Advantages of Innovative Quality Control Devices

Fast Sample Dryers, Bucket Test System and Beyond

One of the problems encountered in the paint industry is the long drying times of samples sent from production for color control. Solvent-based paints take hours to dry, while powder coatings can take 10-15 minutes to cure. Another problem is the need to quickly and independently of laboratory technicians determine whether packaging has sufficient mechanical strength before filling. Here we will address new equipment and techniques developed for these two problems. The long drying times of paints and similar coating materials, especially when additives are involved, can cause disruptions to manufacturing schedules, leave production machinery idle for extended periods, and result in inefficient staff downtime. eMEDa has designed emok for solvent-based paints and etok for powder coatings to accelerate this process. emok reduces the drying times of paint samples from hours to minutes without compromising color and gloss values. This equipment has three radiation sources. The temperature of the film during drying must be controlled; the heat transfer needed for solvent evaporation or reaction energy must be transmitted to the material by radiation. The wavelength and intensity of radiation sources, as well as their duration and intervals, become important in finding the fastest program.

For example, water-based products are affected rapidly by microwave radiation. When the appropriate wavelength, angle, filters and intervals suited to microwave are applied, water can be separated from the film in seconds, almost like a molecular sieve.

Of course, such a fast program can damage the film. For this reason, microwave must be combined with other radiation sources and the power of these sources must be adjusted appropriately. Additionally, the rotating turntable should move samples in front of the sources to ensure even drying. emok has been specifically designed and developed to provide optimal conditions for rapid drying of paint samples. emok can dry some industrial paints in 20 minutes. It can dry luxury and enamel-style paints in 8 minutes and water-based paints in 2-3 minutes. High-texture water-based paints can be dried in 6-7 minutes, and plasters several millimeters thick can be dried in 10-12 minutes. Thanks to its user-friendly software, drying times can be easily optimized for products and product groups, allowing the drying process to be performed independently of laboratory technicians. The energy needed to dry a film ranges from 10 to 60 watts, and approximately 240 watts of energy must be absorbed and discharged as harmless hot air. This process is especially necessary for microwave. Additionally, harmful gases that may be produced during drying must be exhausted through a separate duct. This is an important point to be considered for workplace safety and health. emok is a unique device and standards have not yet been established for this type of equipment. Thanks to its multiple radiation sources, it can be used as a fast film dryer and also as a conditioning unit. Although comparable results are not yet available, test methods can be developed similar to standard tests for conditioning units and can offer faster testing capabilities. For example, UV resistance of a new type of pigment or resin/binder can be accurately tested within several hours. It can provide baseline information before lengthy conditioning tests that take days or months.

emok was essentially designed to reduce production downtime, but it can also be useful for research, product development and improvement projects. It may also find applications in other chemistry fields such as food, ceramics and similar areas.

The most common problems with packaging are the unwanted costs of weak buckets. Buckets are generally stacked, and the buckets at the bottom must continuously bear the load. Additionally, they must be resistant to heat, cold and impacts. If the strength of the bottom bucket is insufficient, the bucket's lid or plastic wall can break. The strength of the handle is also important. Other examples of problems include excessive dust accumulation due to electrostatic effects, breakage upon dropping, and leakage from the lid. Packaging manufacturers have begun testing their products to increase quality levels and reduce rejection rates for unapproved products. Manufacturers typically test when they change their product formulations, raw material formulas, or design. Like packaging manufacturers, many packaging users test several buckets before accepting or rejecting products. Companies using packaging may have greater need for these types of tests because they tend to request different packaging from different suppliers. ekta has been specially designed to test packaging and performs strength tests by applying controlled force on materials. At reasonable speeds (for example 5 mm/s), a plastic container with a capacity of approximately 20 liters can withstand a maximum load of around 750 kg. A plastic container of approximately 3 liters can withstand a maximum load of 300 kg. Metal containers of similar capacity can be 20-50 percent more resistant than plastic. Handles can withstand loads of around 65 kg for 20-liter plastic containers and around 30 kg for 3-liter containers at similar speeds. Metal handles display resistance above 100 kg, while recently developed plastic handles can also withstand loads of around 80 kg. The speed at which force is applied for testing is close to actual conditions (someone lifting a container or impacts during transport) and is 5 mm/s.

Material testing speeds in the plastics industry may vary, but since standards have not yet been developed for this type of testing, like in conditioning tests, each organization must establish criteria appropriate for itself. This type of testing should be regarded as technical quality control testing rather than scientific research and development work.

Using air pressure to apply force is one method, but since air is a compressible fluid, it is nearly impossible to determine speed precisely and the repeatability of results is low. Pressure fluctuations in the facility's air line also negatively affect repeatability. An electrical mechanism provides more reliable results and operates stably. ekta has speed and ramp definition capabilities thanks to servo motors. For this reason, tests can be performed independently of laboratory technicians. Traditional tensile-compression devices and their attachments are quite expensive. For this reason, ekta, which is specifically designed for this test and more cost-effective, may be preferred. At the same time, since buckets are used for packaging in the food sector, it can also be used in that sector. Additionally, stack strength testing of cardboard packaging or routine strength tests of different adhesives with an appropriate attachment can be performed with ekta.

Our customers who saw the advantages of emok, which reduces wet paint drying times, indicated that a device that could also shorten powder coating drying times would be useful for them. In response to this request from our customers, we designed our etok device.

In etok, like our emok device, infrared and ultraviolet sources are used, but induction technology is also utilized. etok reduces normally 10-15 minute curing times to 3-5 minutes, achieving reductions of up to 300 percent. This allows rapid testing of samples during powder coating production, shortening the production process and reducing costs. It can also be useful for research, product development and improvement projects. Our device can be useful not only for powder coating manufacturers but also in other sectors. The innovative devices mentioned above have undergone numerous tests after the design phase and continue to be developed over many years. In the new model of ekta, which we specifically designed for bucket testing, we are working on adding the capability to measure the antistatic condition of plastic material, that is, its resistance to dust accumulation. Our work continues to reveal the advantages provided by establishing correlations between the programmable multi-source emok fast film dryer and standard conditioning results. Finally, all eMEDa products are manufactured in accordance with CE directives and provide safe operation.   Hasan Hüseyin Engin Senior Chemical Engineer Owner and Director eMEDa