A special cutting tool for PFA pipe material in high-clean environment

Abstract

The utility model relates to a kind of special cutting tools for high clean environment PFA tubular product, including main body shell and blade, main body shell includes left shell, right shell, left shell and right shell blade left and right are clamped in corresponding triangle groove. The blade tip angle is 22 °±1 °, and the blade edge has the microfillet reverse blunt processing of R0.05mm-R0.1mm;The blade is treated by vacuum deep cryogenic quenching using 440C stainless steel, and hardness is HRC58-62.Using PEEK or PVDF material is made to the main body shell, and it is treated by antistatic. Advantage is convenient to operate, can quickly cut tubular product, will not hurt, safe and reliable, and blade replacement is convenient, disassembly bolt can be opened, replacement is convenient;The combination of specific blade angle and microfillet blade edge, perfect adaptation PFA material characteristics, cutout inner and outer wall smooth without burr.

Description

Technical Field

[0001] This utility model relates to the technical field of ultra-high cleanliness fluid transport systems, specifically to a special manual tool for on-site cutting of PFA (perfluoroalkoxyalkane) pipes in the semiconductor manufacturing, biopharmaceutical, and high-purity chemical industries. Background Technology

[0002] In high-tech fields such as semiconductors and biopharmaceuticals, PFA tubing is the preferred choice for conveying ultrapure chemicals, pharmaceutical solutions, and specialty gases due to its excellent chemical inertness, high purity, and flexibility. However, the cutting process during its installation and maintenance faces unique challenges: 1) Extremely sensitive tubing walls: Any tiny scratch on the inner wall can become a breeding ground for particle residue or biofilm, leading to product contamination; 2) Special material processing properties: PFA is relatively soft and resilient, and using ordinary cutting tools can easily result in burrs, dents, or uneven cuts; 3) Stringent cleanliness requirements: The cutting tools themselves must prevent the release of metal particles and be easy to clean and disinfect.

[0003] Currently, on-site cutting is mostly done manually using general-purpose utility knives or scalpels, which has problems such as uncontrollable cutting depth, easy damage to the inner wall, poor cut quality, and the risk of introducing contamination. Some automated cutting equipment is complex in structure and expensive, and cannot meet the flexible and rapid construction needs on site. Therefore, there is an urgent need in this field for a cutting tool that can simultaneously meet the requirements of cleanliness, precision, efficiency, and portability, and is specifically designed for the characteristics of PFA pipes. Utility Model Content

[0004] The technical problem this invention aims to solve is to overcome the deficiencies of existing technologies and provide a cutting tool specifically designed for PFA pipes in high-cleanliness environments. This tool must achieve a smooth, burr-free cut on both the inner and outer walls in a single cut, fundamentally eliminating the risk of contamination introduced by the cutting operation, and possessing the characteristics of long lifespan, easy maintenance, and complete compatibility with cleanroom environments.

[0005] The technical solution adopted in this utility model is as follows: A specialized cutting tool for PFA pipes used in high-cleanliness environments includes a main body shell and a blade. The main body shell comprises a left shell and a right shell, which are symmetrically designed and both are square. Each shell has a U-shaped groove near one end on its inner side, and a triangular groove in the middle of their inner sides. A mounting hole is located near the long side of this triangular groove. The blade is trapezoidal in shape, with chamfered corners on both long sides and inclined U-shaped grooves on the inner sides of these corners, creating a U-shaped groove at each corner. Two hook-shaped cutting edges; a round hole in the middle of the blade; the left and right outer shells clamp the blades in corresponding triangular grooves, and screws are passed through the mounting holes of the left outer shell, the round hole of the blade, and the mounting hole of the right outer shell in sequence before being locked with nuts; the short side of the blade is mounted by the inclined side of the triangular groove; the U-shaped through grooves of the left and right outer shells, which are snapped together, form a cutting channel, and one corner of the hook-shaped cutting edge is inclined in the cutting channel, with the tip of the hook-shaped cutting edge located in the middle of the cutting channel and the tip pointing towards the entrance of the cutting channel.

[0006] The blade tip angle is 22°±1°, and the cutting edge has a micro-rounded chamfering treatment with R0.05mm-R0.1mm; the blade is made of 440C stainless steel and has undergone vacuum deep cryogenic quenching treatment, with a hardness of HRC58-62.

[0007] The blade has a double-ended asymmetrical structure, with one end being the main cutting edge at 22°±1° and the other end being an auxiliary trimming edge at 30°±1°.

[0008] The main body shell is made of PEEK or PVDF material and is treated with antistatic agents.

[0009] The two long corners of the triangular groove are connected to the two ends of the left and right outer shells, respectively.

[0010] The beneficial effect of this utility model is that, through the synergistic effect of the above features, a technical effect far exceeding that of simple superposition is produced: the pipe is inserted into the cutting channel and cut through the blade, which is convenient to operate and can quickly cut the pipe. Moreover, the blade is hidden inside the cutting channel and will not hurt people, making it safe and reliable. Furthermore, the blade is easy to replace; the main body shell can be opened by removing the bolts, making replacement convenient. The main body shell protects the blade and is also easy for personnel to operate by hand without hurting their hands.

[0011] Groundbreaking cutting quality: The combination of a specific blade angle and a micro-rounded cutting edge perfectly adapts to the properties of PFA material, achieving true "one-cut molding". The inner and outer walls of the cut are smooth and burr-free, fundamentally eliminating the risk of contamination and leakage caused by poor cuts.

[0012] Excellent cleanroom compatibility: The combination of high-hardness, corrosion-resistant blades and a cleanroom polymer housing ensures zero contamination contribution from the tool itself, fully meeting the highest cleanliness requirements of the semiconductor and pharmaceutical industries.

[0013] High reliability and predictability: All key parameters (22°±1°, R0.05-0.1mm, HRC58-62) have been verified and defined, making the technical effect stable, reliable and repeatable, breaking away from the traditional tool's reliance on operator experience. Attached Figure Description

[0014] Figure 1 This is a three-dimensional schematic diagram of the overall structure of this utility model (bolts and nuts are omitted in the figure).

[0015] Figure 2 This is a schematic diagram of the overall design of this utility model (the left outer shell is shown in perspective).

[0016] Figure 3 This is a schematic diagram of the left outer casing of this utility model after it has been opened. Figure 1 .

[0017] Figure 4 This is a schematic diagram of the left outer casing of this utility model after it has been opened. Figure 2 . Detailed Implementation

[0018] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0019] See attached document Figure 1-4A special cutting tool for PFA pipes in high-cleanliness environments includes a main shell (1) and a blade (2). The main shell (1) includes a left shell (11) and a right shell (12), which are symmetrically designed. Both the left shell (11) and the right shell (12) are designed as square bodies, with a U-shaped through groove (111, 121) on one end of their inner sides, and a triangular groove (112, 122) in the middle of their inner sides. A mounting hole is opened near the long side of each of the triangular grooves (112, 122). The blade (2) is designed as a trapezoid, with chamfered corners on the two long sides of the blade (2), and inclined U-shaped grooves (21) on the inner sides of the two long corners of the blade (2), thus forming two hook-shaped cutting edges (22) at the two long corners. A round hole is opened in the middle of the blade (2). The left outer shell (11) and the right outer shell (12) clamp the blade (2) in the corresponding triangular grooves (112, 122), and screws are passed through the mounting holes of the left outer shell (11), the round hole of the blade (2), and the mounting hole of the right outer shell (12) in sequence before being locked with nuts. The short side of the blade (2) is installed by the hypotenuse of the triangular grooves (112, 122). The U-shaped through grooves (111, 121) of the left outer shell (11) and the right outer shell (12) are fitted together to form a cutting channel (5). One corner of the blade (2) is a hook-shaped cutting edge (22) located obliquely in the cutting channel (5), and the tip (221) of the hook-shaped cutting edge (22) is located in the middle of the cutting channel (5) with the tip (221) facing the entrance side of the cutting channel (5).

[0020] The blade (2) has a tip (221) angle of 22°±1° and a chamfered edge with a radius of 0.05mm-0.1mm. The blade (2) is made of 440C stainless steel and has undergone vacuum deep cryogenic quenching treatment, with a hardness of HRC58-62.

[0021] The blade (2) has a double-headed asymmetrical structure, with one end being the main cutting edge (22a) at 22°±1° and the other end being the auxiliary trimming edge (22b) at 30°±1°.

[0022] The main body shell (1) is made of PEEK or PVDF material and is treated with antistatic agents.

[0023] The two long corners of the triangular groove (112, 122) are connected to the two ends of the left outer shell (11) and the right outer shell (12), respectively.

[0024] In use, the PFA pipe is inserted into the inlet of the cutting channel until it reaches the tip of the blade. The blade tip first inserts into the pipe, and the blade edge is angled to fit the pipe to be cut, making cutting easy and effortless, resulting in a smooth cut. After cutting, the pipe is pulled out from the outlet of the cutting channel. This invention achieves the above objectives through the following systematic design: 1. Material-based blade co-design: Geometric Design: The blade features a sharp design with a specific angle α, preferably 22°±1°. This angle represents the optimal balance point verified through creative experiments: if the angle is too small, the blade tip strength is insufficient, making it prone to chipping; if the angle is too large, the cutting resistance increases dramatically, easily compressing the soft PFA tube and causing cut deformation.

[0025] Edge treatment: The blade tip undergoes micron-level rounding and blunting (R0.05mm-R0.1mm). The core purpose of this is not to pursue "extreme sharpness", but to achieve a "scraping" rather than "wedge" cutting action: a) to prevent the extremely sharp blade tip from "biting" too deeply and scratching the inner wall; b) thus obtaining a smooth shear surface; c) to greatly reduce the generation of metal particles during cutting.

[0026] Materials and Processes: The blade is made of 440C high-carbon martensitic stainless steel and has undergone vacuum cryogenic hardening treatment, achieving a hardness of HRC58-62. This combination ensures extremely high wear resistance (long service life) while providing excellent corrosion resistance, avoiding the risk of tools rusting in humid cleanroom environments.

[0027] 2. Unique dual-head asymmetrical interchangeable structure: The blade is a double-ended design, but the functions of the two ends are asymmetrical. One end (end A) is the main cutting edge at a 22° angle, used for conventional precision cutting; the other end (end B) is an auxiliary trimming edge at a 30° angle, specifically used for micro-beveling of the inner wall of the cut pipe or trimming burrs, realizing the integration of cutting and trimming functions.

[0028] The main body shell is equipped with a precisely positioned rotating slot structure to ensure that the repeatability of the blade positioning after reversal is less than ±0.05mm, thereby ensuring the consistency of the cutting effect each time.

[0029] 3. Cleanroom compatibility design of the outer shell: The main outer shell is made of PEEK (polyetheretherketone) or PVDF (polyvinylidene fluoride) material through a one-time injection molding process. These materials themselves have extremely low leaching, excellent chemical corrosion resistance and mechanical strength, and fully comply with international cleanroom material standards such as SEMI.

[0030] The outer shell surface undergoes a permanent antistatic treatment to prevent static electricity from attracting particulate matter from the environment and to maintain the cleanliness of the tool itself.

[0031] 4. Precise depth control and integration: The main body shell is composed of symmetrically interlocking left and right shells. The bottom of the cutting channel formed on its inner side works together with the blade tip that extends into the channel to ensure that its extension amount accurately matches the wall thickness of the target PFA pipe, thereby controlling the cutting depth and preventing overcutting and damage to the opposite side of the pipe wall.

Claims

1. A specialized cutting tool for PFA pipes used in high-cleanliness environments, comprising a main body and a blade, characterized in that: The main body shell includes a left shell and a right shell, which are symmetrically designed. Both the left and right shells are square, and each has a U-shaped through groove near one end on its inner side. A triangular groove is also formed in the middle of the inner side of each shell, with a mounting hole near the long side of the triangular groove. The blade is trapezoidal, with chamfered corners on both long sides and inclined U-shaped grooves on the inner side of each corner, forming two hook-shaped cutting edges. A round hole is formed in the middle of the blade. The left and right shells clamp the blade in the corresponding triangular grooves, and screws are passed through the mounting holes of the left shell, the round hole of the blade, and the mounting hole of the right shell in sequence, and then locked with nuts. The short side of the blade is mounted by the inclined side of the triangular groove. The U-shaped through grooves of the left and right shells, which are snapped together, form a cutting channel. One corner of the blade's hook-shaped cutting edge is inclined within the cutting channel, and the tip of the hook-shaped cutting edge is located in the middle of the cutting channel, with the tip pointing towards the entrance of the cutting channel.

2. The cutting tool according to claim 1, characterized in that: The blade tip angle is 22°±1°, and the cutting edge has a micro-rounded chamfering treatment with R0.05mm-R0.1mm; the blade is made of 440C stainless steel and has undergone vacuum deep cryogenic quenching treatment, with a hardness of HRC58-62.

3. The cutting tool according to claim 2, characterized in that: The blade has a double-ended asymmetrical structure, with one end being the main cutting edge at 22°±1° and the other end being an auxiliary trimming edge at 30°±1°.

4. The cutting tool according to claim 1, characterized in that: The main body shell is made of PEEK or PVDF material and is treated with antistatic agents.

5. The cutting tool according to claim 1, characterized in that: The two long corners of the triangular groove are connected to the two ends of the left and right outer shells, respectively.

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