the material for the FRP reinforcing layer 12, multiple UD sheets should be arranged so that the fiber directions of each sheet overlap (for example, 0°, 90°, 0°, 45°, 90°, 135° etc.) can be laminated and integrated into a cylindrical shape and used as an insert part. When chopped sheets are used as the material for the FRP reinforcing layer 12, a large number of chopped sheets are randomly laminated and integrated so that the fiber directions of each sheet are random (the common name is "random Sheet") can be molded into a tubular shape and used as an insert part. Further, when a woven fabric sheet is used as the material for the FRP reinforcing layer 12, a plain-woven or multiaxial-woven strand can be formed into a cylindrical shape and used as an insert part. In addition, an injection-molded insert part can be used as the material for the FRP reinforcing layer 12 .

Sheets having different filament group orientations and materials may be laminated on the material of the FRP reinforcing layer 12 . For example, a multilayer structure in which a sheet layer in which chopped sheets are randomly laminated is formed on the outside of a sheet layer formed by winding a UD tape into a cylindrical shape, or a sheet layer in which carbon fiber filaments are used. It is also possible to adopt a multi-layer structure in which sheet layers are formed using filaments. As the material of the FRP reinforcing layer 12, short fibers and milled fibers other than filaments can be used together.

[3-2] Matrix resin Regarding the matrix resin of the FRP reinforcing layer 12, polycarbonate is used as the main material in this embodiment, but other thermoplastic resins compatible with the main resin layer 11 can be used. The material can also be selected, and for example, polyethylene, polyethylene terephthalate, polypropylene, ABS resin, AS resin, polyamide resin, acrylic resin, vinyl chloride resin, or a polymer alloy containing these as main materials can be used. From the viewpoint of peel strength and recyclability between the body resin layer 11 and the FRP reinforcing layer 12, it is preferable to use the same thermoplastic resin as the body resin layer 11 as the main material.

[3-3] Shape As for the shape of the FRP reinforcing layer 12 (and the insert part), a cylindrical shape is adopted in this embodiment, but an elliptical cylindrical shape or a square cylindrical shape may also be adopted. can. Further, the thickness (wall thickness) of the FRP reinforcing layer 12 can be arbitrarily changed according to the use of the cylindrical (pipe-shaped) insert blow molded article 1 and the required strength, and a single layer structure and a laminated structure can be locally selected. It is also possible to use them properly or to use different filament materials. Further, in the present embodiment, it is formed in a cylindrical shape without a bottom, but it can also be formed in a cylindrical shape with a bottom.

[4] Applications The pipe-shaped insert blow molded article 1 according to the present embodiment can be used for building materials such as structural materials, vehicle parts, aircraft parts, various equipment parts, etc. Especially, strength and lightness are required. suitable for applications where Further, when the insert blow molded body 1 is no longer needed, the pipe-shaped insert blow molded body 1 can be finely cut and reused as FRP resin pellets. At this time, by using the same thermoplastic resin for the matrix of the main body resin layer 11 and the FRP reinforcing layer 12, it becomes easy to reuse as a molding material.

"Manufacturing method for insert blow molding"
Next, a method for manufacturing the insert blow molded article 1 of this embodiment will be described. First, as shown in FIG. 3(a), an FRP preform C having a thermoplastic resin as a matrix resin is placed as an insert part in the molds M and M of the blow molding machine. A parison P made of a thermoplastic resin compatible with is lowered into the mold M·M. After that, as shown in FIG. 3(b), the molds M and M are closed and clamped, and the parison P is sealed with air seals A and A (punchers) so that the blown air does not escape to the upper side of the parison P. Press the top against the air outlet. Then, as shown in FIG. 3(c), air is blown from the air outlet to inflate the parison P and stick it to the inside of the preform C, the FRP reinforcing layer 12 of the preform C and the main resin layer 11 of the parison P. are heat-sealed. It is also possible to preheat the inner side of the preformed body C to enhance the heat-sealing property between the main body resin layer 11 and the FRP resin layer 12 . Thereby, the insert blow molded article 1 of the present embodiment can be efficiently manufactured.

"Second Embodiment"
"Composition and application of insert blow molding"
[1] Basic Configuration A second embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. In this embodiment, as shown in FIGS. 4(a), 4(b) and 5, the insert blow molded body 1 is formed into a container shape. In addition, different insert parts (preformed bodies _C1 , _C2 , _C3 ) are arranged adjacently according to the part of the container (opening, body, bottom) to form the FRP reinforcing layer 12, and the adjacent insert parts A body resin layer 11 is formed across the boundary of (preformed bodies C ₁ , C ₂ , C ₃ ). As a result, the FRP reinforcing layer 12 having different materials and shapes depending on the part can be integrally formed. The boundary surfaces of different insert parts (preformed bodies _C1 , _C2 , _C3 ) of the FRP reinforcing layer 12 are also heat-sealed and integrated at the time of blow molding.

[2] Main Resin Layer and FRP Reinforcing Layer The material of the main resin layer 11 is the same as in the first embodiment. As for the material of the FRP reinforcing layer 12, in this embodiment, an insert part in which the same UD tape as in the first embodiment is cylindrically wound is used for the body of the container, and chopped sheets are applied to the opening and bottom of the container. Although an insert part made of laminated random sheets is used, the combination of materials for the insert part can be changed arbitrarily. As for the shape of the main body resin layer 11 and the FRP reinforcing layer 12, they can be formed in an arbitrary container shape and thickness depending on the application. Others are the same as those of the first embodiment.

[4] Applications The container-shaped insert blow molded body 1 according to the present embodiment can be used for pressure containers such as high-pressure hydrogen containers, containers for fuel devices, gas storage containers, etc., and strength and lightness are particularly required. suitable for applications where When the insert blow molded body 1 is no longer needed, it can be reused as FRP resin pellets by pulverizing the container-shaped insert blow molded body 1 finely.

"Manufacturing method for insert blow molding"
Next, a method for manufacturing the insert blow molded article 1 of this embodiment will be described. First, as shown in FIG. 6(a), FRP preforms _C1 , _C2, and _C3 having a thermoplastic resin as a matrix resin are placed in molds M and M of a blow molding machine as insert parts. At this time, a plurality of preforms C ₁ , C _{2 ,} and C ₃ are fixed in a state of being adjacently arranged (in a state of being stacked vertically). The method of fixing the preforms _C1 , _C2, and _C3 is not particularly limited, but a method of fitting and fixing the preforms _C1 , _C2 , and _C3 and the mold with unevenness is preferably adopted. can. After that, a parison P made of a thermoplastic resin having compatibility with the matrix resin of the preforms _C1 , _C2 and _C3 is lowered into the molds M and M.

Then, as shown in FIG. 6(b), the molds M and M are closed and clamped, and the parison P is sealed with air sealing tools A and A (punchers) so that the blown air does not escape to the upper side of the parison P. Press the top against the air outlet. Then, as shown in FIG. 6(c), air is blown from the air outlet to inflate the parison P and stick it to the inside of the preform C, the FRP reinforcing layer 12 of the preform C and the main resin layer 11 of the parison P. are heat-sealed. It is also possible to preheat the inner side of the preformed body C to enhance the heat-sealing property between the main body resin layer 11 and the FRP resin layer 12 . Thereby, the insert blow molded article 1 of the present embodiment can be efficiently manufactured.

1 Insert blow molding
11 Body resin layer
12 FRP reinforcing layer C Preform P Parison A Air seal M Mold

Claims (6)

An FRP reinforcing layer composed of an insert part is integrally provided on the outside of the main body resin layer, and the FRP reinforcing layer is formed by bonding a group of directional filaments with a matrix resin, and the FRP reinforcing layer and a thermoplastic resin having compatibility as the main material of the matrix resin and the main resin layer, respectively, and the main resin layer and the FRP reinforcing layer are integrated by heat fusion. 2. The insert blow molded article according to claim 1, wherein at least part of the filament group of said FRP reinforcing layer is helically wound, parallel wound, in-plane wound, or polar wound with respect to said main body resin layer. The FRP reinforcing layer is a UD tape or UD sheet in which the filament group is oriented in one direction and impregnated with resin, a laminate of chopped sheets obtained by cutting the UD tape to a predetermined length, or the direction of the filament group is aligned. 2. The insert blow molded article according to claim 1, which is formed from a woven fabric sheet in which strands bundled together are woven and impregnated with a resin. 4. The method according to any one of claims 1 to 3, wherein the FRP reinforcing layer is formed by arranging a plurality of insert parts adjacently, and the main body resin layer is formed across a boundary between adjacent insert parts. The insert blow molded article described. 5. The insert blow molded article according to any one of claims 1 to 4, wherein the main material of the matrix resin of said FRP reinforcing layer and said main resin layer are the same kind of thermoplastic resin. 2. The method for manufacturing an insert blow-molded article according to claim 1, wherein an FRP preform having a thermoplastic resin as a matrix resin is placed in a mold as an insert part, and then the matrix resin and the preform are combined. A parison made of a soluble thermoplastic resin is expanded in a mold to form a main resin layer, and the main resin layer and the preform are integrated by thermal fusion to form an FRP reinforcing layer. A method for producing a blow molded article.

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