RU2106252C1 - Method for manufacture of power member from polymeric composite material - Google Patents

Abstract

FIELD: molding of compound configured articles, such as conveyor chain flat links used in different branches of industry. SUBSTANCE: method involves forming process pack in two stages, with central part 1 of power members being formed at first stage by winding predetermined number of binder-impregnated filament yarns on process spindles mounted into openings of preliminarily molded thin plates made from similar material; introducing preliminarily molded central parts 1 between filament yarn bundles 10,11 at second stage, with filaments being spread apart in vertical plane in front of spinneret 9 by means of auxiliary spinnerets 12,13; laying central parts 1 in butted relation on lower part 10 of filament yarns movable toward working spinneret; removing process spindles upon hardening of yarns. EFFECT: increased efficiency, wider operational capabilities and enhanced reliability in operation. 3 cl, 5 dwg

Description

 The invention relates to methods for forming power products of complex geometry from polymer composite materials (PCM) by pultrusion and can be used in various sectors of the economy.

 A known method of forming profiles by pultrusion / 1 /, in which the fibers impregnated with a binder, is pulled through a die, including successively located zones: cold, hot - for partial polymerization, a cooling zone and the introduction of molten thermoplastic, hot zone - for the final polymerization of the binder and cooling zones of the molded product.

 However, this method does not allow to produce power elements from PCM, especially in a continuous mode.

 Closest to the technical essence of the claimed is a method of manufacturing a connecting rod from PCM for internal combustion engines / 2 - prototype /. According to this method, first, using a special mandrel, including a table with two metal technological axes fixed on it and six support rollers whose tangents are drawn to their outer surface, form an oval, the perimeter of which is equal to the perimeter of the connecting rod profile, a bag of pre-impregnated fiber is wound. An insert cut from the PCM along a given contour is introduced inside the package. Then the oval is crimped using a snap until it is shaped like a connecting rod. Support rollers are removed as the bag is crimped. The bag is closed by a lid and transferred onto a table with metal axes in a crimping press, where it is first crimped perpendicular to the axis of symmetry, and then along it. The working body of the press consists of four parts, the connection of the internal surfaces of which forms the outer contour of the connecting rod. When the working bodies of the press are heated, the binder is polymerized.

 This method allows you to make a power part of a complex configuration from PCM, working on compression. However, this method is inefficient, since the molding process cannot be carried out continuously. The requirement of synchronism of individual press elements during compression of a PCM molded part by punch parts leads to a complication of the press design.

 The purpose of the invention is to increase the productivity of the method due to the simplification of technological operations while maintaining high physical and mechanical characteristics of the resulting product.

 To achieve the goal, a technological package is formed, and first, the central part of the formed chain link is formed by winding a predetermined number of fiber bundles, impregnated with a binder, on the technological axes. Technological axes are mounted in the holes of preformed thin-walled plates. The central part thus formed is inserted between the bundles of fiber tows that are spaced apart with the help of an auxiliary spinneret in a vertical plane, while the formed central parts are stacked end-to-end on a movable lower tape / bundle / moving in the direction of the working spinneret in the area between two auxiliary spinnerets. After the profile is cured in the working die, the technological axes are removed, and the profile is cut into elements along the connecting line of the central parts and the cut lines are cleaned to obtain the product.

 The height of the technological axes is 5-20% less than the thickness of the power element.

 When forming the central part of the chain link, fiber bundles impregnated with a binder can be partially cured previously to the degree of polymerization ≤ 50% together with thin-walled strips.

 The winding on the technological axis can be carried out in a spiral or crosswise manner, and if the holes in the molded product are more than two and, therefore, the technological axes are more than two, then the winding is carried out in a sinusoid.

 To increase strength and improve the appearance of the formed technological package may also include tissue introduced by means of auxiliary dies from above and below the fiber bundles.

 In FIG. 1 shows the options for molded power elements: a) with two holes, b) with three holes; in FIG. 2 - the central part of the molded chain link; in FIG. 3 - a device for winding the central part of the links of power elements; in FIG. 4 is a diagram of winding the central part of the links of power elements with three holes; in FIG. 5 is a diagram of an implementation of a method for manufacturing power elements.

Example. Using the proposed method, elements of a chain link with a cross section of 10 • 20 mm and a distance between axles of 125 mm were made. Link elements were made as if in two stages. At the first stage, the central part of link 1 was formed as follows. Unidirectional plates with a cross section of 1 • 24 mm were made by pultrusion of fiberglass, containing RBR-13-2520 glass roving and a binder based on epoxychlordian resin at a drawing speed of 21 m / h and a curing temperature of 210 ^o C. Next, the plates were cut into strips 2 with a length of 149 mm and punched there are two holes 3 ⌀ 9 mm with a distance between the axes of the holes 125 mm and two auxiliary holes 4 ⌀ 6.5 mm with a distance between the axes of these holes 90 mm. Next, the strips were placed in a special device (Fig. 3), where, between the strips, two technological axes 5 ⌀ 9 mm and a height of 8 mm were mounted. After that, the cheeks 6 of the device were pulled together with bolts 7. The device was fixed on the shaft (not shown in the drawing) and wound between the strips of 25 turns of glass roving 8 RBD-15-2520, impregnated with a binder based on EHD. After that, the planks with fiber bundles wound on the technological axis were removed from a special device - mandrels. Thus, the central part of the chain links was formed.

 At the second stage (Fig. 5), the formed central parts of the chain links 1 were inserted into the working die 9, placing them between the vertically spaced ribbons 10, 11 of fabric and glass-fiber bundles RBR-13-2520 butt, laying them continuously on the lower side moving working spinneret tape 10 in the area located between the first and second auxiliary spinnerets guiding the tape. Auxiliary dies 12, 13 are installed in front of the working die 9 at a distance from it of 300-400 and 100-200 mm, respectively.

 In the working die 9, the central part of the links of the lower and upper parts of the bundles of fibers and ribbons is uniformly crimped on all sides. In the working die 9, the formation of the technological package is completed, the reinforcing material is impregnated, the binder is gelled and cured, and the profile 14 is finally formed.

 After exiting the working die, profile 14 is cut along the junction lines of the central parts of the links into separate elements, then the ends are rounded off at a given radius. Technological axes are removed from the profile, and the edges of the holes are cleaned. Chain links are ready for operation.

 A three-hole receiving pattern is shown in FIG. 4, where preferably the hollow axes 5 are used, and the reinforcing material is wound in a sinusoid with a successive bypass of each of the technological axes. After winding, the workpiece of the central part of the package is removed, a second bar is installed on the technological axis. The workpiece is prepared for further molding.

 The tensile strength of the material of the chain link was 1500 kgf, which is two times greater than the tensile strength of the material of the chain links obtained by pultruding with unidirectional reinforcement.

Claims (3)

 1. A method of manufacturing a polymer composite material by the method of force element pultrusion, comprising forming a technological package from a fiber impregnated with a binder, drawing it through a working die and then cutting the resulting profile into individual elements of a given length and curing, characterized in that the technological package is formed in two stages , on the first of which the central parts of the manufactured power elements are formed by winding a predetermined number of fiber bundles impregnated with a binder to them, on technological axes, mounted in the holes of preformed thin plates of the same material, and in the second stage, the preformed central parts are inserted between bundles of fiber tows, which are bent in front of the working die in the vertical direction with auxiliary dies, and the central parts are laid butt on the lower part of the bundles of fiber tows being moved towards the working die, and after curing, the technological axes are removed.  2. The method according to claim 1, characterized in that in the manufacture of a power element with three holes, the winding is carried out on three technological axes along a sinusoid, sequentially bypassing each of them.  3. The method according to claim 1, characterized in that the use of technological axis with a height of 5 to 20% less than the thickness of the manufactured power element.

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