End-of-line testing under hygienic conditions

TASK

Inspection and packaging of 36,000 syringes per hour

A compact and flexible robotic cell handles the end-of-line inspection, labelling and palletizing of 36,000 syringes per hour. Three Stäubli robots designed for hygienic production are responsible for handling the trays in which the syringes are transported.

What is the safest and most economical way to test and palletize 36,000 syringes per hour? A multinational manufacturer of pharmaceutical products posed this question to the experts at Ward Automation in Sligo, Ireland. Founded in 1995, the company has specialized in designing and building customized automation solutions for the medical device and pharmaceutical industries.

The manufacturer’s specifications included the following key details: The syringes arrive in trays containing 100 units at a rate of six trays per minute. They must be inspected, labelled and palletized. The chief concern here is to eliminate the risk of damaged or missing syringes or anti-tamper seals. Regulations concerning medical device production (21 CFR Part 11) apply here.

SOLUTION

Three robots in one cell

Based on these specifications, Ward Automation designed a cell with three Stäubli robots. In Step 1, a Stäubli TX2-60 robot takes a tray of 100 syringes and conveys it to an image processing system. Two vision systems check the contents of the tray for faulty syringes, missing PRTC caps and the correct number of syringes. Trays that fail inspection are diverted to a reject station, where a human operator replaces the defective contents and returns the tray to the inspection line.

Trays that have been identified as “OK” proceed to a labelling station where inner and outer labels are printed and immediately checked for accuracy. Error-free labels are affixes to the inside and outside of the tray. The first TX2-60 applies the inner label, and at the end of the process the labels are checked for presence and position.

In the next step, the trays are sealed prior to palletizing and shipping. Ward Automation developed an innovative lid-separating station for this task. It feeds the second robot – also a Stäubli TX2-60 – individual lids. A vision system verifies the position of the lid, and the robot grips it and places it on the tray.

A customer-specific application tool applies a tamper-proof seal to the lid and wraps the label around the outside of the lid as an extra security barrier. The tray is rotated 180 degrees and a second label is applied. The robot then lifts the tray and places it on a buffer conveyor. In the final step, a larger Stäubli RX160L robot stacks the finished trays on a pallet.

CUSTOMER USAGE

High precision – virtual programming

The requisite degree of flexibility is ensured by the robotic cell’s modular design and advanced control system, which allows, the cell to be configured with new parameters in a short time. The machine is capable of handling 3- or 4-inch trays containing 100 or 160 syringes respectively, all within a compact space.

A decisive factor in the selection of the Stäubli robots was their hygienic design. The HE (humid environment) versions offer the additional advantage of being able to withstand regular wash-downs with aggressive cleaning agents without sustaining any damage. The cell documents the inspection and packaging process of each individual tray with individual labelling – very important for traceability – and all GMP-critical data.

The system runs trouble-free. The user can now carry out a fully automated 100% inspection of syringes, labels and tamper-evident seals, immediately identifying individual defective syringes, replacing them, and reintegrating them into the process. In addition, the user can select different parameters for syringe sizes, tray sizes and number of syringes, providing even more flexibility.