Packaging Glossary

ANNEALING - A controlled temperature method of gradually cooling glass containers in ovens or lehrs to avoid the creation of stresses and strains within the glass due to natural or uneven cooling.

APPLIED COLOR LABELING (ACL) - A colored lettering or design of a ceramic nature permanently fused onto glass bottle surfaces.

ART WORK (ACL) - A separate drawing is made for each color used in each front and back body or shoulder design. These are drawn larger than actual size not only to eliminate imperfections when reduced but to make them easier and more quickly.

BLOW MOLDING - A method of fabrication in which a parison (hollow tube) is forced into the shape of the mold cavity by internal air pressure.

CAVITY - Depression in a mold made by casting, machining, hobbing, or a combination of these methods; depending on number of such depressions, molds are designated as Single-Cavity or Multi-Cavity.

CENTER GATED MOLD - An injection mold wherein the cavity is filled with resin through an orifice interconnecting the nozzle and the center of the cavity area. Normally, this orifice is located at the bottom of the cavity when forming items such as containers, tumblers, bowls, etc.

CLOSURE - A term used to describe a metal or molded cap which effects a primary seal when properly applied to a container.

COLLAPSE - Contraction of the walls of a container, e.g., upon cooling, leading to a permanent indention or by the creation of a partial vacuum due to the loss of product through the wall of a plastic container.

COMPRESSION MOLDING - A technique of thermoset molding in which the molding compound (generally preheated) is placed in the open mold cavity, mold is closed, and heat and pressure (in the form of a downward moving ram) are applied until the material has cured.

CT FINISH - A continuous thread finish. An uninterrupted protruding helix on the neck of a container to accommodate a screw-type closure.

CYCLE - The complete, repeating sequence of operations in a process or part of a process. In molding, the cycle time is the period, or elapsed time, between a certain point in one cycle and the same point in the next.

DENSITY - Weight per unit volume of a substance, expressed in grams per cubic centimeter, pounds per cubic foot, etc.

EMBOSSING - Techniques used to create depressions of a specific pattern in plastics film and sheeting.

FINISH - That part of the container to which the closure is attached.

FITMENT - A device used as a part of a closure assembly to accomplish certain purposes such as a dropper sprinkler, powder shaker, etc.

FLAME TREATING - A method of rendering inert thermoplastic objects receptive to inks, lacquers, paints, adhesives, etc., in which the object is bathed in an open flame to promote oxidation of the surface of the article.

FLASH - Extra plastic attached to a molding along the parting line; it must be removed before the part can be considered finished.

FROSTING - A crystalline finish or pattern on a glass surface.

HEAD SPACE - The space between the level of the contents in the neck of a container and the closure. It is intended to furnish room for expansion of product due to heat or other action after packing.

HOT-STAMPING - Engraving operation for decorating plastics in which roll leaf is stamped with heated metal dies onto the face of the plastics.

INJECTION BLOW MOLDING - A blow molding process in which the parison to be blown is formed by injection molding.

INJECTION MOLDING - A molding procedure whereby a heat-softened plastic material is forced from a cylinder into a relatively cool cavity which gives the article the desired shape.

LARGEWARE - A name given containers manufactured on machines designed for ware of over one gallon capacity.

METALIZING - Applying a thin coating of metal to a non-metallic surface. May be done by chemical deposition or by exposing the surface to vaporized metal in a vacuum chamber.

NECK RING - That part of the mold which makes the finish.

OFFSET PRINTING - A printing technique in which ink is transferred from a reservoir to a printing plate; from the inked printing plate the image is printed on a cylindrical rubber roll (blanket) and then on to the object being printed.

PARISON - The hollow plastic tube from which a container, toy, etc. is blow molded.

PARTING LINE - Mark on a molding or casting where halves of the mold met in closing.

PHENOLIC - A thermosetting plastic made from phenolformaldehyde with wood flour binder.

POLYETHYLENE - A thermoplastic material composed by polymers of ethylene. It is normally a translucent, tough, waxy solid which is unaffected by water and by a large range of chemicals.

POLYPROPYLENE - A tough, lightweight rigid plastic made by the polymerization of high-purity propylene gas in the presence of an organometallic catalyst at relatively low pressures and temperatures.

POLYSTYRENE - Thermoplastic compound used to make plastic containers, closures and many other items.

POLYVINYL CHLORIDE (PVC) - A thermoplastic material composed of polymers of vinyl chloride; a colorless solid with outstanding resistance to water, alcohols, and concentrated acids and alkalies. It is widely used in the manufacture of containers.

PURGING - Cleaning one color or type of material from the cylinder of an injection molding machine or extruder by forcing it out with the new color or material to be used in subsequent production.

SILK SCREEN PRINTING (SCREEN PROCESS DECORATING) - This printing method, in its basic form, involves laying a pattern of an insoluble material in outline on a finely woven fabric, so that when ink is drawn across it, it is able to pass through the screen in the desired area only.

SHELF LIFE - The length of time that a container or content will remain in a saleable condition.

TOP LOAD - The amount of weight bearing on the top of a container. The term is sometimes used to indicate the maximum load the container will bear without becoming distorted.