Applied Science - Science and Math (6C)
Pre Lab

   
OBJECTIVES:
  • Discussing how fibers become fabric.
  • Learning that fibers are polymers.
VOCABULARY:
  • fibers 
  • hypothesis
  • investigate
  • polymer
MATERIALS:

Students research fibers that are polymers.

BACKGROUND:

Individual fibers have unique characteristics. Natural fibers have very characteristic features.  Cotton is a flat fiber that is twisted. Linen looks jointed like bamboo. Wool looks like scaly corkscrews. Silk has double strands.  However synthetic fibers are less distinguishable.  Rayon is smooth glass-like rods; nylon is smooth clear rods; and polyester is rod shaped like nylon but not as clear.  All fibers are polymers which are monomers that repeat and are aligned in a stretched pattern.  This allows fibers to be spun into threads and used as textiles. 

In 1884, Louis Bernigaut successfully created an artificial silk, which was the precursor to rayon.   Unfortunately, the synthetic fabric  was highly flammable and burnt a young lay's ball gown (while she was still in it!)  Rayon was finally generated from a cellulose polymer in 1926 by the DuPont Company. 

Cellulose is a polymer common in nature like wood, paper, and cotton.  Cotton over the course of human civilization has been used to weave many different fabrics.  Nylon a synthetic fiber, was first used in woman's stockings in 1940's.  Nylon is a light and durable fabric used in parachutes and ropes.  Many bulletproof fabrics are also in the nylon family.

Olefin is a lightweight synthetic fiber found in sportswear and thermal underwear.  Acrylic and modacrylic fibers are used with cotton to make fake sheep fleece,  deep pile coats, and even teddy bears.  Spandex is a stretchable fiber used in bathing suites and other sports wear. 

Paper is not a fabric because paper is made by pressing and flattening fibers by forcing them to "stick" together.  Remember most fabrics or cloth fibers are interlocked by weaving, knitting, or crocheting.  Felt is a cloth made by pressing together, but it is not used to make clothes.  Paper is usually made up  of vegetable fibers that are laid down on a fine screen from a water suspension and then are pressed together through the action of heat, moisture, chemicals, and pressure.  Other natural fibers are used as well as synthetic or mixed fibers.

In lab the students will be observing different fibers so they can identify them.  Then in the post lab, students will look at the fibers in the lint they have from home.   Investigators use fibers many times to identify criminals.  After this unit the students will be able to understand why.   Fibers are unique and can be traced from a criminal to the crime.

PROCEDURE:

  1. Read the poem "Poly Mer" so students are familiar with the term polymer.  Emphasize that all fibers are polymers whether naturally occurring or synthetically produced. This is an introduction to the term.  The "mer" refers to the Greek meaning part. 

    The basic conceptual building unit of a polymer is a monomer that is repeated in a chain or branched form.  A molecule is repeated over and over.  In a polymer fiber the chain  is elongated. 
      
  2. You may want students to "research" about one fiber.  If you have a computer lab this would be a good way to introduce searching for information.  

    If your school has a library this is a good opportunity to investigate what types of books the library has.  You might go over the procedure on using references, what an index is, and how to ask for help.  In lab their research will help them  to distinguish the different types of fibers.
      
  3. You may want students to research types of paper.   Some possible suggestions are: papyrus, rice paper, wax paper, cardboard, tracing paper, history of paper, or even fibers in forensic science.

 [Dictionary]
  [Back to Applied Science Grid]  [Back to Science & Math (6)]