New Jig Tests Blister Pack Foil Peel Strength

Lloyd Instruments has developed a jig for determination of peel strength of the aluminium foil on contact lens blister packs.

Lloyd Instruments has developed a jig for determination of peel strength of the aluminium foil on contact lens blister packs.

Designed for use primarily with the low force LFPlus single column materials testing machine, the jig features a self-adjusting sliding bed for true 90-degree peel tests.

The jig has been engineered for use with two contact lens blister packs, each containing individual lenses in a solution.

One lens pack is clamped in the upper instrument grip, whilst the other is clamped and fitted in to a mount in the jig's sliding baseplate.

As the test machine's crosshead is driven upwards, peeling the foil on the lower blister pack, the baseplate slides horizontally, to ensure that the peel force is always applied vertically.

Peel strength is an important parameter to be measured for contact lens packages, said Lloyd Instruments.

Too high a strength and the blister package is difficult to open and there is the risk of a sudden opening resulting in the lens and fluid being accidentally ejected.

If the peel strength is too low, there is a chance that the foil lid could be detached accidentally, for instance when carried in a bag or pocket, with loss of fluid and damage to the lens.

With material testing and force measurements up to 1 kN (225lbf), test speeds from 0.05mm per minute to 1,270mm per minute and accuracy greater than 0.2 per cent the LFPlus materials tester is suitable for peel test applications of this type, said the company.

Tests can be fully automated through the addition of the new Nexygenplus materials testing software.

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