Cost reduction by sorting according to separate mold cavities

The high costs involved with consistent quality control are a problem for many companies in the manufacture of high-precision parts using the injection molding method. In particular faulty production runs into collecting containers often require for the entire production to be discarded and disposed of although only one single cavity might be responsible for the detected fault.

To achieve a significant reduction of these quality costs, Waldorf Technik has developed a high-performance take-out robot type Direct 1 “S” which places the parts into the collecting container according to the separate cavities.

The tool and product-specific linear robot supplements the injection molding machine. This robot ensures that the individual parts are re-moved securely and placed into a special collecting container where only the parts from a specific cavity are collected. The influence on cycle time is less than 1.0 seconds.

If a fault is detected in the subsequent quality control, it is possible to identify a specific cavity as source of the fault. With the robot sorting the products according to separate cavities, the costs of a quality defect can be limited to a fraction because only the manufactured parts from the defective cavity have to discarded instead of the entire production run. The investment into a take-out robot by Waldorf Technik will pay off quickly in the manufacture of quality-intensive products

If required, automated testing stations (e.g., sensors, cameras or product-specific measuring stations) can be added to the system in the segment between removal and sorting. This type of inline quality assurance allows for an immediate sorting when faults occur and reduces the costs of rejected parts additionally.

This efficient and cost-effective process improvement is already being used successfully by numerous companies — for instance by Weidmann Plastics Technology AG (Rapperswil, Switzerland), Walter Söhner GmbH & Co. KG (Schwaigern, Germany) and PKT GmbH (Tiefenbronn, Germany) — primarily for products in the fields of medical and laboratory technology, packaging, closures, electrical engineering as well as for technical components.