FI97343C - Method of reinforcing an object and an object reinforced with reinforcing tape - Google Patents

Description

97343

METHOD OF STRENGTHENING A PIECE AND A PART STRENGTHENED WITH STRIP STRIP

The invention relates to a method of manufacturing a body, in particular an elongate and substantially cylindrical container or tube, from a reinforcing material and a curable binder, the body being reinforced around the body with a helically wound continuous reinforcing tape attached to the body with a curable binder such as resin.

The invention further relates to a body reinforced with a reinforcing strip, in particular an elongate and substantially cylindrical container or tube comprising a reinforcing strip helically wound around the body, forming at least two layers around the body, and a binder with which the reinforcing strip is attached to the body.

Reinforced tape-reinforced pieces such as tanks and pipes are used in the process industry, the wood processing and pulp industry, wastewater plants and power plants, especially in areas where metal would corrode. Generally, such pipes and tanks are used at reasonable pressures, and the temperature may also be somewhat elevated.

The pipes according to the invention are made of a curable plastic material and a reinforcement, generally a reinforcing strip. The plastic material is usually a resin, other plastics may also be used.

The reinforcing material is usually fiberglass or fiberglass-30 tape; other materials can also be used.

In the manufacture of pipes and containers of reinforcing material and resin, the reinforcing strip is wrapped around a winding core or piece blank so that the trailing edge of each strip turn is somewhat on top of the leading edge of the previous strip turn. Often the layers are wound in an even number if a symmetrical 2 97343 wall is desired. The next layer of tape is wound in the other direction, respectively (shown in Figures 1a and Ib).

In this case, however, the seam points constitute an awkward problem, since at their points there is a double amount of tape on top of each other. In practice, this means that the wall does not become uniform in geometry and stiffening properties. As a result, such multi-strip wall portions have been found to behave differently 10 than other tube or container wall portions. Especially at elevated temperatures, the deformations are localized differently than at other points in the pipe or tank.

The situation is similar when manufacturing pipes 15 or tanks by means of a staple fiber mat with fiber fragments in different directions. Such a staple fiber layer is also drawn as a strip on the body to be reinforced, and typically the winding is carried out so that the rear edge of the strip goes over the front edge 20 of the strip of the previous round, again forming a problematic seam.

The situation is similar when using a continuous woven mat as a strip woven from the fibers crosswise.

The above drawback is further complicated by winding a layer of reinforcing tape on top of the second layer 25, the direction of the tape in the latter layer crossing the direction of the tape in the previous layer. In this case, at certain points, the reinforcing strip forms up to four overlapping layers.

It is an object of the present invention to obviate the above drawbacks. In particular, it is an object of the invention to provide a method for reinforcing a body around a body by means of a spirally wound reinforcing strip, so that the reinforcing strip forms at each point an equal number of pieces and 35 layers with uniform strength and other properties at different temperatures.

It is a further object of the invention to provide 3 97343 of a body reinforced with a reinforcing strip which meets the above requirements.

For aspects of the invention, reference is made to the claims.

The invention is based on the basic idea that a first layer of reinforcing tape is wound on the surface of the body or blank to be reinforced and a second layer of reinforcing tape overlaps the first layer so that half, preferably even half, of the strip of the latter layer is on top of the previous layer. Thus, the reinforcing tape is wrapped around the body at the same pitch and in the same direction, and each strip of tape overlaps the previous strip of tape by half the width of the strip so that two layers of tape are formed at each point of the coated body. In this case, the reinforcement layers form a uniform reinforcement layer, which is essentially uniform in all its properties. The part to be manufactured becomes homogeneous in geometry and stiffening properties. At elevated temperatures, the deformations are similarly localized at all points in the tube and tank. Further said reinforcing layer, i.e. in fact, the two layers of reinforcing tape can be formed by a single machine setting, in which the reinforcing tape forms a uniformly strong, strong and reinforcing layer with uniform stiffness and strength properties. Furthermore, the method according to the invention saves the reinforcing material, in addition, the surface is excellently smooth. In short, the invention satisfies the set requirements and substantially improves the properties of the part to be manufactured, in particular the deformation. set at elevated temperatures are similarly located at different points in the pipe or tank

The method 35 of the present invention is suitable for use in the manufacture of a wide variety of tubular materials, such as cylindrical tubes and cylindrical containers, from a reinforcing material and a curable plastic material, such as a resin.

The invention will now be described in detail by way of example with reference to the accompanying drawing, in which Figures 1a-b schematically show a method according to the invention and a body made according to the invention, and Figure 2 shows a tubular reinforced body when making a method according to the invention.

Figure 1a shows the manufacture of a cylindrical body 1 by a method according to the prior art, in which the strip 2 is wrapped around a pipe blank 3.

The strip 2 is first wound so that the rear edge 22 of the strip 2 of each strip round overlaps somewhat 15 with the leading edge 2l of the strip of the previous strip round. In this case, the rounds of reinforcement tape overlap somewhat. In the finished pipe, Fig. Ib, the overlapping points 4 and 5 form points with different strength properties from the other points. In particular, the points 5 where the coating strips form four overlapping layers form inhomogeneous points in the stiffness and other properties of the pipe.

Figures 2a-b show a method according to the invention, in which a reinforcing strip 2 is wound or wound on the surface of the blank 3 so that it has the same pitch, i. the angle of inclination with respect to the axis of the cylindrical body 2, and in the same direction each strip of tape overlaps the previous strip of tape by half the width of the strip. This is particularly evident in Figure 2b, 30 where each strip turn is overlapped over the previous strip turn by half the width of the strip; about. In this case, one round of winding actually forms exactly two layers of tape at each point on the surface of the piece. If desired, a second layer of reinforcing tape 35 can be wound on the body, e.g. crosswise with the first layer, and again each strip turn overlaps the previous strip turn exactly by half the width of the strip 5 97343. In this case, the strength properties, thermal expansion properties and other properties of the pipe or tank are essentially uniform at each point of the pipe or tank.

The exemplary embodiment is intended to illustrate the invention, and embodiments of the invention may vary within the scope of the appended claims.

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Claims (9)

A method of forming a body (1), in particular an elongated and substantially cylindrical container or a tube of reinforcing material and curable binder, the body being reinforced with a spirally wound continuous reinforcing band (2) around the body, which is attached to the body having a curable bonding agent, such as resin, characterized in that the reinforcing band (2) is wound around the body (1) with the same pitch and in the same direction and each band turn overlaps on the previous band turn with half of the width of the band, two layers of tape are formed at each point on the covered body. 15 2. A method according to claim 1, characterized in that the reinforcing strip (2) is a break-fiber mat. Method according to Claim 1 or 2, characterized in that the reinforcing strip 20 (2) consists of strips woven from fibers. A method according to any of claims 1. 3, characterized in that the fibers of the reinforcing strip (2) are made of fiberglass. Method according to any one of claims 1 to 4, characterized in that the reinforcing band (2) is wound around the body (1) at least twice, with each thread on the surface of the body two layers of band being formed. 6. Body (1) reinforced with a reinforcing band (2), in particular an elongated and substantially cylindrical container or tube, to which a helical band (2) is wound around the body (1), forming at least two layers around it. the body, and a binder, by which the reinforcing band 35 is attached to the body, characterized in that the reinforcing band (2) is wound around the body (1) 97343 with the same pitch and in the same direction, so that each band revolution is overlapped with the previous band revolution with half the width of the band so that at each point on the body covered with the band two layers of band are formed. Body according to claim 6, characterized in that the reinforcing belt (2) is a break-fiber mat. Body according to any one of claims 6 or 10, characterized in that the reinforcing web (2) consists of bands woven of fibers. 9. A method according to any of claims 6 to 8, characterized in that the fibers of the reinforcing strip (2) are made of glass fiber.