Refractory Coat Oven Dry for Die Casting

Coated cores that are small enough to fit in some available oven are assumed to be oven dried. So this process is included when at least one coated core fits in an oven (see Refractory Coat Oven Dry Machine Selection).

This process occurs multiple times in a costing when at least one oven-dried 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 oven-dried core that has the greatest number of coats. The ith instance of the oven-dry process 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 (see formula below)

• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs.

Process Time = Oven Dry and Cool Time * Number Oven Cycles Required

This is the time to dry and cool one part’s oven-dried cores. If this is the ith occurrence of Refractory Coat Oven Dry, this is the time to dry and cool those oven-dried cores that have at least i coats. Note that the cost model assumes that each oven cycle processes a full load. Process time is the product of the following:

• Oven dry and cool time: this is the time required to dry and cool one machine load of cores. By default, it is specified by the cost model variable defaultOvenDryAndCoolTime (19 minutes in starting point VPEs). Users can override the default of a per-part basis with the setup option Oven Dry and Cool Time.

• Number of oven cycles required: this is the number of machine loads required to accommodate one part’s oven-dried cores. This value can be fractional. If this is the ith occurrence of Refractory Coat Oven Dry, only cores with at least i coats are included. The machine property Oven Type determines whether the number-of-loads calculation is area based (Conveyor) or volume based (Rack). See the formulas Number of Oven Cycles Required Area Based and Number of Oven Cycles Required Volume Based, below.

Number of Oven Cycles Required Area Based =

Total Mold and Core Projected Area /

(Machine Bed Area * Available Oven Spatial Factor)

For Conveyor machines, the number of required oven cycles depends on the following:

• Total core projected area: this is the total surface area (on the conveyor) occupied by one part’s oven-dried cores. For each core, the surface area occupied is assumed to be the projected area of the core’s bounding box. If this is the ith occurrence of Refractory Coat Oven Dry, only cores with at least i coats are included.

The cost model assumes that each core lies on the conveyor in the “flattest” orientation (with the shortest dimension vertical). So the projected area of a core’s bounding box is the product of the longest two bounding box dimensions (see Core Bounding Box Dimensions).

• Machine bed area (product of the machine properties Bed Length and Bed Width)

• Available oven spatial factor: the cost model assumes that the cores in one machine load are arranged so that the total projected area of their bounding boxes is this fraction of machine bed area. The fraction is specified by the square of the cost model variable defaultRefractoryCoatOvenSpaceAvailableFactor (0.8 in starting point VPEs). (The cost model variable specifies a linear allowance, so the area allowance is the square of this.)

Number of Oven Cycles Required Volume Based

Total Mold and Core Volume /

(Machine Bed Volume * Available Oven Spatial Factor)

For Rack machines, the number of required oven cycles depends on the following:

• Total core volume: this is the total volume occupied by one part’s oven-dried cores. For each core, this is the volume of the core’s bounding box (see Core Bounding Box Dimensions).

• Machine bed volume (product of the machine properties Bed Length, Bed Width, and Bed Height)

• Available oven spatial factor: the cost model assumes that the cores in one machine load are arranged so that their bounding boxes occupy this fraction of machine volume. The fraction is specified by the cube of the cost model variable defaultRefractoryCoatOvenSpaceAvailableFactor (0.8 in starting point VPEs). (The cost model variable specifies a linear allowance, so the volume allowance is the cube of this.)

Core Bounding Box Dimensions

Core bounding box dimensions are specified by the following geometric properties of the cored GCD:

• Simple Hole:

o Diameter (used for two of the three bounding box dimensions)

o Length

• Multistep Hole or Ringed Hole:

o Total Length

o Max Diameter (used for two of the three bounding box dimensions)

• Void or Combo Void:

o Box Length

o Box Width

o Box Height