Thermoforming processes
aPriori models costs of thermoforming by drape forming or vacuum forming, based on the number of cavities.
• Single, 2x1, and 2x2 Cavity Drape Forming – In this process, the heated sheet is formed over a positive mold.
• Single, 2x1, and 2x2 Cavity Vacuum Forming – In this process, the heated sheet is formed in a negative mold.
These processes are for heavy-gauge thermoforming, with an initial sheet thickness of 2mm (0.120 inches) to 13mm (0.500 inches).
You can configure the drape forming and vacuum forming processes to include pre-stretching and pressure assist. Pressure assist is only supported for vacuum forming, but plug-assisted pre-stretching is supported for both thermoforming processes.
To configure the common thermoforming process
1 Do one of the following to display the Process Setup Options window:
• If a mold branch node (Single Cavity Mold, 2x1 Cavity Mold, or 2x2 Cavity Mold) is included in the current routing, right-click the node in the Manufacturing Process pane and select Process Setup Options from the context menu.
• If the node is not included in the current routing, select Edit > Routing Selection in the Manufacturing Process pane to display the Routing Selection window, then right-click the node and select Process Setup Options from the context menu.
2 Modify any of the following component cost driver options:
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Two cavities mold orientation | For the 2x1 Cavity Mold process, aPriori assumes the two cavities are oriented along the part length direction, but you can select Along the Part Width Direction from the drop-down list to model the costs associated with that mold orientation. This option is available only for the 2x1 Cavity Mold process. |
Initial sheet sizes | aPriori automatically calculates the dimensions of the sheet required to create the component. |
Initial sheet length | aPriori automatically calculates the initial sheet length based on the component’s geometry and the stretch factor of the selected material, but you can select Override Initial Sheet Length and enter a value to specify the length manually. |
Initial sheet width | aPriori automatically calculates the initial sheet width based on the component’s geometry and the stretch factor of the selected material, but you can select Override Initial Sheet Width and enter a value to specify the width manually. |
Colorant cost | aPriori uses a colorant cost based on gray by default. You can select another colorant cost from the Colorant Cost drop-down list or select Override Colorant Cost and enter the exact cost of the colorant pellet in the field. |
Let down ratio (LDR) | aPriori uses a default let-down ratio to model the percentage of colorant pellets to plastic pellets by mass. For example, a let-down ratio of 0.04 means that there are four kilograms of colorant pellets and 96 kilograms of plastic pellets in 100 kilograms of material. You can select Override Colorant Let Down Ratio and enter a value in the field to specify the percentage of colorant pellets manually. |
3 Modify any of the following tooling cost driver options:
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Number of undercuts | An undercut is required when a part has a “T” shape, where the top of the mold must collapse so that the part can be drawn out of the bottom of the mold. aPriori automatically calculates the number of undercuts based on the component’s geometry, but you can select Override Number Of Undercuts and enter a value in the field to specify the number manually. |
Undercut handling | This option lets you specify whether a mold contains a removable (core) or actuated insert. Actuated inserts expand and contract to allow the part to be removed from the mold. aPriori assumes that removable inserts are used, but you can select Actuated Inserts from the drop-down list to include the costs associated with this type of mold insert. |
Mold frame standard | aPriori assumes that the molds used for sheet plastic have the basic mold frame, but you can select High Quality Mold Frame from the drop-down list if you want to model the costs associated with higher quality molds. |
4 Click OK to save your changes and close the window.
5 Click OK on the Routing Selection window to close the window and re-cost the component using the modified processes.
You can click Apply to re-cost the component without closing the window
To configure the drape forming and vacuum forming processes
1 Do one of the following to display the Process Setup Options window:
• If a thermoforming process is included in the current routing, right-click the node in the Manufacturing Process pane and select Process Setup Options from the context menu.
• If the process is not included in the current routing, select Edit > Routing Selection in the Manufacturing Process pane to display the Routing Selection window, then right-click the node and select Process Setup Options from the context menu.
2 Modify any of the following options:
• Cooling time – aPriori automatically calculates the time required to cool the plastic sheet before it can be removed from the mold based on sheet thickness and material type, but you can select Override Cooling Time and enter a value in the field to specify the cooling time manually.
• Pressure forming required – aPriori automatically calculates the additional costs associated with pressure-assisted forming, including tooling and machine cost increases as well as the change in forming time. This option is available only for vacuum forming.
• Pre-stretching required – aPriori automatically calculates the cost of pre-stretching the heated sheet using temperature-controlled cast aluminum plugs and adjusts the forming time.
3 Click OK to save your changes and close the window.
4 Click OK on the Routing Selection window to close the window and re-cost the component using the modified processes.
You can click Apply to re-cost the component without closing the window.