Generate your Abstract and line of thought using the following keywords:
Polymers: thermoplastics (LLDPE) ; manufacturing processes: plastic film extrusion; Characterization: thermal: dimensional stability

Discuss the following topics in correct language and organized flow of ideas within your introduction:
1. Practical uses of polymer films.
2. Material property requirements for film applications.
3. Typical materials.
4. Difference between section extrusion and film extrusion.

The introduction should be followed with "Material" section, containing the following properties:
-Chemical Name, Trade Name, Wt. % of U.S. Plastic Sales(*), Bulk List Price $/Ib (*), Type of Plastic, Density, Tensile Strength, Young's Modulus (E), Impact Strength: Izod, Elongation % , Hardness, Dielectric Strength, Max. Service Temperature (no load), Melting Point, Glass Transition Temperature
(Properties marked with (*) are not necessary).
-Repeated unit
-General properties of the polymer: advantages and limitations
-Typical applications

The section has to include a complete description of the process used (film extrusion) with a picture for the device used, explaining the following:
1. The film extrusion system (heating zones).
2. Film extrusion die (Kalpakjian)
3. Process parameters
4. Effect of extrusion on the alignment of mers.

Include a full account for the experimental procedures.

1. Shrinkage test: measure linear and transverse shrinkage
2. Physical properties
3. Linear versus transverse strength (by observation)

Discuss the agreement or disagreement of the experimental results with the tabulated data for the used polymers, and those obtained in the experiment.
1. General comments about film extrusion and the quality and shape of the product
2. Shrinkage test and strength results in relation to structure.

--The following sites and books contain useful information and images for several articles that we have encountered in this experiment. Make sure to check them.

MatWeb

Kalpakjian, Serope. Manufacturing Process for Engineering Materials. Addison Wesley, 3^rd Ed., 1997.

Smith, William F. . Principles of Materials Science and Engineering. McGraw Hill, 3^rd Ed., 1996.