Implementation of an online thermal imaging to study the effect of process parameters of roller compactor

Chalak S Omar,Agba D Salman,Michael J Hounslow

doi:10.1007/s13346-018-0493-9

Chalak S Omar, Agba D Salman + Show 1 more

Open Access

https://doi.org/10.1007/s13346-018-0493-9

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Abstract

During roller compaction, not only the properties of the primary powder affect the product quality but also the process parameters. Any change in the process parameters during roller compaction will result in changing the properties of the ribbon. In this study, the temperature of the ribbon during production was monitored online using a thermal camera. The information from the thermal camera was used to explain the differences in ribbon properties at varying process parameters. Lactose powder was used as a primary powder, and ribbons were produced at different process parameters. The surface temperature of the ribbon during production was found to increase with increasing both the gap between the two rollers and the roller speed. This was attributed to the screw feeder speed, which increased to feed additional powder as required to adjust to the change in process parameters. Increasing the roller gap resulted in wider ribbons and decreased the percentage of fines in the product, which was a signature of better powder distribution across the roller width. The results were also supported by the uniform temperature distribution recorded across the ribbon width. It was found that increasing the roller speed during roller compaction decreased the width of the ribbon while increasing the percentage of fines in the product. The feeder screw speed was found to have a similar effect as the roller gap.

Highlights

Roller compaction is a dry granulation technology in which high pressure is used to compress the primary powder particles into ribbons, which are milled to granules of different size classes
In order to examine the effect of the roller speed, the powder was compacted at a constant pressure of 50 bar and using different speeds of the roller (3, 4, 5 and 6) rpm
The decrease in the stress applied on the powder during the roller compaction, as a result of increasing the roller gap, resulted in ribbons with lower tensile strength and higher porosity. This is in agreement with the finding of [14, 22, 23] in that increasing the roller gap during the compaction decreases both the strength and the density of ribbon of microcrystalline cellulose (MCC) and sodium chloride

Summary

Introduction

Roller compaction is a dry granulation technology in which high pressure is used to compress the primary powder particles into ribbons, which are milled to granules of different size classes. The roller compaction process consists of three units working simultaneously: feeding, compaction and milling unit. The feeding unit provides and transports the powder to the compaction unit using different methods (gravity or screw feeder system). The compaction unit consists of two counter-rotating rollers which apply high stress on the powder [1]. The ribbon is used to produce granules with the desired size after passing through a milling step

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