PET sheet is thermoformed into trays for freezer to oven or microwave meals, pre-prepared snacks or airline meals and also packaging for medical devices. Applications include strapping tape, photographic film, video tape and food trays. The higher the tensile, burst, impact or temperature specification, the higher the IV. Amorphous and crystalline grades of PET are extruded as sheet or film mostly for the packaging industry. Out of specification high IV PET waste can be recycled or reused to make fibre or strapping tape. Polyester used in the fibre and textile industries is the amorphous or low IV form of PET. It can also be used in R&D laboratories, technical support departments and in PET plants to monitor the critical stages of the polymerisation process.īy far the largest application for PET is bottles for colas and carbonated drinks, mineral water and edible oils, cosmetics and personal care products. Routine testing carried out on the shop floor leaves skilled laboratory staff more time for other work. Once the sample is dried, tests can be completed in less than 20 minutes.
#High vs low viscosity plus#
The PET Plus Intrinsic Viscosity Measurement Instrument is robust and simple enough for use on the shop floor. These and other characteristics change with time and environmental conditions, whereas the IV of the material does not. According to the resin suppliers and manufacturers of injection and blow moulders, it is an indirect method showing the ability of a preform to blow to a certain size.
#High vs low viscosity free#
The free blowing method does not measure the IV of the material itself. Other factors such as health and safety requirements for working with solvents, consideration for the environment and the need for specialist personnel to carry out these tests (which must be carried out in a laboratory) add to the high popularity of the solvent-free method, which has been used by the world’s major resin producers and processors as a tried and tested method for measuring the IV of PET and other hygroscopic polymers. Methods involving the dissolution of the polymer in halogenated solvents are costly both in terms of solvent purchase and disposal. This is a powerful alternative to both solvent-based techniques and the free blowing method. One technique that fulfils these needs uses a unique solvent-free method based on the extrusion of the polymer through a die using a dedicated instrument such as the Davenport PET Plus Intrinsic Viscosity Measurement Instrument. Intrinsic Viscosity (IV) Measurement Methods With such a variety of applications and measurement locations, the need for an easy, safe, accurate and repeatable measurement method is of paramount importance. Twenty four hour process lines and recyclers routinely test incoming resin, the dryers and extruders and finished product. Material is tested at all stages from the R&D laboratories who develop new polymers and chemical companies who draw off samples from their polymerisation towers to the processors who want to control their process and quality of finished goods. The IV is used as part of the specification to select the right grade of PET for a particular application, and is measured at various points of the supply chain. Intrinsic Viscosity (IV) is a measure of the polymers molecular weight and therefore reflects the material’s melting point, crystallinity and tensile strength. The polymer chain length in PET determines the molecular weight of the material and with it the physical properties that make PET such a useful packaging material. Career - Shape Your Future with AMETEK STCīy: Toby Rogers, Director of Lloyd Instruments Materials Testing Equipment and Chatillon Force Testing Instruments.Talent Development, Diversity & Inclusion.Looking to Replace your Test Equipment?.International Standards - Wire, Yarn and Thread.International Standards - Textiles and Fabrics.International Standards - Plastics and Rubber.
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