Main basis for mold design is customer's plastic parts data, which includes drawings, templates and electronic files. Input plastic parts data, carry out corresponding conversion and processing, in order to meet requirements of mold design.

Form of data source of plastic parts and corresponding processing.
(1) Drawings and documents. Build 3D plastic parts models or 2D graphics according to drawings.
(2) Sample data. Build a 3D plastic model or 2D graphics based on actual test sample. In addition, mold is processed by engraving method according to model.
(3) Electronic files. Include 2D or 3D electronic files; common 2D formats are: xxx.prt, xxx.dwg, xxx.dxf and xxx.igs; 3D formats are: xxx.prt.x, xxx.igs, xxx.dxf And xxx.stp. If file format meets requirements, use it directly; otherwise, file must be converted and processed accordingly.
When same plastic material describes a certain part and the two are inconsistent, it needs to be confirmed by TE group.

Commonly used software for CAD/CAM mold room includes CADKEY, Pro/ENGINEER, Space-E/CAM and Mastercam.
2D file is xxx.dwg transferred with CADKEY; transfer is unsuccessful because lower version software is not compatible with files of higher version software. You can first output a low version xxx.dwg or xxx.dxf file in AutoCAD software, and then return to CADKEY to transfer it. Or, use higher version of CADKEY to transfer xxx.dwg file.
3D file provided by customer was created by Pro/E software. If import is unsuccessful, reason is that lower version software is not compatible with files of higher version software. You can output xxx.stp or xxx.igs files on higher version of Pro/E, then transfer to lower version of Pro/E.
When 3D file provided is created by other software, file format is usually xxx.igs. In Pro/E, a closed area is formed between curved surface and curved surface, and Pro/E system will automatically form a solid in closed area (solid boundary line is a white line). If there is a gap between curved surface (generally Called "cracks"), areas with gaps appear yellow on screen. Therefore, after transferring to xxx.igs file, some areas on screen show yellow lines, which means these areas need to be repaired.

Transfer into xxx.igs file forms a crack due to following reasons:

 

(1) Original two adjacent curved surfaces are not connected, and situation is as if curved surfaces are peeled off, as shown in Figure 1-1, or one curved surface penetrates the other curved surface.
(2) Surface that was merged (Merge) or trimmed (Trim) will not be merged or trimmed, and edges of surface will be extra, as shown in Figure 1-2.

 

(3) Edges of curved surface are twisted and deformed, as shown in Figure 1-3.
(4) Curved surface is missing, showing a missing surface.
(5) Part of curved surface is disrupted.
(6) Some auxiliary curved surfaces have been transferred in, showing a chaotic surface.
Basic concept to deal with above problems is to organize boundary lines of curved surface into a normal (or reasonable) state. Way to repair cracked surface is as follows:
(1) Remove redundant or auxiliary curved surfaces. Before software outputs xxx.igs, solid surface can be copied first, and then xxx.igs file with only solid surface can be output, so that redundant auxiliary surfaces are not brought in. Or, delete redundant surface, its steps;
Feature ® Redefine ® [Select any place of transferred surface] ® Heal Geometry (geometric renovation) ® Delete ® [Select redundant surface to be deleted].
(2) Software automatically repairs small cracks and its steps;
Feature ® Redefine ® [Select any part of transferred surface] ®Heal Geometry® Manual (manually trim boundary line) ® Fix Bndries (fix boundary line) ® Zip Gaps (repair small cracks) ® Auto Select (automatically select repairable Small cracks) ® Zip Gaps ® Accept (repair results)
(3) Cracks that software cannot automatically repair, repair steps;
Feature ® Redefine ® [Select anywhere on transferred surface] ®Heal Geometry ®Manual® Fix Bndries ® Edit Bndry (Edit boundary line of crack surface) ® [Select surface to be repaired] ® SelContour (select yellow boundary line to be repaired and turn it into a light brown display) ®Modify®MoveVertex (method of moving endpoint is repaired, that is, first select old endpoint, and then select new endpoint to move, as shown in Figure 1-4)® Done

 

To repair boundary line of surface again, select Fix Bndries ®Zip Gaps ® Sel Chain (select surface that needs to be repaired between two adjacent boundaries) ® Done ® Zip Gaps ® Accept Other methods to repair boundary of surface: Edit Bndry® [Select surface to be repaired] ® Sel Contour ®Modify
® Straighten (Draw a straight line, select two points, and restore boundary line to straight line)
® Merge Edges (Merge segment lines, merge multiple segments in chain into a whole segment line)
® Move Vertex (Move end point to bring old line segment to correct position)
® SetTanCond (change two segments to be tangent or perpendicular)
® Divide (Add a breakpoint on line)
In addition, when editing and finishing boundary, method of creating new lines is as follows: Edit Bndry® [Select curved surface to be repaired] Sel Contour ® Create
 ® Project (Select a line and project it onto the surface to be trimmed)
® Make Isoline (select intersection of two lines, select desired line from two lines)
® Connect (Select two points, draw a straight line or curve, and then project to surface to be trimmed)
® Intersect (select a surface, get intersection of surface to be trimmed and selected surface)
(4) Curved surface is lost, showing a crack with a missing surface. Before repairing it, first determine surface characteristics, then rebuild curved surface, and merge it. For some surfaces that are difficult to repair and have clear features, you can also delete them first, and then rebuild surface.