The stringent specifications to which Interplast harmonizes in order to produce the UNISOL, NOVA-PLUS and AIR-SOL pipes and fittings from U-PVC (hard or non-laminated polyvinylchloride), are certified in its state-of-the-art laboratories by experienced scientific personnel, with tests specified by European standard EN 1329
The order to release a lot is issued only after successful results reached through the following testing procedures:
Related to measurements of external diameter, wall thickness and oval of pipes and fittings by calibrated instruments. All Interplast measurement instruments are of German and Japanese manufacture and are distinguished for the exceptional accuracy of their measurements.
These are checks that examine and certify ongoing measurements carried out throughout production.
Microscopic homogenization check of the material of the pipes and fittings, and check for dispersion and size of additive particles within the material
It is related to one of the most important quality checks and it is carried out according to the specifications of international standard ISO 18553. The full compliance of the material of Unisol pipes with the specifications of the standard, translates into a certainty of pipe resistance due to lack of imperfections in the structure of the pipe and fittings’ material.
Checking of % of adjusted contraction of pipes and fittings after heating and after cooling (test of return after heating)
Specimens from each production lot remain in a lab stove at 150oC for 30min (0.5h) and after they are cooled down to 23oC the % of their adjusted contraction is measured (original measurement – final measurement) / (original measurement) x 100).
According to the specifications, the results of the measurements cannot exceed 5.0%. The results of Unisol pipes are in the order of 0.4%, which means that they are lower than the standard’s specification. This translates into certainty that the raw materials used are of the highest quality and that they are perfectly processed, and also that thermal linear expansions of the pipes during their operation are particularly low.
The advanced impact testing device that uses a dropping weight (according to standard EN 1329), consists of the dropping tower and a variety of calibrated spheres of various weights. The testing procedure and the impact speed are specified in standard EN 744.
Unisol pipes greatly exceed the requirements of the standard, with mechanical strengths during impact of heavier spheres from greater heights compared to the standard’s specifications, and mainly at temperatures much lower than 0oC, which are in the order of 3 degrees Celsius below zero (-3oC)
Tensile strength tests are performed in a tensile appliance and the elasticity and elongation factor of the material is determined in pipe and fitting specimens appropriately prepared by a special instrument. All results are recorded on a computer, where the measurements are then analyzed with the help of special diagrams.
Pipe specimens from production are placed inside a tank with dichloromethane, a strong solvent, at 15oC. The specimens remain for 30min within the tank and they are then checked for chemical alterations on their inner and outer surface, peripherally and at cross sections according to the specifications of standard EN 580. The test ensures the absence of problems when gluing pipe to pipe and pipe to fitting.