Canadian Plastics

A very dry forecast

Canadian Plastics   

Canadian Plastics NPE2024 Plastics Processes

Dryers were a big part of technology introductions for some companies at NPE2024, with new models offering a range of features, from faster cycles to lower dewpoint values to artificial intelligence.

Moretto’s X COMB mini dryers. Photo Credit: Moretto

Overstating the importance for molders of dehumidifying or drying plastics in the processing phase verges on the impossible. Plastic resins, particularly hygroscopic ones like nylon, PET, and polycarbonate, have a natural tendency to absorb moisture from the environment – and even when they appear dry on the outside, these and other materials can be loaded with moisture on the inside. If not controlled, this moisture can cause surface imperfections such as splaying, silver streaks, or delamination, any one of which will ruin your plastic parts.

Which is where dryers come in. Resin drying prior to processing maintains the performance characteristics of your resin and ultimately your parts. And it’s never more important than during the summer, when the hot, humid weather really puts a strain on both the regeneration and process.

And speaking of hot and humid, the NPE2024 show wrapped up recently after a sweaty week in Orlando, Fla., and new dryers were a big part of auxiliaries introduced by some of the exhibitors. Here’s a look at some of the new offerings, just in time to help you beat the summer processing heat.

ALL ABOUT REGENERATION

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Advanced Blending Solutions (ABS) has now made the formerly optional Regeneration Power Saver mode as a standard feature on its 14 desiccant dryer models. Known by the prefix “TD” followed by a number signifying capacity, the 14 dryers have capacities ranging from 25 to 2,000 pounds per hour. Benefits of the Regeneration Power Saver include faster cycles that save time, money, and energy, ABS officials said. The Regeneration Power Saver feature shuts down the heater the moment that the exhaust temperature of a bed being regenerated reaches a specified temperature. And while, as we’ve just noted, dryers tend to be most advantageous during the summer months, this feature is especially beneficial in the winter, ABS officials continued, when the standard regeneration cycle is too long and wasteful.

AEC’s new line of desiccant wheel dryers is designed to provide high-performance moisture removal and has adjustable process air flow that prevents resin overdrying and reduces energy consumption. Available in three configurations – ADP, ADW, and ADC – the AD series is a direct replacement for AEC’s earlier NGX and RDX dryers. The new dryers are said to be well-suited for most beside-the-press drying applications and small central drying systems, and are available with throughputs ranging from 50 to 2,500 pounds per hour. Options include an internal dewpoint sensor, level sensor, take-off boxes, and integration with Industry 4.0 equipment. For precision control, the AD series also utilizes a high-resolution HMI touchscreen and proprietary PLC. Key drying data is visible on a single screen: drying temperature, dewpoint, material throughput, and total energy consumption.

The new ResinWorks with Optimizer, an optional AI-driven feature for Conair Group’s ResinWorks centralized multi-hopper drying systems, is designed to automatically keep process-ready resins at the right temperatures and varied throughputs, while preventing overdrying and saving money on energy costs. The Optimizer starts with the same conditions as a manual operator would: a required resin delivery temperature and predicted throughput of each resin through each hopper. In operation, the Optimizer monitors overall airflow, first ensuring that only active hoppers are served. Then, its AI-driven logic optimizes airflow through each active hopper based on changes in mass flow and temperature. Once material at the bottom of the hopper achieves the proper temperature, the Optimizer logic holds it steady, while incrementally adjusting airflow through the rest of the hopper to match the actual processing rates, incoming material condition, and material drying requirements. Not only can its AI-driven logic efficiently dial back and rebalance airflows for unused hoppers or reduce airflows for less-than-full hoppers, company officials said, but it can also boost airflows — and alert operators — when process resin rises unexpectedly. And the ResinWorks with Optimizer has demonstrated energy savings of 10 to 40 per cent in virtually every situation, Conair said.

VERY COOL (AND DRY) PARTNERSHIP

Auxiliary equipment suppliers Dri-Air Industries and Maguire Products have combined to develop Dri-Air’s second generation of on-demand drying/blending systems for the circular economy, enabling molders to dry virgin material, reclaim and redry regrind material; add colourant; and blend these components just prior to conveying to the injection molding machine. Dri-Air’s approach dries materials separately at different temperatures and keeps materials isolated until the blending step, which eliminates the inventory issues and the waste of premixed materials that are no longer needed after the job runs out while keeping materials dry throughout the blending and conveying process. Positioned below the discharge of the drying hoppers is Maguire’s weigh-scale blender (WSB series blender). Configured with a touchscreen control, it provides gravimetric accuracy, data recording/reporting, and additional component flexibility. Once the dried components are blended, Dri-Air’s closed loop, dry-air conveyance system ensures the blended material stays dry and properly blended during conveyance to the process. A small minimum inventory receiver is mounted on the feed throat. The castered blender can easily be removed for ease of cleaning and docked into position for production.

Moretto’s X COMB mini dryer is a super-compact, all-electric dryer specifically designed for engineering resins, and with an “adaptive” feature designed to ensure a very gentle and consistent polymers treatment with dewpoint levels up to -52°C or -61°F. The LCD touchscreen is a standard built-in intelligence feature that only requires two parameters: the type of material and throughput. All the other parameters are automatically set. The interaction between the operator and the system is said to be very easy thanks to the graphic user interface. The dryer includes multiple connectivity options such as RS485, Modbus, and USB for data downloading. It also can be connected to MOWIS, Moretto’s proprietary supervision and management software which enables connectivity between different systems, processes, plants, and even facilities. And X COMB is equipped with an assisted lid and safety device, which enable operators to carry out inspection and maintenance procedures safely and easily.

GOODBYE TO GUESSWORK

Novatec’s new DryerGenie technology is designed to take the guesswork – and the risks of underdrying or overdrying – out of drying, allowing processors to dry resin based on material condition, not the time recommended by the material supplier. “Until now, processors have had to rely on arbitrary drying times suggested by resin spec sheets, which are based on unknown moisture levels,” said Novatec president Conrad Bessemer. “Given that the moisture content of each batch of resin varies at the time it’s processed, adhering to a generalized set time leads to significant inefficiencies.” The DryerGenie features a resin-moisture analyzer situated below the receiver and directly above the drying hopper that measures the incoming moisture level of the material and, depending on that reading, suggests the drying time/residence time based on the dryer/drying hopper used. Inside the hopper, a drying process scanner measures the temperature and intergranular humidity – which is the moisture released through the drying process – and adjusts as needed to airflow, dewpoint, and temperature. By incorporating real-time, AI-powered resin moisture sensing technology, DryerGenie ensures the resin is properly dried in the shortest time possible and with the least amount of energy consumed. “Each batch of resin is processed to perfection, and the technology can be integrated with many of Novatec’s new dryers,” Bessemer said.

Novatec’s DryerGenie system enables processors to dry based on material condition, not time. Image Credit: Novatec Inc.

Piovan’s DPA compressed air dryers for hygroscopic polymers offer running parameters that can be easily loaded from the internal database, and with the use of desiccant cartridges can reach lower dewpoint values of up to -40°C or -40°F. The control manages the airflow in seven increments and adjusts the dryer’s functioning according to the material throughput, which avoids wasting energy and compressed air. Also, DPA dryers can be equipped with the IMD (Intelligent Material Drying) feature, which ensures an optimal management of the drying process, avoiding material overheating and thermal degradation. And thanks to the material database, the control automatically regulates the process condition once the material has been selected and the hourly throughput has been set.

Wittmann’s new Drymax plus is the latest generation of the company’s dual desiccant bed dryers. Key features include Wittmann 4.0 integration, and a colour touchscreen display with AmbiLED status indication. Wittmann also touted its Drymax central dryers at NPE2024, which are equipped with two desiccant beds and provide continuous high-quality process air. The addition of a premium dewpoint sensor allows for dewpoint-controlled changeover of the desiccant beds, which can reduce the energy consumption of the dryer.

In the end, drying tends to be vexing for even the savviest of processors, since overdried parts tend to be brittle, making them prone to breakage, while underdried parts can cause splay and an assortment of other problems. These new technologies can help you hit that sweet, dry spot in between.

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