Improving injection molding thanks to 3D printing

The concept of conformal cooling of molds has been around for a long time. The cooling channels that follow the contours of the mold provide advantages during injection molding. To date, the technology has never really made a breakthrough, partly due to the high investment costs in metal printing technology. However, the latter is changing. Additive manufacturing with metal becomes accessible to SMEs.

A cooling channel that follows the surface contour of a mold has much more cooling capacity than a traditional channel made with deep hole drilling. This is because the cooling takes place directly below the surface and the flow is more optimal. This causes the mold to cool down faster. The cooling capacity can also be increased in a very targeted manner at places in the mold where heat causes problems. Mold inserts are 3D printed for this purpose.

The metal printing technology used for this, such as the laser powder bed metal printers from Exact Metal, delivers high-quality mold inserts with a high density. More than 99.5% is normal. Surface roughness of 3D printed metal components may be lower than that of CNC milling parts, but they can be subtractively finished with common machining techniques. This does not necessarily have to be an obstacle to applying this technology. Nor are the costs, because Exact Metal has managed to significantly reduce investment costs in metal printing technology. With an AM machine like the XM200G (with a single or double 100 or 400W Yb fiber lasers), the American manufacturer builds a metal printer that is accessible to every metal company. This is possible thanks to the self-developed high-speed system platform that uses light and simple mirrors to position the laser beam in the x and y plane. The costs of such an AM system are less than machining companies usually invest in a 5-axis machining center.

Why 3D metal printing

Why should toolmakers start 3D printing mold inserts? The first reason is the higher productivity when injection molding plastic parts. Because the mold cools down more quickly in places where heat accumulates, the cycle time can be reduced. This means injection molding more products in the same time period. The second reason why injection molding companies should consider using optimized cooling channels is the quality of the injection molding products. Very targeted cooling leads to a higher quality of the surface of the injection molding. Productivity and quality therefore go hand in hand.

Press lead times

The third reason is of a different nature. Lead times are under pressure throughout the manufacturing industry. Additive manufacturing means going directly from the CAD model to the metal product. 3D metal printing helps shorten lead times in the mold making industry. Complex shapes, which may require several clamping operations or even several machining steps, are printed in one go with Exact Metal's AM systems. Mechanical post-processing may be required, but this takes less time than completely milling a complex mold with integrated cooling.

Curious about the possibilities of 3D metal printing ? Seido Systems can demonstrate Exact Metal's technology live in the showroom in the Benelux. Make an appointment with one of our sales engineers to experience the possibilities of 3D metal printing yourself.