What is Specific Gravity Testing?

The Specific Gravity Test may be performed on specimens of Injection molding, Extrusion, Sheet-stock & Profiles, etc. Two (2) Specific Gravity Test methods currently exist for this standard (A &B).

1.2.1 Specific Gravity Test  Method A --For testing solid plastics in water, and

1.2.2 Specific Gravity Test Method B--For testing solid plastics in liquids other than water.

Note 1--Alternatively, Test Method D1505 may be applied to many such forms, as well as to films and sheeting.

1.3 The Specific Gravity Test values stated in SI units are to be regarded as the standard.

Specimens are conditioned in a lab environment and inspected for defects or imperfections prior to testing. Olefin materials are well known for using this test as a quality control measure for incoming materials.

Although Specific Gravity and Density are sometimes termed the same, there are differences in each method. Specific Gravity is the ratio weight of water of a given volume of material at room temperature (this test may also be conducted in a methanol environment). This is expressed as Specific Gravity 23/23⁰C.

Density is the weight per unit volume of material at room temperature, and is expressed in g/cm3.

Specimens: 2" Disks x 1/8" thick. For Sheet material 1" X 3" is the standard. Specific Gravity Testing can also be done on pellets. CRT will mold a specimen for the Specific Gravity Test.

Should you need additional information about CRT Laboratories' Specific Gravity testing capabilities please contact us via our RFQ Form or call us at (714) 283-2032. You may fax a request for a proposal at (714) 283-1365.