Standard Test Methods for Impact Resistance of Rigid Poly(Vinyl Chloride) (PVC) Building Products

Importancia y uso:

5.1 The impact strength values obtained on the flat sections of a building product profile are relevant only to the flat section that has been tested and these values do not necessarily indicate the impact resistance of the whole product, which is affected by the configuration of the profile (that is, corners, ribs, etc).

5.2 Constant weight and variable height, employed in these test methods, allow the velocity of impact to vary and, therefore, by Procedure B, can determine the energy of ductile-to-brittle transition, which cannot be determined if a variable weight is dropped from a constant height.

5.3 These test procedures have been found to be useful elements in rigid poly(vinyl chloride) (PVC) building product characterization. Compound qualification, finished product quality control, environmental and weatherability research and development studies, and fabrication tolerance prediction constitute useful applications.

FIG. 2 Impact Tester

5.4 Choice of the specific impactor head configuration used is related to a variety of product attributes, such as specimen thickness and product toughness as well as abstract factors, such as the anticipated mode of failure in a specific application. The geometric uniqueness of the impactor head configurations prevents any comparison or correlation of testing results on samples tested with differing impactor head configurations. In general, the conical impactor, C.125, is useful to ensure failure of thicker specimens where the H.25 impactor caused no failure.

Note 2: Equivalent surface conditions are more likely to occur when specimens are prepared by compression molding or extrusion than by injection molding.

5.5 When comparing different samples tested with the same impactor head configuration, impact resistance shall be permitted to be normalized for average specimen thickness over a reasonably broad range (for example, 1 to 3 mm).3 However, this should only be done when the surface conditions listed in 6.1 are essentially equivalent.

Subcomité:

D20.24

Referida por:

D4726-24, D7793-24, D8427-21, F0964-13R24, D5420-21, D7254-21, D4477-24, D3679-24, F1735-21, D7445-24, D4216-22, F3459-21

Volúmen:

08.03

Número ICS:

83.080.20 (Thermoplastic materials)

Palabras clave:

brittle failure energy; building products; failure energy; falling weight; impact test;