A PET bottle is only as good as its preform and the blowing process, and defects such as haze, thin spots or leaking necks show up too late if testing is left to the customer. As stretch blown testing instruments manufacturers in India and suppliers in India, we supply the preform and bottle instruments a PET plant lab needs.
Testing is arranged in two stages. Preform checks include the polariscope for residual stress, density gradient column for crystallinity, gate and dimension gauge set, intrinsic viscosity viscometer and acetaldehyde analyzer for resin and process quality. Bottle checks include the thickness profile scanner, brimful capacity station, top load crush tester, combined load pressure torque tester and the drop impact rig.
A new PET line usually starts with the stress polariscope, gauge set, thickness scanner and top load tester, and then adds viscometer and acetaldehyde analysis as quality demands grow.
Last updated: November 2026
Drop test rig that drops filled PET bottles from set heights onto a concrete or steel plate. Used for validating bottle design and base petaloid geometry.
Rotating bottle scanner that maps sidewall thickness at many heights and angles. Used by stretch blow molders to tune preform heating and blow settings and to find thin zones.
Balance based station that determines brimful capacity of bottles by weighing water filled to the rim. Used to check bottle volume tolerance from stretch blow molding.
Combined test stand that checks top load, internal pressure resistance and closure torque of finished PET bottles on one frame. Used by stretch blow plants for final bottle qualification against customer drawings.
Automatic capillary viscometer for intrinsic viscosity of PET resin and preforms in a thermostatic bath. Used by preform makers to check molecular weight and degradation during drying and molding.
Headspace gas chromatograph set up to measure residual acetaldehyde in PET preforms and bottles. Used by water and carbonated drink packers to control off-taste risk.
Polarized light viewer that reveals residual stress and crystallinity in injection molded PET preforms. Used by preform makers and stretch blow molders to spot gate and neck stress before blowing.
Glass density gradient column that measures density of PET preform sections to estimate crystallinity of neck, gate and sidewall. Used by preform makers to check crystallization and stretch quality.
Combined gauges for neck finish, preform length, wall thickness and gate dimensions of PET preforms. Used by injection molders and bottle makers to inspect preforms before stretch blowing.
Compression tester that applies vertical load on empty or filled PET bottles to find top-load strength. Used by bottlers and bottle makers to confirm that a bottle design will survive stacking and pallet loads.
| Function | Products | What to confirm |
|---|---|---|
| Preform quality | PET Preform Stress Analyzer with Polariscope, Preform Crystallinity Density Gradient Column, Preform and Bottle Gate Thickness and Dimension Gauge Set | Polariscope field size, column temperature stability, and gauge coverage for your neck finish and preform lengths. |
| Resin quality | PET Intrinsic Viscosity Tester Automatic Viscometer, PET Preform Acetaldehyde Content Analyzer | Viscometer solvent system and temperature bath, GC detector type and headspace sample conditions for acetaldehyde. |
| Bottle strength | Top Load Crush Tester for Stretch Blown Bottles, Combined Load Pressure Torque Tester for PET Bottles, Bottle Drop Impact Tester for Stretch Blown PET Containers | Load range, pressure limit, torque range, drop height and whether filled and empty bottles are tested. |
| Bottle geometry and volume | Bottle Thickness Profile Scanner for Stretch Blown Bottles, Bottle Volumetric Capacity and Brimful Measuring Station | Bottle height and diameter range, scan resolution, balance capacity and brimful method. |
Stretch blown instruments are tuned to biaxially oriented PET: preform stress, crystallinity, intrinsic viscosity, acetaldehyde and carbonated bottle strength. Blow moulding instruments serve extrusion blown HDPE, PP and PVC containers and cover pinch-off weld, parison swell, drum compression and stress cracking. A plant making both PET and HDPE bottles would use each set for its own process.
See also: Blow Molding Testing Instruments
The complete Stretch Blown Testing Instruments range (10 products), in alphabetical order:
Confirm the viewing aperture fits your largest preform, and that the light source and polarising filters give an even field. Ask if a quarter wave plate or colour reference is included, since stress patterns are compared with a reference. Check mounting for preform rotation so the entire body and gate can be viewed.
Pick a load range with comfortable headroom above your bottle top load, often 500 N to 5 kN. Check platen parallelism, speed settings and whether the tester can be programmed for a fixed deflection. The test relates to stacking and capping force, so compare readings between empty and filled samples.
A rotating scanner using a probe maps wall thickness in rings and presents a profile along the bottle height. Check bottle size range, probe type, number of readings per bottle and software reporting. Thickness profiles show if stretch ratio, preform temperature or blow pressure needs adjustment.
PET bottle and preform manufacturers, contract blowers for water, carbonated drinks, edible oil and pharma bottles, beverage brand owners with in-house QC, and packaging test labs. A new bottle line normally orders the polariscope, gauge set, top load tester and thickness scanner together, then adds the viscometer, density column and acetaldehyde analyser.
Acetaldehyde is a by-product of melting PET and can migrate into water and drinks, giving a fruity off taste. Headspace gas chromatography measures it, and the result guides melt temperature and residence time control.
It is a measure of the polymer chain length in PET resin. Lower values mean weaker bottles and poor stretch behaviour, so resin lots are checked on receipt and again after moulding to see how much degradation occurred.
A density gradient column holds liquids of graded density. A preform piece floats at its own density level, from which crystallinity is calculated. High crystallinity near the gate causes haze and poor blowing.
Yes. We manufacture the instruments in India and supply plants, test labs and distributors across the country and for export orders. Specifications and drawings can be prepared for tenders and on-site installation can be arranged.
Brimful capacity is the volume of liquid the bottle holds when filled to the top of the neck. A balance based station weighs the water and calculates the volume, so bottle dimensions and blowing consistency can be monitored.
We are leading manufacturers and suppliers for tender requirements from India, serving civil laboratory and industrial testing tenders and supplying mechanical engineering and testing laboratory equipment in bulk and on OEM terms. Send us your tender specifications, and a complete quotation for Stretch Blown Testing Instruments will be prepared accordingly.
Send us your equipment list or tender specification. We quote against IS, BS, EN, ASTM and AASHTO standards and ship to 90+ countries.
