3D printing |
Three-dimensional printing. A process for making a physical object from a digital model by laying down many layers of material. 3D printers often use plastic resin as the raw material. |
abrasion |
Damage from repeated rubbing or scraping that is concentrated in the same place. Abrasion-resistant plastics include hard thermosets, such as phenolics. |
additives |
A substance that is added to a material during manufacturing in order to improve its properties. Additives perform a range of functions, from changing the color of plastic to improving its strength. |
additives |
A substance that is added to a plastic during manufacturing in order to improve or alter its properties. Additives can help add strength to a plastic. |
additives |
Any substance that is added to a material during manufacturing in order to improve its properties. Additives in plastics perform a range of functions, from changing the color to improving strength. |
adhesive |
A substance used to join two or more materials. Adhesives include phenolic resins due to the water-resistant properties of phenolics. |
amber |
Fossilized plant resin that forms over millions of years and involves a complex oxidation and polymerization process. Amber is used in varnishes, jewelry, and other ornamental items. |
amorphous regions |
A polymer molecule formation in thermoplastics that lacks a definite repeating structure. Amorphous thermoplastic materials form clear plastic parts. |
antioxidants |
An additive that prevents oxidation from damaging a plastic. Antioxidants can extend the life of a manufactured plastic part. |
atoms |
The smallest unit of an element. Atoms bond together to form molecules. |
branched arrangement |
A molecule chain with multiple branches or extensions of mer units. Branched arrangements of molecules can appear in both thermoplastics and thermosets. |
brittle |
A material's resistance to being drawn, stretched, or formed. Brittle materials can fracture when subjected to mechanical forces. |
butyl rubber |
An elastomer that is odorless and impermeable to air. Butyl rubber can form an airtight seal. |
carbon |
A common, non-metallic element. Carbon molecules bond with hydrogen molecules to form polyethylene. |
carbon black |
A soot-like additive that is used as a colorant and/or a protector against ultraviolet radiation in polymers. Carbon black is a type of light stabilizer. |
ceramics |
A hard, brittle material that can withstand high temperatures and resist corrosion. Ceramics include traditional materials such as brick and clay as well as advanced ceramics used in abrasives and cutting tools. |
chemical reaction tank |
A vessel designed to contain chemicals. Chemical reaction tanks require an inert material, such as polyethylene, in which to store chemicals. |
chloroprene |
An elastomer that effectively resists oil, weather, heat, and flame. Chloroprene was one of the first successful synthetic rubbers. |
circuit boards |
A thin, insulating board that supports electronic components and chips. A circuit board base can be made from plastic. |
coating |
A finish used for protective and decorative purposes in manufacturing. Coatings can include different plastics because of their low thermal and electrical conductivity properties. |
coefficient of thermal expansion |
The degree to which a material increases in size as temperatures increase. Plastic has a low coefficient of thermal expansion. |
coloring agents |
An additive that can be used to help a plastic absorb ultraviolet light or change the color of a plastic part. Coloring agents include dyes and pigments. |
composite |
A material made by combining a plastic resin with small particles of solid reinforcements. Composites often contain fillers, reinforcements, and other additives. |
composites |
A material made by combining two or more materials. Composites can contain laminar, particulate, or reinforced fibers. |
corrosion |
The deterioration of a material caused by exposure to environmental or chemical elements. Some plastics are designed to resist corrosion. |
corrosion resistance |
The ability of a material to resist deterioration and chemical breakdown due to surface exposure in a particular environment. Plastic is able to resist corrosion from most chemicals. |
covalent bonds |
A type of primary bond formed between atoms that holds polymer molecules together. Covalent bonds hold thermoset molecules together. |
covalent bonds |
A type of primary bond formed between atoms that holds polymer molecules together. Covalent bonds in thermosets result in a tougher plastic. |
creep resistance |
A material's ability to resist distortion when under a load over an extended period of time. Creep resistance in a plastic decreases as polymer molecules uncoil. |
creep rupture |
When an object breaks or permanently deforms after supporting a load over time. Creep rupture can occur when the molecules in a plastic begin to uncoil. |
cross-linked |
The covalent bonds that form between polymer molecule chains. The degree of cross-linking determines the characteristics of the plastic. |
cross-linked |
The covalent bonds that form between thermoset molecule chains. The degree of cross-linking determines the characteristics of the plastic. |
cure |
The process of using thermal energy or ultraviolet radiation to harden a polymer material so that it can be manufactured. Curing a thermoset creates a chemical reaction that permanently cross-links the molecules. |
damping |
The ability to resist deformation through vibration. Damping capabilities in plastics are higher than the damping capabilities of metals. |
ductility |
The measure of a material's ability to be drawn, stretched, or formed without fracturing. The ductility of plastic depends on its molecular structure. |
durometer |
The testing instrument used in a Shore hardness test. A durometer has a needle and a spring on one end that presses into the plastic to measure hardness levels. |
dyes |
A liquid coloring agent that is mixed with resin. Dyes are an additive used to color a plastic throughout. |
elastic |
Having the ability to return to an original shape after being stretched or deformed. Most plastics exhibit elastic qualities. |
elasticity |
A measure of a material's ability to reshape itself after being stretched or deformed. A rubber band is an example of an object with elasticity. |
elastomers |
A type of plastic with slightly cross-linked molecules that can stretch and then return to its original shape once the stretching force is removed. Elastomers will eventually lose some elastic properties after repeated stretching. |
electrical conductivity |
The ability of a material to act as a medium for conveying electricity. Plastic has low electrical conductivity. |
electron |
A negatively charged particle that orbits the center of an atom. Tight electron bonds result in the low electrical conductivity of plastic. |
extrusion |
A plastic molding process in which melted resin is pushed out of the machine into a shaping die. Extrusion is a continuous process that creates parts with a uniform cross section. |
feedstock material |
A raw material used in additive manufacturing. Feedstock material for many 3D printing applications includes polymers. |
fiberglass |
A lightweight and strong material composed of fine glass fibers. Fiberglass particles are used as a reinforcement in many plastics. |
fiberglass-reinforced plastic |
FRP. A composite made from thermoset polyester resin and fiberglass particles. Fiberglass-reinforced plastic cannot be re-formed once it has hardened, due to the cross-linking that occurs during curing. |
fillers |
An inert particle added to plastic resin to take up space and lower costs. Fillers do not add significant amounts of strength to a material. |
flame retardants |
An additive that helps a material to resist igniting when exposed to a flame or elevated temperatures. Flame retardants are often added to polyurethane foam. |
foam molding |
A shaping process that involves pouring foamed plastic into a mold. Foam molding is a low-pressure molding process. |
foaming agents |
A substance that generates gases to produce foam. Foaming agents used in foam molding are added before the resin is molded. |
hardness |
The ability of a material to resist penetration, indentation, or scratching. Hardness properties in a plastic are increased by the presence of covalent bonds. |
high-density polyethylene |
HDPE. A common thermoplastic known for its high strength-to-density ratio. High-density polyethylene has a higher chemical resistance than low-density polyethylene. |
hydrogen |
A colorless, odorless gas that is the most abundant element on the planet. Hydrogen molecules bond to carbon molecules to form polyethylene. |
hygroscopic |
Able to effectively absorb moisture from the air. Hygroscopic plastics are often used in plastic wrap. |
impact tests |
Used to measure a material's ability to absorb the energy of a sudden impact without breaking. Impact tests measure the toughness levels of a plastic. |
inert |
The state of being non-reactive. Inert fillers are often added to plastics to take up space and save cost without affecting material properties. |
injection molding |
A shaping process in which resin is heated in a barrel and then injected into a mold. Injection molding uses high pressures to create complex parts. |
injection molding |
A shaping process in which resin is melted in a barrel and then injected into a mold. Injection molding uses high pressures to create complex parts. |
insoluble |
A substance that cannot be dissolved. Insoluble plastics can be a result of increased cross-link density. |
insulator |
A material with low electrical conductivity and a high resistance to electrical charges. Plastic has low electrical conductivity and is used as an insulator. |
latex |
A milky resin produced in plants that is the main source of natural rubber. Latex rubber is treated with heat and chemicals in order to be used commercially. |
load |
The weight or burden that a material supports. A constant load may cause deformation over time. |
low-density polyethylene |
LDPE. A translucent to opaque thermoplastic with loosely packed molecules. Low-density polyethylene is not as chemically resistant as high-density polyethylene. |
macromolecules |
A large molecule that consists of repeating molecular units. Polymers consist of long chains of multiple macromolecules. |
magnetism |
The power of attraction and repulsion that exists in some materials. Plastic is non-magnetic. |
mechanical properties |
The collection of properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break. Mechanical properties of a plastic are determined by its molecular structure. |
mer units |
A single unit of atoms that chemically bonds to other similar units to form long, repeating polymer molecule chains. Mer units are also called monomers. |
metals |
A naturally occurring material with high electric and thermal conductivity. Metals include copper, iron, nickel, and lead. |
molding |
A plastic shaping process in which molten plastic is forced into a mold to form a shape and then released once it cools and solidifies. Molding involves higher pressure, whereas casting does not. |
molecules |
Two or more atoms joined together by chemical bonds. Large polymer molecules bond together to form long polymer chains. |
monomers |
A single unit of atoms that chemically bonds to other similar units to form long, repeating polymer molecule chains. Monomers are also called mer units. |
MRI scanner |
Magnetic Resonance Imaging. A medical device that uses a magnetic field and radio waves to produce a detailed image of the soft tissues and bones in the body. MRI scanners typically include hard plastic casings. |
natural polymers |
A polymer that occurs in nature. Natural, or organic, polymers are not synthesized by humans. |
natural rubber |
An elastomer that is extracted as a sap from tropical trees. Natural rubber must be hardened and treated with sulfur in order to be used commercially. |
natural rubber |
An important commercial elastomer that is harvested from the sap of tropical trees. Natural rubber is also a natural polymer. |
opaque |
Unable to transmit or reflect light. Opaque materials are not transparent. |
oxidation |
A material's chemical reaction with oxygen. Oxidation can damage a plastic, but manufacturers can use additives to prevent damage. |
oxidation |
A material's chemical reaction with oxygen. Oxidation can result in polymer degradation. |
permeability |
A measure of how easily moisture or gases pass through a material. Low permeability means that is difficult for liquids or gases to pass through a material. |
petroleum |
A fossil fuel that provides the raw base for many plastics through a chemical reaction called polymerization. Petroleum-based polyethylene is one of the most popular plastics. |
phenolics |
A rigid and relatively inexpensive thermoset with tightly cross-linked molecule chains. Phenolics are often used as an adhesive for plywood. |
physical properties |
A set of characteristics that describes how a material responds to environmental, thermal, electrical, and magnetic forces. Physical properties describe how a material reacts to forces other than mechanical forces. |
pigments |
A powder coloring agent mixed with resin. Pigments are an additive used to color the surface of a plastic product. |
plastics |
A lightweight polymer material that has high corrosion resistance, a high strength-to-weight ratio, and a low melting point. Most plastics are easily shaped and formed. |
plywood |
A thin, strong wooden board consisting of two or more layers glued and pressed together. Plywood often contains phenolic resins as an adhesive. |
polyester |
A plastic that can be used as a thermoplastic or a thermoset. Polyester is commonly combined with additives and reinforcements for numerous commercial uses. |
polyester |
A plastic that is highly compatible with additives or other chemicals that will give it desired characteristics. Polyester can be manufactured as a thermoplastic or a thermoset. |
polyethylene |
A thermoplastic in the polyester family that is highly resistant to electricity and heat. Polyethylene is often used to manufacture tough plastic bags and beverage containers. |
polyethylene |
A type of plastic formed from carbon and hydrogen molecules. Polyethylene can resist electricity and heat. |
polylactic acid |
PLA. A biodegradable thermoplastic in the polyester family. Polyactic acid is a natural polymer derived from corn starch and other renewable resources. |
polymer |
A material made of very large molecules. Polymers are either natural or synthetic. |
polystyrene |
A thermoplastic that is transparent and easily shaped. Polystyrene has elastic qualities because of its secondary bonds. |
polyurethanes |
A plastic that can be manufactured as a foam or as a solid. Polyurethane can be used as a coating, in paints and varnishes, or in solid parts such as medical implants. |
polyvinyl chloride |
PVC. A thermoplastic that can be rigid or flexible. Polyvinyl chloride usage is controversial because of its potentially toxic environmental effects. |
properties |
The physical and mechanical characteristics of a material that distinguish it from other materials. The properties of plastic can be altered with additives. |
reciprocating screw |
A component of an injection molding machine that melts the resin and builds up pressure. Reciprocating screws inject melted resin into a mold cavity. |
reinforcements |
A material added to a plastic that provides strength, stiffness, and the ability to carry a load. Reinforcements are typically fiberglass or carbon fibers. |
reinforcements |
An additive that improves mechanical properties, such as toughness or strength. Reinforcements are added to most plastics during manufacturing. |
resin |
A raw polymer, usually in the form of beads or pellets, that is not yet molded into its final shape. Resin is melted to form plastic parts. |
rigid |
Unable to bend or resistant to bending. Rigid plastics can include polystyrene or polyvinyl chloride, depending on how they are manufactured. |
rotational molding |
A plastic shaping process in which resin is heated, rather than melted, inside a rotating mold. Rotational molding is a no-pressure process that creates hollow parts. |
secondary bonds |
A bond formed between atoms that holds the atoms in the polymer molecules together. Secondary bonds hold thermoplastic molecules together. |
secondary bonds |
A bond formed between atoms that involves an attraction between molecules without the transfer or sharing of electrons. Secondary bonds are found in thermoplastics. |
secondary bonds |
A type of chemical bond formed between atoms that involves an attraction between molecules without the transfer or sharing of electrons. Secondary bonds hold thermoplastic molecules together. |
self-extinguishing |
The inability to support flame after the source of the flame is withdrawn. Self-extinguishing plastics include polyvinyl chloride. |
semicrystalline regions |
A polymer molecule formation in thermoplastics in which the molecules follow an ordered and structured pattern as they cool. Semicrystalline thermoplastics have a higher melting point. |
shaping |
The process of forming plastic resin. Shaping processes include injection molding and extrusion. |
shaping die |
A component of an extrusion machine that cuts or shapes material. A shaping die is used in extrusion while a mold cavity is used in injection molding. |
shellac |
A resinous substance that can be used as a coating. Shellac is a natural polymer that is chemically similar to synthetic polymers. |
Shore hardness test |
A hardness test designed for elastic materials. The Shore hardness test uses a durometer that attempts to indent the plastic to determine hardness. |
silicone |
A thermoset that is both heat resistant and water repellant. Silicone can be a liquid, gel, rubber, or hard plastic. |
solubility |
The measure of a material's ability to dissolve in a solvent. The solubility of plastic depends on its molecular structure. |
solubility rating |
A rating system that gauges a material's likelihood of dissolving in a solvent. A low solubility rating is assigned to plastic that is not likely to dissolve in a solvent. |
solute |
A material that dissolves in a chemical. When testing the chemical reactions of plastics, the plastic material is the solute. |
solvent |
A chemical that attempts to dissolve another material. Solvents are rated by their solubility. |
solvents |
A chemical that attempts to dissolve another material. Solvents are rated by their solubility. |
soot |
A black powder that forms when wood or coal is burnt. Soot and carbon black are similar, but soot is an unwanted byproduct whereas carbon black is produced in a controlled environment. |
stabilizers |
An additive that helps prevent a plastic from breaking down when exposed to adverse environments. Stabilizers protect a plastic from ultraviolet radiation by absorbing ultraviolet rays. |
strain |
The physical deformation that occurs in an object when it is under stress. Strain in a plastic can exist while the object is under stress but can also exist once the force has been removed. |
stress |
A force that attempts to deform an object. Common forms of stress include compression, shear, and tensile. |
surface finishes |
The degree of roughness and variation on the surface of a manufactured part. Surface finish affects how a plastic component will function. |
synthetic |
An artificial or human-made material that does not occur in nature. Plastic and nylon are examples of synthetic materials. |
synthetic polymers |
A polymer that is chemically manufactured. Synthetic polymers include many different types of plastic. |
tensile stress |
A force that attempts to pull apart or stretch a material. The ability to withstand tensile stress is a measure of ductility. |
tensile test |
Stretching a material until it breaks or fails. Tensile tests determine different mechanical properties of plastics. |
thermal conductivity |
A physical property that indicates how well heat travels through a material. Plastic has low thermal conductivity. |
thermal degradation |
Deterioration of a material due to overexposure to heat or sun. Thermal degradation can accelerate oxidation in a plastic. |
thermoplastic |
A group of plastics that can be repeatedly heated, shaped, and cooled. Thermoplastic molecules are not cross-linked. |
thermoset |
A group of plastics that is permanently hardened by heating. Thermosets, also known as thermosetting plastics, have covalent bonds and cross-linked molecule chains. |
thermosetting plastics |
A group of plastics that is permanently hardened by heating. Thermosetting plastics, also known as thermosets, have covalent bonds and cross-linked molecule chains. |
toughness |
The measure of a material's ability to absorb mechanical forces before it breaks. Toughness includes specific categories such as impact toughness. |
transparent |
Having the ability to allow light to pass through. Transparent plastics, such as polystyrene, are useful in eyeglass lenses or food packaging. |
ultraviolet degradation |
UV degradation. The deterioration of a material due to overexposure to the ultraviolet radiation in sunlight. Ultraviolet degradation is typically associated with plastics. |
ultraviolet rays |
UV rays. Potentially harmful wavelengths from the sun that are invisible to the naked eye. Ultraviolet rays can damage a plastic at the molecular level. |
viscoelastic |
Having both elastic and viscous properties. Viscoelastic materials have the ability to return to their original shape after undergoing stress, but they will lose shape over time. |
viscoelasticity |
The ability to be both elastic and viscous when undergoing deformation. Viscoelasticity allows some plastics to be recycled and reshaped. |
viscosity |
A measure of a material's resistance to flow. Heating a plastic decreases its viscosity and improves flow. |
viscosity |
A measure of a material's resistance to flow. Viscosity in a plastic decreases when the material is heated, resulting in improved flow. |
vulcanized |
Increasing the number of cross-linked bonds in an elastomer by using additives, chemicals, heat, and pressure. Vulcanization adds strength and toughness to an elastomer. |
wood flour |
Wood that has been finely ground to have the consistency of powder. Wood flour is an inert filler in many plastics. |