Material testing provides insights for conveyor selection

In the industry, it is common for food processors to test — and even re-test — their products on the conveyor systems they are considering purchasing. After all, every food product or raw ingredient has distinct characteristics that will determine how it behaves under the stresses and pressures of conveyance. This testing offers crucial insights into flow characteristics, throughput, breakage potential, safety measures, cleaning requirements and maintenance protocols. It also plays a vital role in enabling accurate equipment evaluation and sizing.

However, many in the industry are now seeking a deeper understanding of the material characteristics of their product prior to this step. In a fully equipped laboratory, powders can be evaluated to determine bulk density, moisture content and angle of repose to determine flowability.

The information derived from these tests is proving invaluable to address product-specific challenges with powder such as compaction, abrasiveness, stickiness and insufficient flowability. These factors can even play a critical role in selecting the type of conveyor system — whether aeromechanical, flexible screw or tubular cable drag.

“With material testing, the main concern is usually conveyability. Through laboratory analysis, we can assess the flowability of the material to determine the throughput [a conveyor] will be able to deliver,” said Dr.-Ing. Emmanuel Ricohermoso III, Operations and Testing Manager of Automated Handling Solutions (AHS) Germany GmbH Test Center in Friedrichsdorf.

AHS has a suite of material handling equipment and industrial automation, including Cablevey Conveyors, an OEM of tubular cable drag conveyors for food and high-value industrial applications, and Spiroflow, a material handling equipment manufacturer and provider of control systems integration.

Using comprehensive testing can provide food processors with the knowledge to make well-informed decisions regarding conveyor type and brand selection based on known material properties. This approach also allows equipment engineers to create customised solutions that align with processors’ specific requirements, leading to improved product quality, conveyor reliability, productivity and uptime.

As an example, AHS Germany GmbH Test Center is a 645 m² testing facility centred on a test workshop equipped with product transfer systems from brands that fall under the AHS and Advanced Material Processing (AMP) umbrella.

The test facility includes a state-of-the-art in-house laboratory dedicated to material characterisation.

“Laboratory analysis is a quick and simple way to assess product conveyability,” Ricohermoso said. “Instead of testing a bulk of sample, 150 kg or more, lab analysis will only require a kilo of the sample to measure the densities (bulk and tapped), moisture content, particle size distribution, friability, flowability indices such as Hausner ratio, Carr’s Index, angle of repose and slip angle. We also consider qualitative analysis such as the tendency of the sample to be static, to form ratholes, to bridge or to compact.

“Lab analysis requires less work but offers a lot of data about the material itself. This process helps us come up with a suitable device that is tailored to the product,” he said.

If the tests indicate the product is prone to breakage or damage, for example, an enclosed tubular conveyor system from Cablevey Conveyors is often recommended. Tubular drag cable conveyors are designed to excel at reducing product damage since the units gently move product through a sealed tube using a coated, flexible stainless-steel drag cable pulled through on a loop. Solid circular discs (flights) are attached to the cable, which pushes the product through the tube without the use of air. These conveyors can transport delicate, precise blends for a wide variety of food types, and up to 2000 cubic feet per hour of materials in versatile layouts and configurations.

When preventing product damage is less of a concern to processors, other options can include a range of conveyor types. Aero mechanical conveyors such as Aeroflow can be used for rapid product transport. These conveyors have a tubular design where a cable assembly, with evenly spaced polyurethane discs, moves at high speed. Enclosed aero mechanical conveyors are suitable for conveying large volumes of products such as powdered and granulated sugar.

For less sensitive products, flexible screw conveyors are designed to transport materials in any direction, from horizontal to vertical. The flexible screw conveyor’s only moving part, the spiral, continuously mixes as it conveys, making it suitable for products like flour. The simplicity of the design makes these conveyors a low-maintenance operation.

After identifying the optimal conveyor style, the food processor should proceed with conducting bulk tests on the actual equipment at the site. During conveyor testing, the facility’s technicians and engineers can diagnose and prescribe solutions to concerns over breakage, temperature, stickiness or other issues. Food processors are provided with full documentation of the results, including a detailed report with video as well as recommendations.

In this regard, AHS has an array of conveyor types to food processors for testing purposes. The facility also provides testing on a full range of other associated equipment necessary for material handling and production, including bag conditioning, bulk bag discharging and filling, dewatering, sieving, mixing and drying.

Since Germany Test Center is part of a network of international test sites available to food processors within AHS’s family of companies, it is a simple matter to perform a required test at one site and transfer the results to the needed location around the world.

For example, Cablevey has tested more than 1900 products, including beans, rice, grains, cereals, coffee, chocolate, and caramel corn peanut snacks, for some of the largest global brands. All products are run through a tubular disc and cable conveying system to observe the effects and fine-tune the results.

For those unable to visit the test facility in person, Cablevey now has the ability to view and respond to product testing live in a “virtual visit” with a link to real-time video.

With sufficient testing and conveyor selection prior to purchase, processors can significantly improve their production and performance.

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