1. Formulation and calculation for a recipe for certain rubber product 1)Analyze the property requirement for a product 2)Choose the rubber and the ingredients 3)Choose vulcanization system (CV/ EV or semi-EV) 4)Calculate total volume of the compound required considering fill factor (for internal mixer) 5)Calculate the volume of the ingredients 6)Calculate the amount of the ingredients required for the total volume of the compound Subhendu Bhandari

2. Let us try for a typical formulation (EV system) IngredientsFunctionLoading (phr) NRMatrix100 TMQAntioxidant3 ZnOAcelerator activator5 Stearic acidAcelerator activator2 DPGAcelerator4 Naphthenic oilProcessing aid/ plasticizer 5 Carbon black (ISAF) Filler40 SulfurCuring agent0.8

3. IngredientsSpecific gravity Volume of ingredients for 100 g of NR (cm 3 ) Required wt. For total 49 cm 3 volume (g) NR0.9100/0.9=111.11100x49/150.89=32.47 TMQ1.43/1.4 = 2.143x49/150.89=0.97 ZnO55/5=15x49/150.89=1.62 Stearic acid0.82/0.8=2.52x49/150.89=0.65 DPG1.34/1.3=3.074x49/150.89=1.3 Naphthenic oil0.75/0.7=7.145x49/150.89=1.62 Carbon black (ISAF) 1.740/1.7=23.5340x49/150.89=13 Sulfur20.8/2=0.40.8x49/150.89=0.26 Total vol. = 150.89 cm 3 If total volume of internal mixer = 70 cc, fill factor is 0.7 Then, required volume of the compound = 0.7x10 cm 3 = 49 cm 3 (maximum)