Core Refractory Coat for Sand Casting
This process occurs multiple times in a costing when at least one core receives multiple coats (see Number of Coating Applications). The number of times the process occurs is the number, N, of coats applied to that core that has the greatest number of coats. There are N instances of Core Refractory Coat, where the ith instance includes the cores that receive at least i coating applications, for all i between 1 and N.
Cycle Time = Process Time * Cycle Time Adjustment Factor
Cycle time is the product of the following:
• Process time: this is the sum of the times required to coat each core that receives a coat in the current instance of this process. (If this is the ith instance, all cores that receive at least i coats are included.) See the formula for Process Time Core Refractory Coat, below.
• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs.
Process Time Core Refractory Coat =
(Total Surface Area / Application Rate per Mold) / Number of Operators
This is the time required to apply one coat to the core for a given cored feature. It depends on the following:
• Total surface area: this is the area covered by one coat applied to the core for the given feature. It is 0 the core is not coated. For Voids, it is Surface Area. For holes, it is the sum of the values of Finished Area for all the feature’s descendent surfaces. (Descendent GCDs include children, children’s children, and so on, recursively.) For Combo Voids, it is the sum of the values of Finished Area for all the feature’s descendent surfaces, as well as Surface Area for all the feature’s descendent voids.
• Application rate: this is looked up by Application Method in the lookup table tblRefractoryCoating.
The value is converted to square millimeters per second for use in this formula.
• Number of operators: by default, this is specified by the cost model variable defaultMoldRefractoryCoatingNumOperators. (1 in starting point VPEs). Users can override the default on a per-part GCD with the setup option Number of Operators.
This value is rounded up to a whole number of seconds.
Additional Direct Costs
Additional direct costs include the cost for the volume of refractory coating material used for all cores that receive a coat in the current instance of this process. (If this is the ith instance, all cores that receive at least i coats are included.) See the formula for Additional Direct Costs Core Refractory Coat, below.
Additional Direct Costs Core Refractory Coat =
(Coating Volume * Refractory Coating Cost * Number of Operators) / Final Yield
This is the cost for the volume of refractory coating material used for one coat of the core for a given coated core. It depends on the following:
• Coating volume: volume of refractory coating material applied to the core by one operator during the current process. See formula.
• Refractory coating cost: unit cost of the coating material, specified by the toolshop variable refractoryCoatingCost.
• Number of operators: by default, this is specified by the cost model variable defaultCoreRefractoryCoatingNumOperators. (1 in starting point VPEs). Users can override the default on a per-part basis with the setup option Number of Operators.
• Final yield (see Yields for Sand Casting)
Coating Volume = Process Time * Coating Output Rate
This is the volume of refractory coating material applied to the core by one operator during the current process. It is the product of the following:
• Process time (see formula)
• Coating output rate: this is the volume per unit time of coating material that is expended during application. It is looked up by Application Method in the lookup table tblRefractoryCoating.
• This value is converted to liters per second for use in this formula.