(1) Recovery from Compression:

Compress cork to a diameter of 1/3 the original size allowing deformation for 24 hours. Diameter is measured as a percent of the original size after 15 minutes.
Acceptable values: Min 80% Target 90-95%

(2) Specific Weight

Measure agglomerated cork - without disks - at max 6% humidity level(1) Measurements recorded as a ratio in terms of Kilograms per cubic meter.
Acceptable Values: Min 255kg Max 320kg

(3) Migration

Treated stoppers are marked and placed on their bases in a colored ethanolic solution containing 10% alcohol by volume which will reach a height of 3mm on the cork. After 24 hours remove the stoppers and measure the maximum height reached by the solution. Measurement should be rounded off to the nearest .5mm.
Acceptable Values: 3mm - and not to exceed disk

(4) Torsion

Torsion will be measured in accordance to NP2803 A Method - whereby the cork is submitted to torsion at a 100o/min rate - twisting until the cork cracks. Measurement will be in terms of shear strength as measured by the formula 16T/pd3 where d is the diameter of the cork and T is the momentum calculated as T=FxBxsin(a/2) where a is the torsion angle.
Acceptable Values Min 7 daN/cm2 

(5) Residuals

Treated or Untreated stoppers are marked and placed in a an ethanolic solution containing 10% alcohol by volume adjusted to 3.5ph. Vigorously agitate for 20 minutes. Filter solution using a .45 micron membrane. After drying weigh any residuals in a ration of mg/cork.
Acceptable Values < 2.0 mg per cork

(6) Binders

Binding agents will be prepared in compliance with USFDA regulations as seen in Title 21 CFR 175 Subpart B [175.105].

(7) Composition

Agglomerate corks must contain a minimum 80% natural cork as measured by weight.