Ultra-accurate viscosity measurement.

A pre-pilot mixing plant is using wireless TorqSense transducers for ultra-accurate viscosity measurement of high-value compounds.

The plant is used to prepare small batches of compounds from shampoo and detergent to cosmetics, therapeutic and medical preparations. Some of the ingredients in the compounds are very expensive, so product developers are loath to make large batches early in the formulation process. 

Instead, they start with 850 millilitre samples for the early stages of each project, then once the recipe is well-proven, move on to pilot-scale work where the samples are measured in thousands of litres. The final stage is, of course, full-scale production where volumes may be truly enormous.  

The TorqSense transducers were supplied by Sensor Technology,  whose Mark Ingham explains the design of the pre-pilot plant: “It can take three hours or more to make a single sample, each produced with precision accuracy – and development programmes need a great many samples. Clearly this cannot be done manually. Automating the basic mixing process is in principle straightforward; for this the plant has four workstations based on paddle mixers, each of which is monitored by a TorqSense.”

TorqSense constantly assesses the level of torque in a driven shaft. Often, this is used to measure the power being provided by the drive motor. However, in this case it is the opposite – TorqSense is used to calculate the drag being exerted on the paddle and shaft by the liquid being mixed.

“The mixing process changes the viscosity of the liquid, which is what causes the drag,” says Mark. “In the first instance the TorqSenses are looking for the viscosity to stabilise to a steady value that won’t change any further no matter how much more mixing is done. 

“Then they measure that very accurately. The viscosity is what gives the final commercial product its sense of quality: a low viscosity and the product feels watery, cheap and ineffective; overly high viscosity and it is unpleasant and greasy. 

“There is an optimum point where the product feels luxurious and high quality, which is what needs to be identified for each formulation. In the past this was done manually, so was completely subjective and unquantifiable: TorqSense has changed this to a precise and scientific procedure.”     

TorqSense is a wireless sensor, which is not physically connected to the mixer shaft by slip rings. Instead, it monitors the torque via radio waves.

A shaft deforms very slightly when it rotates, the amount of deformation being proportional to the torque. TorqSense measures the deformation so that it can calculate torque. To do this two tiny piezoelectric combs are glued to the surface of the shaft at right angles to one another; shaft deformation will expand one comb and compress the other. The radio frequency signal emitted by the TorqSense is reflected back by the combs, with its frequency changed in proportion to the combs' deformation.

"The procedure to set up the TorqSense is very simple," says Mark. "Solutions using other technologies would probably take several hours to set up. With a regime of up to 30 tests per day, TorqSense is the only real solution for this plant.”

Other TorqSense attributes that have been made full use of are its enormous overload capacity, which enables it to cope with robust and demanding test cycles, and its digital output. The output is fed straight into a computer program that compares viscosity measurements with the ingredient ratios and calculates changes to the recipes for optimised results.

Mark sums up: “This plant is in effect a totally automated laboratory that can develop perfect formulations in a closed loop calculation. It has changed pre-pilot tests from time-consuming trial and error procedures to precision materials science.”

@sensortech #PAuto 

Operational excellence journey in cosmetics

GE Intelligent Platforms's Proficy® Software platform has been chosen by Kao Brands of Cincinnati (OH US) for a complex batch execution system in primary operations across its many consumer products. The company is looking toward improved quality, decreased cycle time in the process and implementation, increased versatility, testing and reduced commissioning time for its production lines.

A Kao Brands product

Kao Brands, a global manufacturer of premium beauty brands including Jergens, Ban, Biore, Curel, Guhl and John Freida, prides itself on innovation and quality. Therefore, when the company added new equipment or implemented different procedures, they realized that they needed a system that was both agile and secure to allow optimizing the manufacturing of many different recipes on the same equipment.

Over the last seven years, Kao has expanded its operations globally, particularly in Europe and Australia. In March 2009, new equipment was added to accommodate the additional needed capacity. This increase in sales had necessitated using outside contractors to fulfill product commitment. The company saw value in cost savings and quality improvement while protecting the confidentiality of recipes by bringing that manufacturing capacity back to the plant. Kao produces many different products and SKUs on the same equipment and packages those products on the same lines.

“This was a logistical problem,” said Andy Pickens, Engineering Manager for Kao Brands’ Cincinnati plant. “With three major production areas – making, storage and packaging – producing many products with the same equipment and having to validate cleanings between products, results in a complicated system. We needed to continue to provide high quality products but with more agility to address the increased capacity requirements.”

Kao’s control system is complex and its PLC platform was driving the operation. Many operations are interconnected and if a change in one system was made through the PLC, due to sequencing, it could have an adverse effect on another operation down the line. The team thought that, due to the rate that things change, they needed a solution that would allow them to develop PLC code once and not have to change it with each tweak to the process. Kao implemented Proficy Batch, a powerful and feature-rich solution used to increase product quality, consistency and efficiency, and Proficy Historian to capture high-resolution process data enabling true process visibility.

The Proficy solution was implemented on the new equipment and now the team is implementing on all equipment. “We now change recipes more quickly and more reliably,” said Pickens. “Changes that used to take days to implement are now taking hours instead.”

Kao isn’t stopping there, according to Pickens. The company would like to use the data collected by the Proficy Software solution for process improvement. “We are working to optimize what is a good time for each step of every product we make,” he said. “We would like to see what the impact any manufacturing bottlenecks have on the schedule made by the production team, and adjust our schedule dynamically to compensate.”

“Kao Brands is a great example of how companies achieve efficiencies by laying a solid foundation of reliability and predictability,” said Erik Udstuen, Vice President of Software & Services for GE Intelligent Platforms. “Operational excellence starts with visibility into operations, moves to efficiency, reliability and then, by standardizing work processes, improving planning and execution across the company results in a sustainable competitive advantage for the company in the marketplace.”

Selenium in shampoo!

Rapid and accurate analysis of Selenium in shampoo ensuring compliance with EU cosmetic products legislation

Thermo Fisher Scientific has published a new method guide for the analysis of selenium in shampoo. The method, which aligns with the European Union commission directive 97/73/EEC
stipulating the methods of analysis necessary for checking composition of cosmetic products, features the Thermo Scientific iCE 3000 Series atomic absorption spectrometers. These spectrometers include deuterium background correction as standard and offer a fast and accurate solution for the analysis of selenium in shampoo. The iCE 3000's wizard-driven SOLAAR software also provides simple spectrometer optimization and method development
tools. The method is detailed in an application note, entitled "The Determination of Selenium in Shampoo by Flame Atomic Absorption Spectrometry."


Pityriasis capitis, more commonly known as dandruff, and seborrheic dermatitis, an inflammatory disease of the skin, are treated with selenium disulphide, which is contained in lotions and shampoos. After rinsing, selenium disulphide residues may remain on the scalp and can enter the body through broken or damaged skin. Since the element is considered to be a potential carcinogen, limits have been set for its content in shampoos and lotions. Commission directive 93/73/EEC mandates flame atomic absorption spectrometry with deuterium background correction as the formal method to measure and regulate the concentration of selenium disulphide in shampoo.

The new application note demonstrates how the iCE 3000 Series can be used for the identification and determination of selenium disulphide in a range of medicinal shampoos. Identification is performed by observation of a reactionary color change, while flame atomic absorption spectrometry is used for the quantitative determination of selenium. The spectrometer can be optimized simply and quickly using the wizard-driven SOLAAR software.
Deuterium background correction is implemented to ensure regulatory compliance and spiked recoveries used to verify the accuracy of the method. Experimental results have demonstrated that flame atomic absorption spectrometry with deuterium background correction is the ideal technique for the dependable analysis of selenium disulphide in shampoo.

The iCE 3000 Series atomic absorption spectrometers are high-performance, flexible, easy-to-use and compact systems. The iCE 3300 is a fully PC-controlled flame atomic absorption spectrometer with full graphite furnace and vapour generation options. The iCE 3400 features a dedicated Zeeman furnace system, superior optics and flexible background correction options to maximize analytical performance and simplicity. The iCE 3500 is a dual flame/furnace atomiser allowing automatic, efficient and safe switching between flame and furnace analyses. Advanced optics and background correction accuracy ensure best analytical performance.