Continuous manufacture and casting

Process for combining at least three raw materials to produce a highly filled output product for use in a subsequent casting process, the process functioning to continuously and consistently produce acceptable products and comprising the steps of

• continuously and simultaneously feeding at least three raw materials into a combining zone in a continuous fluid flow system while measuring the amount of each of the raw materials being fed,
• the raw materials including first and second liquid constituents which react with one another to form an elastomeric binder,
• the raw materials also including a particulate, solid filler material,
• establishing continuous plug flow of the materials through the system,
• determining at intervals an average of the measured amount of each of the raw materials being fed,
• determining a time-averaged percentage composition for each of the raw materials in the output product of the system from the average amounts determined at intervals,
• comparing the time-averaged percentage composition for each of the raw materials to predetermined high and low tolerance limits for the materials in the desired output product, and
• causing time-delayed transfer of acceptable output product to the casting process only when all material percentages are within the high and low tolerance limits,
• whereby all output product from the system which is transferred to the casting process meets product specification.

Process for producing a highly filled thermosetting elastomeric output product for use in a subsequent casting process, the product being produced in a continuous fluid flow system which receives as inputs at least three raw materials in a combining zone in the system, the raw materials including first and second liquid constituents which react with one another to form an elastomeric binder, the raw materials also including a particulate solid filler material, the materials being transferred through the system in plug flow and having a residence time T from the time when the raw materials enter the combining zone until the time when mixed output product is transferred out of the combining zone, the residence time T being equal to the product of the volume of the combining zone times the degree of fill of the combining zone, divided by the total volumetric feedrate of the raw material entering the combining zone, the process including control of whether or not the output product is transferred into the casting process or to a waste outlet based upon measurements and calculations to determine whether or not the output product meets specification, comprising the steps of

• measuring the gravimetric flow rates of the respective input raw materials as they are fed into the system,
• averaging the measured gravimetric flow rates of the respective input raw materials over a time interval which is a fraction 1/n of the residence time T to obtain an intermediate flow rate value for each of the respective input raw materials,
• maintaining a running average of n intermediate flow rate values for each of the respective input raw materials over a period of time equal to the residence time T to obtain residence time average values for the respective input raw materials,
• summing all of the residence time average values for all of the input raw materials to obtain a residence time average value for all of the materials in the combining zone,
• dividing the residence time average values for the respective input raw materials by the residence time average value for all of the materials in the combining zone to determine the respective residence time percentage values of the total mix made up by each of the constituent raw materials,
• comparing each of the residence time percentage values with predetermined tolerance limits to determine if the percentage of each component within the mix is acceptable or not acceptable,
• if any one of the residence time percentage values is not acceptable, creating an indication of non-acceptability in the form of a no-go indication, and otherwise creating a go indication,
• testing the plug flow stream of mixed material downstream of the combining zone, including viscosity and density testing, over a predetermined period of time before the material is ready to be transferred to a casting process, the post-mixing testing also generating a go/no-go indication,
• delaying acting upon the go/no-go indications obtained by the comparison of the residence time percentage values with the tolerance limits and by the post-mixing testing until the passage of the predetermined period of time so that the different sets of go/no-go indications acted upon at one time refer to the same part of the plug flow stream, and
• if all go/no-go indications are go indications, diverting the plug flow output stream to the subsequent casting process, and otherwise, if any of the go/no-go indications are no-go indications, diverting the plug flow output stream to a waste outlet.