Terephthalate Bottles Research Articles

Effect of Internal Gas Pressure on the Compression Strength of Beverage Cans and Plastic Bottles

Abstract This study investigated the compression strength of various sized polyethylene terephthalate (PET) bottles and steel and aluminum two-piece cans. Compression tests were performed on both empty and filled containers under pressure. A stress analysis is developed to provide a simple prediction formula. The predictions are shown to be in fair agreement with actual values obtained from the compression tests. The results show that internal pressure can increase the compression strength of a beverage package by as much as three times. Erratum to this paper appears in 21(4).

Vortex‐Induced Loadings on Taut Cables with PET Shrouds

The hydrodynamic forces on taut nylon cable segments with PET shrouds in steady uniform flows are determined experimentally. Commercial 1.25 L (polyethylene terephthalate (PET) bottles are used as shroud material; the cable used has a diameter of 2.1 cm. The range of flow velocity is from 0.25 to 1.35 m/s. Both inline and transverse force coefficients are given as functions of the reduced velocity for three test models: Bare cable; cable with 50% area perforated shrouds; and cable with nonperforated shrouds. Comparisons of the dominant vibrating-force coefficients indicates that a cable with 50% area perforated shrouds may be a good candidate for fish and kelp aggregation devices.

Processing PET bottles into high-purity flake

This work gives a quantitative insight to the parameters governing a series of unit operations which were assembled to convert poly( ethylene terephthalate) (PET) bottles into a high-purity flake of PET suitable for end use or further chemical conversion. The interest in developing a relatively simple but effective mechanical system for processing PET bottles is related to the fact that approximately 75% of the more than 400,000 Mg of PET consumed in the U.S. is used in the manufacture of soft-drink containers [ 11. Other estimates [ 21 give somewhat lower amounts, corresponding to PET bottles yielding 165,000 Mg of PET and 60,000 Mg of high-density polyethylene (HDPE) per year. Although it is believed that as much as 25% of these containers are returned, their fate in terms of the manner of processing, reuse etc. is not clear. Present practice would indicate that the majority of the PET bottles become part of municipal solid waste streams destined for conventional disposal via landfill, incineration, etc. Various social and technical issues influence the manner in which PET can be reused. For example, although there is no regulation barring the reuse of PET bottles for food containers [ 31, general sanitary considerations [ 2, 41 presently preclude this mode of reuse. Presumably, the subsequent thermal processing of recovered PET would negate these concerns. However, a valid technical concern regarding the reuse of PET, for example for the popular twoliter bottles, is related to the fact that the slight decrease in intrinsic viscosity of the polymer which occurs in the reprocessed material has a deliterious effect on strength and formability when new bottles are made [ 31. In addition, recycled PET from two-liter bottles does not have the preferred molecular weight for film or textile fiber applications [ 21. Consequently, contrary to the claims made in 1977 regarding the ease of recycling, when polyester containers were first introduced [ 51, it appears that in addition to the limited applications as a filler material (fiber fill, stuffing, etc.) the promise for recycling PET lies in