Measure Tensile Strength

TENSILE STRENGTH is the measure of the force or stress required (resistance to lengthwise stress) to pull a sample to the point where it breaks or before permanent deformation results.  

Usually it is the maximum amount of tensile stress that it can be subjected to before failure, although the definition of failure can vary according to material type and design methodology.

In the fields of material science, mechanical engineering and structural engineering there are three typical definitions of tensile strength:

• Yield strength: the stress at which material strain changes from elastic deformation to plastic deformation, causing it to deform permanently.
• Ultimate strength: the maximum stress a material can withstand.
• Breaking strength: the stress coordinate on the stress-strain curve at the point of rupture.

Edible films as scrumptious packaging

Yummy! Edible Packaging! Eat a drink. Munch your entire yogurt, right through the cap. Indulge in a ball of mousse…

Edible packaging has entered the playing field and can be as tasty as the food it's protecting. Fruits are brilliantly designed since they come in their own protective packaging, so they're easy to toss in a bag and eat on the go. This is exactly the thinking behind the David Edwards WikiCells project.

Last year, Edwards, 51, a bioengineer at Harvard, launched WikiCells, which makes edible packaging for everything from yogurt to coffee and even alcoholic drinks. “We can basically surround any food or beverage with a skin like a grape skin that’s fully edible, and then consume it,” he says.