search.noResults

search.searching

saml.title
dataCollection.invalidEmail
note.createNoteMessage

search.noResults

search.searching

orderForm.title

orderForm.productCode
orderForm.description
orderForm.quantity
orderForm.itemPrice
orderForm.price
orderForm.totalPrice
orderForm.deliveryDetails.billingAddress
orderForm.deliveryDetails.deliveryAddress
orderForm.noItems
56 TESTING


Novel in-line rheology measurement technology


Thomas Machin – Senior Technology Officer, Stream Sensing, UK


Rheology is defined as the study of the deformation and flow of matter.1


The rheology


of a fluid system governs both in-process efficiency and final product quality. It is therefore critical to the manufacturing of liquid personal care products, such as shampoo and liquid soap. For example, if a product is too thick,


problems may arise with pumping and packaging; too thin, and it may run straight through the consumer’s hands. Getting the rheology just right can be challenging from a manufacturing perspective, but is central to the product’s success. In the manufacture of these products,


conventional rheometry testing typically takes place off-line, with sampling required from the process stream. This can take approximately ten minutes (depending on the number of measurement points required), not including the time needed to obtain the sample, send it to a QC lab and conduct internal checks. Once analysed, if the product does


not meet specifications, it often has to be scrapped or re-worked, resulting in large volumes of waste being generated, or excess energy being consumed. It has been estimated, that the annual product loss in liquid personal care products globally is the equivalent to two million bath tubs (around 320 million litres). A large part of this could be reduced through the use of in-line rheology measurements. The rheological properties from off-line


measurements are often also considered, with assumptions, as directly applicable to real process flows. However, this approach only provides a retrospective characterisation of a fluid sample and the measurement does not account for any changes to the sample when extracted from a process, such as cooling down and gelling or settling. It is often therefore considered unsatisfactory. As in situ measurements are conducted within the flow environment, they deliver a direct, real-time rheology measurement, which provides essential, accurate information to plant managers and QC professionals about the product as it is being processed. Due to the critical nature of rheology in processing liquid personal care products, the ability to monitor rheology in-line, in real time could elevate rheometry from a QC tool at the process end-point to one which is able to control and optimise processes and material structures.


PERSONAL CARE November 2021 Figure 2: ERR sensor To realise this goal, Machin et al. developed


a novel, in-pipe, tomographic measurement capable of obtaining real-time rheological information of process fluids within pipe flows.2 This is termed electrical resistance rheometry (ERR). Its ability to predict rheological parameters was validated at the industrial pilot plant of a multinational manufacturer. The trial focussed upon the characterisation of


a wide range of industrial personal and homecare products, including shampoos, fabric washes, conditioner and body washes. The aims were to compare rheological parameters obtained from ERR directly with off-line rotational rheometry and to determine its suitability to operate as an in-line quality control technique.


Introducing ERR ERR enables the characterisation of a fluid’s rheological properties within a pipe under


Figure 1: Electrical resistance rheometer electrode configuration with associated tomograms


steady state, incompressible, laminar flow conditions. To achieve such conditions, the Reynolds number of the flow must be less than 2,000.3


By cross-correlating fluctuations


of computed conductivity pixels across and along a pipe, using non-invasive microelectrical tomography sensors, rheometric data is obtained through the direct measurement of the velocity profile.2 As this technology uses electrical resistance sensing, the measured fluid should be relatively conductive, within the range of 0.5 – 50 mS cm-1


. The wide-ranging applicability and simple


implementation of microelectrical tomography sensors to industrial processes make it an ideal platform for the development of an in-line rheometer. This approach is an extremely robust,


non-invasive technique which can interrogate complex process fluids. ERR can combine significant engineering quality and process control concepts of rheology and mixing to form a powerful characterisation tool. The electrical resistance rheometer supplied


by Stream Sensing (Figure 1), uses a novel arrangement of microelectrical tomography sensors, which ensures that a complete velocity profile is obtained with high sensitivity near to the pipe-wall boundary. This arrangement is operated using the v5r EIT system which was controlled and operated by the v5r software, (also from Stream Sensing), which captures a rheology measurement every 30 seconds. The modified-sensitivity back-projection


www.personalcaremagazine.com


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104