Plastics: Materials & Techniques

Question 1

You are using polypropylene to mold a plastic lower limb orthotic. The oven used to heat the plastic sheet is set at 250 degrees Fahrenheit. The plastic does not warm to its molding state. What is the correct temperature range in Fahrenheit for modeling polypropylene?

Answer 1

375-400

Question 2

A thermoforming plastic with optical clarity is required for a patient fitting. What is a commonly used rigid plastic that is transparent (check socket)?

Answer 2

Copolyester

Question 3

A foam pad material that will mold is required for a foot orthotics. The base plastic for most moldable foams is:

Answer 3

Polyethylene

Question 4

You are fabricating a rigid piece and using thermosetting plastic. During the lamination process, what SAFETY precaution has been identified?

Answer 4

Off gases that can be protected against with a mask.

Question 5

A molded piece is to be fabricated using thermoforming plastic. What commonly used sheet plastic offers good resistance to repeated bending loads?

Answer 5

Polypropylene