Glossary of Plastic Injection Molding Terms

Contact Welding - A welding process in which heat is supplied with convection of pincher tips instead of electrical conduction. Two plastic parts are brought together where heated tips pinch them, melting and joining the parts in the process.

Containerization -A system of intermodal freight transport cargo transport using standard ISO containers (known as shipping containers, ITUs (Intermodal Transport Units) or isotainers) that can be loaded and sealed intact onto container ships, railroad cars, planes, and trucks.

Desiccant - A desiccant is a hygroscopic substance that induces or sustains a state of dryness (desiccation) in its local vicinity in a moderately-well sealed container. Commonly encountered pre-packaged desiccants are solids, and work through absorption of water.

Diode Laser Systems - A laser system in which the active medium is a semiconductor similar to that found in a light-emitting diode. The most common and practical type of laser diode is formed from a p-n junction and powered by injected electric current.

Electronic Article Surveillance - A technological method for preventing shoplifting from retail stores or pilferage of books from libraries. Special tags are fixed to merchandise or books. These tags are removed or deactivated by the clerks when the item is properly bought or checked out. At the exits of the store, a detection system sounds an alarm or otherwise alerts the staff when it senses active tags.

Granules - Granule is a generic term used for a small particle or grain.

High Frequency Welding - High frequency welding uses the chemical properties of certain plastics to soften the plastics for joining by heating them with high frequency electromagnetic waves.

Hot Plate Welding - A hot plate, with a shape that matches the weld joint geometry of the parts to be welded, is moved in position between the two parts. The two opposing platens move the parts into contact with the hot plate until the heat softens the interfaces to the melting point of the plastic. Then the hot plate is removed, and the parts are pressed together and held until the weld joint cools and solidifies into a permanent bond.

Hot Stamping - Hot stamping is defined as a dry printing process, which uses controlled heat, pressure, and precision timing to transfer a color pigment from foil to surfaces of varied shapes and materials.

Induction Welding - A form of welding that uses electromagnetic induction to heat the work piece. Nonmagnetic materials such as plastics can be induction-welded by implanting them with metallic or ferromagnetic compounds, called susceptors, that absorb the electromagnetic energy from the induction coil, become hot, and lose their heat energy to the surrounding material by thermal conduction.

In-Mold Labeling - In-mold labeling is a process for labeling or decorating a plastic object while the object is being formed in the mold.

Insert Molding - Insert molding is an injection molding process whereby plastic is injected into a cavity and around an insert piece or pieces placed into the same cavity just prior to molding.

Laser Welding - This technique requires one part to be transmissive to a laser beam and either the other part absorptive or a coating at the interface to be absorptive to the beam. The two parts are put under pressure while the laser beam moves along the joining line. The beam passes through the first part and is absorbed by the other one or the coating to generate enough heat to soften the interface creating a permanent weld.

Life Cycle Assessment - A life cycle assessment (LCA, also known as life cycle analysis, ecobalance, and cradle-to-grave analysis) is the investigation and valuation of the environmental impacts of a given product or service caused or necessitated by its existence.

Logistics - The management of the flow of goods, information and other resources, including energy and people, between the point of origin and the point of consumption. Logistics involve the integration of information, transportation, inventory, warehousing, material handling, and packaging.

Mandatory Labeling - The requirement of consumer products to state their ingredients or components.

Modified Atmospheres - The practice of modifying the composition of the internal atmosphere of a package (commonly food packages, but this technique is also used for drugs) in order to improve the shelf life.

Over Molding - An injection molding process where one material is molded over a second material.

Oxygen Absorbers - Oxygen supports the growth of microorganisms and causes changes in color and rancid odors in packaged foods. Plastic packaging is less able to exclude oxygen from packaged foods than are the older glass and metal containers. Oxygen absorbers collect oxygen that might diffuse into a food package.

Package Pilferage - The theft of part of the contents of a package. It may also include theft of the contents but leaving the package, perhaps resealed with bogus contents. Small packages can be pilfered from a larger package such as a shipping container.

Permeation - In physics and engineering, permeation is the penetration of a permeate (such as a liquid, gas, or vapor) through a solid, and is related to a material's intrinsic permeability.

Pharmaceuticals - A drug, broadly speaking, is any chemical substance that, when absorbed into the body of a living organism, alters normal bodily function.

Point of Sale Display (POS) - A point-of-sale display is a specialized form of sales promotion that is found near, on, or next to a checkout counter (the "point of sale"). They are intended to draw the customers' attention to products, which may be new products, or on special offer, and are also used to promote special events.

RFID Tags - Radio-frequency identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders.

Shelf Life - The length of time that food, drink, medicine and other perishable items are given before they are considered unsuitable for sale or consumption.

Spot Welding - Spot welding is a type of resistance welding used to weld various sheet metal products. Forcing a large current through the spot will melt the metal and form the weld.

Standards Organizations - A standards organization, standards body, standards development organization or SDO is any entity whose primary activities are developing, coordinating, promulgating, revising, amending, reissuing, interpreting, or otherwise maintaining standards that address the interests of a wide base of users outside the standards development organization.

Sustainability - The capacity to maintain a certain process or state indefinitely. Similarly the absence of certainty in terms climate change, global warming has raised the profile of sustainability. In recent years the concept has been applied more specifically to living organisms and systems. As applied to the human community, sustainability has been expressed as meeting the needs of the present without compromising the ability of future generations to meet their own needs.

Sustainable Packaging - The development and use of packaging which results in improved sustainability. It involves increased use of life cycle inventory and life cycle assessment to help guide the use of packaging which reduces the environmental impact and ecological footprint. The goals are to improve the long term viability and quality of life for humans and the longevity of natural ecosystems.

Tamper Evident - Describes a device or process that makes unauthorized access to the protected object easily detected. This may take the form of seals, markings or other techniques.

Tamper Resistance - Resistance to tampering by either the normal users of a product, package, or system or others with physical access to it.

Tampo Pad Printing - A printing process that can transfer a 2-D image onto a 3-D object. This is accomplished using an indirect offset (gravure) printing process that involves an image being transferred from the printing plate (cliché) via a silicone pad onto a substrate (surface to be printed).

Ultrasonic Welding - In ultrasonic welding, high frequency (15 kHz to 40 kHz ) low amplitude vibration is used to create heat by way of friction between the materials to be joined. The interface of the two parts is specially designed to concentrate the energy for the maximum weld strength.

Verification & Validation - The process of checking that a product, service, or system meets specifications and that it fulfils its intended purpose. These are critical components of a quality management system such as ISO 9000.

Vibration Welding - In vibration or friction welding, the two parts to be assembled are rubbed together at a lower frequency (typically 100-300 Hz) and higher amplitude (typically 1-2 mm) than ultrasonic welding. The friction caused by the vibration motion combined with the clamping pressure between the two parts creates the heat to melt the contact interface between the two parts, and results in a strong weld.

Waste Hierarchy - The waste hierarchy refers to the 3 Rs of reduce, reuse and recycle, which classify waste management strategies according to their desirability. The 3 Rs are meant to be a hierarchy, in order of importance. The waste hierarchy has taken many forms over the past decade, but the basic concept has remained the cornerstone of most waste minimization strategies. The aim of the waste hierarchy is to extract the maximum practical benefits from products and to generate the minimum amount of waste.

Water Vapor - Water vapor is the gas phase of water.