What are Blow Molds?
Blow molds are used for mainly containers, toys, or other molded objects that need to contain a volume of air or liquid in them. They only mold the outer shapes by blowing a hollow tube of molten plastic, which gets molded by the cavity shapes of the blow mold. Usually, there are two halves of a blow mold, which join together at the parting line of the mold, and have a pinch edge, which cuts off the excessive resin material during the molding process. It is very common for companies to need blow mold reverse engineering to redesign or recreate an old mold.
Due to the repetitive process, a high amount of wear and tear is caused on the mold. This results in rejected parts, or too much material leaking out at the parting lines.
Our customer, who is a premier mold maker and production house in the country, has many such molds which do not have the exact CAD data. The CAD data is used to cut new tools or to repair an existing tool by welding, and re-cutting specific parts of the tool.
Usually, the smaller-sized molds are shipped to our location. These are then first 3D scanned with high-resolution white light 3d scanning. This process measures millions of surface points, very accurately. The points are then meshed together into a polygonal model, which is made up of millions of small triangles. These triangles join the measured points. See image below.
Reverse Engineering Process
The STL model of the mold is then used for blow mold reverse engineering in further downstream CAD programs. The dents or deformities in existing molds are cleaned and smoothed over. New surfaces are created, trimmed, and stitched together into 3D Solid models. This detailed surface modeling results in engineering-grade models. These are then exported out in various formats, such as .stp , .igs, .catprt, x_t, .sldprt, etc.
Finally, these new CAD models are delivered to our customer. Then the CAD can be used on a CNC milling machine to cut brand-new molds.
Please contact us with any questions you have regarding our mold work via our contact form or call us at (248) 853-7700.