Matching Sensor Shape To Package Form Factor

Ian McKelvey

by Ian McKelvey

Smart Skin delivers optimal test cases by engineering its sensors to closely match package specifications.

When designing a sensor drone to measure the forces acting on a packaging line, matching the form factor is one of the most important considerations. Conveyors, starwheels and guiderails are often purpose-built for the shapes of the containers being used with them, and at Smart Skin our drones are often purpose-built in turn. In most cases, a general-purpose sensing unit simply isn’t sufficient for studying multiple package types.

How we custom engineer any one drone for the unique measurement situation can vary greatly. Often the job is as simple as matching the container diameter exactly, so that the precise conveyor accumulation pressures can be accurately quantified. In other cases, contoured drones are needed to measure specific forces being exerted from guiderails or other equipment. Sometimes custom shapes are simply required so that the drone can pass smoothly through the line.

The way bottles and cans pack on a conveyor is another important consideration – the diameter of the sensor drone should match the diameter of the container as closely as possible. If a drone is even slightly too small, it can become nested in between containers, indicating much less pressure as a result. By contrast, a drone that is larger than the surrounding containers can show amplified pressure. These observations have been confirmed by research conducted at VLB Research and Teaching Institute for Brewing in Berlin using a diameter difference of 5-7mm in glass bottles:

“An oversized Drone diameter can lead to falsified results in line pressure which are clearly too high. An undersized Drone diameter in the worst case has not any pressing containers on itself due to the geometry that is formed by the pressed bottles on the conveyor.”

Other situations mean that a standard cylindrical drone will not be sufficient for the test criteria. Many PET bottles for food or cosmetics, for example, require a more oval-shaped drone to match the container profile. Examples that Smart Skin has studied include soap bottles and a variety of condiments. For these products, Smart Skin has designed drones with oval or rounded rectangle-diameter profiles. These custom profiles allow the drone to imitate the movement of the product being tested while travelling down single-file conveyors.

In addition to these, Smart Skin has also designed a number of drones for large PET containers such as 2L soda or juice bottles.

While the variety of sensor surface shapes is an important factor, it is not the only consideration. Through our testing process, Smart Skin has also found that designing the ABS plastic housing components to match package dimensions as closely as possible can also lead to an improved testing process. Bottlenecks – custom-made for each glass bottle design – are a useful feature for making sure that a beer bottle drone can travel through inverting rinsers, fillers and drop-packers. Can rim profiles are also closely matched to can schematics using ABS housing components.

As we continue to work closely with our industry partners, Smart Skin understands the value of developing custom solutions for the packaging line problems that our customers want to solve.