Materials of Decoration: Plastics

Definition of Plastics

• Plastics are materials of synthetic origin that can be shaped during manufacture.
• They are not rubber, wood, leather, or metal.
• Made from common sources like coal, salt, natural gas, cotton, wood, and water.
• Sources are used to create monomer chemicals, which are then built into chain-like molecules called polymers.

Characteristics of Plastics

• Polymers have low extensibility.
• Can be molded, extruded, cut, or worked into different shapes and objects.
• Can be rigid or non-rigid, light or heavy, heat-resistant or easily softened by hot water.
• Like metals, plastics can be mixed with other materials to improve their characteristics.

Components of Plastics

• Resin: The basic component of plastic.
• Fillers: Added to change a characteristic, like durability or heat resistance.
• Stabilizers: Offer protection against degradation from exposure to ultraviolet rays or oxygen.
• Plasticizers: Make a material more flexible, resilient, and impact resistant.

Processing Methods

• Injection Molding: Produces moldings of high quality and accuracy, often used with thermoplastics.
• Blow Molding: Used with extrusion, suitable for making hollow plastic products.

Types of Plastics

• Polyolefins: A family of plastics, including polybutylenes, polyethylenes, and polypropylenes.
• Polybutylenes: Exhibit good retention of mechanical properties at elevated temperatures and high tensile strength.
• Polyethylenes: Known for their strength and flexibility, used for electrical wire insulation and vapor barriers.
• Polypropylene: The lightest of all commercial plastics, used in many fabrication methods, including upholstery fabric and carpet backing.
• Polystyrene: Inexpensive and easy to process, known for their sparkling clarity and hardness.
• Vinyls: A large group of plastics, including polyvinyl chloride (PVC) and polyvinyl butyral (PVB).
• PVC (Polyvinyl Chloride): Resin itself is rigid, plasticizers add flexibility, used for pipes, floor tile, and paint lacquers.
• PVB (Polyvinyl Butyral): Used as an interlayer in safety glass and as a textile coating.
• Thermosets: Cannot be softened and remolded once set, resist higher temperatures.

Applications of Plastics

• Floor and Gymnasium Finishes: Powder coatings based on heat-cured epoxy resins.
• Melamine and Urea: Hard, durable, clear, and dimensionally stable, resistant to stains, chemicals, electrical potential, and heat.
• Phenolic: Strong, durable, and heat-resistant, limited to dark colors.
• Polyesters: Include a large family of plastics, used for fiberglass, laminating materials, and contact adhesives.
• Silicones: Unique among plastics, based on the silicon atom, used for water-repellent fabric finishes and joint sealants.
• Urethane: Appears as flexible and rigid foams and coatings, also as adhesive and sealants.

Advantages of Plastics

• Ease of Fabrication: Readily adaptable to mass production methods, intricate parts can be easily made.
• Weight-Saving: Density parts of plastics are less than that of metals.
• Resistance to Corrosion: Most plastic parts are immune to rust, rot, or corrosion.
• Electrical Insulation: Does not conduct electricity, hence it is a good preventive against electrical shocks.
• Thermal Insulation: Plastics are poor heat conductors, used in control handles and steering wheels.

Learn about the basics of plastics, their definition, and how they are made from common sources like coal, salt, and natural gas. Discover the properties and characteristics of plastics.