JPS6287335A - Composite paper tube and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composite paper tube made of fiber-reinforced resin and paper, and a method for manufacturing the same.

[Conventional technology]

Paper tubes are laminated cylinders made of paper. Small diameter ones are made by winding tape-like paper spirally around a mandrel to form a cylindrical body with a specified wall thickness, and large diameter ones are made by flat winding. It is manufactured by wrapping wide sheets of paper around a drum while gluing them together to form a cylindrical body of a predetermined thickness, and then cutting it into desired dimensions. Therefore, since paper tubes have low manufacturing costs, are easy to manufacture, and can be freely selected in wall thickness and diameter, they have a wide range of potential uses, for example, as winding cores or cylindrical containers.

[Problem that the invention seeks to solve]

However, since paper tubes are actually formed by laminating paper, they have extremely low water resistance, undergo large dimensional changes due to moisture absorption, and may even collapse when wet. In addition, when used industrially, the mechanical strength is not sufficient, and there is a method of increasing the wall thickness to provide the necessary strength, but this increases the weight and is desirable from both handling and economical points of view. However, even if the wall thickness is increased, it is difficult to prevent damage to the adhesive interface between the paper layers.

A first object of the present invention is to provide a paper tube with improved water resistance, dimensional stability, surface hardness and mechanical strength.

Furthermore, a second object of the present invention is to provide a method for manufacturing a paper tube having the above-mentioned properties.

[Means to solve problems]

According to the present invention, the first object is achieved by a composite paper tube in which the outermost layer and the innermost layer are made of fiber-reinforced resin layers, and the layer between the outermost layer and the innermost layer is made of paper. That is, since the outer and inner surfaces of the paper tube are covered with a fiber-reinforced resin layer, water resistance is imparted to the paper tube, and dimensional changes due to moisture absorption can be minimized. Regarding mechanical strength, in order to adopt a so-called three-layer sandwich-like composite structure, if strong layers are formed as the outermost and innermost layers, even if the thickness of those layers is small, the thickness of the paper in the middle layer will be smaller. As long as it has a certain thickness, sufficient strength can be achieved even if the overall thickness is smaller than that of paper alone, and it is also possible to make it lighter and heavier by using carbon fibers for the fibers in the fiber-reinforced resin layer. In addition, the strength in the circumferential direction depends on the strength of the fibers used, but if carbon IR fibers with high tensile strength are wound in parallel to form a fiber-reinforced resin layer, it can withstand centrifugal force when used as a high-speed rotating body. It is durable.

The second object of the present invention is to wind the R-fiber impregnated with resin in a cylindrical mold, and then insert a paper tube. It is possible to improve the adhesion between the paper tube and the fiber-reinforced resin layer by the tension applied during winding, and it is also characterized by the fact that it requires fewer manufacturing steps and is simple, since it requires only a few manufacturing steps and can be bonded together after being made separately.

The fibers used in the present invention may be any long fibers, but substantially endless long fibers are preferred. Specifically, long fibers such as carbon fiber, Gafnu IJ&fiber, metal fiber, and aramid fiber can be mentioned, and among them, long fibers of carbon fiber with high strength and low specific gravity are preferable. It is desirable that the fiber diameter is 2 to 20 microns, preferably 5 to 10 microns.

In the present invention, as the resin for bonding the fibers, thermosetting resins such as unsaturated polyester resins, epoxy resins, and phenol resins, or thermoplastic resins such as vinyl chloride resins, polyacetal resins, and polyimide resins can be used.

Uncured fiber-reinforced resins can be made by impregnating fibers with the resin or its solution.

The amount of resin impregnated is 10 to 80% by weight, preferably 20 to 70% by weight, and more preferably 30 to 50% by weight based on the total fiber and resin from the viewpoint of the strength and dimensional stability of the paper tube.
It is desirable that it be within the range of .

The paper tube used in the present invention can be any conventionally manufactured paper tube, but it is preferable that the surface is untreated to ensure good resin impregnation. If it is intended to be used as a body, it is necessary to use one with good weight balance. Although the wall thickness of the paper tube cannot be generalized, it is usually within the range of 0.5 to 20 m.

Hereinafter, the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a sectional view of a composite paper tube of the present invention, which has a sandwich structure consisting of an outermost layer 1 made of fiber-reinforced resin, an intermediate layer 2 made of paper tube, and an innermost layer 3 made of fiber-reinforced resin. A cross section of the paper tube is shown. The thickness of the outermost layer and the innermost layer can be determined as appropriate, but is usually 0.1 to 20
It is desirable that it be within the range of control.

FIG. 2 is a schematic diagram of an apparatus for forming a layer made of uncured fiber-reinforced resin, and a model obtained by winding uncured fiber-reinforced resin 1' around mold 4 and inserting paper tube 2. complex (
It is a figure which shows the state of the stage which is about to form the fiber reinforced resin layer which forms the outermost layer 3 on Pl. That is, the long fibers 8 are led through guide rollers 7,747' to a tank (impregnating tank 6) containing a resin or its solution 5, and are subjected to an impregnation treatment with the resin or its solution. The impregnated long fibers are adjusted to a constant adhesion amount by a squeeze roller 9, and wound onto the rotating composite (Pl) to form an uncured fiber-reinforced resin layer 3'. The composite thus obtained is cured in a conventional manner to form a composite paper tube.

The composite paper tube of the present invention, like conventional paper tubes, can be used for winding various threads, fabrics, papers, films, synthetic leather, foils, and the like.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained using Examples, but the present invention is not limited thereto.

Example 1 An unsaturated polyester resin (
Carbon fiber (Torayka T-3000, 3000 filament, manufactured by Toshi Co., Ltd.) impregnated by passing it through a mixed solution of 100 parts by weight of Rivolac 158 BQT (manufactured by Showa Kobunshi) and 1.0 parts by weight of a curing agent (Permec N, manufactured by Nihon Yushi). ) to a thickness of 1ml
I rolled it until it was. Then, a paper tube with an inner diameter of 90+++n (manufactured by Toyo Shikan Kogyo, wall thickness: 5 mm) was inserted, and one end was fixed in the mold. Furthermore, the carbon fiber impregnated with the resin obtained as described above was wound to a thickness of 2.0 mm, and cellophane tape was then wrapped to harden the resin. After the resin has hardened, remove the mold, remove the cellophane tape, and cut it into the required size.
The surface was ground. The dimensional stability of the thus obtained composite paper tube was measured and
As a result of comparison with m), a significant improvement effect was observed as shown in Table 1.

Example 2 Example 1 except that glass fiber (manufactured by Nittobo, glass roving R8240PE-535) was used as the endless long fiber.
A composite paper tube was obtained in the same manner. As a result of measuring the dimensional stability, a significant improvement effect was observed as shown in Table 1.

〔Effect of the invention〕

The composite paper tube of the present invention has excellent water resistance, dimensional stability, surface hardness, and mechanical strength. Moreover, the manufacturing method thereof is simple and requires few manufacturing steps.

[Brief explanation of drawings]

FIG. 1 is an example of a cross-sectional view of a composite paper tube of the present invention. FIG. 2 is an example of a schematic diagram of an apparatus for forming a layer made of uncured fiber-reinforced resin. The numbers in the diagram are as follows.

Claims (2)

[Claims] (1) The outermost layer and the innermost layer are made of a fiber reinforced resin layer,
A composite paper tube in which the layer between the outermost layer and the innermost layer is made of paper. (2) Composite paper characterized by winding resin-impregnated fibers around a cylindrical mold, inserting a paper tube, further winding resin-impregnated fibers, curing the resin, and removing the mold. Method of manufacturing tubes.