Monday, 2 June 2014

Polymer strength testing

Equipment

Clamp and stand
Slotted masses (100g) and hanger
Strips of plastic bag of different widths (1 to 5cm in 1cm intervals)
Sticky tape
Ruler

Method

Take a strip of plastic bag and use the tape to secure the end into a loop.
Hang the loop with the taped end over the clamp and secure the loop using some more tape. Use the ruler to measure the unstretched length of the bag.
Add the masses 100g at a time until the loop breaks or until you reach 1kg and record the mass. If you reach 1kg without the loop breaking measure the length to which the loop has now stretched.
Repeat this three times for each width of loop.

Risk assessment

The bag can break suddenly so care should be taken to stand clear when adding masses so that they do not fall onto the floor and land on the feet of the experimenter. The experiment should be set up in the middle of a table so that it does not risk tipping over . The Bag loop should be suspended over the base of the stand to ensure the experiment remains stable.