JP-2026076148-A - Traceable gasket and compression packing materials

Abstract

[Problem] To provide a gasket that contains traceable particles that hold information about the manufacturing of the material, which can be used to trace its origin, and which can form gaskets used for sealing flanged fittings in the food and beverage industry, or compression packings used for sealing around machinery such as valve shafts and pump shafts. [Solution] A gasket having filaments, comprising a polytetrafluoroethylene (PTFE) matrix and tracer particles 110 selected from fluorescent dye molecules and fluorescent dyes, wherein the tracer particles absorb light and emit light of a specific wavelength detectable by a microscope equipped with a filter set for the specific tracer particles, and the tracer particles are distributed throughout the matrix. [Selection Diagram] Figure 3

Inventors

• バロッソ、カルロス、ダニエル、ブラガ ギラオ
• デイ、クリストファー、ルイス
• ヴェイガ、ホセ、カルロス、カーバルホ
• クリステロ、ジョスマー バルファルディ
• リッグス、ロバート、アダム
• ヴァッレ、アンドレ、カルロス デ アゼヴェド

Assignees

• ティアディット エヌ．エー．、インク．

Dates

Publication Date

20260511

Application Date

20251216

Priority Date

20200727

Claims (11)

1. It is a filament, It comprises a polytetrafluoroethylene (PTFE) matrix and tracer particles selected from fluorescent dye molecules and fluorescent dyes, The tracer particles absorb light and emit light of a specific wavelength detectable by a microscope equipped with a filter set for the particular tracer particles, and the tracer particles are distributed throughout the matrix, forming filaments.
2. In the filament according to claim 1, further, A filament having a mineral or synthetic filler selected from barite, graphite, and carbon black.
3. It is a composite yarn, It comprises a flexible graphite tape and a PTFE filament having a PTFE matrix and tracer particles, The flexible graphite tape is reinforced with PTFE filaments by a method selected from the steps of weaving the flexible graphite tape and the PTFE filaments in symmetrical directions, twisting them, or arranging them, thereby forming a composite yarn.
4. A compression packing for sealing valve shafts and pump shafts, comprising a PTFE matrix and filaments containing tracer particles.
5. A compression packing according to claim 4, comprising a core and an outer layer, wherein the core and the outer layer each have one or both of the following: a filament containing a PTFE matrix and tracer particles, and a flexible graphite tape-reinforced filament containing a PTFE matrix and tracer particles.
6. In the compression packing according to claim 4, further, A compression packing having at least one of a lubricant and a blocking agent.
7. The compression packing according to claim 6, wherein the lubricant is one or more of the following: graphite, paraffin, silicone, mineral oil, grease, animal fat, vegetable oil, petroleum-based or mineral-based lubricant, synthetic lubricant, chlorofluorocarbon, mica, tungsten disulfide, and molybdenum disulfide.
8. A compression packing according to claim 6, wherein the lubricant and blocking agent are added in a form impregnated with PTFE.
9. In the compression packing according to claim 4, further, A compression packing having an activated corrosion inhibitor selected from zinc and zinc wire.
10. In the compression packing according to claim 4, further, Compression packing having a passive corrosion inhibitor selected from phosphates, barium molybdate, and sodium molybdate.
11. It is a filament, A polytetrafluoroethylene (PTFE) matrix and phosphor tracer particles, wherein the tracer particles are distributed throughout the matrix, absorb light in the invisible wavelength range, and emit light in the visible range; Porous silicon tracer particles distributed throughout the matrix, wherein the porous silicon tracer particles have synthetic nanopores, and the nanopores reflect visible white light, and/or A filament comprising microdot tracer particles distributed throughout the matrix, wherein the microdot tracer particles are identifiable by microscopic examination.

Description

This application claims the filing date benefit and priority of U.S. Application No. 16/939,786, filed on 27 July 2020 and issued as U.S. Patent No. 10,989,304, the entire disclosure thereof being incorporated herein by reference. This disclosure relates to sealing materials such as gaskets for sealing flanged joints and compression packings for sealing around valve shafts, pump shafts, and similar mechanical elements. Sealing materials include static seals, such as gaskets, and dynamic seals, such as compression packings. Generally, gaskets are installed between flat surfaces, while compression packings are positioned around mechanical elements such as valve shafts and pump shafts. A gasket is a material widely used in various industrial fields as a sealant for flanged joints. Gaskets are designed to fill the gaps between two or more mating surfaces of machine parts, preventing leaks and inflows. They can also withstand harsh conditions such as load, temperature, and pressure. Polytetrafluoroethylene (PTFE) polymer is the most widely used gasket material. PTFE is well-known for its excellent chemical and mechanical properties. It exhibits superior performance from low to high temperatures, has a low coefficient of friction, excellent electrical insulation, and is resistant to chemical attack. Furthermore, it is easy to enhance several functions by combining it with other substances such as fillers and additives. However, the use of gasket materials in certain industries, such as the food and beverage industry, is not so straightforward. In such applications, these materials are exposed to varying temperatures and pressures, can undergo chemical attacks, and can degrade over time. Even worse, they can contaminate process flows. Therefore, in these industries, a comprehensive safety strategy to avoid contamination is required, and the aforementioned gasket materials must be carefully selected. Therefore, the gasket material must meet the requirements of numerous standards and regulatory guidelines. For example, in the United States, the Food and Drug Administration (FDA) and the National Sanitation Foundation (NSF) play a crucial role in managing the safety and quality of consumer products. Both organizations provide rigorous standards and testing for the approval of materials that come into contact with food and beverages during processing, packaging, or storage. For example, two common standards used for testing PTFE gasket materials are FDA 21 CFR 177.1550 "Perfluocarbon Resins" and NSF/ANSI 51-2019 "Food Equipment Materials." Tests under these standards certify and guarantee that contaminants from the gasket material are below the maximum permissible limits. In addition to compliance with guidelines, it is desirable to have means to indicate that the gasket material, if it degrades in any way and needs to be removed, is contaminating the process flow. Therefore, several tools, such as metal detectors and visual inspections, are provided to track the purity of the product along the process flow and to identify foreign matter from broken machinery and processing equipment parts. Traceability of foreign objects along the aforementioned process flow ensures the safety and quality of food and beverage products and prevents contamination. Foreign object contamination incidents typically lead to production line shutdowns, wasting enormous time and money, making this crucial. Therefore, machine parts and objects that can be detected if the process flow is contaminated in any way are of great value. Therefore, conventional methods have involved changing the color of the gasket material or incorporating ferromagnetic additives. However, both methods have limitations in accurately tracking the source of contamination. First, the first method can only identify foreign matter if it is near the surface, and this identification may only occur after a large number of products have been destroyed, resulting in wasted time and money. The second solution, conversely, has the limitation that the additive may be indistinguishable from its surroundings, making it difficult to truly determine whether the contamination is due to a failure in the gasket material or to other components in the process flow. Furthermore, ferromagnetic additives may be associated with oxidation problems during the sintering process of the gasket material. Compression packing is one of the most common leak-proof sealing materials used in industrial sectors such as refining, chemical, pharmaceutical, shipbuilding, and the pulp and paper industry. Compression packing involves inserting a packing member made of a soft, flexible material into the space (the so-called stuffing box) that seals the rotating or reciprocating members of a pump or valve between the pump or valve body and the valve itself. When bolt stress is applied to the compression packing, the material is compressed axially and expands radially within the stuffing box, forming a seal. Comp