Accurate moisture measurement improves plastics processes

Injection moulding companies are utilising more accurate humidity sensors to meet customers’ increasing demands for greater precision, consistency and sustainability.

Based in southwest Finland, Camteam Oy designs and produces high quality plastic products and moulds, serving a range of industry and consumer needs around the globe. As one of the Nordic region’s leading multi-component plastic moulding companies, Camteam attributes much of its success to listening closely to customers. This allows the company to consistently meet evolving market requirements through precise selection of the right materials and processes.

As the pace of innovation in the plastic moulding sector continues to increase, Camteam knows that meeting their customers’ needs is more challenging than ever. For example, a growing number of polymer combinations are being developed in response to customer demands for greater precision, consistency and sustainability. This increasingly calls for multi-component injection moulding (combining different types of plastic in one part) with each production batch requiring the same high-quality standards, with minimal variation.

Camteam’s experts know from experience that to get this right requires continuous and highly accurate measurement data. Hygroscopic materials require the right moisture level from the start; some materials as low as under 0.02% RH, and seasonal changes in humidity cannot be allowed to influence the moisture level of the moulded material. For example, polyamides and polycarbonate filled with glass fibers absorb moisture easily, and excessive moisture can break the molecular chains of the material.

Of course, product quality variations are not always visible, which means that careful testing of final products is also important. However, it is also necessary to carefully monitor moisture levels during the production process, through continuous measuring, monitoring, and analysis. This is especially significant in multicomponent moulding, where successful drying is very important in the optimisation of bonding with components. For example, some elastomers which normally do not need to be dried, have to be dried during certain property modifications.

One of the challenges is that not all of the drying equipment used by plastic moulding companies, including Camteam, is factory-fitted with proper moisture measurement technology. This means that it is each manufacturer’s responsibility to ensure that they maintain the right level of dryness without using excess energy. In addition, even drying units that include integrated moisture measurement sensors regularly require manual checking and calibration.

In addition to increasing demand for higher quality, the plastics industry is also seeking to improve sustainability. For example, products are required to be longer-lasting, and electric vehicles need more plastic parts than fossil fuel vehicles to operate efficiently.

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With many of Camteam’s customers ordering products that require more accurate production monitoring and control, injection moulding specialist Matti Majava was keen to investigate the best ways to optimise drying processes. “The way forward is to enhance the plastics injection process and by understanding more about material characteristics,” Majava explains. “On top of this, the move away from oil-based materials means that we need to expand our knowledge about new material bases and additives that have the right qualities.”

Matti already knew some of Vaisala’s technical experts, so he contacted them in 2022 to learn more about his best options regarding high-accuracy moisture measurements. As it happened, Vaisala was just then completing pre-launch testing of their Indigo80 portable moisture measuring instrument, and invited Camteam to play an important testing role in the final development stages.

Reporting on his experience with the new instrument, Majava says: “The Indigo80 is designed to check the dew point at different stages of the mould injection process, and we really liked how simple it was to use, and that it had all the features we need, including portability and easy handling during measurements.”  In addition to spot-checks Majava also has a requirement to log data for a longer time. “We particularly appreciated the option to hang the Indigo80 near the drying machines and to leave it logging measurements, for review at a later time,” he explains.

Typically, Matti checks various process conditions with the Indigo80 on a daily basis, and this data is used to inform his decisions. For example, certain drying processes can be shut down sooner when – thanks to the Indigo80’s accuracy – optimal dryness has been reached, which saves both time and energy.

During this pre-launch evaluation, Majava suggested useful improvements to the product’s cable design as well as the possibility to save not only numerical data but also the device’s graphical visualisations. Expressing his pleasure with the successful partnership between Camteam and Vaisala, Majava says: “We were especially pleased that Vaisala encouraged our opinions and really took our input seriously. Consequently, we are very open to further co-operation and process development with Vaisala.”

In summary, market demand for higher quality and improved sustainability is driving the requirement for more knowledge about materials and their behaviour characteristics when selecting raw materials for different products and processes. This in turn increases the need for advanced moisture measurement technology such as that provided by the Vaisala Indigo80.

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