Sheet Plastic Material

The Sheet Plastic cost model supports thermoplastic material sheets, for example some forms of acrylic, polycarbonate, polypropylene, and ABS.

Note: The Sheet Plastic cost model represents materials only in their sheet form. Pellet forms are not supported.

You can view the supported materials in the Material Selection window in the aPriori UI or in the Sheet Plastic section of the Digital Factory. For more information, see the relevant sections in the aPriori Professional User Guide and the Digital Factory Administration Guide.

The Sheet Plastic cost model uses virtual sheet stocks by default. You can add your own stock using the Digital Factory Manager, in which case aPriori will select these in preference to virtual stock, so long as the stock meets feasibility requirements (see Thermoforming Feasibility).

Sheet Plastic Material Composition

The following are a selection of key Sheet Plastic material composition properties, several of which affect the cost of the Sheet Plastic component.

Property	Description
Name	Reference field containing the specific name of the material.
Description	Reference field containing material descriptors.
Material Type	Reference field containing the generic name of the material type.
Unit Cost	Cost per mass of the unconverted raw plastic material.
Normal Forming Temp	The temperature at which the sheet is normally formed. A higher normal forming temperature requires additional time for heating and cooling the sheet, resulting in a higher Cycle Time and associated cost.
Upper Forming Temp	A temperature at the upper end of the range at which the material can be formed.
Lower Forming Temp	A temperature at the lower end of the range at which the material can be formed.
Set Temp	The temperature at which the sheet is considered structurally stable for release from the mold. A higher set temperature means the sheet becomes stable more quickly, resulting in a lower cooling Cycle Time and associated cost.
Oven Temp	The oven temperature required to heat the material to the forming temperature.
Mold Temp	The temperature of the mold tool in which the part is formed.
Specific Heat	The specific heat of the material melt. Used to calculate thermal diffusivity.
Thermal Conductivity	The thermal conductivity of the material melt. Used to calculate thermal diffusivity.
Emissivity	The effectiveness of the material in emitting energy as thermal radiation.
Density	Material density. More dense materials result in a greater mass per sheet and affect cost based on the material’s unit cost.
Heat Time Per Unit Thickness	The time required to heat the material. The heat time is based on a time per unit thickness of the material.
Max Draw Ratio	The maximum depth to width ratio of features that this material can be used to form. aPriori calculates the overall draw ratio based on the component’s geometry. The calculated draw ratio must not exceed the maximum draw ratio for the material shown in this field.
Morphology	Reference field that affects average cooling thermal diffusivity. Crystalline material has a lower average thermal diffusivity than amorphous material, resulting in a higher Cycle Time and associated cost.

Sheet Plastic Material Utilization

You can specify how aPriori should calculate material utilization using the Material Selection window. For details, see Material Cost and Utilization for Sheet Plastic.