K 2022: LSR Cell Makes Four Different Lids With Each Cycle

Liquid silicone rubber (LSR) moldmaker and dosing equipment supplier Elmet (Oftering, Austria) will showcase its SMARTshot E valve-gate cold-runner system and SMARTmix Top 7000 Pro dosing system at K 2022 in injection molding machine maker Sumitomo (SHI) Demag’s booth, manufacturing four different lids for beverage and food cans, as part of its new SMARTcap offering. In addition to Sumitomo, Elmet has partnered with material supplier Shin-Etsu and Mettler Toledo on the cell, which utilizes a weighing system from the latter to measure and record individual part weights for the parts prior to their laser marking.

All four lids have different diameters, according to an Elmet spokesperson, with three offering sealing lips for different beverage can sizes, and the fourth with a slightly different sealing lip designed for standardized food cans.

Elmet says the accuracy of the injection process is ensured and documented by the weighing cell, while laser marking the four different SMARTcaps ensures traceability. The cell is built around an Elmet injection mold, featuring its all-electric SMARTshot E valve-gate cold-runner system. Shit Etsu material is fed to the machine by the Elmet SMARTmix Top 7000 Pro dosing system. In addition to providing the all-electric Intelect molding machine, Sumitomo also supplied a linear handling device to the cell to remove the lids from the mold.

Elmet says the SMARTmix TOP 7000 Pro dosing system is all new. Featuring a condensed footprint of 1150 by 790 mm (45 by 31 in), Elmet says this SMARTmix is the smallest LSR dosing system on the market for the standard 200-liter (53-gal) LSR material containers. The spokesperson told Plastics Technology that the previous model—the SMARTmix TOP 5000 Pro—had a footprint of 1320 by 900 mm (52 by 35 in). Building off the previous SMARTmix TOP 5000 P, the SMARTmix TOP 7000 Pro features a completely new pump system. In this design, only one third of the LSR in the system is within the pump at any given time, making it easier to clean. In medical and pharmaceutical applications, where the pump unit must be dismantled and cleaned between any material changes, this greatly simplifies changeovers. By the numbers, the Elmet spokesperson told PT that the latest SMARTmix pump holds 1.25 liters vs. 3.60 liters. Elmet says its optimized follower plate geometry utilizes up to 99.6% of material in the drums, which can be changed in a fully automated fashion. FDA-approved seal materials open up the SMARTmix TOP 7000 Pro for use in medical applications.

The all-electric Elmet SMARTshot E valve-gate cold-runner system features an 18.5-in display, and the system’s servomotors allows needle adjustments in increments of just. 0.002 mm. Needle movements happen in real time and smaller motors allow nozzle spacing or pitch of just 44 mm (1.7 in). Servodriven operation eliminates pneumatic components, saving energy and simplifying cable management with industrial plug connections.