Glass Packaging Institute the glass finish number. For example, an 8-425 finish is approximately 8 mm neck outside diameter with a 425 finish corresponding to a threaded neck typically found on small vials. Glass Packaging Institute The Glass Packaging Institute (GPI) is the North American trade association for the glass container industry, headquartered in Arlington, Virginia. Through GPI, glass container manufacturers advocate job preservation and industry standards, and promote sound energy, environmental, and recycling policies. The GPI membership consists of 5 glass container manufacturing member companies, and 33 supplier member companies, who provide raw materials, recycled glass, equipment, decorating, and other services to
Thermal expansion shows the normal positive thermal expansion. The thermal expansions of liquid is usually higher than in solids because of weak intermolecular forces present in liquids. Thermal expansion of solids usually shows little dependence on temperature (except for low temperatures) whereas liquids expand at different rates at different temperatures. The expansion of liquids is usually measured in a container. When a liquid expands in a vessel, the vessel expands along with the liquid. Hence the observed increase in volume of the liquid level is not actual increase in its volume. The expansion of the liquid relative to the container is called