Bookmark 09-20-2017

3D-Printed Collapsible Core

Laser-Sintering Optimizes Cooling System, Reducing Costs per Unit

The spiral-shaped cooling channel of the new 3D collapsible core enables temperature control close to the contour, as well as short cycle times (© Strack Norma)

Collapsible cores are indispensable whenever undercuts such as threads in bottle caps make it impossible to simply eject the product. If the part is cast around a collapsible core, the function of collapsing prevents the molded part from being stuck when it comes to demolding. Strack Norma, manufacturer of standard molds situated in Lüdenscheid, Germany, has the first-ever 3D-printed collapsible core on showcase at this year’s Fakuma. The metal-laser sintering technique, by building up the part in layers, enables novel design of the collapsible core.

The spiral-shaped cooling channel makes sure heat is dissipated homogeneously, while, being close to the contour, temperature control is effective and fast, according to producer information. Accordingly, the 3D-collapsible core is expected to enable high quality of the molded part as well as short cycle times, which will reduce costs per unit in injection molding. It is compatible with cooling by water and oil, and can be applied with any kind of tool design. Strack Norma have filed a patent for the product, which is able to demold parts with up to 17 % undercuts and is supplied starting from 40 mm diameter. In the last processing step, the collapsible core’s inner core and guide rings are DLC coated – so that everything runs smoothly.