| Dyneema® BT hard ballistic protection materials are woven and laminated sheets made from Dyneema® Ultra High Molecular Weight Polyethylene (UHMWPE) tape forming a continuous roll. The tapes are arranged in a woven structure of 0/90 degrees giving the product a checkerboard appearance. Visual Defects Dyneema® BT hard ballistic protection materials can contain minor visual defects. When a visual defect is found to be greater than the allowable dimensions it will be clearly marked with a bright colored sticker and compensated with 20 cm (7.87 inch) of additional material per visual defect. Lifetime Expectancy BT10 is expected to preserve its quality for a period of at least 10 years during storage from the date of delivery, provided that the material: - is stored under dry conditions at normal ambient temperature;
- has not been subjected to peak temperatures exceeding 90°C;
- is protected against long-term direct exposure to sunlight;
- is not exposed to unusual wear and tear.
The lifetime expectation is derived from accelerated aging data, using acceleration factors typical to the material and assuming no wear or tear. If the material is exposed to more extreme conditions and unusual wear and tear, it may have shorter life time expectancy. Most of the actual longer term accelerated and prolonged storage evaluations have been performed on a specific prototype woven tape construction. There are no reasons to assume a different long-term behavior for other Dyneema® BT materials for hard ballistic applications. The relation between aging and the ballistic performance has been assessed using the 9 mm FMJ bullet in a STANAG 2920, V50 rating. Other threats and different target constructions might give deviating results. |
