JPH0668359B2 - Composite material cylinder and method of manufacturing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite material cylinder and a method for manufacturing the same. More specifically, it relates to a light-tight, lightweight composite material cylinder and a method of economically manufacturing the cylinder.

[Prior Art] A cylinder is used as a container for storing gas and / or liquefied gas. Conventionally, generally sold and used cylinders are made of steel, but since such cylinders are pressure-resistant containers, they have the drawback of being thick and heavy. Therefore, in recent years, those made of light metals such as aluminum and alloys thereof have been developed and are commercially available.

Furthermore, recently, a cylinder of composite material has been developed and put on the market. For example, SCI (Stractual Composite Industrie), which is marketed under the trade name "Ultresa"
This is the cylinder made in s). Currently, commercially available composite material cylinders have a fiber reinforced plastic layer formed on the outside of a metal inner cylinder by a filament winding method.

[Problems to be Solved by the Invention] The composite material cylinder that has already been developed is one in which a part of the wall thickness of a conventional metal cylinder is replaced by reinforcing fibers and plastics, which is more than that of a conventional cylinder. It is lightweight. However, in order to further promote this weight reduction, it is necessary to eliminate the metal portion or further reduce the weight. It is thought to be lighter if the metal mandrel is removed from the cylinder wound by the filament winding method,
In order to remove the mandrel, the mandrel must be destroyed or deformed, and although this method can be theoretically implemented, the current technology has a cost disadvantage. There is also a problem of gas permeability of plastics, and there is also a problem of whether or not a filament winding product that does not leave a mandrel as a gas or liquefied gas cylinder is appropriate. On the other hand, a method of thinning the thickness of the metal mandrel can be easily considered, but it is difficult to make a thin metal mandrel, and it becomes very expensive in some cases.

Therefore, in order to obtain an inexpensive and lightweight mandrel,
After all, developing a plastics mandrel and a thin mandrel is considered to be one solution.

However, as already mentioned, plastics are gas permeable, and there is a problem as a container for gas and liquefied gas in a composite material cylinder made of a plastics mandrel and fiber reinforced plastics. Will be required. Further, the lightened mandrel is thin and soft regardless of whether it is made of metal or plastic, and is unsuitable as a mandrel for molding filament winding because of distortion during molding. This also needs to be resolved.

[Means for Solving the Problem] The present inventor has developed a new hybrid composite material cylinder in which a plastics mandrel (which corresponds to a plastics inner cylinder as a cylinder), a thin metal material, and a fiber reinforced plastics is developed. Solved the problem.

That is, according to the present invention, the cylinder body is one in which a thin metal is wrapped around the outer circumference of a plastic inner cylinder to cover the outer circumference, and a fiber reinforced plastic layer is formed on the outer circumference by a filament winding method. A novel composite cylinder is provided that features.

Such a cylinder is manufactured by using a filament winding method, that is, a method of winding a resin-impregnated fiber (filament) around an outer periphery of a mandrel and hardening the resin in that state to form a plastic hollow fiber. The body is used as a mandrel. At this time, a thin metal such as a metal foil is wound around the outer periphery of the plastic hollow body in advance, and substantially the entire outer periphery is covered with the thin metal, and then filament winding is performed.

In this method, first, a plastic mandrel is made. At this time, injection molding and other molding methods are also used, but the preform is injection molded,
The most preferable method is blow molding. Prior to this blow molding, a metal nozzle can be attached in advance to the mouth of the preform in order to use it as a cylinder nozzle.

Since this plastic mandrel will be the inner cylinder of the cylinder, its material is selected according to the contents of the cylinder. Generally, it is selected from polyester (polyethylene terephthalate, polypropylene terephthalate, etc.), polyamide (nylon 6, nylon 66, etc.), polyolefin, polyvinyl chloride, polycarbonate, ABS resin, etc. Especially in the case of LPG, polyester or nylon is preferable. From the problem of gas permeability, it is also preferable to make a resin having a low gas permeability into a multilayer. For example, for carbon dioxide gas, it is preferable to interpose a polyvinylidene chloride layer in the intermediate layer of the polyester mandrel.

By forming the inner cylinder from plastics in this way, not only is the cylinder lighter in weight, but it is also useful as a container for a gas that is corrosive to metals, such as a halogen gas.

The mandrel is then covered with thin metal. It is sufficient to wind a metal foil (so-called silver paper) to cover almost the entire outer periphery, but if tape-shaped thin metal foil is tape-wound, it can be wound cleanly and surely. At this time, it is preferable to wrap the resin and the adhesive together, and it is preferable to use a material obtained by coating the metal foil with the adhesive resin at the time of implementation.

The metal foil may be aluminum, tin, copper or the like, and may be any metal foil such as gold or silver. Aluminum is preferable in terms of gas barrier property and cost balance.

A fiber reinforced plastics layer is formed on the outer circumference by a filament winding method. The reinforcing fiber used in the filament winding method may be a general fiber used in this method, and the kind thereof is not particularly limited, but practically, glass fiber, carbon fiber, aramid fiber and the like can be mentioned. From the viewpoint of cost and physical properties, glass fiber is most preferable.

As the plastics (resin), similarly commonly used resins may be used, and unsaturated polyester resin, epoxy resin, vinyl ester resin, etc. may be used, and may be a part of thermoplastic resin that melts at low temperature. The temperature of post-treatment such as hardening of plastics is selected according to the heat resistance of the material polymer of the mandrel. In other words, the resin is selected by considering the material of the mandrel.

The filament winding method may be dry or wet, and the winding pattern may be spiral or polar. As a low pressure cylinder, because it is thin filament winding,
Polar winding may be preferable to suppress elongation. It is also preferable to further wrap the hoop winding on the spiral or polar winding.

In addition, on the outer periphery of the blow molded plastic inner cylinder,
When forming a thin metal and fiber reinforced plastics layer such as a metal box, if the plastics inner cylinder is filled with a fluid, workability is improved. This effect is particularly remarkable when the plastic inner cylinder is thin.

The cylinder is usually provided with a nozzle, but the nozzle may be made of plastic soot or metal. In the former case, it may be formed integrally with the inner cylinder, and in the latter case, a metallic sleeve may be used.

The surface of the cylinder may be painted or covered with plastic soot.

[Example] A test tube-shaped molded product (preform) was made from a polyethylene terephthalate resin by an injection method. This was blow molded into a bottle shape. A rod for supporting this was attached, and using this as a mandrel, the polyester adhesive film and the aluminum foil were overlapped and wound. Dry this,
After curing, glass fiber was impregnated with an unsaturated polyester resin around the periphery and wound up by a filament winding method. The winding method is 20 ° spiral winding and 4
Layered. Furthermore, one layer of hoop winding was laminated on it. Then, it was dried and the resin was cured to obtain a cylinder body, and a nozzle was attached to the cylinder body to obtain a target composite material cylinder.

The attached FIG. 1 is a view showing a cross-sectional structure of this composite material bobbin. In the figure, (1) is a mandrel (cylinder inner cylinder) made of polyethylene terephthalate resin, (2) is an aluminum foil, and (3) is Filament winding layer made of glass fiber reinforced unsaturated polyester resin, (4)
Is the nozzle of the cylinder.

The obtained composite material cylinder was subjected to a butane gas permeation test,
No permeated gas could be detected after at least 18 hours, and the pressure resistance test withstood 30 kg / cm ² .

[Advantages of the Invention] According to the present invention as described above, it is possible to obtain a lightweight composite gas cylinder which does not leak gas. Composite cylinders that do not pull the winding mandrel over a metal mandrel are not only heavy, but the cylinder of the present invention is lightweight and inexpensive in comparison to the mandrel costing at or above that of a metal cylinder. Further, unlike a cylinder made of only plastic soot and a composite material cylinder, gas permeation is extremely small or does not occur. Further, the one in which the innermost layer is made of plastic soot is stable against a metal corrosive gas, and can be applied to a field in which a conventional metal or metal inner cylinder cylinder cannot be used.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view showing an example of a composite material cylinder according to the present invention. (1) is plastic mandrel, (2) is metal foil,
(3) shows a filament winding layer and (4) shows a nozzle.

Claims (3)

[Claims] 1. A cylinder body, wherein a thin metal is wrapped around an outer circumference of a plastic inner cylinder to cover the outer circumference, and a fiber reinforced plastic layer is formed on the outer circumference by a filament winding method. Composite material canister. 2. A blow-molded plastic inner cylinder is wrapped with a thin sheet metal around the outer circumference by a tape winding method to cover the outer circumference with a thin sheet metal, and then the outer circumference is impregnated with a resin by a filament winding method. A method for producing a composite material cylinder, which comprises winding the fibers and curing the resin to form a fiber-reinforced plastic layer. 3. The manufacturing method according to claim 2, wherein the thin metal is wound and the filament winding is performed in a state where the plastic inner cylinder is filled with the fluid.