1440 Timberwolf Drive, PO Box 964, Holland, OH 43528-0964 USA | 1 (419) 867-5400 | Email Us

1440 Timberwolf Drive, PO Box 964, Holland, OH 43528-0964 USA
1 (419) 867-5400 | Email Us

Region Location

1440 Timberwolf Drive
PO Box 964
Holland, OH 43528-0964 USA

Cystallinity: Gradient Column

Sample Type Required Quantity Equipment Used
Preforms Bottles 5 Techne Density Gradient Column

Purpose

This procedure determines a sample density and correlates that density to crystallinity using theoretical PET amorphous and crystalline densities according to ASTM D1505.


Description

Five samples are prepared by cutting approximately 1/4" samples from a preform or bottle without touching the samples to prevent oils from disturbing the testing. The entrapped air is removed from the surface of the sample and the samples are then dropped into a density gradient column and allowed to settle for approximately 15 minutes. The height of the samples is then carefully measured. Standard density balls are used to calibrate the density of the column. The sample density is then correlated to the theoretical amorphous (1.3331) and crystalline (1.45234) PET densities to determine the % crystallinity.