CPVC Production Quality Control System
1、Raw-Material Control
- PVC resin: high-grade resin with controlled molecular-weight distribution and purity.
- Chlorine gas: ≥99.5 % purity to prevent side-reactions.
2、Chlorination Process Control
- Temperature, pressure, residence time and chlorine feed rate monitored on-line; alarms and interlocks shut down feed when limits are exceeded .
- Reaction medium (solvent or suspension) selected for uniform chlorination; post-reaction washing, drying and pelletizing are performed under validated temperature and moisture limits.
3、Product Performance Testing
- Chlorine content (63–69 %) by titration.
- Thermal stability: TGA onset ≥260 °C, DSC glass-transition ≥110 °C.
- Mechanical: tensile ≥55 MPa, Izod impact ≥10 kJ/m².
- Chemical resistance: 168 h immersion in 40 % H₂SO₄ and 10 % NaClO shows <0.5 % weight change.
4、Processing Quality
- Melt flow index (MFI) 190 °C/2.16 kg 1.0–3.0 g/10 min for consistent extrusion.
- Rheological curve monitored to set optimum extruder and injection parameters.
5、Finished-Goods Inspection
- Dimensional tolerance ≤±0.2 mm (OD & wall thickness).
- Visual: no bubbles, black spots or discoloration.
- Hydrostatic pressure test: 1.5 × rated pressure for 1 h without leakage.
6、Quality Management
- ISO 9001-certified system covering incoming material to final shipment.
- Full lot traceability via barcode linked to production data and test results.
7、Environment & Safety
- Scrubbed exhaust, closed-loop water treatment; chlorine detectors and emergency interlocks protect personnel .
CPVC quality control spans raw materials, production processes, product performance, processing behavior, finished-goods inspection, quality-management systems, and environmental & safety oversight. Rigorous controls guarantee CPVC’s high performance and reliability.
