This research experimentally evaluated the mechanical performance of UPVC door and window profiles produced using three industrial formulations designated TF-01, TF-02, and TF-03, which contain varying amounts of "ACR" and "CPE" impact modifiers, as well as Calcium Carbonate (〖"CaCO" 〗_3). A comprehensive series of standard tests, including flexural modulus, tensile impact strength, material and profile Charpy impact strength, falling-weight impact test, and compression and tensile stress tests on welded corner joints, were conducted in accordance with the Iranian National Standard INSO 12291-1 and corresponding international standards, at the Plastics Technology Institute of the Roozwin Industrial Complex.

The results clearly demonstrate that the TF-03 formulation, characterized by the optimized balance of "ACR" and a reduced 〖"CaCO" 〗_3content from “36Phr” (in TF-01) to “29Phr”, yielded significant performance improvements. Specifically, TF-03 achieved a maximum tensile impact strength of “683 kJ/m2”, substantially higher than the “297 kJ/m2” recorded for TF-01. Furthermore, its profile Charpy impact strength reached “51 kJ/m2”, surpassing the minimum standard requirement (≥〖"\"45 kJ/m" 〗^2"), while TF-01 only reached “30.8 kJ/m2 kJ/m2”. Additionally, the falling-weight impact tests indicated that all three formulations exhibited satisfactory performance (zero failures in ten applied impacts). It can be stated that the reduction of Calcium Carbonate concentration to “29Phr”, by mitigating stress concentration, was a key factor enabling TF-03 to attain the highest toughness and achieve full compliance with the standard’s impact requirements.