Coinjection Technology Showcases Recycled Material Containment

Dubbed the “Turtle project,” KraussMaffei (KM) presents a sandwich application with recyclate at Fakuma, utilizing an all-electric PXZ Multinject injection molding machine and debuting the LRXplus linear robot with MC7 control. The machine applies KM’s APCplus database, which includes individual material properties from ELIX Polymers and uses material-specific compression curves.

The small blue turtles are molded on an all-electric PXZ 121-380-180 Multinject using the sandwich process to surround a black core made of mechanically recycled PC/ABS with an outer layer made of chemically recycled ABS. The press features the new sandwich panel, near-contour mold temperature control from Contura MTC, while also applying the Adaptive Process Control (APC) plus process assistant, which accounts for the values of different material types to make the multicomponent process more efficient.

KM notes that the increased use of recyclates has brought sandwich technology back into focus as a multicomponent technology that can hide recycled materials within virgin plastics. The turtle’s core consists of mechanically recycled PC/ABS E-LOOP 5120MR from ELIX Polymers. The outer skin, meanwhile, is made of chemically recycled and processed ABS E-LOOP P2H-AT CR, which can be supplied in various colors. The turtle’s cold runner and sprue are removed, shredded and fed directly back into the production process for the core material. Granulation is handled by Getecha’s new mini sprue mill.

The all-electric PXZ 121 Multinject with 135 tons of clamping force features a compact, space-saving Z-position with electric injection units. In addition, the attached, removable sandwich platen offers production flexibility so the PXZ 121 can be used as a single-component, two-component or sandwich machine.

The machine also enables the switchover from skin to core, such that the skin material can be added in order to seal and hide the gate, or molders could switch between component A and B several times, enabling effects like marbling. Dynamic mold temperature control is supplied by Contura MTC and near-contour temperature control, which is used to achieve the required high-quality surface and speedy cycle times.

Part removal, runner/sprue separation and subsequent grinder feeding, as well as part depositing on the convey are automated by the new LRXplus linear robot, which debuts at Fakuma together with the MC7 control system. The new LRXplus offers numerous new functions that make production even more flexible and economical. Because of its compatible interfaces, the LRXplus can be combined with almost any system, be it KM or competitive injection molding machines.