Monitoring quality of chocolate bars in production line

One of the most popular snacks in the world, chocolate, comes in a variety of sizes, shapes and flavours to choose from. It is generally available in various forms mixed with other types of snacks or in the form of solid chocolate bars. The taste and flavour of the solid chocolate bar highly depend on its dimension and shape. Moreover, deformed and ill-shaped bars also lead to a bad impression on the consumer by appearing unappealing to the eyes, which ultimately affects a company’s branding and reputation in a negative way. For this reason, well-known brands always strive to consistently produce chocolate bars with identical dimensions since it acts as a trademark for their company.

As mentioned above, the exact dimension of the manufactured chocolate bar needs to be intact. It determines how quickly a chocolate bar would melt in the mouth, impacting the order and speed with which food molecules are released onto the tongue and indirectly influences the intensity of flavours in the chocolate. Therefore, a brand needs to keep a check on the produced bars by applying quality control techniques in the production line, in order to maintain the high-quality taste and customer satisfaction.

Chocolate is now manufactured in a series of automated processes and the finished products are checked to ensure that they meet the standards. However, the quality control process is still not as advanced as the manufacturing process. Traditional quality control methods were based on manual inspection of chocolate bars, which was very time-consuming and more prone to errors in judgment, or tactile measurements. The visual inspection method also does not produce consistent and reliable results as they largely depend on the mood and condition of the operators. Some manufacturers have also used laser point sensors, which turned out to be a rather slow process for this task. For faster and more efficient testing, manufacturers need to implement advanced sensor technology that is capable of providing high-speed scanning with accurate, reliable and precise results.

Advanced laser scanning technology

Modern technology enables the use of non-contact sensors integrated in the processing line to monitor the contour and surface profile of the finished products. Using a laser profile scanner offers the possibility of significant time savings as compared with the traditional inspection process as well as high-precision quality checking in the production line. This measurement system can be employed to the entire production range instead of relying on random checks to give real-time measurements.

Profile measurement using laser scanners is based on the triangulation principle. A laser diode projects visible light onto the surface, which is reflected from this point and then projected onto a CCD or CMOS detector. Special lenses are available for the purpose of enlarging the laser beam to create a static laser line instead of a point. This is considered a better technology as a more flexible field of view is achieved with the laser line technology.

Such an example is the scanControl 2960-100 laser profile scanner from Micro Epsilon. This sensor can be installed at some distance away from the objects which makes it suitable for measurement in most industrial applications. This sensor can reliably measure on objects with different surface properties such as light or dark chocolates. It also possesses a high throughput rate of 60 m/minute, it can accurately detect profiles of each chocolate bar and instantly transmit these data to the software. A software configuration tool enables easy set-up of predefined parameters and sensors.

The software enables the measured values to be calibrated to predefined parameters, consisting of the profile, width, height, depth, edge, groove, flatness and deformation. After all the parameters are scanned and processed, an “OK” or “NOK” signal is transmitted to the control system of the production line, so that any required modification can be applied immediately to the production process. Hence, this non-contact laser scanner makes it possible to prevent rejects and wastes by enabling intervention in an ongoing production process of finding a defect in the produced bars.

A blue laser scanner is also available which provides an accurate and reliable measurement on difficult surfaces such as organic materials. This blue-laser technology has some significant advantages over the red-diode based sensors as it doesn’t penetrate the target. Therefore, it gives better results when used on a difficult surface and it doesn’t get affected by emission of high-intensity light due to its shorter wavelength.

Bestech Australia supplies the high-quality sensors and instrumentations for measurement pf physical parameters in Australia and New Zealand. With a team of factory-trained applications engineers and product specialists, we are more than capable to attend to any measurement difficulties in your industry.

Image credit: ©stock.adobe.com/au/Sebastian Duda