Surface treatment to improve adhesion between the boss and liner
Publication Date: 2010-Jan-05
The IP.com Prior Art Database
Problem to be solved
In type 4 gas cylinders having a plastic, gas-containing liner and an outer, load-bearing composite layer, a metal boss must be connected to the liner so that a connector and pressure regulator can be attached to the cylinder.
Metal-polymer interfaces are typically weak and gas leaks often stem from the boss-liner junction. These leaks can arise from internal cracking of the liner, loss of adhesion between the metal boss and the plastic liner, cracking in the metal boss, or some combination of these mechanisms.
In particular, adhesion between the boss and liner can allow gas to escape to the liner-boss-composite interface where it will either escape to the surroundings or possibly be trapped between the composite layer and the liner causing additional problems.
There are numerous ways of affixing the boss to the liner. The most simple is to use the fiber composite wrapping to mechanically hold the junction in place. This method balances the internal gas pressure versus the tensile strength of the composite layer to hold the junction in place.
Additionally, “teeth” can be placed on the boss, holes can be put in the boss for the liner to mechanically attach to, or the metal-polymer interface can be strengthened by improving the chemical bonding in order to improve the mechanical stability of the junction.
Drawbacks to the existing solution
Existing solutions primarily use a reinforcement of mechanical properties of the boss-liner interface. Most of these solutions focus on adding teeth or holes to the boss to limit the movement of the junction.
This solution ignores any gains that may be had by improving the adhesion between the met...