What is the PMS and what does it measure?+
The PMS (PET Preform Measurement System) is an automated, non-contact optical inspection system for PET preforms — the injection-moulded blanks that are blow-moulded into PET bottles. It measures all critical dimensions including T (thread major diameter), E (external thread diameter), I (inside bore diameter), S (support ring diameter), neck diameter, body diameter, overall length, and wall thickness. Inspection completes in seconds with ±10 µm accuracy and up to 6 parts per minute throughput.
What are the T, E, I, and S thread dimensions on a PET preform?+
T, E, I, and S are the four standard thread finish dimensions per ISBT (International Society of Beverage Technologists) specification: T is the thread major (outer) diameter, E is the external thread diameter at the root, I is the inside bore diameter, and S is the support ring diameter. These four dimensions control cap fitment, seal integrity, and compatibility with filling and capping machinery — making them the most critical dimensions on any PET preform.
What accuracy does the PMS achieve?+
The PMS achieves ±10 µm measurement accuracy with a 1 µm least count. PET preform thread tolerances are typically ±0.05 mm to ±0.15 mm depending on the neck finish standard — the PMS operates at a fraction of these tolerances, providing a reliable guard band against false acceptance or rejection.
How fast can the PMS inspect preforms?+
The PMS inspects up to 6 preforms per minute — compared to manual gauging with ring and plug gauges, which typically takes 3 to 5 minutes per preform for a complete dimensional check. This makes the PMS suitable for 100% inspection at incoming quality control or high-frequency sampling directly at the injection moulding machine.
How does PMS compare to ring gauges and plug gauges?+
Ring gauges and plug gauges give a pass/fail answer only — they tell you whether the preform is in or out of tolerance, not by how much. They also wear over time, require periodic replacement, and produce no digital records. The PMS gives actual measured values, CPK/SPC data, full digital traceability, and completes a full 8-dimension inspection in the time it takes a gauge operator to check one dimension manually.
Can PMS generate CPK and process capability reports?+
Yes. CPK and Statistical Process Control (SPC) analysis is built into every inspection cycle. The PMS automatically computes process capability per dimension, tracks trends by shift and batch, flags out-of-control signals, and generates fully traceable reports for quality audits and customer submissions. All data is stored to the onboard 512 GB SSD with remote access via network interface.
How long does it take to set up a new preform template?+
Setting up a new inspection template takes approximately 10 to 20 minutes. The operator places a reference preform, defines the measurement points, enters nominal T/E/I/S dimensions and tolerances from the preform drawing or ISBT standard, and saves the template. Once saved, the template is recalled instantly for all future inspections of that preform design — any operator, any shift, identical results.
Which preform neck finish standards does the PMS support?+
The PMS is not limited to any specific neck finish standard — the measurement template is defined by the operator using the nominal dimensions and tolerances from the preform drawing. This means the PMS handles all ISBT-standard neck finishes (PCO 1810, PCO 1881, BPF, 30/25, 38/33 and others), as well as custom proprietary neck finishes, without any hardware changes.
