1.What are the effects of physical damage to the galvanized coating?
The crimping process involves severe plastic deformation. During this process, the zinc layer on the surface is stretched, squeezed, and rubbed, which can easily cause microcracks, flaking, or peeling.
A complete sealing surface requires continuity and density. These tiny defects can directly undermine the integrity of the sealing surface and create tiny leak paths.
2.What are the effects of uneven surface hardness and wear resistance?
The zinc layer is relatively soft, but it has a different hardness from the base material. On the compression surface of the crimp seal, the softer zinc layer may be worn or transferred, causing sealing pressure changes and leakage.
3.What are the risks of chemical corrosion?
If the sealing medium is acidic or alkaline, it will chemically react with the zinc, corroding the sealing surface and accelerating seal failure.
Even if the sealing medium is water or air, zinc will oxidize (forming white rust) over time, and the resulting product will expand in volume, potentially compromising the tightness of the sealing interface.
4.In what situations would you "likely" see galvanized coil used for sealing?
In some static sealing applications with minimal requirements, non-critical requirements, and dry environments, galvanized coil hems may be used for cost reasons. For example:
Low-cost toolbox and instrument box covers.
Ordinary cabinets to prevent the ingress of large dust particles.
However, it should be noted that this structure primarily provides a "shielding" function, not a true "seal." It does not effectively prevent the ingress of liquids, pressure, or fine dust.
5.What are the recommended materials for crimp seals?
Stainless Steel - The Most Common and Best Choice
304/304L Stainless Steel: Offers excellent corrosion resistance, formability, and strength, making it a top choice for the food, pharmaceutical, chemical, and general industrial sectors.
316/316L Stainless Steel: Contains molybdenum, offering enhanced chloride corrosion resistance and suitable for marine and harsher industrial environments.
Advantages: Surface hardness, density, corrosion resistance, and stable performance, allowing for machining to produce a very flat and smooth sealing surface.
Aluminum Alloy
Anodic oxidation treatment is often required to create a hard, wear-resistant, and corrosion-resistant oxide film. This film serves as an ideal sealing surface.
Advantages: Lightweight, strong, and with proper surface treatment, provides excellent sealing performance.
Carbon Steel + Plating or Coating
If carbon steel must be used for strength or cost reasons, consider adding a more reliable surface treatment after crimping.
Hard chrome plating: The surface is extremely hard, smooth, wear-resistant, and corrosion-resistant, making it an excellent sealing surface.
Other industrial coatings, such as Teflon (PTFE), provide both corrosion protection and a degree of elasticity, aiding sealing.