A processing method for glass mold punch

Abstract

The present invention discloses a method for processing a glass mold punch, comprising the following steps: preliminary processing; laser cladding treatment; stress relief annealing; processing a stepped pre-hole; one-time turning of the glass contact surface; and inner cavity processing. The present invention utilizes a processing procedure design that sequentially processes the stepped pre-hole processing, one-time turning of the glass contact surface, and inner cavity processing after laser cladding treatment, effectively ensuring the concentricity of the punch's glass contact working outer cylindrical surface with the base, and the outer periphery of the punch's glass contact working outer cylindrical surface with the punch's inner cavity, with the error controlled within ±0.03mm. The one-time turning of the glass contact surface ensures that the wall thickness of the punch's glass contact working outer cylindrical surface is consistent and controlled within the range of 2 to 2.5mm, significantly improving the punch's machining dimensional stability and thermal conductivity. Laser cladding is used to increase the punch's surface hardness to over 60HRC, resulting in excellent overall performance and an ideal choice for glass mold punches used in small-mouth pressure-blowing processes.

Description

Technical Field

[0001] The invention relates to the field of glass molds, in particular to a processing method for a glass mold punch. Background Art

[0002] It's no secret that lightweight bottles are the future development direction of the glass bottle industry. For glass bottle manufacturers, this not only complies with national environmental protection policies and reduces carbon emissions, but also offers substantial economic benefits. For glass bottles meeting the same packaging requirements, while meeting equivalent physical and chemical specifications, lightweighting can reduce the weight of bottles produced using conventional blow-blow processes by approximately 40%. Furthermore, they also surpass conventional blow-blow processes in terms of appearance, quality, and production efficiency. This is a highly advantageous development for the entire glass packaging and related industries, including upstream mold manufacturers, glass factories themselves, and downstream transportation and beverage bottling industries.

[0003] For bottles with a neck finish less than 30mm, such as common beer, wine, and soy sauce bottles, traditional bottle-making methods typically rely on blow molding due to limitations in glass material properties, punch stroke, punch material, and processing technology. Lightweight bottles are primarily produced using the small-neck pressure-blowing process. The so-called small-neck pressure-blowing process uses the pressure-blowing method to produce glass packaging bottles with an inner diameter of less than 30mm and a height generally greater than 120mm. Recent improvements in bottle-making equipment, optimized glass raw material formulations, the development of new glass mold materials, and the application of high-end machining equipment in the glass mold processing industry have created the foundation for the small-neck pressure-blowing process. To conserve resources, reduce production costs, and increase profits, glass packaging manufacturers are eager to adopt the increasingly sophisticated small-neck pressure-blowing process. Consequently, the small-neck pressure-blowing process has experienced rapid growth in recent years.

[0004] The biggest difference between the small-mouth pressure-blowing process and the blow-blowing process in terms of the use of glass molds is that the small-mouth pressure-blowing process requires a "punch" to complete the molding of the bottle mouth and the uniform distribution of the prototype. Since the small-mouth pressure-blowing process requires much higher dimensional accuracy of the glass bottle prototype than the blow-blowing process, the punch in the glass bottle preparation process is not only a direct component of the glass bottle prototype molding, but also serves as a heat transfer medium for the conversion of the glass drop into the glass bottle prototype. Therefore, the driving force of the glass bottle prototype molding is mainly provided by the punch's stamping. The prototype's heat distribution and glass distribution must be uniform, otherwise it will affect the subsequent blow-blowing process.

[0005] The distribution of the glass blank is determined by the punch's dimensions and the relationship between the other components. The punch itself plays a crucial role in heat distribution. Specifically, the punch's high-frequency, periodic application of heat into the hot glass frit, exceeding 1100°C, transfers heat from the frit through the punch's surface to the punch's inner cavity. A punch cooler within the inner cavity then removes the heat from the punch and into the surrounding environment. Therefore, uniform temperature transfer from the punch is crucial; otherwise, not only will the quality of the glass blank be affected, but the punch itself can also deform and fail due to uneven heating.

[0006] The punch's machining dimensions, including the concentricity between the inner and outer circumferences and the consistency of its wall thickness, are key factors in determining its heat transfer. Furthermore, during operation, the punch's outer surface, aside from the base connecting it to other components, is largely encased in hot glass. This creates metallic friction between the punch and the hot glass, and creates considerable pressure. This operating environment is among the harshest of all glass mold components. Consequently, the punch's material and machining requirements are extremely high.

[0007] For example, Chinese patent CN 102626847 A discloses a method for processing a punch for a small-mouth pressure-blow process. The method uses a method of spray-welding nickel-based alloy powder on the surface. However, the industry's production practices in the past two years have generally recognized that spray-welding nickel-based alloy powder on the outer circle cannot achieve the wear resistance and high-temperature resistance required by the small-mouth pressure-blow process for bottle making. In addition, the disclosed processing method cannot guarantee the concentricity of the punch outer circle and the inner cavity. Summary of the Invention

[0008] The present invention solves the above-mentioned shortcomings of the glass mold punch for small-hole pressure-blowing in the prior art by providing a processing method for the glass mold punch.

[0009] In order to solve the above technical problems, the present invention provides a method for processing a glass mold punch, comprising the following steps:

[0010] (1) Primary processing: one end of the selected cylindrical bar is turned into a base, and the other end is processed into a punch glass contact working surface to be laser clad, thereby obtaining a semi-finished glass mold punch;

[0011] (2) Laser cladding treatment: using nickel-based tungsten carbide alloy powder as raw material, laser cladding the punch glass contact working surface processed in step (1) to form a nickel-based tungsten carbide alloy powder layer;

[0012] (3) Stress relief annealing: Stress relief annealing is performed on the semi-finished glass mold punch after laser cladding to remove the stress produced by laser cladding welding;

[0013] (4) Processing a stepped pre-hole: Clamp one end of the laser cladding layer on the working surface of the punch glass, first semi-finish turning the outer circle of the base to the design required size, and leaving a margin, then drill a stepped pre-hole inward from the end surface of the base, and process a process thread on the first stepped hole of the base;

[0014] (5) One-time turning of the glass contact surface: using the process thread processed in step (4) to thread the glass mold punch semi-finished product to the processing fixture, and then performing one-time turning of the glass contact surface on the outer circle of the nickel-based tungsten carbide alloy powder layer and the outer circle of the base coated thereon to ensure the concentricity of the entire outer circle surface of the punch;

[0015] (6) Inner cavity processing: Clamp the outer circle of the base and bore and mill the stepped pre-hole processed in step (4) into an inner cavity, so that the outer periphery of the punch glass contacting the working outer circle surface is consistent with the concentricity of the inner cavity.

[0016] In a preferred embodiment of the present invention, the glass mold punch includes an integrally connected base and a punch glass contact working surface, the base and the punch glass contact working surface have a connected punch inner cavity, and the periphery of the punch glass contact working surface is laser-clad with a nickel-based tungsten carbide alloy powder layer.

[0017] In a preferred embodiment of the present invention, in step (2), the process conditions of the laser cladding are as follows: the focal spot is φ5 mm, the distance between the powder feeding nozzle and the cladding surface is controlled to be 18 to 20 mm, the laser output power is 3000 to 3500 W, the powder feeding amount is 28 to 35 g / min, the protective gas is argon, the argon flow rate is 8 to 12 L / min, the trajectory parameters of the trajectory mode of the cladding powder feeding nozzle are a linear speed of 2 to 4 mm / s, and a step interval of 1.5 to 2.0 mm.

[0018] In a preferred embodiment of the present invention, in step (2), the nickel-based tungsten carbide alloy powder includes the following components in percentage by mass: C 0.8%, Cr 15%, B 3.0%, Si 4.0%, Fe 3.5%, W 16.5, and the balance is Ni.

[0019] In a preferred embodiment of the present invention, in step (3), the process conditions of the stress relief annealing are: heating from room temperature to 600-650°C at a heating rate lower than 100°C / h, maintaining the constant temperature for 3-4 hours, then cooling to 200-250°C at a rate lower than 30°C / h, taking out of the furnace, and air cooling to room temperature.

[0020] In a preferred embodiment of the present invention, in step (5), the method for one-time turning of the glass contact surface is: using a cubic boron nitride turning tool to perform one-time turning of the glass contact surface on the laser-clad nickel-based tungsten carbide alloy layer and the entirety including the outer circle of the base.

[0021] In a preferred embodiment of the present invention, the thickness of the nickel-based tungsten carbide alloy layer after the one-time turning of the glass contact surface is 0.4-0.6 mm.

[0022] The beneficial effects of the present invention are as follows: a processing method for a glass mold punch of the present invention is designed to process a stepped pre-hole, a one-time turning glass contact surface and an inner cavity in sequence after laser cladding treatment, which effectively increases the concentricity of the punch glass contact working outer cylindrical surface and the base, as well as the concentricity of the punch glass contact working outer cylindrical surface and the punch inner cavity, and controls the error within ±0.03mm; the one-time turning of the glass contact surface makes the wall thickness of the punch glass contact working surface consistent and controlled within the range of 2 to 2.5mm, thereby significantly improving the stability of the punch's machining dimensions and improving its thermal conductivity; the laser cladding is used to make the punch surface hardness reach above 60HRC; the prepared punch has excellent comprehensive performance and is an ideal choice for glass mold punches for small-mouth pressure-blowing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the finished product structure of a preferred embodiment of a glass mold punch prepared by the present invention;

[0024] Figure 2 This is a schematic diagram of the semi-finished structure of the glass mold punch after the stepped hole is processed in the present invention;

[0025] The components in the accompanying drawings are marked as follows: 1. base, 2. punch glass contact working outer cylindrical surface, 3. punch inner cavity, 4. nickel-based tungsten carbide alloy powder layer, 5. process thread, 11. end face. DETAILED DESCRIPTION

[0026] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0027] See also Figure 1 and Figure 2 , embodiments of the present invention include:

[0028] Example 1

[0029] The present invention discloses a method for processing a glass mold punch. The glass mold punch is a glass mold punch for a small-mouth pressure-blowing method, comprising a base 1 and a punch glass contact working outer circular surface 2 that are integrally connected. The base 1 and the punch glass contact working outer circular surface 2 are connected with a punch inner cavity 3. The outer periphery of the punch glass contact working outer circular surface 2 is laser-clad with a nickel-based tungsten carbide alloy powder layer 4. Figure 1 As shown; the processing method of the glass mold punch comprises the following steps:

[0030] (1) Material selection: According to the drawing requirements, select a No. 40 carbon steel cylindrical bar that meets the size as the base material of the small-mouth pressure-blowing punch;

[0031] The dimensions of the No. 40 carbon steel cylindrical bar are as follows: the total length is 6 mm longer than the finished product of the small-mouth pressure-blowing punch, the single side is 3 mm longer, the diameter is 6 mm larger than the maximum diameter of the finished product of the small-mouth pressure-blowing punch, and the single side is 3 mm longer;

[0032] (2) Primary processing: Clamp one end of the carbon steel cylindrical bar and turn the other end into a base; leave a 1mm margin during the processing to prepare for deformation after stress relief annealing and for further finishing;

[0033] Clamping the base 2, the other end of the carbon steel cylindrical bar is processed to form an area where the nickel-based tungsten carbide alloy powder needs to be laser clad, i.e., the punch glass contacts the working outer cylindrical surface 1, to obtain a semi-finished small-mouth pressure-blown glass mold punch;

[0034] (2) Laser cladding treatment: using a robot laser cladding device, the base 1 is clamped by a three-jaw chuck with self-centering and stepless speed change, and the end face 11 of the base 1 is used as the height reference. The three-jaw chuck is set to rotate at a speed of 200 r / min, and a laser powder spraying nozzle is controlled by a 6-axis robotic arm to laser clad the outer surface of the punch glass contact working outer circle 1 of the pre-processed small-mouth pressure-blowing punch semi-finished product with nickel-based tungsten carbide alloy powder to obtain a laser cladding layer 4;

[0035] The process parameters of the laser cladding are as follows: the focal spot is φ5 mm, the distance between the powder feeding nozzle and the cladding surface is controlled to be 18-20 mm, the laser output power is 3000-3500 W, the powder feeding amount is 28-35 g / min, the protective gas used is argon, the flow rate is 8-12 L / min, the trajectory parameters of the cladding powder feeding nozzle are a linear speed of 2-4 mm / s, and a step interval of 1.5-2.0 mm;

[0036] The formula of the nickel-based tungsten carbide alloy powder is as follows: calculated by mass percentage, it includes: C 0.8%, Cr 15%, B 3.0%, Si 4.0%, Fe 3.5%, W 16.5%, and the balance is Ni.

[0037] (3) Stress relief annealing: Stress relief annealing is performed on the semi-finished small-mouth pressure-blowing punch after laser cladding to remove the stress produced by laser cladding welding; the process conditions of the stress relief annealing are: heating from room temperature to 600-650°C at a heating rate of less than 100°C / h, maintaining the constant temperature for 3-4 hours, then cooling to 200-250°C at a rate of less than 30°C / h, taking out of the furnace, and air cooling to room temperature;

[0038] (4) Machining a stepped pre-hole: Clamp the punch glass contacting the working outer cylindrical surface 2, i.e., the end with the laser cladding layer 4, and then semi-finish the outer cylindrical surface of the base 1 to the design requirements, leaving a 0.2mm margin; Starting from the end face of the base 1 in the direction of the punch glass contacting the working outer cylindrical surface 2, drill a stepped pre-hole in the inner cavity of the semi-finished punch of the small-mouth pressure-blown glass mold, and leave an appropriate boring and finishing margin, and then machine the process thread 5 on the first stepped hole of the base 1, as shown in FIG. Figure 2 As shown;

[0039] (5) One-time turning of the glass contact surface: using the process thread 5 as the turning reference, tighten the semi-finished product of the small-mouth pressure-blown glass mold punch to the stud fixture of the turning tool in the opposite direction of the turning force, and use a cubic boron nitride turning tool to perform one-time turning of the glass contact surface on the laser-clad nickel-based tungsten carbide alloy layer and the entire body including the outer circle of the base, so as to avoid the concentricity deviation between the punch base 1 and the laser-clad layer 4 caused by secondary clamping and turning; in addition, the cubic boron nitride turning tool processes the 60HRC super-hard nickel-based tungsten carbide material cladding layer to ensure smooth turning and ensure that the surface roughness after turning meets the requirements; the thickness of the nickel-based tungsten carbide alloy layer after the one-time turning of the glass contact surface is 0.5mm;

[0040] (6) Inner cavity processing: Clamping the base 1, boring and milling the stepped pre-hole processed in step (4) to ensure the concentricity of the outer periphery of the punch glass contacting the working outer cylindrical surface 2 of the small-mouth pressure-blown glass mold punch and the inner cavity;

[0041] (7) Post-processing: Polish and grind the semi-finished products after machining to complete the production and processing of small-mouth pressure-blown glass mold punches.

[0042] The small-mouth pressure-blowing glass mold punch prepared by the above method was tested. The hardness of the punch glass contact working outer cylindrical surface 2 with a nickel-based tungsten carbide alloy powder layer 4 laser-clad on its surface reached above 60HRC; the concentricity of the punch glass contact working outer cylindrical surface 2 and the base 1, as well as the concentricity error between the outer periphery of the punch glass contact working outer cylindrical surface 2 and the punch inner cavity 3 were both within ±0.03mm; the wall thickness of the punch glass contact working outer cylindrical surface 2 was 2~2.5mm; the roughness of the nickel-based tungsten carbide alloy powder layer 4 laser-clad reached Ra of 0.1~0.2μm; and it met the use requirements of the small-mouth pressure-blowing bottle making process.

[0043] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for processing a glass mold punch, characterized in that: The steps include: (1) Primary processing: one end of the selected cylindrical bar is turned into a base, and the other end is processed into a punch glass contact working surface to be laser clad, thereby obtaining a semi-finished glass mold punch; (2) Laser cladding treatment: using nickel-based tungsten carbide alloy powder as raw material, laser cladding the punch glass contact working surface processed in step (1) to form a nickel-based tungsten carbide alloy powder layer; (3) Stress relief annealing: Stress relief annealing is performed on the semi-finished glass mold punch after laser cladding to remove the stress produced by laser cladding welding; (4) Processing a stepped pre-hole: Clamp one end of the laser cladding layer on the working surface of the punch glass, first semi-finish turning the outer circle of the base to the design required size, and leaving a margin, then drill a stepped pre-hole inward from the end surface of the base, and process a process thread on the first stepped hole of the base; (5) One-time turning of the glass contact surface: using the process thread processed in step (4) to thread the glass mold punch semi-finished product to the processing fixture, and then performing one-time turning of the glass contact surface on the outer circle of the nickel-based tungsten carbide alloy powder layer and the outer circle of the base coated thereon to ensure the concentricity of the entire outer circle surface of the punch; (6) Inner cavity processing: Clamp the outer circle of the base and bore and mill the stepped pre-hole processed in step (4) into an inner cavity, so that the outer periphery of the punch glass contacting the working outer circle surface is consistent with the concentricity of the inner cavity.

2. The method for processing a glass mold punch according to claim 1, characterized in that: The glass mold punch includes an integrally connected base and a punch glass contact working surface, wherein the base and the punch glass contact working surface have a connected punch inner cavity, and the periphery of the punch glass contact working surface is laser-clad with a nickel-based tungsten carbide alloy powder layer.

3. The method for processing a glass mold punch according to claim 1, characterized in that: In the step (2), the process conditions of the laser cladding are as follows: the focal spot is φ5mm, the distance between the powder feeding nozzle and the cladding surface is controlled to be 18-20mm, the laser output power is 3000-3500W, the powder feeding amount is 28-35g / min, the protective gas is argon, the argon flow rate is 8-12L / min, the trajectory parameters of the trajectory mode of the cladding powder feeding nozzle are a linear speed of 2-4mm / s, and a step interval of 1.5-2.0mm.

4. The method for processing a glass mold punch according to claim 1, characterized in that: In the step (2), the nickel-based tungsten carbide alloy powder includes the following components in percentage by mass: C 0.8%, Cr 15%, B 3.0%, Si 4.0%, Fe 3.5%, W 16.5%, and the balance is Ni.

5. The method for processing a glass mold punch according to claim 1, characterized in that: In the step (3), the process conditions of the stress relief annealing are: heating from room temperature to 600-650°C at a heating rate lower than 100°C / h, maintaining the constant temperature for 3-4 hours, then cooling to 200-250°C at a rate lower than 30°C / h, taking out of the furnace, and air cooling to room temperature.

6. The method for processing a glass mold punch according to claim 1, characterized in that: In the step (5), the method for one-time turning of the glass contact surface is: using a cubic boron nitride turning tool to perform one-time turning of the glass contact surface on the laser-clad nickel-based tungsten carbide alloy layer and the entire body including the outer circle of the base.

7. The method for processing a glass mold punch according to claim 6, characterized in that: The thickness of the nickel-based tungsten carbide alloy layer after the one-time turning of the glass contact surface is 0.4-0.6 mm.

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