There is strong demand for recycled PET, polyethylene terephthalate, in the US and Canada with many uses including industrial, cosmetics, medical and health care packaging. Manufacturers like it because it’s safe, strong, transparent and versatile. However, the lightweight design and unique bottle shapes have challenged packaging suppliers. Seasoned packagers have good insight and experience when it comes to melding robotics with PET applications.

How are robotic palletizing and depalletizing being utilized in PET manufacturing?
Robots are a very important part of the process since they are not just being used to build pallets. You can see them even before the containers make it to the end of the line. Robots are being used to remove the containers from the blow mold and in quality control upstream, in the material handling process, and even in handling dunnage. After delivery to the end user, they are utilized in dunnage removal and recycling, and of course in the depalletizing. In depalletizing, floor level and high level container discharging may be incorporated as well as direct placement into a descrambler.

How do robotics compare to the conventional equipment in the PET manufacturing process?
The most obvious difference is that robots have a smaller footprint and inherent flexibility. The engineered systems are ergonomically designed to handle a wind range of containers with a quicker and simpler changeover.

What are some of the hurdles that have to be addressed in the automation of PET production?
There are several issues that are addressed in the design phase. Exotic containers are becoming more frequent and require a very flexible end of arm tool. Also, the tool needs to address the other hurdles like increased line speeds and rapid changeovers. Ability to handle full layer trays and tier sheets (see video below) all while maintaining food safety for the open containers is a goal for many manufacturers. An advantage for any company automating their PET line is to partner with an integrator that has close connections with material handling suppliers to help with the transition and conveyance in the overall system. It will enhance the overall handling throughout the complete line.

What are some of the trends and how are packaging suppliers working to address the changes and hurdles?
Constant improvement to end of arm tools for flexibility is key. This tool is the back bone of the palletizing system and the manufacturing process has been able to increase the production capacity. The robot programming needs to keep up with the rates and the tool has to handle the exotic containers and the rapid changeovers.

pet foods robotic system

PET Bottles on a Tray

The robot erects a tray, loads PET product into the tray, and moves tray/bottle combination to the palletizing station.

 PET Bottles on a Slip Sheet

The robot first picks a tier sheet, then a layer of PET product, and places the product on the sheet.