Thread locking fluid or thread is a thin single component adhesive, applied to fasteners such as screws and screws to prevent loosening, leaking, and corrosion.
Most thread locking formulas are methacrylate based and depend on the electrochemical activity of the metal substrate to cause fluid polymerization. The thread locking liquid is thixotropic, which allows it to flow well over time, yet retains shock and vibration. Can be permanent or removable; in the latter case, it can be removed by heat, for example. Typically, brands are color-coded to show strength and whether they can be removed.
Video Thread-locking fluid
History
The yarn locking fluid was developed by American professor Vernon K. Krieble in 1953. His company, American Sealants, founded the Loctite brand. Early versions of the compound were patented in 1960.
Maps Thread-locking fluid
Properties
Typically, yarn-based methacrylate fluid, and anaerobic cure. The thread locking liquid is a thixotropic liquid: under shear stress, it shows a time dependent viscosity reduction. This allows it to flow well over time, but still withstand short durations, such as vibrations or shocks.
The yarn locking liquid is usually sold in small containers, in quantities from 5 milliliters (about one teaspoon) to 250 milliliters (8.5Ã, US flÃ, oz). Threadlocker is also sold in stick form and in ribbon form, similar to Teflon ribbon.
Applications and maintenance
The yarn locking liquid may be applied before or after assembly, depending on the type. Threadlockers are available in various "permanent", "removable", and "low power" formulas. Many brands of color-coded containers and liquids themselves to show the degree of immortality. The low-strength type prevents loosening under vibration, but may still be easily disassembled. The detachable type retains a higher amount of vibration, but may still be disassembled by hand or by power tools. The strongest permanent threader is rated 3,000 psi (21 MPa) in shear strength. The torque required to loosen the threaded binder permanently may exceed the yield strength of the fasteners themselves, so that the forced unloading effort can twist off the binding rod. However, a high-strength permanent threadlock becomes potentially discharged by heating the assembly, typically being 230 Ã, Ã, Â ° C (450 Ã, Ã, Â ° F).
The working temperature for threaded fasteners is typically limited to 150 ° C (300 ×, Ã, Ã, Â ° F), which is below the softening point of the methacrylate polymer. Above this temperature, the material softens and strength decreases.
Since the yarn-locking adhesive usually depends on the electrochemical activity of the metal substrate to form the bond, the surface must be clean to develop a full bonding strength. In the case of electrochemically less electrochemically active metals such as aluminum surfaces that are normally oxidized, additional steps are required for full strength results.
Lock rings, locknuts, peanut butter, and safety wire can be used together with screw locking fluid to prevent loosening of the bolt junction.
Since electrochemical activity is one of two triggers that cause threaded polymerization of fluid, care should be taken to avoid contamination of all threaded containers with threads in contact with metal, otherwise the material in the container may polymerize.
References
External links
- Allen, Mike (September 2009). "How to Secure Bolt Using Threadlocker: Auto Clinic". Popular Mechanics .
- Current Loctite Thread Lock
- Threadlocker
Source of the article : Wikipedia
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