Vismec plastic granule dryers and management systems worldwide: continuous innovation and efficiency
The March 2026 issue of Upgrade Magazine – Speciale Noale e dintorni (Noale and surroundings special) includes an article dedicated to Vismec, its history, and the decisions that have guided its technical, strategic, and commercial evolution.
Here on our website, we also want to retrace the path that has led us to become a leader in the development of technologies for technical polymer molding, starting with technologies for drying plastic granules: an evolution built on expertise, innovation, and the ability to best meet customer needs.
Plastic dryers: the starting point for an advanced technological approach
Vismec was born with the specific goal of developing high-tech solutions for plastic injection molding companies, starting with a central element of the process: the plastic dryer.
The role of granule dehumidifiers in the molding process
Plastic granules are, in fact, hygroscopic materials that tend to absorb moisture from the environment. Without proper treatment, the absorbed humidity compromises the quality of the finished product, causing cosmetic and structural defects. A plastic granule dryer is specifically designed to remove humidity before processing, ensuring stable and controlled conditions during molding.
From the beginning, we have focused on innovation, introducing advanced solutions in rotary desiccant dehumidifiers to improve process control and reduce energy consumption: a significant improvement in system performance that has also helped raise industry standards.
Innovation redefining process standards
The advantages of our dryers for plastic materials translate into measurable benefits for companies. Let’s see them all.
- More effective process control: accurate dehumidification of plastic granules prevents problems caused by evaporation during molding, ensuring consistent results in terms of uniformity and quality of the finished product, even in high-volume production.
- Reduced energy consumption: the optimization of drying cycles and the efficiency of rotary dehumidifiers enable excellent performance while reducing the energy required for processes.
- Lower incidence of scrap and rework: by eliminating the causes of moisture-related defects, scrap is significantly reduced, improving overall efficiency.
Our technological identity and the value of our solutions have set the standard over time, establishing themselves as the benchmark even for our competitors.
Plastic granules management systems, digitalization, and integration: the evolution of Vismec
Starting with plastic dehumidifiers, we have progressively expanded our product range, developing complete systems for plastic granule management: dosing, conveying, and control to offer a comprehensive technological solution.
From stand-alone machines to integrated systems
Today, the solutions we offer are not simply machines but systems designed for precision, modularity, and ergonomics to integrate into complex plants and existing production layouts, to operate in a coordinated manner to optimize processes, and simplify the tasks of operators.
Vismec plastic polymer management systems allow users to organize every phase, from drying to transport to dosing, with a high level of precision and repeatability. This results in greater operational efficiency and reduced maintenance requirements and downtime, features that are particularly appreciated by our customers.
VisiBus and OPC UA protocol: the connected factory
Digitalization is a key aspect of our evolution, including our most recent developments. Recently, for example, we developed VisiBus, an advanced communication system that enables machines to communicate with one another and with customers’ management systems via the OPC UA standard.
We have also trained our staff on topics related to the use of Artificial Intelligence (AI) and its applications in production processes.
Digital innovation tools allow us to:
- monitor process parameters in real time, improving operational control and the ability to intervene in case of anomalies;
- integrate machinery into corporate management systems, facilitating the collection and analysis of production data;
- optimize plant performance over time, thanks to a comprehensive, structured, and integrated view of data and information.
In this way, our systems become an integral part of an interconnected factory, focused on efficiency and performance.
An industrial model that bridges local roots and a global vision
From the very beginning, we have chosen to expand our business into international markets, building a solid presence in Europe and North America over time. Until a few years ago, innovative technologies were embraced and adopted more quickly abroad: a result that, however, requires the ability to build a solid reputation and network of relationships, while effectively adapting to different contexts.
At the same time, we have maintained a strong connection with the Veneto region: an area that offers advanced technical and manufacturing expertise across the supply chain, an asset to be valued and preserved not only as a competitive advantage, but as a source of wealth to be recognized.
This is why we also support local sports and cultural initiatives: a way to contribute to the growth of the community where our company was founded and has grown, giving back a portion of what we have received.
We have also chosen to invest in people and their skills: technical training, up-to-date know-how, and collaborations with universities and research centers. Our motivation stems from the fact that we operate in sectors where plastic polymers are used to produce high-value components in terms of performance and safety, from medical devices to electronics and telecommunications.
Do you want to improve the efficiency of your molding processes and optimize the management of plastic granules in your company? We’re here to help you develop customized solutions.
Find out how Vismec systems can support your production needs with reliable, integrated, performance-oriented technologies: contact our team.
How pneumatic suction conveying of plastic pellets works
Pneumatic suction conveying of plastic pellets is used in plastic processing plants to move plastic granules in an automated, controlled manner that is integrated into the production cycle.
In this in-depth analysis, we examine how pneumatic conveying works, how it differs from other technologies, and the role of the so-called Venturi principle.
How pneumatic suction conveying of plastic pellets works
In pneumatic conveying of plastic granules by suction, the material is conveyed through the conveying pipes using a vacuum generated upstream of the system.
In other words, it is not the air that pushes the pellets, but the pressure difference that draws them from the storage point to the machinery used for processing.
General principle of vacuum operation
The operating cycle is based on three stages: vacuum generation, air-material transport and final separation. A pump or turbine creates a lower pressure zone: as a result, air enters the circuit and transports the pellets along the pipe.
In the receiver unit, special filters or separation systems allow the material to be discharged into the hopper while the air is expelled. This system guarantees:
- clean handling of the pellets, reducing dispersion and waste;
- centralised management of the feeding of multiple processing machines, thanks to vacuum units that manage multiple lines simultaneously;
- control of loading cycles, using automatic systems.
Each element of the system contributes to flow stability and production continuity.
Centralised vacuum conveying
Pneumatic conveying of plastic pellets, therefore, uses a controlled air flow to move the granules in a closed circuit. In the case of suction, the vacuum can be generated on board the machine or in a shared vacuum unit, depending on the plant configuration.
Many companies adopt a centralised solution for specific reasons:
- system efficiency, with the ability to feed multiple machines from a single central unit;
- reduced risk of leaks along the line, thanks to constant vacuum;
- greater order in the production layout, with storage containers and collection points organised in a structured manner.
The centralised configurations offered in many cases by Vismec allow for optimisation of space and material handling times. Our centralised transport systems integrate vacuum units, automatic switching systems and cycle supervision into a single coherent architecture that is scalable and adaptable to future plant expansions.
How do you size a pneumatic pellet conveying system?
A frequently asked question concerns the sizing of feeding systems. The correct configuration depends on several variables:
- distance between the collection point and the processing machine, which affects pressure drops and the power required to generate stable negative pressure along the line;
- required air flow rate, to be calibrated according to the quantity of material to be transferred and the cycle times of the user machine;
- number of machines connected, a determining factor in choosing between a decentralised or centralised vacuum solution;
- type of plastic material transported, because specific weight, pellet shape and sensitivity to abrasion influence air speed and pipe diameter.
The flow speed must keep the pellets in suspension, avoiding accumulation or excessive wear. The choice of filters also affects operational continuity, especially in contexts with intensive production cycles.
With this process in mind, Vismec pneumatic transport systems can be integrated with gravimetric or volumetric dosing systems and dryers for granules, to ensure excellent material quality for machine feeding and, consequently, to promote a good final result.
The decentralised Venturi suction system in granule conveying
The Venturi suction system, on the other hand, is a technical solution used in some pneumatic pellet conveying configurations, particularly in compact or decentralised systems.
What is a Venturi vacuum conveying system?
The Venturi principle exploits the variation in speed of a fluid in a duct with a reduced cross-section. When compressed air passes through the constriction, its speed increases and the static pressure decreases. This difference generates a zone of negative pressure that draws the pellets into the transport line.
In this context, the Venturi system is used when it is necessary to feed individual machines without resorting to a centralised system, in applications with:
- short transfer distances between the pickup point and the individual processing machine;
- moderate flow rates compatible with non-continuous production cycles or limited material requirements;
- need for quick and flexible installations, i.e. in departments subject to frequent reconfigurations.
Since the Venturi system uses compressed air, energy consumption must be evaluated in relation to the required productivity. In very dynamic environments, this solution still allows the creation of dedicated lines with limited intervention on the existing layout.
Vismec solutions for pneumatic pellet conveying
Designing a pneumatic granule conveying system requires a detailed analysis of the production layout, distances, volumes transported and the desired level of automation.
Vismec designs and supplies both modular and centralised systems for the conveying of plastic granules, which can be integrated with storage containers, dehumidifiers and dosing units. The available configurations may include, among other things:
- single-phase and three-phase receivers, sized according to flow rate;
- centralised vacuum units, to feed multiple machines;
- automatic control systems, with cycle management and supervision.
We configure each system according to the customer's needs, with a focus on operational continuity, material quality, efficiency and scalability.
If you operate in injection moulding, extrusion or plastic blow moulding and want to improve your granule transport systems, contact Vismec. We will offer you a configuration tailored to your goals, your company's production layout and the required levels of automation.
Vismec at MECSPE 2026, the international trade fair for the manufacturing industry
From 4 to 6 March 2026, Vismec will once again take part in MECSPE, the International Trade Fair for the Manufacturing Industry. The 24th edition of the event will be held in Bologna.
Our exhibition area will be located in Hall 36 – Stand A30.
Vismec at MECSPE 2026: our strengths
The event will feature 13 thematic halls, with dedicated areas for machine tools, automation, metalworking, plastics and much more. As usual, MECSPE will also devote ample space to innovation, Industry 5.0, sustainability and digital factory technologies.
Our company continuously keeps pace with the latest innovations in drying, conveying and dosing of plastic granules.
Recently, for example, we introduced the new Perfecto doser, designed to ensure ease of use, speed and precision in processing results.
Would you like to see our technologies live?
Come and meet our team at MECSPE 2026 – Hall 36, Stand A30.
Vismec will take part in SAMUEXPO 2026, the trade fair dedicated to machinery and technologies for the manufacturing industry.
From 5 to 7 February 2026, Vismec will take part in SAMUEXPO 2026, the biennial international trade fair where leading manufacturers of machinery and technologies for the manufacturing industry come together.
The event, which for years has confirmed itself as a highly anticipated appointment, will once again take place in Pordenone.
Vismec will be exhibiting with its own stand: visit us and experience our technologies firsthand at Hall 1, Stand 04 B.
Vismec at SAMUEXPO 2026: our focus
The 2026 edition of SAMUEXPO will give ample space to innovation, highlighting the solutions offered by companies that stand out as particularly attentive to the latest technological developments.
Vismec has always kept pace with the most recent advances in plastic granule drying, conveying and dosing.
Recently, for example, we introduced the new Perfecto doser, designed to ensure ease of use and fast processing times, combined with the precision that has always distinguished our products.
Want to know more?
We look forward to seeing you at SAMUEXPO 2026 – Hall 1, Stand 04 B.
Vismec takes part in K 2025 and presents the last innovations:
Düsseldorf, Germany, 8–15 October
Vismec takes part in K – the international trade fair for innovations in the plastics and rubber industry.
The event will take place from 8 to 15 October in Düsseldorf, Germany.
It will be an opportunity to present our drying, conveying, and dosing systems for plastic granules, as well as the latest innovations we have developed.
Specifically, Vismec returns at K2025 with a real demo area showcasing the new solutions designed to make plastics-processing automation more efficient, modular, and intelligent.
Six new products will make their debut at the show, including next-generation dosers, high-efficiency dedusters, a fully redesigned HALO Server, and new supervision modules also available in a mobile version. All innovations focus on native line integration, ensuring more continuous processes, consistent data collection, and faster setup.
Discover all the new technologies we’ll present in Düsseldorf: download the full PDF here.
And to explore our innovations in detail, visit us at Hall 11 – Stand G34: we look forward to seeing you!
Vismec participates in MECSPE 2025, the international trade fair for the manufacturing industry
From March 5 to 7, 2025, Vismec will take part in MECSPE, the International Trade Fair for the Manufacturing Industry. This year marks the 23rd edition of the event, which will take place in Bologna.
Our company will be present at Hall 36, Stand B 66 – come meet our team in person!
Vismec at MECSPE 2025: highlights
Among the key topics, the 2025 edition of MECSPE will focus on sustainability and the digitalization of industrial processes.
Vismec has extensive expertise in both areas. Our drying, conveying, and dosing systems for plastic granules:
- Enable efficient process management in terms of energy savings and resource optimization, while ensuring excellent quality results.
- Are integrated with Industry 4.0 control systems, which facilitate operators' tasks and allow for data interoperability in advanced industrial automation.
One example? The integration of our machines with the universal OPC UA interface, enabling Vismec industrial devices to communicate seamlessly with manufacturing companies' management systems and existing control devices.
Want to learn more? Come visit us at MECSPE 2025: Hall 36, Stand B 66!
Plastic raw materials: the different types of plastic granules
Plastic raw materials are used in many industrial sectors and are the starting point for a wide range of production processes. They mainly consist of plastic granules and pellets.
In this post, we will analyze the characteristics and differences between granules and pellets. Then, we will propose a classification of plastic granules according to the material they are made of and their behavior during processing. Finally, we will offer an overview of Vismec systems for dehumidifying, transporting, dosing and storing plastic granules.
Plastic raw materials: granules and pellets
Within the field of plastics, the words ‘granules’ and ‘pellets’ are often used interchangeably. However, there are also significant differences between these two types of plastic raw materials, regarding the production method, shape and fields of use.
- Plastic granules are small plastic particles, generally irregular in shape, resulting from crushing processes or the recycling of pre-existing materials. They are used both for ordinary processes and for specific applications, such as the production of technical polymers or bioplastics.
- Pellets, on the other hand, are obtained by extrusion and subsequent cutting of the molten material. Unlike granules, plastic pellets have a regular shape, generally cylindrical. Their regularity makes them ideal for industrial processes that require a precise and constant dosage.
Both are key elements in the plastics production chain: the choice between one or the other format depends on the needs of the production process and the characteristics of the desired product.
The different types of plastic granules: classifications
The classification of plastic granules can be carried out according to different criteria, including their hygroscopic properties and their composition. These aspects also determine the processing conditions and their possible industrial applications.
Hygroscopic and non-hygroscopic granules
A first criterion is based on the granules' ability to absorb moisture from the environment.
- Hygroscopic granules absorb and retain moisture in their molecular structure: this can compromise their properties during processing, altering the characteristics of the finished product. Consequently, the dehumidification phase before their use in production processes must be extremely effective. The most common hygroscopic materials include polyamide (PA), polycarbonate (PC), polyethylene terephthalate (PET) and polyurethane (PU).
- On the contrary, non-hygroscopic granules do not absorb moisture internally but can still retain water on the surface. Polymers such as polyethylene (PE), polypropylene (PP) and polystyrene (PS) belong to this category. So it is easier to manage the elimination of humidity in these materials during the preparation phase for the production process, although they still require drying.
When working with hygroscopic granules, control of the dew point becomes particularly important. The dew point is the temperature at which the humidity present in the air begins to condense. Measuring the dew point, in this case, helps to correctly manage dehumidification, helping to ensure the quality of the finished product.
Classification based on the material
A second classification criterion concerns the material the granules are made of, an element that influences the mechanical and chemical properties of the granule and, consequently, the organization of the production process. Among the most common materials are:
- Polyethylene (PE), used for packaging, pipes and films thanks to its chemical resistance and flexibility;
- Polypropylene (PP), valued for its rigidity and heat resistance, used in sectors such as automotive and packaging;
- Polystyrene (PS), suitable for light applications such as food containers and insulating materials;
- Polyamide (PA), known as nylon, used for gears and technical components thanks to its resistance to wear;
- Polycarbonate (PC), used for applications that require transparency and impact resistance, such as lenses and screens;
- Polyethylene terephthalate (PET), very common in packaging, especially for food;
- Polyurethane (PU), valued for its elasticity, resistance to abrasion and versatility, used in applications ranging from industrial coatings to components.
There are many other raw materials used to make plastic granules: we have listed the main ones.
Vismec machinery for the treatment and management of plastic granules
Drying, transportation, dosing and storage of plastic granules and pellets are essential during the plastic processing stages to ensure the quality of the finished product and production efficiency. Vismec designs systems and machinery for the effective management of these processes, offering customized solutions to optimize performance and reduce costs.
- Drying. We have already mentioned how dehumidification is crucial, as residual humidity in the polymers can compromise the quality and resistance of the final product. Vismec wheel dehumidifiers are innovative and efficient dehumidification solutions with low energy consumption.
- Conveying. The transportation of plastic granules, whether individual or centralised, allows for the automatic distribution of the material to the various processing stations. Vismec pneumatic transportation systems reduce downtime and ensure safe material handling: efficiency and high performance.
- Dosing. Accurate granule dosing allows for a high-quality, homogeneous mixture, especially in applications that require the combination of several polymers or additives. Vismec offers volumetric doser and gravimetric doser systems that ensure perfect control over the quantity of dosed material, avoiding waste and guaranteeing a uniform result.
- Storage of granules and pellets. Vismec offers robust and reliable solutions for the storage of granules and pellets, to preserve the integrity of the material and facilitate its use. The containers are designed to facilitate manual or automatic loading and are made with a modular structure that makes them suitable even for the most demanding industrial applications.
Are you looking for innovative, high-performance systems for managing plastic granules in your company? Contact our team: we will be glad to help you.
De-oilers: what they are used for, applications in plastic granule drying
The de-oiler (or oil trap) is a device used to ensure efficiency and cleanliness in various industrial processes. In this article, we will see how it works, discuss its main uses and present its role in drying plastic granules. Then, we will analyse the characteristics and advantages of de-oilers designed and manufactured by Vismec.
De-oiler: what it is and its uses in industry
A de-oiler is a device designed to purify an air or liquid flow from oils or oily residues, to ensure that the machinery or plant in which it is used remains clean and efficient at all times. Its operating mechanism is based on advanced filtration principles, often combined with mechanical or centrifugal technologies, to capture oil particles and other impurities.
The process generally involves the following steps:
- oil inlet, i.e. the fluid (air or liquid) enters the de-oiler through a dedicated opening;
- oil separation, i.e., thanks to specific filters, combined in some cases with the generation of centrifugal movements according to the principles of physics, the oil particles are effectively removed from the fluid;
- collection of impurities, i.e., the newly separated oil is collected in a dedicated chamber, which can be emptied manually or automatically;
- clean fluid outlet which, now free of oily contaminants, flows out of the device ready to be fed back into the plant or machinery.
The de-oiling device is used in several industrial sectors where the cleanliness of machines and production or processing systems is particularly important. Examples of its main uses include its application in the food industry, where this device is used to remove oily contaminants from food or beverage conveying systems, maintain food safety and help to ensure its safety for consumption by the end user.
Oil traps are also very frequently used in wastewater treatment or reclamation. In this case, they operate to separate oil and grease from water before discharge or eventual reuse.
In the industrial sector, they are used, for example, in hydraulic mechanical systems: in this case, they help to separate the oil from the fluids to ensure the correct functioning of the equipment and prevent possible problems or interruptions. Similarly, in industrial air compressors, our de-oilers ensure the removal of oily residues in the compressed air flow, preventing damage to machinery and pneumatic systems.
In the plastics industry, de-oilers are particularly relevant in the drying of plastic granules, a sector in which our company operates. In this context, this device ensures that the air used in the drying process is free from oily contaminants, improving the quality of the finished material and the service life of machines and equipment. In the next section, we will describe the Vismec de-oilers, explaining their features and advantages.
The advantages of Vismec Oiltrap
The Vismec Oiltrap is an effective solution to ensure that the airflow used in plastic drying processes remains clean and free from oily residues. As a result, this device also safeguards the perfect cleanliness and properties of the granules, preventing them from causing problems during processing or lead to flawed end products.
The operating mechanism of the de-oiler, that our company designs and manufactures, operates by the condensation of oily vapours. The fluid passes through the device following well-defined paths, condensing by means of special heat exchangers and allowing effective separation of the oil particles.
These particles concentrate at the bottom of the de-oiler tank, where they are collected in a transparent glass container for easy disposal. A butterfly valve allows easy and safe draining of the condensed oil.
Vismec de-oilers have many technical features tailored to the needs of the customer companies:
- practical quick couplings that facilitate the removal of the exchangers during maintenance operations;
- durable design with brass connections and hydrophilic aluminium frame, designed to resist corrosion;
- energy efficiency, especially in the cross-flow exchanger version, that allows heat recovery;
- high filtration capacity thanks to the two-stage system (optional) to remove up to 99.99% of oil;
- suitable for air flows up to 200 m³/h and temperatures up to 200 °C;
- simplified maintenance, since the exchanger geometry is designed to minimize the need for cleaning.
Therefore, our Oiltrap offers many advantages including, as mentioned, the very high effectiveness of the cleaning action and the reduction of maintenance costs. Moreover, it is also suitable for use in sectors with extremely stringent technical specifications, such as the medical, pharmaceutical or bioplastics sectors.
If you operate in the plastics sector and need reliable and innovative dehumidification solutions for your company, our Vismec technical team is at your disposal. Contact us and find out how our dryers can improve the efficiency and quality of your production processes.
Venturi aspirator: all about it and why it is important in granule conveying
The Venturi aspirator is an innovative device that exploits the laws of physics to create a vacuum flow without using the movement of mechanical parts. Thanks to this feature, it is widely used in various industrial sectors, including the conveying of plastic granules.
In this article, we will explain how the Venturi vacuum cleaner works, the advantages it brings and its applications. Then we will focus on the Venturi vacuum cleaners designed and manufactured by Vismec for conveying plastic granules.
Venturi suction unit: how it works
The operation of the Venturi vacuum cleaner is based on the so-called “Venturi effect”, a principle of the physics that exploits the pressure variation created by the passage of a fluid through a variable-shaped duct. This effect creates a low-pressure area that allows air or other substances to be sucked in, without the need for moving parts or motors.
In order to better understand the mechanism that regulates this unit, here is a description of the operating phases of a Venturi vacuum cleaner.
- Engine fluid injection. A fluid, usually compressed air, is introduced into the vacuum cleaner through a special duct.
- Passage through a narrow duct (nozzle). The fluid is subjected to an acceleration as it passes through a narrow area of the inner duct, increasing the speed and reducing the pressure according to Bernoulli's principle.
- Creation of the suction zone. After the narrowing, a low-pressure zone is created. It allows air or materials to be sucked from a side or dedicated opening.
- Mixing and outlet. The aspirated fluid mixes with the motor fluid and is expelled through the outlet of the device.
Thanks to this simple and effective operation, the Venturi aspirator offers several advantages. The first is the absence of moving parts, which eliminates the need for mechanical maintenance and extends the life of the unit. Another advantage is a usually very compact design, easy to integrate into existing systems. Finally, it is a very reliable suction system, that suits even the most demanding operating conditions.
The applications of the Venturi vacuum cleaner are many and varied and include, for example:
- chemical industry, where the device is used for conveying and handling powders and fluids;
- food industry, where the aspirator is used to transport dry ingredients such as cereals;
- plastics industry, with particular reference to plastic granules conveying.
In granule conveying, the Venturi vacuum cleaner ensures a continuous and uniform flow of materials, reducing the risk of blockages and optimising process efficiency. In the next section, we will take a closer look at the use of this device, introducing the solutions designed and manufactured by Vismec.
Venturi suction in granule conveying: Vismec solutions
The Venturi vacuum cleaner designed and manufactured by Vismec is an ideal solution for conveying plastic materials such as masterbatches or granule additives. Freestanding and powered by compressed air, it is particularly suitable for low volume production and can be installed directly above a drying hopper. Its design allows a smooth and continuous feeding process, with the possibility of adjusting the conveying air power by means of flow regulator.
The main technical features of the Venturi vacuum cleaner we offer include:
- reliability over time, stable and safe operation even under continuous use;
- solid and compact structure, entirely made of stainless steel to guarantee robustness and durability;
- dust separation efficiency, the spiral lid and the unique cyclonic vortex improve suction and separation performance;
- advanced filtration, equipped with a stainless steel expanded micro mesh filter, it is easily washable;
- intelligent monitoring, integrated with a capacitive sensor to monitor the material level and a visual alarm to warn of any shortage;
- simple control, that is a basic simple, intuitive and functional control system to facilitate adjustment by operators.
The advantages of this unit include, as already mentioned, the absence of mechanical moving parts and the consequent reduction in maintenance costs. The vacuum cleaner is also extremely silent, helping to reduce noise in the production environment and the associated inconvenience.
Thanks to its structural and functional characteristics, the Venturi vacuum cleaner we propose is ideal for handling the conveying of plastic granules over short distances and for quantities up to 70 kg/h. These elements make it perfect for short-scale applications.
Are you looking for innovative and effective solutions for granule conveying in your plastics company? Contact our team: we will offer you technical support and personalised advice to improve the performance and efficiency of your conveying processes.
Hot air dryer for plastic dehumidification
Hot air dryers are essential in the plastic processing industry. Effective drying of plastic granules ensures that businesses in this sector have completely dry materials for use in processing stages, thereby guaranteeing the quality of the final product. In this article, we will explore what hot air dryers are, how they work and what advantages they offer. We will explain the differences between drying and dehumidification and present the technical solutions and advantages offered by Vismec air dryers.
What a hot-air dryer is and how it works
A hot air dryer is a device designed to remove surface moisture from plastic granules by using heated air. Below are the detailed process steps.
- Heating the air. The air is heated using electric heating elements or other heating systems. As we are going to see in more detail in the last paragraph, in the case of Vismec dryers, specific systems control the air temperature very precisely.
- Hot air circulation. Hot air flows through the hopper, absorbing surface moisture present on the plastic granules. This process is particularly effective for non-hygroscopic polymers, which do not retain moisture within their structure.
- Expulsion or recirculation of moist air. In particular, in open-circuit systems, moist air is expelled and replaced with fresh air. In total or partial recirculation systems, on the other hand, moist air is filtered, reheated and reused, reducing energy consumption.
- Control and regulation. The air flow rate can be adjusted manually or automatically to suit specific operating requirements. Advanced models, such as those from Vismec, include smart mode management functions and temperature probes to optimise energy efficiency.
These steps, when conducted efficiently, ensure a perfect drying of the granules while minimising residual moisture. In this way, plastics processors can have completely dried polymers, guaranteeing the quality of the final product. The drying cycle can also be continuous, ensuring a constant flow of dry granules to the machinery.
Drying and dehumidification: differences
Although they are often used synonymously, drying and dehumidification are two distinct processes.
- Drying refers to the removal of surface moisture from materials: a process suitable for non-hygroscopic polymers that, as mentioned, do not absorb moisture from their surroundings. In other words, these polymers do not significantly change their physical and chemical properties when exposed to moisture or water. This makes them different from hygroscopic polymers, which instead tend to absorb moisture, altering their structure and behaviour.
- Dehumidification, on the other hand, applies to hygroscopic materials that absorb moisture from the environment, such as PET. This dessication process uses more advanced and structured technologies.
With regard to this last point, the wheel dehumidifiers that our company designs and manufactures have an internal rotor to dehumidify the granule. However, in dryers, this element is omitted.
In various industrial contexts, both drying and dehumidification prepare the plastic granules for optimal processing. This condition, as we have already seen in previous articles, is particularly important in processes such as moulding or extrusion, or in sectors such as the electronics industry and the medical or food industries, which require perfectly dry granules to meet high quality standards.
Vismec air dryers: features and advantages
Vismec hot air dryers are designed to remove surface moisture from non-hygroscopic polymers. Combined with an adsorption dehumidifier, they can also handle highly moist hygroscopic polymers.
Key features of our dryers include:
- Variable air flow. Vismec dryers are equipped with a system that allows the air flow rate to be adjusted according to operational requirements, optimising consumption.
- Energy optimisation is achieved through smart mode management, a return air temperature probe, and a PID algorithm, which maintains a constant and precise air temperature during the process, ensuring uniform drying.
- High-efficiency blowers. The smaller models use brushless blowers, while the larger versions are equipped with IE2/3 motors and inverters, ensuring efficiency and durability.
- Advanced technology. The AG models have a 7-inch touchscreen control and a valve to manage recirculation, eliminating the need for cooling.
Vismec hot air dryers offer a number of advantages, thanks to their advanced technical features.
- Continuous drying process, for an uninterrupted workflow that maintains high productivity.
- Adaptability and energy savings. The internal devices we have described in detail allow the dryer to be adapted to specific needs, optimising energy consumption.
- Ease of use. Touch screen controls and remote monitoring options make Vismec dryers easy to operate and manage, improving operational efficiency.
Our hot air dryers offer flexible installation options, either mounted on machinery or placed next to moulding or extrusion equipment.
Looking for a high-performance hot air dryer for your plastic processing needs? Contact us to find the ideal solution for your business.