Polymers, Wood, Ceramics, Textile Fibers and Composite Materials

Flashcards with key vocabulary terms and definitions related to polymers, wood, ceramics, textile fibers and composite materials.

Polymers

Large molecules formed by carbon atoms with hydrogen, oxygen and more.

Natural Polymers

Polymers present in plants or animals.

Artificial Polymers

Polymers obtained industrially by modifying natural polymers.

Synthetic Polymers

Polymers obtained industrially from their elemental components.

Poliaddition

Process of obtaining polyethylene from ethylene monomers where monomers react with each other and join to form a chain until a polymer is formed.

Policondensation

Process where water condenses through a chemical reaction, first the chemical reaction occurs and then polymerization. It is used to form chemical products that cannot form polymers individually such as phenol and formaldehyde.

Extrusion

Making the plastic circulate inside a heating tube thanks to the action of a screw. The molten plastic exits through the end of the tube where there is a die with the desired shape, and then passes through a cooling chamber. This is how long objects are made.

Blow Molding by Extrusion

Obtaining a tube or preform with an extruder and before cooling, closing it inside a mold, and then adhering it to the mold, blowing air under pressure inside. This technique is used to manufacture hollow objects.

Injection Molding

The screw displaces the molten plastic and forces it into the mold. Then it is cooled and removed from the mold. It is used to make objects with complicated shapes that must be precise.

Foam Molding

The raw material must have a foaming additive. The material is placed inside a mold and heated to the appropriate temperature. Due to the heat, the plastic inflates, filling the mold completely even though it remains spongy.

Vacuum Molding

An open mold with small channels where air can circulate is used. A plastic sheet is placed on top and heated until it hardens. Then, the air between the sheet and the mold is extracted, causing the former to take the shape of the latter due to atmospheric pressure.

Compression Molding

A mold with two parts, one fixed and the other mobile with heating systems. The required amount of polymer is placed on the fixed part and the mold is closed, the mobile part applying great pressure. Due to the temperature and pressure, the plastic has the same shape as the mold.

Calendaring

Heating rollers are fed with the required amount of plastic. In a viscous phase, the plastic is circulated between the rollers until it has the desired thickness and texture.

Plasticizers

Organic substances that reduce the hardness and fragility of polymers and increase their ductility and toughness. They are used in the production of fragile polymers at room temperature.

Stabilizers

Chemical compounds that increase the resistance of polymers against the action of ultraviolet radiation and oxidation.

Termoplastics

Polymers that can be repeatedly molded by applying heat.

Thermoset

Polymers that when polymerized, heat breaks their atomic bonds and degrades them.

Green Wood

Wood that has just been cut, it has a very high moisture content that makes it unusable.

Wood Drying

Process to reduce the wood moisutre content to be utilized. It is done outdoors (for a year or more) or in hot air ovens (six or seven weeks).

Plywood

Made by gluing sheets of wood at 90° angles, offering resistance and a good finish.

Particle Boards

Made with shavings or particles glued with synthetic resins, compressed to be denser.

Tablex

Material formed by wood fibers, pressed wet without gluing. It is hard but not very resistant and sensitive to moisture, deforming easily.

DM

Also made of wood fibers, but it is dry pressed and glued with synthetic resin. It is harder, has a fine texture and can be machined well.

Liston Boards

Formed of softwood glued and coated with hardwood veneers. They have a resistance between chipboard and plywood.

Portland Cement

Cement produced by heating to 1400ºC in a rotating kiln a mixture with a certain amount of clay and limestone. Clinker is obtained, which is ground very finely and mixed with a small amount of gypsum to obtain Portland cement.

Refractories

Materials that withstand high temperatures without any change, do not react chemically with the elements they have contact with and have thermal insulation.

Abrasives

Materials that can polish, sharpen and cut steels, metals, rocks and other hard materials. They are very hard, wear resistant, tenacious and refractory.

Textile Fibers

Thin, elongated fibers and are used alone or in threads. Its main application is spinning and weaving to make clothes, but they are also used as insulators, filters, ropes and composite materials.

Vegetable Fibers

Made of cellulose, with cotton and linen as the most important.

Animal fibers

Come from animal hair and are mainly proteins.

Artificial Fibers

Manufactured from cellulose, with its industrial production starting in France in 1889, and later in Catalonia.

Synthetic Fibers

Created from elemental components without natural products, through polymerization processes.

Concrete

A composite material made with Portland cement, sand and gravel, known for its high compressive strength.

Fiber reinforced resins

Consist of fibers that give strength and rigidity within a polymeric rein.

Plywoods

Obtained by gluing sheets of wood with fibers at 90° angles, light and resistant.