We continue now with other important features of this material:
What do tensile strength and tear Elmendorf mean?
Let us imagine for a while we apply tension on a small piece of Tyvek measuring 1 cm by 20 cm length. The tensile strength is the force measured in kilograms (or other force unit) we should do to break that single centimeter of Tyvek. It is the same the length of 20 cm or 1 meter, what matters is the width of the piece we are willing to break by applying a firm, and constant tension from both extremes of the piece.
The tear Elmendorf resistance is the force we should apply once a cut was initiated to continue it. The random thickness of Tyvek makes that Tear Elmendorf may vary from one piece to another. Anyway DuPont presents us an average value.
These mechanical properties, not the only ones, are essential to understand which Tyvek suits better each end use. After 22 years working with Tyvek, we developed a lot of experience that allows us to advice our customers.
There is a common believe that the heavier the tougher. This is not true. For example Tyvek 43 g/m2 resists tearing 4,6 times more than Tyvek 75 g/m2, and Tyvek 80 g/m2 enhances 12,2 times tearing respect to Tyvek 75 g/m2.
Each type of bonding behaves differently with gluing, sewing, ultrasound, etc.
There are other mechanical properties like internal bonding, Gurley porosity, water resistance, weight, thickness, opacity, corona treatment, antistatic treatment, etc, that should be studied in order to select the best Tyvek for each application.