ASTM D706-98 pdf free.Standard Specification for Cellulose Acetate Molding and Extrusion Compounds.
Materials supplied shall be as uniform in compositionand size, and as free of contamination, as can be achieved bygood manufacturing practice.
These materials may contain colorants in the nominalamounts ordinarily employed, but such additives shall not alterthe ability of the materials to meet the specified properties.6.3 The color of material supplied shall be comparable,within commercial match tolerances,to the color of standardsamples prepared by the manufacturer.Grade 2 materials shall be verified by the manufacturerto be of extrusion quality.
Test specimens of the material shall conform to therequirements prescribed in Table CA.Molded specimens, for those tests requiring them, shallbe prepared in accordance with Section 10. Conformance to the requirements of this specificationshall be determined in accordance with Section.The material shall be sampled in accordance withSections 9 to 12 of Practice D 1898. Adequate statisticalsampling prior to packaging shall be considered an acceptablealternative.For sampling purposes, a batch or lot shall be considereda unit of manufacture as prepared for shipment and may consistof a blend of two or more production runs of material.Routine testing of each batch or lot shall be limited toproperties designated in Table CA of this specification.
One set of samples for those tests that are designated(Section 12) shall be considered sufficient for testing the batchor lot. The average results from those samples shall complywith the requirements prescribed in this specification.
If any failure occurs, the materials may not be certifiedto this specification.
Physical property requirements in Table CA are basedon injection molded specimens 3.2mm thick. Specimensmachined from compression-molded blanks or extruded stripsmay be used，provided it can be shown that the results arecomparable.
Prior to molding cellulose acetate, dry the material to amoisture content of 0.2 % or less. The primary reason fordrying the material is to eliminate visual defects such assurface imperfections and bubbles. Material spread in a tray toa maximum depth of 50 mm and exposed in a circulating-airoven at 75 to 90°C for 3 h should be satisfactory.ASTM D706 pdf download.