ASTM D3184-11 pdf free.Standard Practice for Rubber - Evaluation of NR (Natural Rubber). ASTM D3184 covers the standard materials, test formulas, mixing procedures, and test methods for the evaluation and production control of natural rubber (NR). 5. Sample Preparation 5.1 For tests intended for referee purposes obtain and prepare the samples in accordance with Test Methods D1485. 6. Mixing Procedures...