A processing tool for a cylindrical spinneret hole of spunbond nonwoven fabric and a processing method thereof

Abstract

The present invention relates to a processing tool for a cylindrical spinneret hole of spunbond nonwoven fabric and a processing method thereof. The processing tool is made of cemented carbide and includes a drill shank and a drill rod arranged coaxially. The outer diameter of the drill rod does not exceed 3 mm, and a cutting portion is provided at its free end. A linear chip removal groove extending axially is provided on the cutting portion. The rake angle λ of the cutting edge of the cutting portion is designed with a negative angle, and the cutting edge is designed to be passivated. The flank angle k1 of the drill tip edge of the cutting portion is a ground circular flank angle of 10°, and the flank angle k2 of the tapered edge is a ground circular flank angle of 3° - 5°, so as to solve the problem that it is difficult for existing tools to process spinneret holes meeting the requirements.

Description

Technical Field

[0001] The present invention relates to the field of spunbond non-woven fabric production, and specifically relates to a processing tool for cylindrical spinneret holes of spunbond non-woven fabrics and a processing method thereof. Background Art

[0002] The main function of the spinneret is to extrude the polymer melt or solution through micropores to transform it into a fine stream with a specific cross-sectional shape, and form filaments through solidification by a solidification medium such as air or a coagulation bath. The spinneret is an essential high-precision part in a textile machine. The channels on the spinneret, as the carrier of the newly synthesized fiber, the quality of its processing is the key condition to ensure the quality of the fiber finished product.

[0003] The channel shapes of solution spinneret holes are usually cylindrical and irregular. The common irregular shapes are conical and hyperboloidal. The most common cross-sectional view of the cylindrical spinneret hole is shown in the appendix Figure 1 As shown, it is composed of a guide hole chamfer 11, a guide hole 12, a transition hole 13, and a filament outlet hole 14 in sequence from the inlet to the outlet direction.

[0004] Among them, the guide hole 12 is not only the flow guiding hole for spinning, but also the positioning hole for the filament outlet hole 14 with a high precision level (hole tolerance ±0.002 mm). The diameter of the guide hole 12 is usually between Φ1.6 and Φ2.5 mm, the hole depth is about 20 mm, the roughness cannot exceed Ra1.6, and there are also certain requirements for straightness.

[0005] The transition hole 13 is a transition hole connecting the guide hole 12 and the filament outlet hole 14, which affects the flow rate of the solution. The surface roughness of the hole needs to be within Ra0.8, the common angle is about 60°, and the angle tolerance is within ±1.5°.

[0006] The filament outlet hole 14 is the most precise part of the entire solution channel. The hole diameter is usually between Φ0.03 and Φ2.0 mm, the aspect ratio is usually between 5 / 1 and 10 / 1, the hole tolerance is ±0.002 mm, the roughness needs to be within Ra0.2, and the deviation of the coaxiality with the guide hole 12 does not exceed Φ0.08 mm.

[0007] Since the length of the guide hole exceeds 5 times the aspect ratio of the diameter, its processing belongs to the category of deep hole processing. Because the guide hole has requirements for both straightness and roughness, and the coaxiality requirement of the guide hole relative to the filament outlet hole is within Φ0.08 mm, the existing processing methods such as radial drilling machines, automatic drilling machines, electric discharge machining, deep hole processing, etc., the drills and processing methods used are difficult to process spinneret holes that meet the requirements in the processing of solution spinneret holes, and multiple clamping is required during the processing, which further amplifies the coaxiality tolerance. Therefore, the existing spinneret holes of the spinneret are all manually processed by technicians with rich experience, resulting in the quality of the spinneret holes being greatly affected by human factors.

[0008] In addition, many key tools for machining precision holes also need to be hand-ground by technicians with rich experience. For example, the half-moon drill for machining the transition holes of spinneret holes is hand-ground by technicians with rich experience to achieve relatively precise parameters such as its angle, the clearance angle of the blade back arc, and the radius value of the drill tip head. It is very difficult for technicians lacking experience to grind a half-moon drill that meets the requirements. The grinding of the extrusion needle (also known as the pear-shaped needle in the industry), which is the most precise tool for machining the smooth holes of the wire outlet holes, also relies on the experience of technicians. Moreover, the outer diameter tolerance value needs to be guaranteed within ±0.0015 mm, and even the grinding success rate of experienced technicians is very low. Summary of the Invention

[0009] The present invention aims to provide a machining tool for cylindrical spinneret holes of spunbond non-woven fabrics to solve the problem that existing tools are difficult to machine spinneret holes that meet the requirements.

[0010] The specific solution is as follows:

[0011] A machining tool for cylindrical spinneret holes of spunbond non-woven fabrics, which is made of cemented carbide material, includes a drill shank and a drill rod arranged coaxially. The outer diameter of the drill rod does not exceed 3 mm, and its free end has a cutting part. The cutting part has a linear chip removal groove extending axially. The rake angle λ of the cutting edge of the cutting part is designed with a negative angle, and the cutting edge is passivated; the flank angle k1 of the drill tip of the cutting part is a ground circular flank angle of 10°, and the taper flank angle k2 is a ground circular flank angle of 3° - 5°.

[0012] Further, the passivation value of the rake angle of the cutting edge is r0.01 mm.

[0013] Further, the drill tip angle of the cutting part is 140°, the eccentricity b of the drill tip center is 0.03 mm on both sides, and the through-center amount of the drill tip center is 0.02 mm on both sides.

[0014] Further, the length of the chip removal groove is half of the length of the drill rod.

[0015] Further, the cutting-off angle δ of the cutting part is 125°, and the cutting-in angle ε is 25° - 28°.

[0016] Further, the core thickness f of the cutting part is 32% of the outer diameter of the drill rod, and the peripheral edge width e is 7% of the outer diameter of the drill rod.

[0017] Further, the cutting edge of the cutting part also has an AlTiN coating.

[0018] The present invention also provides a machining method for cylindrical spinneret holes of spunbond non-woven fabrics, including the following processes:

[0019] Process 1: Clamp and fix the workpiece on a machining center with qualified precision. Then, use a spot drill and a deep hole drill to drill a positioning hole first, then a deep hole, and finally use a chamfering tool to machine the chamfer of the pilot hole.

[0020] Process 2: Rough machine the transition surface on the originally clamped workpiece with a rough machining straight flute drill, and the rough machining straight flute drill is any one of the above-mentioned machining tools.

[0021] Process 3: Rough machine a tapped hole on the originally clamped workpiece with a micro drill.

[0022] Process 4: Finish machine the transition surface on the originally clamped workpiece with a finish machining straight flute drill, and the finish machining straight flute drill is any one of the above-mentioned machining tools.

[0023] Process 5: Finish machine a tapped hole on the originally clamped workpiece with a micro reamer.

[0024] And before each next process, blow out the chips in the hole first.

[0025] Further, when the filament outlet hole of the cylindrical spinneret hole is less than 0.3 mm, there is also a process 21 between process 2 and process 3. The process 21 is to use a spot drill to make a fixed point on the rough machined transition surface.

[0026] The processing tool and processing method for the cylindrical spinneret hole of the spunbond nonwoven fabric provided by the present invention have the following advantages compared with the prior art:

[0027] 1. The chip removal groove of the processing tool provided by the present invention adopts a straight groove design on the premise of not affecting chip accommodation and chip removal to ensure the rigidity of the entire drill rod. The cutting edge adopts a negative rake angle design, followed by a post-passivation treatment and an AlTiN coating to make the cutting edge have excellent wear resistance, high strength, and chipping resistance. The drill tip is made into 140°, plus a transition diameter ΦD1, and the drill tip center over-center amount and eccentricity are designed to be within 0.03 mm, so as to realize the processing of a spinneret hole with a filament outlet hole of Φ0.15 mm on the premise of meeting the rigidity of the drill tip head, and stable processing of spinneret holes with a filament outlet hole specification above Φ0.2 mm.

[0028] 2. The processing method of the present invention can realize multiple processes on a machining center with only one clamping in place by means of the above-mentioned straight flute drill. The process is reliable, stable, and the position accuracy, roundness, straightness, and surface finish of the machined hole can all meet the requirements. It not only eliminates the influence of the manual link but also improves the production efficiency. Moreover, the straight flute drill also solves the problems of slipping and off-hole of the traditional half-moon drill in this process. The integrated machining process of reaming holes on the machining center is adopted during the process, reducing the additional extrusion hole process in the traditional process. Description of the Drawings

[0029] Figure 1Shows a schematic structural diagram of an existing cylindrical spinneret hole.

[0030] Figure 2 Shows a schematic diagram of the dimensions of a cylindrical spinneret hole in an embodiment.

[0031] Figure 3a , Figure 3b , Figure 3c Shows a schematic diagram of the processing process of Process 1.

[0032] Figure 3d Shows a schematic diagram of the processing process of Process 2.

[0033] Figure 3e Shows a schematic diagram of the processing process of Process 3.

[0034] Figure 3f Shows a schematic diagram of the processing process of Process 4.

[0035] Figure 4 Shows a schematic structural diagram of a straight flute drill.

[0036] Figure 5 Shows a schematic diagram of the straight flute drill's cutting part in the c direction.

[0037] Figure 6 Shows Figure 4 The cross-sectional view at B - B in

[0038] Figure 7 Shows Figure 5 The cross-sectional view at A - A in

[0039] Figure 8 Shows a partial enlarged view of the cutting part of the straight flute drill.

[0040] Figure 9 Shows a picture of the solution spinneret hole processed by the method of the present invention.

[0041] Figure 10 Shows a picture of the roughness measurement data of the solution spinneret hole processed by the method of the present invention. Detailed implementation manners

[0042] To further illustrate each embodiment, the present invention provides accompanying drawings. These accompanying drawings are a part of the disclosure of the present invention, mainly used to illustrate the embodiments, and can be combined with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0043] The present invention will now be further described in conjunction with the accompanying drawings and specific implementation manners.

[0044] The present invention provides a processing method for cylindrical spinneret holes of spunbond non-woven fabrics, comprising the following processes:

[0045] Process 1: Clamp and fix the workpiece on a machining center with qualified precision, then use a spot drill and a deep hole drill to drill a positioning hole first, then drill a deep hole, and finally use a chamfering tool to machine the chamfer of the guide hole.

[0046] Process 2: Rough machine the transition surface on the originally clamped workpiece with a rough machining straight groove drill.

[0047] Process 3: Rough machine the wire hole on the originally clamped workpiece with a micro drill.

[0048] Process 4: Finish machine the transition surface on the originally clamped workpiece with a finish machining straight groove drill.

[0049] Process 5: Finish machine the wire hole on the originally clamped workpiece with a micro reamer.

[0050] Among them, due to the problem of hole depth, debris is likely to be hidden at the bottom of the hole, which affects the processing quality of the subsequent processes. Before each subsequent process, it is necessary to blow off the debris in the hole.

[0051] In this embodiment, Figure 2 taking the machining of a cylindrical wire hole with a diameter of Φ0.5mm as an example to illustrate the overall machining scheme. The relevant dimensional parameters of the cylindrical wire hole are shown in the Figure 2 markings in. Refer to Figures 3a - 3e , the described cylindrical wire hole is processed by the following processes:

[0052] Process 1: Clamp and fix the workpiece 1 to be processed on a machining center. In this embodiment, the machining center used is a machine tool of model S500X1 of Brother Industries, Ltd., Japan. Then use a centering drill (specification: A130*D1.5*3L*3D*38L) to machine a fixed point 10 on the surface of the workpiece (refer to Figure 3a ). The machining of the fixed point 10 can be realized by using a tool that meets the requirements in the prior art. Therefore, the specific structure of the centering drill will not be described in detail here. The fixed point 10 is used to ensure the accuracy of the subsequent drill for drilling. After machining the fixed point 10, use a deep hole drill (specification: D2.0*27L*3D*60L) to machine a guide hole 12 with a diameter of Φ2.0mm. The depth of the guide hole 12 is 20.79mm (refer to Figure 3b ). The machining of the guide hole 12 can be realized by using a tool that meets the requirements in the prior art. Therefore, the specific structure of the deep hole drill will not be described in detail here. Finally, use a chamfering tool (specification: A60-6D-50L) to form a 60° chamfer 11 of the guide hole at the entrance of the guide hole 12 (refer to Figure 3c ). The machining of the chamfer 11 of the guide hole can be realized by using a tool that meets the requirements in the prior art. Therefore, the specific structure of the chamfering tool will not be described in detail here.

[0053] Process 2: Before the machining process 2, first blow out the debris in the pilot hole 12, and then use a 70° straight flute drill (specification: A70*D0.5*D1.9*15L*28L*3d*65L) to rough drill a 60° transition hole 13 (refer to Figure 3d ), and drill to a depth of 21.30 mm.

[0054] Process 3: Before the machining process 3, first blow out the debris in the pilot hole 12, and then use a micro drill (specification: D0.49*3.5L*D1.5*26L*3d*60L) to rough machine a wire hole 14 first (refer to Figure 3e ), and drill through the wire hole 14 through the workpiece 1.

[0055] Process 4: Before the machining process 4, first blow out the debris in the pilot hole 12, and then use a 60° straight flute drill (specification: A60*D0.43*D1.98*15L*26L*3d*65L) to finish drilling the 60° transition hole 13 (refer to Figure 3f ), and drill to a depth of 21.60 mm.

[0056] Process 5: Before the machining process 5, first blow out the debris in the pilot hole 12, and then use a micro reamer (specification: D0.5*3L*D1.5*26L*3d*60L) to finish machine the wire hole 14 on the originally clamped workpiece 1, that is, complete the machining of a complete solution spraying hole on the workpiece.

[0057] In the machining method provided in this embodiment, the main difficulty is that the straight flute drills in Process 2 and Process 4 cannot use the drills in the prior art. The reason is that the straight flute drills in the prior art are limited by the design of the cutting edge of the drill bit. Its cutting edge has poor rigidity and a thin edge. When machining deep holes with a large length-diameter ratio, chipping often occurs, resulting in the inability to machine a transition hole 13 that meets the requirements. The transition hole 13 is not only the transition hole connecting the pilot hole 12 and the wire hole 14, but also the fixed point when machining the wire hole 14. Therefore, when the machining accuracy of the transition hole 13 does not meet the requirements, it often leads to the coaxiality of the wire hole 14 and the pilot hole 12 exceeding the maximum deviation of Φ0.08 mm, resulting in the scrapping of the entire solution spraying hole.

[0058] Therefore, this embodiment also provides a straight flute drill that can meet the machining accuracy requirements and is not prone to chipping during the machining process. Refer to Figures 4 - 7, the straight flute drill is made of cemented carbide material (such as GU25UF), and it includes a drill shank 20 and a drill rod 21 arranged coaxially. The drill rod 21 has a smaller outer diameter than the drill shank 20. The outer diameter ΦD2 and the length of the drill rod 21 are determined according to the inner diameter of the pilot hole 12. Usually, the length of the drill rod 21 is 2 - 10 mm more than the depth of the pilot hole 12, and the outer diameter ΦD2 of the drill rod 21 is 0.02 - 0.05 mm smaller than the inner diameter of the pilot hole 12.

[0059] The free end of the drill rod 21 has a cutting part 210, and the cutting part 210 has a straight chip groove 211 extending along the axial direction (c direction). The length l1 of the chip groove 211 is half of the length l2 of the drill rod 21 (also called the clearance length), which can ensure both the chip removal capacity and the strength of the drill rod 21.

[0060] The diameter ΦD1 of the drill tip head is designed according to the diameter of the wire outlet hole 14. During finish machining, the diameter ΦD1 of the drill tip head is between -0.05 mm and -0.1 mm of the wire outlet hole diameter; during rough machining, the diameter ΦD1 of the drill tip head is ±0.02 mm of the wire outlet hole diameter.

[0061] The drill included angle θ is 140°. The taper angle α is determined according to the taper of the transition hole 13. For example, in this embodiment, the taper of the transition hole 13 is 60°, so the taper angle α during rough machining is 70°, and the taper angle α during finish machining is 60°. The eccentricity b of the drill tip center is 0.03 mm (bilateral), the over-center amount of the drill tip center is 0.02 mm (bilateral), the core thickness f is 32% of the outer diameter of the drill rod 21, and the peripheral edge width e is 7% of the outer diameter of the drill rod 21.

[0062] The edge of the cutting part 210 is designed with edge passivation to improve the surface finish of the peripheral wall of the transition hole 13. The cutting-out angle δ is 125°, and the cutting-in angle ε is 25° - 28°.

[0063] In addition, the flank angle k1 of the drill tip edge of the cutting part 210 is a ground circular flank angle of 10°, the taper flank angle k2 is a ground circular flank angle of 3° - 5°, and the rake angle λ of the edge is designed with a negative angle (in this embodiment, it is -5°) to strengthen the strength of the edge and prevent the problem of edge chipping during machining.

[0064] The chip evacuation groove 211 of the straight flute drill provided in this embodiment adopts a straight flute design on the premise of not affecting chip accommodation and evacuation to ensure the rigidity of the entire drill rod 21. The cutting edge adopts a negative rake angle design, followed by a post-treatment passivation process (passivation value r 0.01 mm), and then an AlTiN coating to endow the cutting edge with excellent wear resistance, high strength, and chipping resistance. The drill tip is made into a 140° angle, with a transition diameter ΦD1, and the center through-hole amount and eccentricity of the drill tip are designed to be within 0.03 mm (the transverse edge length of the drill tip can be obtained to be less than 0.06 mm), so as to realize the processing of the spinneret hole with a diameter of Φ0.15 mm while meeting the rigidity of the drill tip head, and stable processing of spinneret holes with a wire outlet hole diameter of more than Φ0.2 mm can also be achieved.

[0065] With the help of the above-mentioned straight flute drill, the processing method of this embodiment can complete multiple processes on a machining center with only one clamping, and the process is reliable, stable. The position accuracy, roundness, straightness, and surface finish of the processed holes can all meet the requirements. It not only eliminates the influence of the manual link but also improves the production efficiency. Moreover, the straight flute drill also solves the problems of slipping and off-hole of the traditional half-moon drill in this process. During the adoption process, an integrated processing procedure of reaming holes on a machining center is adopted, reducing the additional extrusion hole procedure in the traditional process.

[0066] Reference Figure 9 and Figure 10 , Figure 9 Figure [X] is a picture of the solution spinneret hole made by using the above tool and processing method. Figure 10 Figure [Y] is a picture of the roughness measurement data of the solution spinneret hole. The roughness of the wire outlet hole is detected by a KEYENCE model VK-X1100 instrument to be Ra0.094, meeting the industry requirement of Ra0.2.

[0067] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes can be made to the present invention in terms of form and details without departing from the spirit and scope of the present invention defined by the appended claims, and all of them fall within the protection scope of the present invention.

Claims

1. A processing method for cylindrical spinneret holes of spunbond non-woven fabric, characterized in that: It includes a machining tool, which is made of cemented carbide material and includes a drill shank and a drill rod arranged coaxially. The outer diameter of the drill rod does not exceed 3 mm, and its free end has a cutting part. The cutting part has a linear chip removal groove extending axially. The rake angle λ of the cutting edge of the cutting part is designed with a negative angle, and the cutting edge is passivated; the flank angle k1 of the drill tip of the cutting part is a ground circular flank angle of 10°, and the taper flank angle k2 is a ground circular flank angle of 3° - 5°; It also includes the following processes: Process 1: Clamp and fix the workpiece on a machining center with qualified precision, then use a spot drill and a deep hole drill to drill a positioning hole first, then drill a deep hole, and finally use a chamfering tool to machine the chamfer of the pilot hole; Process 2: Rough machine the transition surface on the originally clamped workpiece with a rough machining straight groove drill, and the rough machining straight groove drill is the above-mentioned machining tool; Process 3: Rough machine a tapped hole on the originally clamped workpiece with a micro drill; Process 4: Finish machine the transition surface on the originally clamped workpiece with a finish machining straight groove drill, and the finish machining straight groove drill is the above-mentioned machining tool; Process 5: Finish machine a tapped hole on the originally clamped workpiece with a micro reamer; And before each next process, blow out the debris in the hole first.

2. The processing method for cylindrical spinneret holes of spunbond non-woven fabric according to claim 1, characterized in that: The passivation value of the rake angle of the cutting edge is r0.01 mm.

3. The processing method for cylindrical spinneret holes of spunbond non-woven fabric according to claim 1, characterized in that: The drill tip angle of the cutting part is 140°, the eccentricity b of the drill tip center is 0.03 mm on both sides, and the over-center amount of the drill tip center is 0.02 mm on both sides.

4. The processing method for cylindrical spinneret holes of spunbond non-woven fabric according to claim 1, characterized in that: The length of the chip removal groove is half of the length of the drill rod.

5. The processing method for cylindrical spinneret holes of spunbond non-woven fabric according to claim 1, characterized in that: The cutting-out angle δ of the cutting part is 125°, and the cutting-in angle ε is 25° - 28°.

6. The processing method for cylindrical spinneret holes of spunbond non-woven fabric according to claim 1, characterized in that: The core thickness f of the cutting part is 32% of the outer diameter of the drill rod, and the peripheral edge width e is 7% of the outer diameter of the drill rod.

7. The processing method for cylindrical spinneret holes of spunbond non-woven fabric according to claim 1, characterized in that: The cutting edge of the cutting part also has an AlTiN coating.

8. The processing method for cylindrical spinneret holes of spunbond non-woven fabric according to claim 1, characterized in that: When the wire outlet hole of the cylindrical spinneret hole is less than 0.3 mm, there is also a process 21 between process 2 and process 3. The process 21 is to use a spot drill to make a fixed point on the rough machined transition surface.

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