Sliding parts, conveying devices, stretching devices and / or conveying devices for stretching devices

Abstract

The present invention aims to provide a sliding part, in particular a sliding piece for a stretching device and / or a conveying chain, and a conveying device or a conveying device for a stretching device equipped with such a sliding piece, which requires a significantly lower lubricant consumption compared to conventional sliding parts, stretching devices or conveying chains. [Solution] A sliding part (21), particularly for a drawing device and / or a conveyor chain, is made of fiber-reinforced thermoplastic resin or contains said material as a main component and has a U-shaped cross section forming a U-shaped recess, and a sliding piece (24) is disposed or fitted into the U-shaped recess of the sliding part (21), and the sliding piece (24) moving along a guide rail and the guide rail form a sliding contact pair. The sliding piece (24) contains porous graphite or electrographite with a porosity between 7.5% and 20% by volume, and the graphite particles constituting the starting material of the sliding piece (24) have a particle size between 3 μm and 15 μm.

Description

[Technical Field]

[0001] The present invention relates to the sliding part described in the preamble of claim 1, and more particularly to a stretching device and / or a conveying device for a stretching device. [Background technology]

[0002] Multiple stretching devices are used, in particular, in the production of multiple thin-film resins (plastic films).

[0003] For example, a continuous multi-stage stretching apparatus for a continuous two-stage stretching method, in which a thin resin film is first stretched in the longitudinal direction and then stretched in the transverse direction (or in the reverse order), is well known.

[0004] A so-called simultaneous stretching apparatus that stretches a thin film resin in both the longitudinal and transverse directions simultaneously is also known.

[0005] A transverse stretching device or transverse stretching stage used in a stretching device is disclosed in Patent Document 1, Patent Document 2, or Patent Document 3 below. Earlier publications show a plurality of gripping devices (clips) that grip the strip material to be stretched, usually a thin resin film, on both sides of the strip material, moving along a plurality of circulating guide rails and fixed to a plurality of chains. The plurality of gripping devices move sequentially from the inlet region of the stretching device (for example, the region that grips both side edges of the thin resin film to be stretched), through the stretching region (the region in which the plurality of gripping devices move along the plurality of guide rails, spaced apart from each other in the transverse direction relative to the transport direction of the strip material), to the outlet region, and then through the return region and back to the inlet region. For example, some internal stress relief treatment and / or heat post-treatment can be applied to the thin resin film within the outlet region. The transverse stretching device is equipped with guide rails that guide the movement of the transport chain.

[0006] The plurality of gripping devices provided on the entire conveying chain (provided at intervals from each other in the longitudinal direction of the conveying chain while contacting a plurality of chain rings) have sliding pieces or roller pieces, and the sliding pieces or roller pieces that move together with the gripping devices abut against a plurality of running surfaces and sliding surfaces of guide rails that are arranged vertically, parallel to each other, and spaced apart. The support body attached to the plurality of chain rings has sliding pieces on which a plurality of sliding surfaces are formed. The guide rail material and the control rail material of the simultaneous stretching device can also be equipped with sliding pieces.

[0007] Patent Document 3 shows an improved lubrication method for a plurality of conveying devices and their plurality of parts, particularly a lubrication method for a plurality of related parts of a stretching device and an improved lubricant device. In the conveying device with the improved lubrication method, continuous micro-lubrication can be performed to reduce the lubricant consumption.

[0008] Patent Document 3 and Patent Document 4 show the principle of a graphite sliding piece and / or an elastic polymer, a thermoplastic resin, or a thermosetting resin containing graphite particles.

[0009] Patent Document 5 shows a belt-like material gripping conveying chain having chain rings with a substantially U-shaped chain cross-section in which a plurality of gripping supports are fixed in the longitudinal direction. A sliding material that does not require a lubricant, a wide-area sliding plate made of polytetrafluoroethylene with a specially formed suitable low coefficient of friction, is fixed to the U-shaped bottom and connecting clamping base of each specially formed chain ring with rivets. A sliding plate that fits into a plurality of chain rings in a correspondingly processed recess is specially formed. In the embodiment of this structure, the manufacture of the basic chain specially formed for the above object requires the manufacture of each support body provided with a plurality of expensive chain rings.

[0010] Patent Document 2 shows a sliding piece that receives the tensile force of a thin film and a chain and the gravity of the chain.

[0011] Patent Document 6 and Patent Document 7 show a sliding piece that uses graphite adhered and impregnated with a synthetic resin.

Prior Art Documents

Patent Documents

[0012] [Patent Document 1] U.S. Patent Application Publication No. 5,797,172 [Patent Document 2] International Publication No. 2014 / 94803 A1 [Patent Document 3] German Patent No. 19857289 C1 [Patent Document 4] German Patent Application Publication No. 3925737 A1 [Patent Document 5] European Patent Application Publication No. 0138117 A2 [Patent Document 6] European Patent No. 0471329 B1 [Patent Document 7] European Patent No. 1652877 B1 [Patent Document 8] German Patent Application Publication No. 19749785 A1 [Summary of the Invention] [Problems to be Solved by the Invention]

[0013] The present invention aims to provide a sliding part, particularly a sliding piece for a stretching device and / or a conveying chain, and a conveying device for a stretching device equipped with the sliding piece, which can significantly reduce the required lubricant consumption compared to conventional sliding parts, stretching devices or conveying chains. [Means for Solving the Problems]

[0014] The present invention solves the problems of the sliding part by the characteristic means of claim 1 and solves the problems of the conveying device by the characteristic means of claim 12. Advantageous embodiments of the present invention are described in the dependent claims.

[0015] By using a plurality of sliding parts of the present invention, the operation of the conveying chain (a guide rail for supporting the conveying chain (a control rail in a vertical and horizontal simultaneous stretching device) moving along), particularly the operation of the stretching device, can obtain a remarkable effect worthy of surprise, which can dramatically reduce the conventionally required amount of lubricant.

[0016] The use of graphite sliding pieces was previously known. Patent documents 6 and 8 also confirm that multiple sliding pieces made of graphite or containing graphite were known. Early known sliding pieces were inorganic salts and inorganic salts impregnated with polymers.

[0017] Research conducted in this invention has revealed that known graphite sliding pieces, particularly those made of graphite, cannot be adequately applied to conveyor chains, especially conveyor chains in stretching devices.

[0018] In the research of the present invention, it was found that particularly good results can be achieved by implementing one or more preferred modified embodiments described below and / or by satisfying the following conditions. Preferably, a plurality of sliding pieces impregnated with an inorganic salt in the form of a phosphate (salt or ester of orthophosphate), In particular, multiple sliding pieces impregnated with a metal salt in the form of aluminum phosphate (AlPO4), In particular, a sliding piece or graphite body embedded with an inorganic salt, especially preferably in the form of aluminum phosphate, in a ratio of 1% to 20% by weight, ·d 50 =30μm, d 90 =100μm~d 50 = 5 μm, d 90 =15μm is a suitable particle size range, and is particularly preferred d 50 =7μm, d 50 =30μm phosphates, especially metallic phosphates, • Not only within the surface area or surface layer of 1 mm or 2 mm, but preferably multiple sliding pieces completely impregnated with inorganic material, Multiple sliding pieces are produced by "sintering" multiple manufacturing starting materials required for multiple sliding pieces using an appropriate method such as isotropic pressing. • Graphite powder within a specific particle size range and particle distribution range used as a starting material for manufacturing multiple sliding pieces. The graphite powder with the maximum particle size (average particle size, expected value) distribution used for the manufacturing starting material and the sliding piece with the maximum particle size (average particle size, expected value) distribution manufactured by compression (isostatic pressure pressing, injection molding, densification) are both, for example, with respect to desired mechanical values such as bending strength, etc., having an average particle size of 3 to 15 μm. It has been found that an average particle size of 7 to 10 μm is suitable and appropriate. The median particle size d(50) of 14 to 18 μm, the 10% particle size d(10) of 24 μm, and the 90% particle size d(90) of 42 to 50 μm were measured as the particle size range (particle size values d 10 , d 50 and d 90 characterize the particle size distribution. The median particle size is taken as the d 50 value according to the average particle size distribution [German Industrial Standard (DIN) 13320]. The width of the particle size distribution is explained by the 10% particle size d 10 value and the 90% particle size d 90 value. That is, the width d width follows the formula: d width = d 90 - d 10 ). · The porosity and / or pore distribution of a plurality of sliding pieces is at least 7.5% by volume, at least ≧8% by volume or preferably ≧9% by volume, 10% by volume, 11% by volume, 12% by volume, 13% by volume, 14% by volume or ≧15% by volume. The corresponding porosity of a plurality of sliding pieces is further ≦20% by volume, particularly ≦18% by volume, 16% by volume, 15% by volume, 14% by volume, 13% by volume, 12% by volume or particularly ≦11% by volume. · For example, under normal operating conditions where the air humidity ≧5 (preferably 8 to 20) [g / m 3 , the sliding piece, for example, has oil-impregnated pores or usually fluid-filled pores.

[0019] For example, it has been found by tests that it is particularly advantageous to immerse the sliding piece in an oil bath several hours before assembling the bearing material to obtain a plurality of sliding pieces having a plurality of fine pores that are impregnated with oil as completely as possible. By primary oil saturation of impregnating the porous sliding piece with lubricating oil, wear can be significantly reduced.

[0020] For example, the graphite particle size and particle distribution, which impart essential mechanical properties to a sliding piece, affect not only wear characteristics but also, for instance, the bending strength of the material. The particle size and particle distribution of graphite powder (both in the starting material form and the final compressed form after manufacturing the sliding piece) also affect thermal and chemical properties.

[0021] Inorganic salts, their particle size (grain size), and particle size distribution all affect their friction and wear properties.

[0022] A key condition for achieving the advantages of the present invention lies in the sliding piece having minimal porosity. Further improvements can be achieved by using inorganic salts (particularly phosphates) and by ensuring proper impregnation and / or isotropic pressure of multiple sliding pieces.

[0023] The present invention achieves its greatest advantage when all three conditions—porosity, inorganic salt impregnation, and isotropic thickness pressurization—are met.

[0024] When multiple sliding pieces or graphite sliding pieces are coated with a polymer and / or multiple pores (particularly multiple pores formed on the surface of multiple sliding means) are filled with a polymer (Patent Document 6), friction increases, contrary to the sliding action of the present invention, and even results in the disadvantage of requiring a larger amount of lubricating substance or lubricant. This creates a risk, especially in stretching devices, that contaminants and impurities in the lubricant, particularly in the lubricant droplets, may be included in the resin thin film to be stretched.

[0025] In stretching devices in particular, which employ multiple sliding pieces that constitute contact pairs between a conveyor chain or guide rail and the multiple sliding pieces of the present invention, the consumption of lubricant or lubricating oil can be dramatically reduced. Conventional sliding pieces or graphite sliding pieces experience increased wear, especially in curved sections subjected to heavy loads, particularly in the stretching region of stretching devices. Therefore, the sliding pieces of the present invention are far superior to conventional graphite sliding pieces.

[0026] Several essential advantages can be obtained from the sliding piece of the present invention, which contains graphite particles within a specific particle size range.

[0027] The features of this invention significantly reduce wear during startup, which typically lasts about 1 to 2 hours.

[0028] The dramatic reduction in lubricant consumption can reduce or avoid contamination of the thin films to be manufactured by condensate precipitation and microdroplets.

[0029] In the plurality of sliding pieces of the present invention, the temperature of the plurality of materials related to the sliding portion that constitutes the contact pair with the guide rail can be increased.

[0030] By utilizing the new material, basic standard components can be used for chain conveying devices of various different structures, and the adapter solution requires only the construction of the gripping device and guide rail (and control rail) to be assembled.

[0031] By utilizing the novel material, a fluid other than high-performance oil can be used as the intermediate layer between sliding contact pairs.

[0032] By employing multiple graphite sliding pieces according to the present invention, lubrication of the sliding track and chain shaft can be achieved in particular.

[0033] The graphite embedded in the polymer matrix exhibits properties similar to several "pure" graphite materials commercially available from Tecasint and Sintimit (registered trademarks of Ensinger and DuPont SCP).

[0034] It has become clear that the aforementioned advantages can be realized not only when using the sliding piece of the present invention, but also, for example, when using the sliding piece of the present invention as a sliding contact pair with a guide rail or control rail having specific material properties or surface properties.

[0035] When lubricating a conveying device or multiple components thereof, the present invention relates not only to methods for reducing the amount of lubricant and, in particular, the amount of lubricating oil, and to the use of special sliding pieces or graphite bodies, but also to a method for lubricating sliding pieces or graphite bodies that face guide rails (and control rails). Accordingly, the present invention proposes a specific sliding contact pair that reduces the amount of lubricant required.

[0036] Sliding contact pair Multiple sliding contact pairs are understood as a combination of guide rails or control rails (for conveying chains), particularly guide rails and / or control rails of stretching devices, and multiple sliding pieces provided or formed on the chain or gripping device chain or rhombic contraction mechanism. Conventionally, the sliding pieces are often carbon fibers, aramid fibers, or glass fibers, and are composed of resins reinforced with material mixtures such as polytetrafluoroethylene (PTFE) or polyetheretherketone (PEEK).

[0037] The prior art (for example, the published patent applications for Patent Document 6 or Patent Document 7) that proposes multiple sliding contact pairs including graphite members does not specify use in stretching devices or any special usage conditions.

[0038] It has been found that a sliding contact pair, consisting of multiple sliding pieces and a rail device (particularly a guide rail or control rail formed of the same or similar thermal expansion coefficient material as the multiple sliding pieces of the stretching device) facing the sliding pieces, is particularly suitable for the present invention. For example, hard materials (with a high graphite content), such as cast iron, hard metals, aluminum oxide, silicon carbide, glass, diamond-like carbon (DLC) coated materials (diamond-like amorphous carbon), and especially hard alloy steel for the guide rails and control rails of the stretching device, have been found to be good contact materials for the sliding pieces of the present invention.

[0039] Embodiments of the present invention will be described in detail below. Each accompanying drawing shows the following. [Brief explanation of the drawing]

[0040] [Figure 1] Schematic plan view of a transverse stretching device, which constitutes part of a continuous stretching device. [Figure 2] Cross-sectional view of a support device equipped with a transport chain having multiple gripping devices, wherein multiple gripping devices that advance in the forward direction of the strip-shaped thin film are provided on one side of the support device, and multiple gripping devices that are returned to the entrance area in the return stroke are provided on the opposite side of the support device. [Figure 3a]An exploded perspective view showing a part of the gripping device for gripping the resin thin film and the transport chain that moves together with the gripping device in a resin thin film stretching apparatus. [Figure 3b] Partial cross-sectional view showing the cross-section of the conveyor chain passing through the chain axis shown in Figure 3a. [Figure 4] Perspective view of the sliding piece or graphite body of the present invention having opposing U-shaped inner cross-sections. [Figure 5] Perspective view of the sliding bottom plate positioned on the lower surface of the transport chain and / or gripping device body, opposite the support surface of the support rail. [Figure 6] A perspective view showing a modified embodiment of Figure 3a, of a sliding piece that is preferably directly inserted and fixed to the conveyor chain and / or gripping device body in a releasable or replaceable manner. [Figure 7] Graph showing lubricant consumption in response to variations in thin film resin thickness and load. [Figure 8] A graph showing the different lubrication oil consumption of four types of chain devices, comparing conventional sliding pieces with the sliding pieces of the present invention. [Figure 9] Graph showing the change in the coefficient of friction of the sliding piece of the present invention with respect to temperature changes. [Modes for carrying out the invention]

[0041] Basic structure of a transverse stretching device The following thin film width stretching apparatus or thin film transverse stretching apparatus (also abbreviated as TD (Traverse Direction) stretching apparatus) has two known drive devices formed symmetrically. Figure 1 shows a pair of drive devices arranged symmetrically in a symmetrical plane SE perpendicular to the drawing plane, and a strip-shaped material in the form of a resin thin film F to be stretched is placed between the pair of drive devices moving on a circulating track 2 and transported by the drive devices to move in the withdrawal direction 1 (machine direction MD). The TD stretching apparatus may be part of a continuous longitudinal and transverse stretching apparatus, but a continuous stretching apparatus usually includes a longitudinal stretching step that is placed before the transverse stretching apparatus (transverse stretching frame) (in case of doubt, the longitudinal stretching step may be placed afterwards). Multiple transport chains are equipped with gripping devices that move along multiple guide rails, and in the stretching region, the multiple transport chains move along multiple control rails via deflection devices, spaced apart from each other laterally in the stretching device, and adjacent gripping devices are spaced apart in the longitudinal direction of the stretching device. Therefore, the present invention can be basically applied to a rhomboid contraction device, i.e., a simultaneous stretching device, that performs simultaneous stretching in the longitudinal and lateral directions.

[0042] The stretching device shown in Figure 1 comprises two chain conveying devices 3 that are driven in the circulating direction on a pair of circulating tracks 2.

[0043] Uniaxially stretched or uniaxially stretched thin film resin F (when a longitudinal stretching device is placed before the transverse stretching device shown in the figure) or unstretched thin film resin F (in the case of a stretching device in an embodiment in which a strip-shaped processed material called thin film resin F is appropriately processed and normally stretched transversely, the present invention is not limited to strip-shaped thin film resin) is introduced into the stretching device from the inlet region E. The gripping device shown in Figure 2, for example, in the inlet region E, simultaneously grips and transports both edges 8 of the thin film resin F on the operator side OS (operator side) and the drive side DS (drive side). Subsequently, the thin film resin F is heated in the subsequent preheating region PH and then introduced into the stretching region R in which the thin film resin F is stretched transversely TD. Subsequently, the stretched thin film F can also pass through various heat treatment regions HT to relieve the internal stress of the thin film resin. In the final stage exit region A of the stretching device, the thin film resin is released from the gripping device by appropriate means and moves away from the transverse stretcher, i.e., the transverse stretching device TD.

[0044] The gripping and conveying device KT, also known as the gripping chain device KK, will be described (Figure 2). The gripping and conveying device KT, i.e., the gripping chain device KK, can be applied to various embodiments / modifications. In this specification, one modification is described as an example, but further modifications will be obvious to those skilled in the art. The gripping and conveying device KT, the gripping chain device KK, comprises a gripping device 6 connected to a conveying device 3 or a chain device 7. In this embodiment, preferably, a conveying chain 13, which represents a part of the chain device 7 of the gripping chain device KK, is used.

[0045] The gripping chain device KK, which includes a known gripping device 6 and a chain device 7 as shown in cross-section in Figure 2, is installed on a transport device 3 that moves in a circulating manner. The transport device 3 comprises a support structure, i.e., a support structure 11, and a circulating transport chain 13. The gripping device 6 is fixed to or formed on the transport chain 13 and moves together with it. The support structure 11 includes a guide rail 15. In addition to the guide rail 15, a support rail 17 or support running rail 17 is provided to support the weight of the chain device 7 and the gripping device 6. As described below, the transport chain 13 is supported and guided on the guide rail 15 using the gripping device 6 which is joined to the transport chain 13 and moves together with the transport chain 13, and a sliding piece (also called a "graphite body") GK to which the present invention is applied. The sliding piece GK which is joined to the rear of the transport chain 13 is particularly joined to or assembled with the gripping device 6 or its main body and moves together as a single unit.

[0046] A common support structure 11 for the conveying device 3, which connects the conveying chain 13, the gripping device 6, and the sliding piece GK, can be used on the extending side or processing side RS, or on the return side RL (Figures 1 and 2). Other modifications of the support structure other than those shown, in which the support structure 11 is composed of a guide rail or control rail 15, are also known to those skilled in the art.

[0047] Figure 2 shows a cross-section of a conveying device 3 that has a common support structure 11 on the extension side RS and the return side RL, which has a column 19 positioned vertically near the center and a crossbeam 21 supported at the top of the column 19. Rails 15 with a roughly rectangular cross-section are vertically attached to the opposite ends of the crossbeam 21, which are spaced apart from each other. The pair of conveying devices 3 of the common support structure 11 are, for example, both placed inside a heating furnace O. Since the heating furnace O also encloses the preheating region PH, the extension region R, the postheating region, or the internal stress relaxation region HT, only the direction changing devices and drive devices provided on the inlet and outlet sides are located outside the heating furnace O.

[0048] As described above, the conveying chain 13 is driven and its direction is changed by a plurality of discharge drive wheels AR on the outlet side and a plurality of feed drive wheels ER on the inlet side.

[0049] Figure 3a shows details of an example of a transport chain 13 having a plurality of known chain links 13.1 that are linked together.

[0050] Figure 3b shows a cross-sectional view through which multiple chain links pass at the center of the chain axis and a perspective view of the transport chain 13 with the gripping device 6 corresponding to Figure 3a removed. Figure 3b shows the sliding piece 24 formed on the gripping transport device that fits the guide rail 15 (fitted into the U-shaped recess 23 of the sliding part 21) and the sliding bottom plate 25 of the gripping transport device. The transport chain 13 is placed on the sliding bottom plate 25, and the sliding piece 24 has a sliding surface that faces the sliding surface of the guide rail 15. Figure 4 shows the sliding part 21 having the sliding piece 24, and Figure 5 shows a perspective view of the sliding bottom plate 25.

[0051] The sliding portion 21 is made of a fiber-reinforced thermoplastic resin, preferably in the form of polyetheretherketone (PEEK), or has this material as its main component. Multiple opposing sliding pieces or plates 24 are mounted on the opposing sides of the sliding piece 21, and the sliding piece or plate 24 is usually adjusted to a vertical position opposite to multiple guide surfaces of the guide rail 15. The sliding base material or sliding base plate 25 shown in Figure 5, which is assembled integrally with the sliding piece 24 of the present invention, usually faces the upward guide surface of the guide rail 15.

[0052] The gripping and conveying device comprises, for example, a gripping device 6 (original clip 5), a chain device 7 (original conveying chain 13), a U-shaped recess 26 provided between the gripping device 6 and the chain device 7, and a connecting body B (connecting the gripping device 6 and the chain device 7) fixed to the bottom of the U-shaped recess 26. A sliding bearing 21' (also referred to as a sliding part 21) is formed on a sliding piece 24 fitted into the U-shaped recess 26, and opposing guide rails 15 are fitted inside the sliding bearing 21'.

[0053] The guide rail / sliding bearing 21' has a width or length corresponding to the direction of the guide rail 15 and includes a U-shaped cross-section sliding piece or sliding part 21 that supports the pulling force to the gripping and conveying device. It is not limited to a U shape, and of course each sliding piece can be formed in any shape.

[0054] Unlike Figures 3a and 3b, Figure 6 shows sliding pieces 24 that are preferably directly mounted in a removable and replaceable manner within corresponding recesses of the conveying chain 13, particularly the gripping device 6 body. Multiple dovetail grooves 31 can be provided in the sliding pieces or sliding parts 21 for fitting, attaching, or fixing multiple sliding pieces 24. A sliding bottom plate 25 can also be fixed to the lower surface of the gripping device 6. There are basically no restrictions on the fixing method and modifications. All modifications are possible in this embodiment.

[0055] Alternatively, a complete sliding portion 21, comprising a plurality of sliding pieces 24 that are (preferably removable) fitted together, can be fitted into the U-shaped recess of the clip 5 body, and for example, the projection 33 shown in Figure 3b can be fitted into the corresponding recess 35 of the clip 5 body (Figure 4).

[0056] Actual oil consumption tests can be performed using a transverse stretching device (for example, the first or second stage of a sequential transverse stretching device) as outlined in the plan view of Figure 1, with multiple different sliding pieces.

[0057] The tests began with multiple sliding pieces made of conventional fiber-reinforced polyetheretherketone, and were conducted using multiple different sliding pieces. In particular, sliding pieces were attached to each clip of the conveyor chain, and the multiple sliding pieces were brought into contact with each other on multiple sliding surfaces of multiple guide rails and / or support rails. Subsequently, contact correspondence tests of the multiple sliding pieces of the present invention were performed and measurements were taken, and the test results are sometimes abbreviated as test piece designation: B21. Actual lubrication oil consumption values ​​were measured by the tests under actual production conditions using a stretching machine. Multiple drive motor torque values ​​at the inlet and outlet of the stretching machine serve as reference and indirect parameter variables. Through these parameter variables, the coefficient of friction of the corresponding multiple sliding contact pairs can be indirectly derived.

[0058] The following test results were obtained using the drive system shown in Figure 1. The torque of the multiple inlet motors was, for example, 55% of the total torque (4,400 [Nm] in this example). The drive-side outlet torque was, for example, 31% of the total torque (18,400 [Nm] in this example). The operator-side outlet torque was, for example, 28% of the total torque (18,400 [Nm] in this example).

[0059] Figure 1 shows the top and bottom surface temperatures of multiple guide rails / support rails in the stretching region and the heat treatment / cooling region.

[0060] In the test conducted with the stretching device shown in Figure 1, lubricant was used at four locations, for example: the inlet, the central drive area, the central operator side, and the outlet of the stretching device.

[0061] Table 1 below (where l represents liters) shows an example of the daily lubricant consumption corresponding to each location, including a specific speed coefficient (1.2) and a specific thickness coefficient (1.0), where lubricant was supplied to four locations. The second column from the right shows the theoretically calculated value: 0.483 / day.

[0062] The last column shows the lubricant characteristic values ​​measured by supplying lubricant to four locations, as well as the actual lubricant consumption, which represents the total amount of lubricant used per day. [Table 1]

[0063] The sliding piece or graphite body of the present invention Sliding pieces or graphite bodies made of graphite or containing a substantial proportion of graphite have been conventionally proposed. Furthermore, the use of graphite sliding pieces impregnated with polymers has also been conventionally proposed.

[0064] In this invention, only an impregnation means is shown herein for using an impregnation polymer to completely fill or impregnate the pores of a graphite sliding piece to the extent that the porosity of the sliding piece is utilized. The impregnation means ultimately reduces the porosity of the sliding piece, preventing further filling or infiltration of lubricants such as oil into the pores of the sliding piece, for example.

[0065] This invention provides a method for using sliding pieces made of graphite, particularly electrographite, having a specific minimum porosity.

[0066] The minimum porosity should be approximately 8% or greater. A porosity of at least 9% or 10% is considered good. A porosity of less than 25% is considered acceptable and good.

[0067] For example, since lubricants such as lubricating oil penetrate into the pores of the graphite sliding piece, the porosity of the graphite sliding piece is significantly improved over a longer period than with conventional solutions. The lubricants and lubricating oil that penetrate into the pores of the sliding piece by capillary force help to reduce the total amount of lubricant required. For example, in a test in which sliding pieces were immersed in a lubricating oil bath for several hours before assembling multiple bearing materials into multiple sliding pieces, it was found to be particularly advantageous to allow the lubricating oil to penetrate as completely as possible into the multiple pores of the multiple sliding pieces. It was also found that the primary saturation of the sliding piece pores with lubricating oil significantly reduces wear of the sliding piece during operation.

[0068] The function and effects of the present invention can be further improved by using graphite sliding pieces impregnated with a minimum proportion of inorganic salts, particularly metal salts, within their pores. Particularly good results can be obtained by impregnating with metal salts in the form of phosphates (e.g., tertiary orthophosphates). Aluminum phosphate (AlPO4) is particularly suitable. Further improvements can be achieved by applying isotropic pressure to the graphite powder used in the manufacturing process of the sliding pieces. The particle size range of the impregnated metal salt should be 3 μm or more, preferably less than 150 μm, and metal salt compounds, especially metal phosphates, should be used.

[0069] In summary, it was found that the following features, one or more, of the sliding piece of the present invention, particularly the combination of features, are important. Preferably, a plurality of sliding pieces impregnated with an inorganic salt, particularly a metal salt in the form of a phosphate (salt or ester of orthophosphate). Multiple sliding pieces impregnated with metal salts, particularly metal salts in the form of aluminum phosphate (AlPO4). A sliding piece or graphite body embedded with 1% to 20% by weight of an inorganic salt, particularly a phosphate, and more preferably an inorganic salt in the form of aluminum phosphate. ·Particle size d 50 =30μm, d 90 =100μm and d 50 = 5 μm, d 90 =Within the range of 15 μm, particularly preferably d 50 =7μm, d 50 =30μm phosphates and especially metallic phosphates Multiple sliding pieces completely impregnated with metal salt in a surface area or outside the surface layer to a depth of 1 mm or 2 mm. Multiple sliding pieces are produced by "joining" multiple starting materials necessary for the manufacture of multiple sliding pieces using appropriate processing methods such as isostatic pressing. · The maximum particle size distribution (average particle size, expected value) of the graphite powder used as the starting material for the manufacture of multiple sliding pieces, and the maximum particle size distribution (average particle size, expected value) of the sliding pieces manufactured by compression, were found to be 3 to 15 μm, with a suitable average particle size of 7 to 10 μm. The median particle size d(50) was measured at 14 to 18 μm, the 10% particle size d(10) at 24 μm, and the 90% particle size d(90) at 42 to 50 μm (particle size distribution is measured using the particle size value d 10 d 50 and d 90 Characterized by: Medium particle size d 50 This defines the average particle size distribution [German Industrial Standard (DIN) 13320]. 10% particle size d 10 and 90% particle size d 90 The width d of the particle size distribution width The expression representing: d width =d 90 -d 10 ). The porosity and / or porosity distribution of the multiple sliding pieces is at least 7.5% by volume, at least ≥8% by volume, or preferably ≥9% by volume, 10% by volume, 11% by volume, 12% by volume, 13% by volume, 14% by volume, or ≥15% by volume. The corresponding porosity of the multiple sliding pieces is further ≤20% by volume, particularly ≤18% by volume, 16% by volume, 15% by volume, 14% by volume, 13% by volume, 12% by volume, or particularly ≤11% by volume. For example, air humidity ≥ 5 (preferably 8-20) [g / m³] 3 Under normal operating conditions, for example, a sliding piece having a lubricating oil saturation hole or a normal fluid filling hole.

[0070] To elaborate, ideally, a Gaussian calculus can be applied to particle measurements.

[0071] test A series of stretching apparatuses were tested using multiple known fiber-reinforced sliding pieces, as well as multiple graphite sliding pieces having preferred features of the present invention, one or more of which were used.

[0072] Table 4, attached at the end of this specification, shows various data values ​​for conventional fiber-reinforced graphite sliding pieces and the graphite sliding pieces of the present invention.

[0073] Table 4 shows multiple values ​​for known graphite sliding pieces based on the data for samples a, b, c, d, e, f, P, SFU, and SR.

[0074] The data for the graphite material of the present invention are shown in Sample B21 of Table 4.

[0075] Using conventional PEEK fiber-reinforced sliding pieces and the graphite material of the present invention having two or three suitable characteristics in a stretching apparatus, a series of tests were conducted on multiple fiber-reinforced sliding pieces and graphite sliding pieces, and the required amount of lubricant obtained is shown in Table 2. A chain device C was used to move the strip-shaped thin film resin to be stretched through the stretching apparatus at a maximum feed rate (limiting speed) of 525 m / min. The sliding pieces used are shown below. C1: Conventional PEEK fiber-reinforced sliding piece impregnated with polymer. C2: A series of tests were conducted by changing the sliding piece C1, for example, a graphite sliding piece with a porosity of 10%. C3: A sliding piece added to the test by completely impregnating sliding piece C2 with aluminum phosphate. C4: A graphite sliding piece with 10% porosity, impregnated with aluminum phosphate and subjected to isotropic pressure.

[0076] A series of tests were conducted using conveyor chains equipped with sliding pieces that had been in operation for 1000 hours and those with more than 1000 hours of operation.

[0077] Table 2 below shows the lubricant consumption per minute / day [l=liters] for multiple sliding pieces C1, C2, C3, and C4, with a resin thin film transport speed of less than 525 m / min, a thin film thickness of ≤20 μm, and a basic coefficient Bf. [Table 2]

[0078] Table 3 shows the lubricating oil consumption for different speeds and thin film loads. [Table 3]

[0079] The speed limit is 525 m / min, the chain length is 350 m, and the lubricant consumption value is shown at the end.

[0080] For clearer understanding, a calculation example for a chain system C1 equipped with a standard PEEK sliding device with a chain length of KL = 350m is shown below. The basic consumption for operating hours exceeding 1000 hours is as follows: Consumption = KL×Bf=14×350m×10 -3 =4.9

[0081] The lubricating oil consumption of the preferred chain sliding device of the present invention, shown in sliding piece C4, is significantly reduced, resulting in a value of only 0.9 [l / 24 hours].

[0082] Preferred characteristic values ​​of the graphite sliding piece of the present invention Table 4 shows the preferred characteristic values ​​of the graphite material of the present invention.

[0083] The use of the graphite material of the present invention with at least a suitable porosity is critically important for the successful reduction of lubricating oil.

[0084] Furthermore, the graphite body of the present invention, impregnated with an inorganic salt, particularly a metal salt, preferably a metal phosphate, and especially aluminum phosphate, can further reduce lubricant consumption. If isotropic pressure is applied to the graphite body instead of, and preferably in addition to, impregnation, further improvement in lubricant consumption can be obtained.

[0085] A sliding piece or graphite body impregnated with a sufficient amount of inorganic salt in its surface layer is generally sufficient. It is preferable to use a sliding piece that is completely impregnated with inorganic salt.

[0086] Suitable sliding contact pair In addition to the sliding pieces of the present invention that produce the aforementioned advantages, it has also been found that the friction components of the support material, which comes into contact with the sliding pieces of the conveyor chain used in stretching devices and has similar inherent properties, are also effectively reduced, further reducing the amount of lubricant required.

[0087] In particular, the guide rail, support rail, and / or, optionally, the control rail, serve as supports for the stretching device, which works in cooperation with the transport chain and / or gripping device. Preferably, the sliding pieces of the present invention, provided on the transport chain or gripping device, come into contact with each other on opposing sliding surfaces of the guide rail and / or transport rail (or control rail). Good physical compatibility (compatibility, suitability) arises from pairs of materials having equal or similar coefficients of thermal expansion. The coefficients of thermal expansion of multiple sliding pieces and multiple rails interacting with each other can also be set by selecting the compositional components according to the intended use.

[0088] The multiple sliding pieces of the present invention, used in stretching devices, have particular advantages. To date, no special tests have been conducted to demonstrate these advantages.

[0089] Physically good compatibility can be obtained between contact pairs of materials having uniform or similar coefficients of thermal expansion. Suitable combination contact pairs for conveying chain / gripping devices equipped with the sliding pieces of the present invention are rails formed from hard materials such as cast iron, hard metals, aluminum oxide, silicon carbide, glass, DLC (diamond-like carbon) coated materials, and especially hard alloy steel. These are materials used for rails, guide rails, and support rails in stretching devices.

[0090] An example of the material properties of the guide rail configuration used in the test is as follows: Metal material symbol: 1.7225=42CrMo4V (tempered steel) Surface roughness: Rz5 (polished) Hardness: Surface >600-650 HV 0.5 Deep 0.2>400 HV 0.5 Center hardness 0.3>300+50 HV 0.5 Thermal expansion coefficient (20℃~200℃): 12.1 × 10⁻⁶ K⁻¹

[0091] Changes in the required amount of lubricant in response to changes in the characteristic coefficient Other characteristic coefficients that affect changes in lubricant consumption can be basically listed.

[0092] The following changes in lubricant consumption also occur with conventional graphite materials, but a particularly remarkable partial effect occurs when using the graphite material of the present invention. When using the graphite material of the present invention, preferably a further treated graphite material of the present invention, the total lubricant consumption required in all tests is reliably and clearly reduced compared to several conventional solutions, in particular, solutions using multiple PEEK sliding pieces.

[0093] Preferably in contact with guide rails / support rails (and / or control rails) made of steel or containing steel as the base material, the sliding piece of the present invention is used, as in the conventional invention, particularly in stretching devices.

[0094] Characteristic coefficient with respect to velocity In addition to the base values ​​shown in the table above, fuel consumption is added in proportion to the linearly increasing speed above the speed limit.

[0095] The following relationship was revealed during the test. F v =( v E- v G)[m / min]×0.3[%min / m]+1 F on the left side v This is the final velocity for a thin film thickness of 20 μm. v This is an auxiliary coefficient for lubrication oil consumption at E. Speed ​​limit v G depends on each chain device. The speed limit of chain device C used. v G is 300 m / min. Speed ​​limit v Up to G, a fixed oil consumption value is applied.

[0096] Load-dependent characteristic coefficient For thin films with a thickness exceeding 20 μm, an auxiliary force is generated due to the greater film thickness, and the coefficient F related to the film thickness th is generated. D As a result, oil consumption increases according to the following relationship: F D =(th-20)[μm]×1.5[% / μm]+1

[0097] Although Figure 6 (graph), which shows the amount of lubrication relative to the thin film thickness, may be perceived as missing or misleading, Table 7 shows the amount of lubricant to use when using graphite sliding pieces (C1, C2, C3, or C4).

[0098] Using the aforementioned compensation values, Figure 7 shows the daily consumption of lubricating oil or lubricant for a corresponding stretching device that uses a transport chain that moves longitudinally along a guide rail together with multiple sliding pieces.

[0099] Figure 7 shows the speed modifier coefficient F corresponding to the sliding pieces C1, C2, C3, and C4. v Load assist coefficient F D And oil consumption is shown. Depending on the sliding pieces C1 to C4, Figure 7 shows the speed auxiliary coefficient F v These are shown by a1, a2, a3, and a4, and the load assist coefficient F D This is shown in bl, b2, b3, and b4.

[0100] As is evident from Figure 7, the sliding piece of the present invention dramatically reduces the amount of lubricant required in the following cases. • When only the desired minimum porosity (8% or more, preferably less than 20%) is present, • In the sliding piece C3, a metal salt, preferably in the form of a metal phosphate, is used, and in the illustrated embodiment, aluminum phosphate is used as an auxiliary impregnation of the graphite body, and • When isostatic pressure is applied to the sliding piece prepared as described above.

[0101] The left side of Figure 8 shows the amount of lubricant consumed in a stretching device using a conventional sliding piece C1 (a sliding device made of PEEK), and the right side shows a preferred modified sliding piece of the present invention, labeled C4.

[0102] Reduced lubricant consumption of sliding contact pairs (guide rail - sliding piece) at high temperatures. Both conventional graphite sliding parts and the graphite sliding parts of the present invention perform better at higher operating temperatures. Sliding contact pair (guide rail - sliding piece) The fact that the coefficient of friction decreases is also noteworthy.

[0103] The temperature characteristics of the sliding piece are shown in Figure 9.

[0104] As the sliding contact pair F reaches higher temperatures, the coefficient of friction decreases further.

[0105] The friction coefficient shown in Figure 9 is divided into three categories: the first friction coefficient R1 from manufacturer data, the second friction coefficient R2 obtained from the test equipment, and the third friction coefficient R3 derived from a linear prediction of the first friction coefficient R1 and the second friction coefficient R2.

[0106] Reduced friction in used graphite components with polished surfaces of graphite sliding pieces, and a reduction in the amount of lubricant required. When compared with used graphite sliding pieces, topography reveals essential morphological differences. New graphite sliding pieces typically show differences of up to approximately 5 μm in the height cross-section of each surface material, while used graphite sliding pieces typically show differences of only about 1 μm in the height cross-section.

[0107] Therefore, the height morphology of the used sliding pieces is homogenized, and the leading edge of the graphite sliding surface is polished. Topographic homogenization contributes to and justifies a further reduction in oil consumption of used sliding pieces.

[0108] Multiple sliding pieces of the present invention Characteristics Table 4 is shown on the final page.

[0109] Table 4 shows the test values ​​of the sliding pieces in various test structures.

[0110] Using similar tests and similar testing equipment, the listed characteristics of the sliding pieces shown in specimens a, b, c, d, e, f, P, SFU, SR, and B21 were obtained. Specimens a-f, P, SFU, and SR are conventional sliding pieces. Specimen B21, the second from the leftmost column, shows the optimized sliding piece of the present invention.

[0111] The relevant values ​​for density, hardness, bending strength, compressive strength, corresponding modulus of elasticity, coefficient of thermal expansion, thermal conductivity, etc., can be understood from the characteristics of the conventional sliding piece and the sliding piece B21 of the present invention shown in Table 4.

[0112] The preferred characteristic value of the sliding piece of the present invention shown in the far right column E is, for example, 75% lower than the test value of the sliding piece B21 of the present invention shown in the column to the left, and there is room to exceed this test value by 25%.

[0113] The rightmost column E shows preferred range data indicating the preferred characteristics of the sliding piece of the present invention.

[0114] For example, it is clear that the porosity of 10% by volume shown in the sliding piece B21 of the present invention can vary in the range of 7.5% by volume to 12.5% ​​by volume.

[0115] Characteristic deviations may exist between the regions of each part indicated in the aforementioned range.

[0116] For example, each value shown as -≦25% may deviate from the optimal value, preferably being less than -25%, -24%, -23%, -22%, ... -5%, -4%, -3%, -2%, or -1%.

[0117] Furthermore, for example, values ​​indicated by +≦25% preferably do not exceed +25% for each value in the rightmost adjacent column, and in particular do not exceed +24%, +23%, +22%...+5%, +4%, +3%, +2%, or +1%.

[0118] The characteristic deviations, particularly in the porous material, are important. In some cases, values ​​other than those mentioned above may exceed or exceed the indicated range limits. [Table 4]

Claims

1. In a sliding part made of or primarily composed of a fiber-reinforced thermoplastic resin, particularly for a stretching device and / or a conveying chain, The sliding part has a U-shaped cross-section that forms a U-shaped recess. A sliding piece is fitted into a groove provided in the U-shaped recess of the sliding part, and is attached or fixed so that it moves along the guide rail, forming a sliding contact pair with the guide rail. The sliding piece contains porous graphite or electrographite having a porosity between 7.5% and 20% by volume, and the graphite particles that make up the starting material of the sliding piece have a particle size between 3 μm and 15 μm. The sliding part is characterized by being impregnated with an inorganic salt and / or having an inorganic salt embedded in it.

2. The sliding part according to claim 1, wherein the fiber-reinforced thermoplastic resin is fiber-reinforced polyetheretherketone.

3. The sliding part according to claim 1 or 2, wherein the sliding piece is fitted into a dovetail groove and attached or fixed.

4. The sliding part according to any one of claims 1 to 3, wherein the sliding piece has fine pores impregnated with an inorganic salt and / or embedded with an inorganic salt.

5. The sliding part according to claim 1, wherein the porosity of the sliding piece is 8% by volume or more and 20% by volume or less.

6. A sliding part according to any one of claims 1 to 5, wherein the particle size distribution of the graphite particles constituting the starting material of the sliding piece includes three types of particle size distributions: 14 μm to 18 μm for the 50% particle size d(50), 2 μm to 4 μm for the 10% particle size d(10), and 42 μm to 50 μm for the 90% particle size d(90).

7. The sliding part according to any one of claims 1 to 6, wherein 60% to 100% of the pores formed in the sliding piece are impregnated with oil.

8. The sliding part according to any one of claims 4 to 7, wherein at least the surface layer of the sliding piece is impregnated with an inorganic salt in a density distribution that differs by only 20% or less from complete impregnation of the inorganic salt.

9. The sliding part according to any one of claims 4 to 8, wherein the amount of inorganic salt impregnated or embedded is 1% by weight to 10% by weight.

10. A sliding part according to any one of claims 1 to 9, formed by isotropic pressure.

11. The sliding part according to any one of claims 1 to 10, wherein the sliding piece has a sliding surface with a maximum roughness of less than 5 μm in height deviation.

12. In a conveying device comprising a support structure and a chain device having a conveying chain, The conveyor chain comprises multiple chain links that are linked together, The chain ring comprises a gripping device for gripping a thin resin film and a connecting body for connecting the gripping device to the chain device. A conveying device characterized in that a U-shaped recess for engaging the sliding part described in any one of claims 1 to 11 is formed in the joint body.

13. The joint connecting the gripping device to the chain device has a sliding bottom plate positioned at the corresponding top of the sliding surface of the support rail, The sliding bottom plate contains porous graphite or electrographite having a porosity between 7.5% and 20% by volume. The conveying device according to claim 12, wherein the graphite particles that constitute the starting material for the sliding bottom plate have a particle size between 3 μm and 15 μm.

14. A stretching device or a conveying device for a stretching device having a sliding part as described in any one of claims 1 to 11.

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