EPDM Rubber Recipe. TO MAKE CONVEYOR BELT THAT CAN WITHSTAND 250DEGC MATERIAL TEMP

1 ANSWERS

1. amomipais82
   

   Hi,
   phr = parts per hundred rubber.
   
   So you use the weight of rubber polymer as the guide.
   
   Say you have a recipe that calls for 350 grams of rubber, then for an ingredient that requires 100 phr, you add 350 grams of it. If the recipe calls for 10 phr of something else, then you add 35 gram of that.
   
   Now the more difficult bit. You asked for a generic recipe for making moulded gaskets.
   
   I can do that, but only by searching on the web -- which I am sure you can do just as easily as me. Before I give you a recipe, however, I have to give one of those warnings.
   
   The thing about rubber production is that the ingredients are only a third of the story. Another third is about how you mix those ingredients together, and the final part is about how you cure and process the mixture.
   
   So two people might take the same set of ingredients, and process them in exactly the same way, but cure them at different rates and temperatures  and the resulting products will be completely different. If you over-cure, for example, then the  component will be hard and less elastic, but have better compression set.
   
   If you cook it for a short time at a high temperature, you might get reversion and poor quality.
   
   
   Alternatively, if you fail to mix the reinforcement in properly, then the final product will not be homogeneous, with some parts harder than others.
   
   OK, having said that, I googled on "EPDM recipe carbon black" and came up with a recipe from ingredient supplier, DOG.
   
   Download the PDF here, and look at the second page
   
   www.rtvanderbilt.com/ DOG%2003018%20Deovulc%20BG187engl.pdf
   
   Each number, is, of course, in phr
   
   100.0   EPDM Keltan 4802
   100.0   Carbon black N 550
   100.0   Whiting
   100.0   Paraffin oil
   5.0       ZnO
   2.0       Deoflow A
   2.0       PEG 4000 S
   1.0       Stearic acid
   
   Calculated Specific Gravity: 1.25 g/cm3
   
   To this , you need to add the curing package. Here are two alternatives, the first is a generic, the second, is recommended as having better crosslink structure:
   
   Deovulc BG 187 powder   5.0       4.0
   CBS                                    –         0.5
   ZBEC                                  –         0.5
   Sulphur                            1.0        1.0
   
   
   Hope this helps.

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