Showcase AM Expo 2020

Highly dynamic vacuum gripper used in clean room

With clever design, Samaplast reduces downtime by 50%. The new vacuum gripper increases productivity significantly, because it weighs only just the half. The design freedom of additive manufacturing of metal provides everything that is needed besides the good idea of an engineer.

Highest quality plastic products, made by Samaplast

Every day, injection-molded medical parts and implants leave the production site in St. Margrethen. And that for over 60 years. The innovative thinking process that Samaplast owes its success, has also led to this flagship project with BSF Bünter AG.

Function

Using a vacuum gripper, a robot removes the medical injection molded parts from the mold. Eight pieces are produced in one shot. To produce economically, the cycle time in the injection molding machine was optimized to the last fraction of a second. As long as the gripper is in use, the machine can not continue to produce. Therefore, in the next step, the peripherals should also be optimized in order to exploit the valuable time in the clean room environment.

Previous situation

The earlier milled version was just too heavy and too sluggish. After each movement, a wait had to be programmed to let the vibration of the gripper fade out. In order for the process to be reliable, the movement speed had to be additionally throttled. In addition, before each start of production, two hours of set-up time were incurred in order to align the gripper precisely with the injection mold due to the vibrations. It should be noted that several batches are produced annually.

Solution with Additive Manufacturing

Today, the vacuum gripper consists of two identical additively manufactured components and a symmetrical milled part. The number of parts and the weight have been drastically reduced. As a result, the maximum speed of the robot can be used without causing greater vibrations on the gripper. In addition, the production of the new gripper system is cheaper than the previous model. All these points mean that the production of the new vacuum gripper has paid off within 8 months.

Changes Percentage Absolute
Total weight -50% from 1.2kg to 0.6kg
Waiting time for injection mold -50% from 4 to 2 seconds
Setup time per batch -100% from 2h to 0
Number of different parts -60% from 5 to 2
Production costs paid off - within 8 months


After just two months of use, BSF Bünter AG was comissioned to produce a vacuum gripper for the next injection mold. On the evaluation of a milled variant was completely omitted due to the experience gained.