Do you Know Your Glass Terms?

ANNEALING - is a process of holding a material at a temperature near, but below, its melting point to permit stress relaxation without distorting the shape. A controlled cooling that prevents additional stress is often part of the process. It is often used to relieve stress created in the manufacturing processes of forming and cooling of parts.

CAPACITY - is the measure, by volume, of the maximum amount that can be contained in a vessel.

CAVITY - is the female component of a mold that forms the outside shape of an object when glass is introduced into mould. Moulds may contain single cavities or multi-cavities. These cavities are produced by machining, hobbing or electrical discharge equipment.

CONTINUOUS THREAD - is a continuous helical bead extending around the neck of a container onto which a closure, with a matching helical bead, is screwed.

CRAZING - is very fine cracks which form a network either on, or under the surface, or through a layer of glass material.

CULLET - is recycled broken glass that is used in the manufacture of new glass.

CYCLE - is the complete repeating sequence of the operation in a specific process in molding. Cycle time is measured by the elapsed time between a point in one cycle ti the same point in the next.

DEBOSSING - is a technique used to create pattern or designs that are recessed below the surface of moulds for easy reproduction on moulded parts.

DENSITY - is the weight of a gas, liquid or solid substance for a given unit of volume. For example: 1 gram of pure water occupies I ml of volume and 1 cubic centimeter of space.

FINISH - is the upper portion of a container in which the threads for capping are located.

I.D.- Inside diameter or inside dimension.

JIG - is a tool. or fixture, that is used for holding a component that's to be worked on during the manufacturing, assembly or decorating process.

LABEL PANEL - Is the portion of a container designed to accept a decoration or label.

LEHR - is a continuous-belt oven for annealing, fusing ceramic color and control cooling of glass.

LUG THREAD - is an intermittent, external protrusion extending around the neck of the container thread, lug style tread does not have a continuous bead.

MOULD - is the tool used to form the shape of the desired product in a repetitive manner.

MOULD SEAM - is a line formed on a moulded part where mating halves of a mould meet.

MULTI-CAVITY MOULD - is a mould with two, or more, cavity positions. These moulds are capable of making more than one part per machine cycle.

NECK - is the portion of a container, including the orifice, to which a closure is attached.

NECK RING - is a mould component that forms the outside of the bottle finish.

OD - is an acronym for outside diameter or outside dimension.

ORIFICE - is the opening in a container through which product is dispensed. Its size and design are commonly specified on dispenser caps and fitments to control the delivery of contents.

ORIFICE REDUCER - is a plug, or fitiment that is formed with a controlled-diameter opening through which the product is dispensed. These fitments are inserted into the I.D. of a bottle finish.

OVERCAPS -are a secondary closure of metal or plastic that fits over the primary closure or seal mechanism. The overcap protects the primary closure from accidental dispensing. Also, the overcaps can unify the total package design.

OVERFLOW CAPACITY - is the volume measurement of a container to the point of overflow.

PARISON - is a hollow glass tube used in the blow moulding process. Air pressure is introduced into the tube to form a container.

PLUG - is a closure that is pressed into a bottle neck opening to close off the passage.

PUSH-UP - describes the bottom contour of a glass or plastic container designed to allow an even bearing surface on the outside edge to prevent the bottle from rocking.

RECYCLE - is the ability to capture, reprocess and reuse a primary material in a productive manner after its first use has been completed.

SHEAR STRENGTH - is the measurement of a material that will withstand a shear force or pressure.

SCREEN PROCESS DECORATING - is the printing method of passing an ink or paint through a patterned, woven fabric screen onto the desired areas of the object to be decorated. A screen can be made photographically by coating the mesh with a light activated insoluble material. When the coating is washed out, the desired image remains on the open mesh.

SRAY FROSTING - is the technique of spry-coating glass containers to create a frosted, matte translucent appearance.

STIPPLING - is the engraving of a mould to produce a system of closely-spaced dots that are raised on surface of plastic or glass container.

STORAGE LIFE - is the time that a product can be stored safely and remain suitable for use.

TAMPER-EVIDENT - is any device that will show visible signs that the container has been opened

TORQUE - is the measurement of force needed to apply, or remove, a threaded closure from a threaded bottle finish. The common measurements is in inch pounds.

TRANSFER BEAD - is a continuous bead located directly under the finish. The transfer bead is used in the forming process to assist in removing the container from the mould section of the glass forming machine.

VENT - is a shallow channel or tiny hole in the cavity of a mould that allows resident-air and gases to escape as the material enters a cavity.

VIAL - is a cylindrical container often made from glass tubing.

WIDE MOUTH - are containers with a large finish-opening or those that have a large finish size in proportion to their capacity.