Density Gradient Column for Preform Crystallinity Testing

Glass density gradient column that determines the density and percent crystallinity of PET preform neck and gate areas. Used by preform producers to ensure the neck finish crystallisation is within spec and the body is amorphous.

Specification

Two solvents are mixed to form a linear density gradient inside a thermostated column, and calibrated glass floats mark the scale. Small preform pieces settle at their equal density level, giving crystallinity from density. It is a classic reference check for neck crystallisation and clarity.

Features

• Precision borosilicate glass column with graduations
• Thermostatic jacket maintains 23 deg C +/-0.1
• Includes calibrated density floats
• Range suitable for 1.33 to 1.40 g/cm3 PET
• Cathetometer scale for float position reading

Technical Specifications

Test standards	ASTM D1505, ISO 1183-2
Density range	1.30 to 1.42 g/cm3
Column length	900 mm, 50 mm bore
Temperature control	23 +/-0.1 deg C
Float set	Minimum 6 calibrated floats
Sensitivity	0.0001 g/cm3 per mm approx.
Bath	Circulating water jacket
Power supply	230 V AC, 50 Hz

Standard Accessories

• Calibrated float set
• Solvent mixing flasks
• Specimen basket