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.