JPH0292624A - Manufacture of reinforced string-rod of long fiber-reinforced resin - Google Patents

Abstract

PURPOSE:To effectively present reinforced long fiber in an engaging protrusion by narrowing long fiber-immersed composite resin material of uncured or unsolidified state in which is viscosity is adjusted to a specific value between pressing members with grooves while moving the material in an axially central direction, filling resin and long fiber in the grooves, and forming a protrusion part. CONSTITUTION:Nylon of thermoplastic resin is filled in a resin bath having heating means, heated to be melted, and immersed with carbon fiber bundle to obtain a long fiber-immersed composite resin material 1 having, for example, 3mm in diameter. The material 1 of uncured or unsolidified state is narrowed between pressing rolls 2 and 2 with grooves while moving the material 1 in an axially central direction, and the resin R of the material and long fiber F are filled in grooves 3 to form a protrusion 5. In this case, the viscosity etaof the material 1 at the time of reception of narrowing pressure is so adjusted as to satisfy the relation of a formula [I], where (d) is diameter (mm) of the fiber, L is the whole length of the narrowed part by the pressing members with grooves, deltaF rupture strength (kgf/mm<2>) of the fiber.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention can be used as a substitute for reinforcing bars, PC steel wire, PC steel wire, etc. used in the civil engineering and construction fields, or as a reinforcing material in various other matrices. Regarding the manufacturing method of reinforcing wires and rods made of long fiber reinforced resin that are buried as embeddings, especially wires and rods with many locking protrusions formed on the surface to enhance the integrity with the matrix.
Some relate to new methods of manufacturing rods.

[Prior Art] Recently, fiber-reinforced resin composite materials containing fibers such as carbon fibers and glass fibers as reinforcing materials have attracted attention, and research is underway to use them as substitutes for reinforcing bars, PC steel wires, and PC steel wires, for example. (Japanese Patent Application Laid-open No. 83-551, 63-552, 63-4158, etc.). In other words, these composite materials overcome the drawbacks found in reinforcing bars (for example, high specific gravity and easy rusting), and are particularly suitable for civil engineering and architectural structures in coastal areas where severe corrosive environments are formed, as well as for marine applications. Its use as a reinforcing material for structures, etc. is gradually expanding.

By the way, these composite materials use long fibers as reinforcing materials, which are impregnated with various resins and molded into wire or rod shapes. Various organic fibers such as IL are used in inorganic IA fibers such as glass fibers or aramid fibers, and thermosetting resins such as unsaturated polyester resins, epoxy resins, phenol resins, area resins, and melamine resins are used. Examples include resins and thermoplastic resins such as polyamide resins, polyolefin resins, and polystyrene resins.

[Problem to be solved by the invention] By the way, ordinary reinforcing wires and rods made of long fiber-reinforced resin are made by aligning and converging a large number of long fibers in the longitudinal direction, and then impregnating the fibers with resin and hardening or solidifying them. It exhibits excellent strength against external forces in the tensile direction due to the action of reinforcing fibers. However, these wires and rods have very high smoothness when viewed in the longitudinal direction, and even if they are used as reinforcing materials for concrete, etc., a satisfactory reinforcing effect cannot be obtained. In other words, the above-mentioned wires/rods cannot be expected to have an interlocking effect with the matrix material when viewed in the longitudinal direction, so shear in the longitudinal direction is generated at the interface between the wires/rods and the matrix material. This is because slipping easily occurs when force is applied, and the combined effect of the matrix material and reinforcing material is not fully exhibited.

In order to eliminate these drawbacks, the present inventors have devised a method of forming locking protrusions on the outer periphery of a reinforcing wire/rod made of long fiber reinforced resin, for example, as shown in FIG. In other words, the line
While running the long fiber-impregnated composite resin material 1 preformed into a rod shape in an uncured or unsolidified state in the axial direction, it is compressed between grooved suppression rolls 2.2.
By filling the grooves 3 formed in the grooves 3 with resin R, and filling the grooves 3 in such a way as to bend the long fibers F as the resin moves (state A in Fig. 3). ), a wire/rod body 6 on which a locking protrusion 5 is formed is obtained.

However, it has been found that the protruding wire/rod body 6 manufactured in this manner has the following problems. That is, when forming the locking protrusion 5, when the composite resin material 1 is pressed between the grooved pressure rolls 2.2, the long fibers F become grooved as the resin R flows as described above. Enter within 3. However, the wire/rod 6 after being released from the pressure roll 2.2
Since there is a fairly strong longitudinal tension acting on B,
In addition, as shown in states C and D, the long fa fibers F are pulled out of the protrusion 5 by tension and are pulled toward the body again, and finally the protrusion 5 is composed only of the resin R. turn into.

In this case, the reinforcing effect of the long fibers F will no longer reach the protrusions 5, and when a tensile force is applied to the matrix, for example in the direction of the arrow, the protrusions 5 will undergo shear failure from their bases as shown in FIG. becomes impossible.

The present invention has been made with attention to such problems, and its purpose is to establish a manufacturing technology that can ensure the presence of reinforcing long ia fibers within the locking protrusion. That is.

[Means for Solving the Problems] The structure of the method according to the present invention that was able to solve the above problems is that the reinforcing wire is made of a long fiber reinforced resin and has locking protrusions formed at arbitrary pitches.・When manufacturing the rod, an uncured or unsolidified long fiber-impregnated composite resin material adjusted to a viscosity that satisfies the relationship of formula [I] below is run in the axial direction between the grooved pressing members. Pressure is applied to the
The gist is that a protrusion is formed by filling the resin and long fibers inside the groove, and then the resin is cured or solidified.

However, d: Diameter of the long fiber (mm) L: Total length of the pinched part by the grooved pressing member δ, : Breaking strength of the long fiber (gf 7mm2) γ: Shear rate by the grooved pressing member (1/5 ec) [Effect ] In the present invention, for example, the length of the uncured or non-solidified state is While running the fiber-impregnated composite resin material 1 in the axial direction, the grooves are formed by pressing between the pressing rolls 2 and 2 and filling the grooves 3 with resin R and long fibers F that make up the composite resin material. When forming the protrusions 5, the viscosity (η) of the composite resin material 1 at the time of receiving the clamping pressure is adjusted so that the relationship of the above formula [I] is satisfied. If the resin R to be used is a thermosetting resin, the viscosity (η) at the time of pressing may be adjusted to satisfy the above formula [II] by controlling the preliminary curing conditions, and if the resin R is a thermosetting resin. In the case of a polyurethane resin, the temperature during pressure processing is kept low, and the viscosity (η) is adjusted so as not to fall below the value on the right side of the formula [I].

Then, the long fibers F are filled into the lateral parts 3 as the highly viscous resin R flows during the pressing process, and also try to stay in the grooves 3 against the tension described in FIG. The force at this time is proportional to the length (L) of the wire/bar held under pressure, and the holding force (f) at this time is given by the following formula. occurs.

f=τ・π・d−L ... [II] Here, the shear stress applied to the resin R is shown, and this is determined by the viscosity of the composite resin material (η) and the shear rate during pressure processing (:f) (τ=η・γ), so if these relationships are taken into equation [I]1 above, the following equation [+11] is derived, and f=η ・γ・π・d−L ... [I
] By substituting η of the above-mentioned formula [II] into this, the following [
! V] formula is obtained.

4.L.γ In other words, the holding force (f) of the long fibers F produced by the high viscosity composite resin material satisfying the relationship of formula II takes a low value, and the long fibers F break within the grooves 3. As a result, the tension applied in the longitudinal direction of the long fibers F is released at the fractured portion, and the long fibers F are no longer pulled out from the projections 5 as in the conventional example. Therefore, as shown in FIG. 3, for example, the depth (h) and length (
If J23) is set, the long fibers F will be broken within the protrusion 5 and will be definitely left behind, and the protrusion 5 will be more integrated with the body part of the wire/rod.
The shear failure of only the protrusion 5 as explained in the figure is eliminated.

In the above examples, the long fibers F are broken by the holding force (f) using the viscosity of the composite resin material and remain in the protrusion 5, but in addition to the above C11
If the composite resin material is heat-cured or cooled and solidified immediately after filling the long fibers F into the groove 3 by performing pressure processing under conditions that satisfy the requirements of the formula, the long fibers F remain continuous fibers and become protrusions. It can also be left within 5. Note that depending on the viscosity of the composite resin material, the pressing conditions, etc., there may be cases where only a part of the long 1a fibers F existing in the protrusion 5 breaks and the rest remains as continuous fibers. It goes without saying that these embodiments are included within the technical scope of the present invention. In addition, when forming the protrusion 5 by pressure processing, the suppression roll 2
．． If you overfeed the composite resin material sent to 2, it will be long! Since the tensile force acting on 1a m F is relaxed, filling of the resin R and the long fibers F into the groove 3 can proceed more smoothly.

The present invention is carried out, for example, as described above, but the feature is that, as a condition when forming the protrusion 5 by filling the resin R, the long fibers f, and ItF into the groove 3 by pressing, The viscosity of the composite resin material at the time of processing is specified, and its holding force is utilized to ensure that the long fibers F remain within the protrusions 5.

Therefore, as long as these characteristics are effectively exhibited, there are no restrictions on the type of long fibers or resin that make up the wire or rod, the dimensions of the wire or rod, the cross-sectional shape, the shape or number of protrusions, etc., and there are no restrictions on the use or purpose. It can be freely changed depending on the shape of the wire/bar, the shape of the protrusion, the type of resin, etc. Although the most common type of pressing member with grooves for forming protrusions is a roll type. It is also possible to use a reciprocating drive type pressure forming device or the like.

[Example] Comparative Example 1 Epoxy resin containing a curing agent was placed in a resin berth, and the diameter d = 7 μm, δ, = 300 kgf/mm was placed in the resin berth.
A fiber-reinforced resin rod-like body (3 mI
IIφ) was obtained.

When this rod-shaped body was cut to a length of about 5 IIm and the viscosity was measured using a capillary viscometer, the viscosity was about 103 boids (= 1 x 10-5 kgf-see/mm').
Met.

Using the obtained elongated rod-shaped body, locking protrusions were formed on the surface according to the method shown in FIG. At this time, since the rod-shaped body had shapeability (that is, it was not cured), it was supplied to the pressure roll without passing through a preheater.

The outermost diameter of the pressure roll is 60 ma+, the groove for forming the locking protrusion is 0.2 mm deep and 2+ nm long, the total length of the pinching part (L) during the pinching process is 5 mm, and the number of roll rotations (
N) was set at 60 rpm. The diameter (do) of the rod-shaped body is 3
It is mm.

Applying these pressing conditions to the formula for calculating the strain rate during roll rolling shown in the following formula [Vl] to determine the shear strain rate (γA) on the surface of the suppressing roll, γ, = 21 +, 45
ec-'.

On the other hand, the viscosity η necessary for holding the fiber, which is obtained by substituting the above dl δP, L and γ^ into the above formula [I], is as follows. As mentioned above, the viscosity of < r 1 x 10-' kgf-sec
/mm', and since this viscosity is lower than the required viscosity (η) determined by the above calculation, almost no carbon fibers remain in the protrusions of the obtained locking protrusion-processed rod-like body. It was confirmed that fa fibers were concentrated only in the feathers.

Nylon (melting point: 265°C), which is a thermoplastic resin, was put into a resin berth equipped with a heating means, heated and melted, and the same carbon fiber bundle used in Comparative Example 1 was impregnated to form a 3mm piece.
A fiber-reinforced resin rod-shaped body having a diameter of φ was obtained.

The viscosity of the obtained rod-shaped body when semi-molten (250° C.) was determined by the following method, and the following values were obtained.

η (at 250℃) = 1.5 x 10'voices' =
0. Q15 kgf-sec/m+n2 [Method for measuring viscosity] Cut rod-shaped bodies into appropriate lengths, arrange dozens of them in one direction, and form them into a flat plate using a hot press (270°C), with a diameter of a = 30 mm. , thickness. = Cut out a 2mm disk. This disk was sandwiched between flat plates heated to 250°C,
This was applied to a universal testing machine, a load (f) was applied, and the following [V
1] Find the viscosity (η) from the formula.

... [Vl] ho: Initial thickness of sample (m+n) h: Thickness after load (mm) t: Time (sec) f: Load (kgf) a Disc diameter (m+n) In the above The obtained rod-shaped body was processed to form protrusions in the same manner as in Comparative Example 1. However, the rod-shaped body is
℃, and the pressure roll has a water-cooled structure.
A method of cooling immediately after the formation of protrusions was adopted. The shape and operating conditions of the suppression roll are the same as those in Comparative Example 1, and the required viscosity (η) determined from these processing conditions is 4 x 10-3 kgLsec/+n+++' as in Comparative Example 1.
The viscosity of the rod-shaped body used in this example was <0.015 as described above.
kglsec/mm2, which exceeds the above-mentioned required viscosity. It was confirmed that a large number of carbon TA fibers were present in a curved state within the locking protrusions formed on the surface of the obtained protrusion-processed rod-like body.

[Effects of the Invention] The present invention is configured as described above, and reinforcing wires and rods in which the protrusions are also reinforced with long fibers can be continuously produced with simple operations. The resulting wires/rods do not have the problem of shear failure occurring only at the protrusions, and can improve their integrity with matrix materials such as concrete. (can exhibit its characteristics as a reinforced resin reinforcing material extremely effectively.

[Brief explanation of the drawing]

Fig. 1 is an explanatory cross-sectional view of a main part showing an embodiment of the present invention, Fig. 2 is a cross-sectional view corresponding to II-11 in Fig. 1, and Fig. 3 is an explanatory diagram showing the state of breakage of long fibers F during pressure processing. Figure 4 is a vertical cross-sectional explanatory view showing the protrusion forming method that is the basis of the present invention, and Fig. 5 is a line with protrusions obtained by the method shown in Fig. 4.
It is an explanatory view showing the fracture situation of a rod. 1: Composite material made of long fiber reinforced resin 2: Press roll for pressure processing 3: Groove 5: Protrusion 6: Reinforcement wire/rod made of long fiber reinforced resin

Claims (1)

[Claims] A method for manufacturing a reinforcing wire/rod made of a long fiber reinforced resin and having locking protrusions formed at arbitrary pitches, the viscosity of which satisfies the relationship of the following formula [I]. A composite resin material impregnated with uncured or non-solidified long fibers, adjusted to 1. A method for producing reinforcing wires and rods made of long fiber reinforced resin, the method comprising forming a long fiber-reinforced resin and then curing or solidifying the resin. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] However, d: Diameter of long fibers (mm) L: Total length of the clamping part by grooved pressing member δ_F: Breaking strength of long fibers (Kgf/mm^2 ) ■: Shearing rate by grooved pressing member (l/sec)