130 results about "Fiber fabrication" patented technology

The invention relates to the field of fiber manufacturing, in particular to a magnetic far-infrared dual-response fiber and a preparation method thereof.The magnetic far-infrared dual-response fiber comprises a polymer matrix and a magnetic far-infrared composite material evenly distributed in the polymer matrix; the magnetic far-infrared composite material comprises a nano ferroferric oxide core body and a zirconium carbide coating layer coating the core body, the interior of the nano ferroferric oxide core is doped with transition metal elements, so that the Curie point temperature of the nano ferroferric oxide core is 40-50 DEG C, and the surface of the nano ferroferric oxide core is modified by a cationic surface active agent to form a positive charge layer; hydroxyl is grafted on the surface of the zirconium carbide material. The Curie temperature of ferroferric oxide is precisely regulated and controlled to range from 40 DEG C to 50 DEG C through transition metal doping, a magnetic-far infrared synergistic energy transfer channel is designed and constructed in combination with a core-shell structure, intelligent response with the far infrared emissivity larger than or equal to 0.90 is achieved under body temperature triggering, and the functional strength and large-scale production feasibility are both achieved.

The invention relates to the technical field of key equipment spinning machines in the fiber manufacturing process, and discloses large-capacity wet-process horizontal spinning machine equipment which comprises a plurality of multi-spindle-position spinning machines arranged in the side direction, and each multi-spindle-position spinning machine is provided with a plurality of spinning spindle positions; a plurality of independent baths are arranged in the multi-spindle-position spinning machine, a spinning nozzle is arranged at one end of each independent bath, stock solution sprayed by the spinning nozzles is formed into fiber tows in the independent baths, and a horizontal steering guide roller and an independent steering guide wheel are arranged at the end, away from the spinning nozzles, of the multi-spindle-position spinning machine. A plurality of spinning machines are designed side by side, each spinning machine is provided with a plurality of spinning spindle positions, the productivity of single equipment is remarkably improved, and the operation difficulty and the equipment maintenance requirement are reduced through fine yarn guiding and shaping processes, so that the production efficiency is improved; the equipment is compactly arranged, occupies a small plant area, is convenient for tour inspection, and is more convenient to operate and maintain.

The invention belongs to the technical field of composite materials, and particularly relates to an environment-friendly composite material for pipelines and a preparation method thereof. The composite material comprises the following components in parts by weight: 75-90 parts of nylon 56, 10-20 parts of a maleic anhydride grafted polymer, 20-25 parts of flat glass fibers, 2-10 parts of fibrilia, 1-10 parts of inorganic nanoparticles, 1-4 parts of a coupling agent, 0-3 parts of a lubricant and 0-3 parts of an antioxidant. As the hemp fibers are good in flexibility, the flat glass fibers are of a special-shaped structure, mutual winding of composite fibers composed of the flat glass fibers and the hemp fibers is facilitated, and the dispersity of the flat glass fibers in the resin and the interface bonding force of the flat glass fibers and the nylon resin are improved. Compared with a single fiber reinforced composite material, the fiber reinforced composite material prepared from the flat glass fibers and the jute fibers has better balance in the aspect of mechanical properties, has better strength and improved toughness, and has wide application in the field of pipelines.

The invention relates to the related technical field of fiber manufacturing, in particular to a manufacturing process optimization method and system for antibacterial spandex fibers.The method comprises the steps that according to the performance requirements of antibacterial spandex fiber raw materials, a dispersing agent and a coupling agent are mixed in a gradient proportion, and stirring and dispersing indexes are set; after the obtained antibacterial master batch and spandex slices are subjected to vacuum drying, through the working procedures of a double-screw extruder and the like, multi-scale regulation and control are performed, various parameters are collaboratively optimized, and a manufacturing process parameter combination is determined. The technical problems that a single or extensive temperature control mode is difficult to depend on the thermal stability difference of antibacterial master batches and spandex slices, local overheating degradation or insufficient melting is prone to occurring, the mechanical property of fibers is affected, and the quality of finished products cannot be guaranteed are solved, the synergistic effect of sectional temperature control parameters and multi-stage stretching hot and cold circulation is achieved, and the production efficiency is improved. The technical effects that the material melting state and the fiber molecule orientation are accurately regulated and controlled, and the stability of the production process and the controllability of the finished product quality are improved through deep analysis of the coupling effect between parameters are achieved.

This invention discloses a doped and optimized ultra-low attenuation single-mode optical fiber, comprising a core, an inner cladding covering the core, and an outer cladding covering the inner cladding. The fiber fabrication method includes the following steps: 1) selecting a glass tube and a solid glass rod, and fitting the glass tube over the solid glass rod; 2) welding quartz rods to both ends of the glass tube; 3) placing the glass tube in a graphite furnace and doping the inner surface of the glass tube and the outer surface of the solid glass rod with alkali metals; 4) controlling the pressure and temperature inside the graphite furnace to fuse the glass tube and the solid glass rod into a single unit, forming the core; 5) forming an inner cladding around the core, followed by forming an outer cladding, to obtain the ultra-low attenuation single-mode optical fiber. The core obtained by this invention has the characteristics of large outer diameter, low hydroxyl content, high potassium concentration, and good longitudinal uniformity. By selecting appropriate inner and outer claddings to fabricate the optical fiber, the resulting fiber exhibits extremely superior ultra-low loss performance.

The utility model discloses composite simulated fur fiber spinning equipment, and relates to the field of polyester filament yarn production.According to the composite simulated fur fiber spinning equipment, a first raw material is metered into a first raw material and a second raw material with different deniers through two metering pumps in a feeding mechanism, the first raw material enters a first cavity through a pipeline and then is sprayed out through a first spinning part at the bottom of the first cavity, and the second raw material enters a second cavity through a pipeline; a second raw material enters a second cavity through the other pipeline and then is sprayed out through a second spinning part at the bottom of the second cavity, meanwhile, a second raw material is sprayed out through the other feeding mechanism, and due to the fact that the component sections of the first spinning part and the second spinning part are different, the denier sections of the sprayed first raw material and the second raw material are different. According to the utility model, two different denier cross sections can be sprayed in one material distributing assembly, so that the technical problem that the existing fiber manufacturing equipment cannot manufacture various different denier cross section fibers in the production process at the same time is solved, and the technical effect that the various different denier cross section fibers can be manufactured in the production process at the same time is achieved.

To provide an apparatus for manufacturing a glass fiber, capable of improving the quality of a cake by excellently keeping the incident angle of a glass strand to a traverse and a collet.SOLUTION: An apparatus 11 for manufacturing a glass fiber includes: a gathering shoe 14 for converging a plurality of glass filaments F to form a glass strand S; a collet 18 for winding the glass strand S; first and second tension adjustment bars 19 and 20 arranged between the gathering shoe 14 and the collet 18 and configured to control the tension of the glass strand S while sliding and contacting the glass strand S; a traverse 15 arranged between the second tension adjustment bar 20 and the collet 18 and configured to reciprocate the glass strand S; and a drive unit 17 for fluctuating a distance between the second tension adjustment bar 20 and the traverse 15 to the collet 18 while maintaining a positional relationship between the second tension adjustment bar 20 and the traverse 15.SELECTED DRAWING: Figure 1

The invention relates to the technical field of fiber manufacturing, and discloses glass wool blowing equipment based on multistage circular seam blowing, which comprises a shell, a mixing tank is fixedly mounted at the bottom of the shell, the shell is communicated with an inner cavity of the mixing tank, and two groups of vent pipe orifices are symmetrically formed in the outer wall of the bottom of the mixing tank. And an adjusting assembly for adjusting the size of the air injection circular seam in a multi-stage manner is rotationally mounted on the lower surface of the mixing tank. According to the equipment, through a twisting barrel, a telescopic sleeve, a first lip ring, a second lip ring and a third lip ring, the twisting barrel is rotated, the telescopic sleeve is driven to retract inwards or extend outwards through the interaction of the twisting barrel and threads of the telescopic sleeve, the telescopic sleeve drives the three sets of lip rings to synchronously move so as to change the distance between the lip rings and the inner wall of a shell, and multi-stage adjustment of the size of an air injection circular seam is achieved; and the production specification and variety range of the equipment is expanded.

The invention discloses composite simulated fur fiber spinning equipment and a preparation method thereof, and relates to the field of polyester filament yarn production.The first raw material is metered into a first raw material and a second raw material with different deniers through two metering pumps in a feeding mechanism, the first raw material enters a first cavity through a pipeline, and the second raw material enters a second cavity through a pipeline; a first raw material enters a first cavity through one pipeline and then is sprayed out through a first spinning part at the bottom of the first cavity, a second raw material enters a second cavity through the other pipeline and then is sprayed out through a second spinning part at the bottom of the second cavity, and meanwhile the second raw material is sprayed out through the other feeding mechanism. The first raw material and the second raw material which are sprayed out have different denier cross sections, so that spinning with two different denier cross sections can be realized in one material distributing assembly, and the technical problem that existing fiber manufacturing equipment cannot manufacture fibers with different denier cross sections in the production process at the same time is solved. The technical effect that various fibers with different denier cross sections can be manufactured simultaneously in the production process is achieved.

The invention discloses a high-strength, temperature-resistant and corrosion-resistant pollutant removal fiber and a self-heating melting type manufacturing method, and belongs to the technical field of manufacturing of filter material fibers for bag type dust collectors. At present, a functional filter material is mainly formed by carrying out a post-treatment process on the filter material, the invention provides a manufacturing method of a fiber with a pollutant removal function, and the fiber is prepared by wrapping a molten glass fiber for wire drawing with a catalyst with a denitration catalysis function and / or a dioxin removal function. A device adopted by the self-heating melting type manufacturing method specifically comprises a glass kiln, a spinneret bushing, powder supply equipment, a high-voltage direct-current power supply, a concentric-square-shaped powder supply cavity, impregnating compound coating equipment and a wire drawing guide wheel. The fiber prepared by the invention is used for preparing a filter material for a bag type dust collector, and can be used for simultaneously removing particulate matters and harmful substances such as nitrogen oxides and dioxin in flue gas.

A manufacturing method of a fiber includes: mixing and stirring a plurality of raw materials, to form a mixed liquid, where the plurality of raw materials includes dry copper nanopowder with a particle size not more than 48 nm, a fiber slurry, and an additive; drying the mixed liquid, to remove moisture of the mixed liquid and form a processed raw material; heating the processed raw material, to make the processed raw material be in a semi-molten state; electrifying the processed raw material in the semi-molten state, and then extruding at least one fibril from the processed raw material in the semi-molten state; stretching the at least one fibril; and performing cooling and shaping on at least one stretched fibril, to form a final fiber product.

1. Procedure 2. Method for manufacturing a fiber filter for a filter element (38) comprising at least the following process steps: - Providing a matrix (37), - Construction of a filter wall (34) with gradually increasing wall thickness of a filter medium (35) by flushing the fibers from a suspension into the matrix (37), - Termination of the coating process after obtaining a hollow filter body (36) consisting of the filter medium (35) of a predetermined wall thickness, in which the matrix (37) is at least partially embedded.

To provide a glass fiber manufacturing apparatus that reduces damages of a touch bar due to friction with a glass strand and enables a long-term use of the touch bar.SOLUTION: A glass fiber manufacturing apparatus 11 includes: a gathering shoe 14 for converging a plurality of glass filaments to form a glass strand S; a traverse 20 for reciprocating the glass strand S along a direction intersecting an extension direction of the glass strand S; a touch bar 21 extending along a reciprocating direction of the traverse 20 and constantly coming into slide contact with the glass strand S; a collet 16 for winding the glass strand S that has passed through the traverse 20; and a slide contact surface changing device 23 for changing a slide contact surface to the glass strand S in the touch bar 21 by rotating the touch bar 21.SELECTED DRAWING: Figure 1

The application provides a fiber process intelligent generation method and system based on a large language model, and belongs to the field of fiber material process design. The method comprises the following steps: designing standardized and analyzable fiber process coding rules; collecting fiber process original data, structurally splitting the original data according to the fiber process coding rules, and obtaining a fiber process training data set; training a preset fiber process large language model by using the fiber process training data set; and automatically generating fiber process codes meeting user requirements by using the trained fiber process large language model. The application breaks through the bottleneck of traditional fiber production relying on manual experience and lacking standardization, realizes the automatic generation of process schemes, and promotes the transformation of the fiber manufacturing industry to data-driven precision and intelligence.

The invention provides a para-aramid fiber processing method based on a microwave-infrared synergistic field effect, and relates to the technical field of high-performance fiber manufacturing. The treatment method comprises the following steps: carrying out heat treatment on undried para-aramid fibers to obtain para-aramid fibers subjected to heat treatment; wherein the heat treatment comprises microwave treatment, infrared treatment and gas quenching shock cooling treatment which are sequentially carried out. According to the processing method of the para-aramid fiber, a'microwave unwrapping-infrared orientation-shock cooling locking 'three-section energy field cooperation mechanism is adopted, gradient energy field time sequence action is performed on the undried fiber, and a'dynamic self-alignment effect' of a molecular chain is triggered, so that the elastic modulus and the orientation degree are remarkably improved.

The invention provides a fiber process intelligent generation method and system based on a large language model, and belongs to the field of fiber material process design. The method comprises the following steps: designing a standardized and analyzable fiber process coding rule; collecting original data of a fiber process, and performing structural splitting on the original data according to the fiber process coding rule to obtain a fiber process training data set; training a preset fiber process big language model by using the fiber process training data set; and automatically generating a fiber process code meeting user requirements by using the trained fiber process large language model. According to the method, the bottleneck that traditional fiber production depends on artificial experience and is insufficient in standardization is broken through, automatic generation of a process scheme is achieved, and the fiber manufacturing industry is promoted to be transformed to data-driven precision and intelligent transformation.

Recently, we have introduced 3D-micro-patterned pharmaceutical dosage forms for enhancing the efficacy, safety, convenience, and cost-effectiveness of drug therapies. Presented herein are an apparatus and a method for the manufacture of such dosage forms. The apparatus comprises at least a first extruder and at least a second extruder. The first extruder comprises an extruder channel having an exit port with a valve mated to an input port of a second extruder. Said second extruder comprises a translatable piston for extruding plasticized fiber at controlled speed. The apparatus further comprises a stage movable at the controlled speed of the extruded fiber for depositing said fiber to a three dimensional structural framework. The method includes extruding plasticized matrix from a first extruder into a second extruder, extruding said plasticized matrix from the second extruder through a fiber fabrication exit port at controlled speed to form extruded fiber, and depositing said extruded fiber onto a fiber assembling stage to form a three dimensional structural framework.

The present invention relates to an NCF composite fiber sheet and a method for manufacturing a wheel rim using same, wherein the sheet can, during the manufacture of a vehicle wheel rim using composite fibers, prevent the slipping of the composite fibers wound around a rounded portion of a mold and facilitate axial fiber arrangement.

The invention discloses a low-content high-performance CMC / PBST composite material as well as a preparation method and application thereof, the composite material comprises nano-crystalline cellulose (CMC), PBST, an antioxidant and a chain extender, and the nano-crystalline cellulose is obtained by sequentially crushing, dissolving and washing, acidifying, alkylating and drying plant fibers; based on the mass of PBST, the addition amount of the nanocellulose crystal is 0.5-5.0 wt%, the addition amount of the chain extender is 0-10 wt%, and the addition amount of the antioxidant is 0.5-2 wt%. The preparation method comprises the following steps: pre-treating the plant fibers; then, the pretreated plant fibers and the pretreated PBST granules are reacted, extruded and blended according to the proportion; under the condition of lower CNC content, the tensile strength and the elongation at break of the prepared composite material are respectively improved by 100-300% and 50-100% compared with those of pure PBST; the melt strength is also improved; the spinning process of the composite material is smooth, the performance of the obtained fiber basically meets the application requirements, and the composite material is expected to be applied to the field of fiber manufacturing.

The utility model relates to the technical field of ceramic fiber manufacturing, and particularly discloses a ceramic fiber liner calendering device which comprises a track plate. A calendering mold plate is connected in the track plate in a sliding manner; a limiting groove is formed in the calendering mold plate; a plurality of calendering grooves are formed in the limiting groove; a suspension is fixedly connected to the track plate; the suspension frame is fixedly connected with a hydraulic push rod; the movable end of the hydraulic push rod is fixedly connected with a middle block; a first fastener is inserted into an opening in the middle block; the first fastener is sleeved with a fixing plate; a rotating unit is arranged on the fixed plate; a hydraulic push rod pushes a rotating unit, a movable plate and a central shaft to descend, so that the central shaft and the inner surface of a limiting groove are in contact with a ceramic fiber gasket in a calendering groove for rotary calendering, the space in the calendering groove is filled, and the final size of the calendered ceramic fiber gasket is consistent; and a large number of ceramic fiber liners can be calendered at a time.

In the existing polyimide paper manufacturing method, there is a problem that polyimide fiber paper of a desired thickness close to an arbitrary value cannot be obtained. In addition, there is a problem that a process of imidizing polyimide precursors contained in a polyimide precursor or a polyimide solution dispersed in an intermediate structure body to the middle is required. A lamination manufacturing method of polyimide fiber paper is provided, which includes: a polyimide short fiber manufacturing step of manufacturing polyimide short fibers; a polyimide short fiber slurry manufacturing step of manufacturing a polyimide short fiber slurry composed of polyimide short fibers and a water-soluble polymer; a polyimide short fiber single intermediate manufacturing step of manufacturing a polyimide short fiber single intermediate by wet papermaking of the slurry; and a polyimide short fiber laminated intermediate manufacturing step of laminating a plurality of the polyimide short fiber single intermediates and performing heat and pressure to manufacture a polyimide short fiber laminated intermediate in which a water-soluble polymer residue remains.

The invention discloses a wire drawing auxiliary device and a wire drawing method, and relates to the technical field of optical fiber manufacturing and processing. The wire drawing auxiliary device comprises a bearing body which is provided with a bearing surface, and the bearing surface is provided with a center hole penetrating through the bearing body in the thickness direction of the bearing body; a first driving member; the extrusion pieces are arranged on the bearing surface at intervals along the periphery of the center hole, and each extrusion piece is provided with an extrusion surface facing the center line of the center hole; wherein the plurality of extrusion parts can be driven by the first driving part so as to be located at a first position or a second position, under the condition of the first position, the plurality of extrusion surfaces are close to the center line so as to define an extrusion space overlapped with the center hole, and under the condition of the second position, the plurality of extrusion surfaces are far away from the center line.

An electrophoresis device is provided. The device may include a tube having an introduction port for a sample, formed therein, the tube having an inner diameter of 100 μm or less, at least two spiral electrodes provided in the tube, and a power supply device that applies a voltage to the spiral electrodes.

To provide a method for producing a glass fiber by which a cake can be formed at a desired position in a collet.SOLUTION: The manufacturing method of the glass fiber includes a first winding step of forming a first cake 41 by winding a glass strand S formed by bundling glass filaments F by a gathering shoe 14 around a first collet 19 while traversing the glass strand S by a traverse 16, a replacement step of replacing the first collet 19 arranged at a winding position with a second collet after the completion of the first winding step, a second winding step of forming a second cake by winding the glass strand S around the second collet, and a control step of controlling a position of the gathering shoe 14 in its own axial direction in the second winding step based on a first measurement value A corresponding to a position of a first end part 41a of the first cake 41 and a second measurement value B corresponding to a position of a second end part 41b of the first cake 41 before the second winding step.SELECTED DRAWING: Figure 2

The utility model discloses a forming operation table for glass fiber products, and relates to the technical field of glass fiber manufacturing. The glass fiber product forming machine comprises a workbench, a through hole is formed in the workbench, a glass fiber product forming device is arranged at the top end of the workbench, a sealing cover is arranged at the top end of the workbench, a sealing door is arranged on the sealing cover in a sliding mode, a handle is arranged on one side of the sealing door, and a controller is arranged on one side of the sealing cover. The sealing cover and the sealing door are arranged, so that the sealing performance of processing can be ensured when glass fiber products are processed, impurities are prevented from diffusing outwards, the environment of a plant is ensured, and meanwhile, after processing is completed, the processing efficiency is improved. The air blowing component and the dust collection component can clean impurities on the surface of the glass fiber product under the cooperation effect, so that the glass fiber product does not need to be cleaned with time later, and the situation that cut small glass fiber impurities are sucked into the mouth and nose of a person to affect the body health of the person can be avoided.

The invention provides a preparation method of polyacrylonitrile carbon fibers, and belongs to the technical field of carbon fiber manufacturing. The preparation method of the polyacrylonitrile carbon fiber comprises the following steps: S1, providing a polyol compound, and then reacting a halogenating reagent with the polyol compound to enable at least part of hydroxyl in the polyol compound to be halogenated so as to obtain an initiator; s2, performing atom transfer radical polymerization reaction on an initiator, an acrylonitrile monomer and a catalyst in a solvent to obtain a polyacrylonitrile spinning solution; s3, carrying out spinning treatment on the polyacrylonitrile spinning solution to obtain a polyacrylonitrile precursor; s4, carrying out pre-oxidation treatment on the polyacrylonitrile precursor to obtain a polyacrylonitrile pre-oxidized fiber; s5, carbonizing the polyacrylonitrile pre-oxidized fibers to obtain polyacrylonitrile carbon fibers, and by means of the preparation method, the high-quality polyacrylonitrile pre-oxidized fibers which are high in pre-oxidation degree and few in skin-core layering defect can be prepared in the pre-oxidation stage.

This invention belongs to the field of micro / nano fiber fabrication technology. It discloses a vanadium dioxide-based micro / nano fiber temperature sensor and its fabrication method, including the following steps: (1) After removing a portion of the coating layer on the surface of a single-mode fiber, the fiber cladding in the area where the coating layer has been removed is etched or the area where the coating layer has been removed is heated and stretched using a melt stretching method to obtain a micro / nano fiber; (2) Vanadium metal is deposited onto the etched or stretched area of ​​the micro / nano fiber by magnetron sputtering to obtain a vanadium metal film with a nanometer-level thickness; (3) The deposited micro / nano fiber is annealed in an inert atmosphere to transform the vanadium metal film into an M-phase vanadium dioxide film, thereby obtaining a micro / nano fiber temperature sensor. This invention uses a method of magnetron sputtering to deposit a metal film followed by tube furnace annealing to obtain a vanadium dioxide thin film. The vanadium dioxide thin film can be prepared in a controllable manner, and the pure vanadium dioxide M-phase thin film can be prepared stably and repeatedly. Moreover, the thickness of the coating can be selected independently.

The utility model relates to the technical field of high-performance fiber manufacturing, and discloses a POD fiber shredding and forming device which comprises a workshop, the bottom of the workshop is fixedly connected with a working platform, the top of the working platform is fixedly connected with a discharging device, the top of the working platform is fixedly connected with a material fixing mechanism, and the top of the working platform is fixedly connected with a conveying mechanism. The top of the working platform is provided with a sliding mechanism, the top of the sliding mechanism is fixedly connected with a material taking mechanism, the top of the working room is fixedly connected with a cutting mechanism, the top of the working platform is fixedly connected with a material storage table, and the material taking mechanism comprises two fixing piles; the bottoms of the two fixing piles are fixedly connected to the tops of the two sliding mechanisms. According to the POD fiber cutting device, the cutting length of POD fiber raw materials is adjusted, diversified production process requirements are met, the lengths of produced POD fiber yarn sections meet the manufacturing standards of different products, the product quality is improved, and the production flexibility and adaptability are improved.

The invention relates to the technical field of fiber manufacturing, and discloses a differential modified polyester fiber production method capable of adding functional powder on line, which comprises the following steps: treating raw material melt, conveying polyester melt to a melt filter through a melt conveying pump to filter impurities, metering through a melt metering pump, outputting in two paths, premixing the functional powder, and drying to obtain the differential modified polyester fiber. Conveying the functional modified pre-melt to a dynamic mixer through a third melt metering pump for secondary mixing, and distributing the functional modified pre-melt to a static mixer through a melt three-way valve for tertiary mixing; after being mixed for the third time through the static mixer, the melts obtained after three times of mixing are accurately metered through a box metering pump and conveyed to a corresponding spinning box, spinning forming of the melts is conducted, the mixing proportion of the basic melts and the functional modified melts is adjusted in real time through cooperative control of a melt three-way valve and a three-stage metering pump, and the functional modified melts are obtained. Production switching can be achieved without shutdown, and powder with different functions can be directly added on line through on-line proportion regulation and dynamic mixing.

To provide a spinneret in which laminated plates with different thicknesses are laminated, capable of being repeatedly used in a fiber manufacturing process, having excellent handleability and capable of long-term usage, without reducing fiber productivity in industrial use.SOLUTION: A spinneret in which laminated plates with two or more types of different thicknesses are laminated is characterized in that a positioning pin hole of the plate with the least thickness (laminated plate B) is bored based on the following formula: 0.010≤(b / a-1) / HAB (Formula 1). Here, a and b represent a short axis (a) and a long axis (b) of a perpendicular cross section of the positioning pin hole, and b / a represents an aspect ratio of the positioning pin hole. HAB represents a thickness ratio of the thickest laminated plate (laminated plate A) to the laminated plate B.SELECTED DRAWING: Figure 3