Kahulugan at Layunin
4.1 Specular gloss is mainly used to measure the gloss appearance of films and surfaces. A precise comparison of gloss values is meaningful only if the same measurement procedure and the same general material type are involved. Sa partikular na, the gloss values of transparent films should not be compared with those of opaque films and vice versa. Glossiness is a complex property of surfaces that cannot be measured entirely by any single number.

4.2 Specular gloss usually varies with surface smoothness and flatness. It is sometimes used for comparative measurements of these surface properties.

ASTM D 2457-2021 Standard Test Method for Specular Gloss of Plastic Films and Solid Plastics

Saklaw ng
1.1 The test method describes procedures for measuring the glossiness of opaque and transparent plastic films and solid plastics. It contains four independent gloss angles (Tala 1) :

1.1.160 mga degree, recommended for medium light films,

1.1.220 mga degree, recommended for high light film,

1.1.345 mga degree, recommended for medium and low light films,

1.1.485 mga degree, recommended for medium and low gloss films, pati na rin ang

1.1.575 mga degree, recommended for plastic siding and soffit.

Tala 1: The measuring devices and methods of 85 mga degree, 75 mga degree, 60 degrees and 20 degrees are repeated with those in test methods D523 and D3679; The equipment and methods for the 45° procedure were also taken from test method C346.

1.2 Ang pamantayang ito ay hindi nilayon upang matugunan ang lahat ng mga isyu sa kaligtasan, kung meron man, na nauugnay sa paggamit nito. Responsibilidad ng gumagamit ng pamantayang ito na magtatag ng angkop na kaligtasan, mga kasanayan sa kalusugan at kapaligiran at upang matukoy ang pagiging angkop ng mga paghihigpit sa regulasyon bago gamitin.

ASTM D 2457-2021 Standard Test Method for Specular Gloss of Plastic Films and Solid Plastics

Tala 2: There is no known ISO equivalent to this standard.

1.3 Ang internasyonal na Pamantayang ito ay binuo alinsunod sa mga internasyonal na kinikilalang prinsipyo ng standardisasyon na itinatag sa Desisyon sa mga Prinsipyo para sa Pag unlad ng Internasyonal na Pamantayan, Mga Patnubay at Rekomendasyon na inilabas ng Komite sa mga Teknikal na Hadlang sa Kalakalan ng World Trade Organization.