Generate your Abstract and line of thought using the following keywords:
Polymers: thermoplastics (polyethylene), HDPE, LDPE; manufacturing processes: plastic extrusion, capabilities, applications, comparison other processes; Characterization: thermal, mechanical, physicochemical

Discuss the following topics in correct language and organized flow of ideas within your introduction:
1. Definition: Extrusion; capacity, process capabilities, typical products, applicability for thermoplastics/thermosets.
2. Extrusion system, compared to injection systems.
3. Typical materials and applications of 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
-Explain the difference between the two polymer types

The section has to include a complete description of the process used (extrusion) with a picture for the device used, explaining the following:
1. The extrusion system (feed zone, melting, melt pumping).
2. Process economics, production rate
3. Process parameters
4. The effect of % crystallinity on the control of the process.

Include a full account for the experimental procedures.

1. Mechanical Testing: tension and compression tests, and impact test to measure the impact strength (toughness).
2. Flammability Testing: Molten material form, flame color, burning fashion, smoke
3. Physical Testing: dimensions, density and physical shape
4. Chemical Testing: effect of chemical attack by different chemicals, depicting changes in weight when immersed in:
-Strong alkali (NaOH)
-Weak acid (HCl (dilute))
-Strong acid (HCl (conc))
-With Water
5. Creep test

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 extrusion and the quality of the product

--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.