Focus on Sustainability 5

 sample lesson

 Unit 5

Change matters

Almost all of your students will have used duct tape. They may even call it Duck Tape – because the tape is waterproof. “Like water off a duck’s back.” duct tape was originally used to keep moisture out of ammunition cases during World War II.

They will probably be able to tell you about their experiences and how they have used duct tape in a variety of ways. Perhaps your students have heard of Red Green, Mr. Duct Tape himself and star of “The Red Green Show”. This very funny show can still be seen in reruns on the Comedy Channel, a variety of PBS stations and CBC. In our video segment, a more serious show, Red Green takes us through a 3M factory to show us how duct tape is manufactured. There are three major components:

Cotton mesh - Cotton mesh forms the backbone of duct tape. It provides tensile strength and allows the tape to be torn in both directions.

Polyethylene coating - The cotton fabric is coated with polyethylene, a plastic material that protects it from moisture and abrasion. This plastic coating is flexible and allows the tape to adhere better to irregular surfaces. The polyethylene is melted and applied to the fabric in a preliminary coating operation. The coated fabric is then stored on rolls until the manufacturer is ready to apply the adhesive.

Adhesive compound - The adhesive used in duct tape is unique for two reasons. First, the adhesive is made with rubber compounds that ensure long-term bonding. Second, the adhesive is applied to the surface in a much thicker coating than those used on cellophane or masking tapes. This helps to increase the adhesive properties of the tape.

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