Vismec a NPE 2024 Orlando Florida

Vismec at NPE 2024, the world's largest plastics trade show

From May 6-10, 2024, Vismec will be at NPE 2024, the world's largest trade show dedicated to the plastics industry. The event has always had a specific focus on innovation and will be held in Orlando, Florida, at the Orange County Convention Center.

The NPE show is held every three years and has become a must-attend event for companies in the industry: more than 2,000 companies will participate in this edition.

Vismec will take the opportunity to present the most innovative of its products. It will also be an opportunity to let industry professionals know more about the activities of our evolving U.S. headquarters.

Come visit us at the Orange County Convention Center: we look forward to seeing you at BOOTH booth S22089!

Il filtro a ciclone nel trasporto centralizzato dei granuli plastici

The cyclone filter in Vismec centralised conveying systems

The cyclone filter is one of the key components in vacuum conveying systems for plastic granules. Its function in Vismec conveying systems, combined with the blower or hook pumps, allows to effectively and efficiently manage the flow of granules while preserving the quality of the material.

In this section we are going to present the characteristics of the cyclone filter in more detail, and then we will focus on the specific features of the filters proposed by Vismec for centralised plastic granule conveying systems.

Cyclone filter: function in granule conveying systems

The cyclone filter and side channel blowers are complementary elements in conveying systems. We have already seen it in the article dedicated to the different types of granule conveying systems and in the presentation of Vismec products for conveying. Now we are going to have a closer look at this topic, focusing on the cyclonic filter.

A vacuum conveying unit works by generating a pneumatic vacuum using side channel blowers or hook pumps. The cyclonic filter integrates the action of these devices, keeping the air flow clean and preserving the quality of the plastic material. 

Let’s see in more detail.

  • Side channel blowers compress the air and generate a negative pressure. The conveying system exploits the pressure difference to convey and suck the plastic granules in, throughout the ducts of the feeding system. Usually, side channel blowers are suitable for applications where a moderately high pressure is required.
  • Hook pumps, as an alternative to blowers, generate a vacuum using the action of rotating lobes. They can handle heavier materials and produce a higher pressure, so they are used in situations requiring higher suction power.
  • The cyclonic filter is used to separate solid particles such as dust or plastic granules waste from the sucked air stream.

The special design of the system, as we have seen in a previous article dedicated to the cyclonic filter, exploits centrifugal force to separate heavier particles from the air stream. This helps prevent the accumulation of debris and impurities, ensuring a more efficient operation.

In the next paragraph, we will present in detail the functions and technical features of Vismec cyclonic filters in the centralised conveying systems that our company designs and manufactures.

The cyclone filter in Vismec centralised conveying systems

The cyclone filter is a key element in the operation of Vismec centralised conveying systems. In fact, its action makes the process more efficient and keeps the plant clean and fully functional, helping to extend its operational life. It also helps to safeguard the quality of the transported granule.

The three-sector filter system guarantees an optimal process outcome. 

Depending on the customers needs, the cyclonic filter can be used in different options, which we will examine below.

  • It can also be supplied in a double version, with manual or automatic switch. The double switch is used to avoid downtime or loss of production, e.g. when the filter is clogged or during maintenance operations.
  • It also provides for a Softstart or Inverter options: both systems are designed to save energy, increase the life of the system, and avoid powder or “angel hair” formation thanks to the possibility of controlling the conveying speed. In particular, the Softstart mechanism provides for a gradual start of the vacuum unit, with less energy consumption during starting phase.
  • In case of high temperatures materials conveying, it can be supported by a special cooling mechanism that protects structure and functions of the vacuum unit.

A pressure switch is also available as an accessory for the filter: the instrument monitors the internal pressure and prevents clogging.

Vismec cyclone filters can also be supplied in a stand-alone configuration. In this case, the side-channel blower is also presented as a separate device, notwithstanding the functional integration between the two elements of the vacuum unit. Furthermore, on request, the conveyor system can be equipped with a back-up blower, which further contributes to maintaining operational efficiency.

As previously mentioned, depending on the needs of the companies and the characteristics of the conveying process, the technical requirements of the blowers, which are available in single, dual or triple stage configurations, also vary. For long-distance conveying systems requiring higher productivity, side blowers can be replaced by hook pumps if necessary.

Do you want to know all the advantages that our granule conveying systems offers to plastics processors? Contact us: our technical team is always available for you.

Vismec a Mecspe 2024

Vismec at MECSPE 2024, the International Fair for the Manufacturing Industry

From 6 to 8 March 2024 Vismec will be at MECSPE, the International Fair for the Manufacturing Industry. The event will be held as usual in Bologna and has reached its 22nd edition this year.

Come and visit us at Hall 36, Stand E18!

Vismec products at MECSPE 2024

This year we will bring some of our flagship products for the dehumidification and conveying of plastic granules to the fair. In particular, visitors will be able to get to know:

  • Drycube, a flexible and independent wheel dryer. Drycube combines the efficiency of a rotor dehumidifier with an integrated pneumatic conveying system, a dehumidification hopper receiver, an IMM receiver and all related accessories. Advanced and efficient, it allows automatic setting of the dehumidification process parameters.
  • Venturi feeder, a feeding system for transporting materials such as master batches or granulated additives. Compact and completely made of stainless steel with a cast body, it allows the conveying of granules in a continuous flow with the possibility of adapting the air power through a pressure regulator.
  • FW 50 Touch control system. It manages up to 48 transport stations per empty line with possible emergency reserve system. FW50 is integrated with the universal OPC UA interface, for automatic and efficient supervision of the production system. Also available in touchscreen version with remote control

Would you like to know more? Come and visit the Vismec stand: Hall 36, Stand E18!

Trasporto granuli in plastica

Plastic granule conveying: types, alternatives and Vismec systems for centralised transportation

In the plastics industry, efficient granule conveying ensures smooth production operations. Companies in this sector know how important this phase is to optimise costs and time and preserve the quality of the material. Thus, in this article, we will present the different systems for conveying granules. Then we will focus on the solutions proposed by Vismec and explain their advantages.

Conveying of plastic granule: types and alternatives

The conveying of plastic granules can be managed in different ways. Let’s present them below:

  • Manual conveying. This is the most traditional method using manual handling and emptying of sacks. It does not require specialised manpower and has low labour costs. However, it requires longer times and exposes to the risk of waste, material contamination and safety risks.
  • Mechanical conveying. It involves the use of mechanical systems to facilitate the movement of the granules: augers, rigid or flexible spiral feeders, conveyor belts. It does not require ordinary maintenance of the filter, which is not present, but entails problems of cleaning and wear of the mechanisms. Moreover, it can only be used over limited distances.
  • Pressure conveying. It uses compressed air pumps to push the plastic granules through a system of pipes and containers. It offers a higher transport speed, with a capacity of more 1000 kg/h. In addition, it can be operated through stable or mobile conveying units. However, it usually involves the presence of single stations: a multi-station configuration is only possible with the use of special diverter valves. Furthermore, the air is discharged through a cyclonic filter (or other filtering system) that requires periodic maintenance.

A different and more efficient mechanism is the vacuum plastic granule conveying system: we will talk about it in the next paragraph, presenting the innovative solutions offered by Vismec. 

Vismec solutions for vacuum conveying of granule

The vacuum granules conveying system uses differential pressure to move plastic granules through a pipeline system. This method is based on the creation of a partial vacuum generated by a special pump inside the pipes. The pressure difference between the suction point and the destination point of the granules allows the conveying of the material.

Vismec offers several solutions for vacuum conveying. Below we will present the main ones, focusing on the centralised conveying system

  • Vismec feeding kit: connected to the drying system, from which it is controlled, it offers an integrated drying/ conveying and allows connecting up to two stations with receivers. It can be installed near the drying system or on its frame, but manages a limited flow rate of plastic granule (100 kg/h) over short distances. These limit can be crossed by integrating the feeding kit with a VB system. However, the connection remains limited to two receiver stations.  
  • Single-phase feeder: it entails a reduced initial economic investment and enables automatic filter cleaning, reducing time and costs for maintenance. It is also equipped with an automatic alarm system that signals the exhaustion of material.  
  • Conveying by Venturi system: independent compressed air feeder for transporting materials such as masterbatch or granule additives. Compact and reliable, it can also be installed on top of a drying hopper and is suitable for low throughputs. It allows a continuous granule conveying with the possibility of adapting the air power and transport speed through a flow regulator. It ensures an accurate separation of powders thanks to the unique cyclonic vortex.
  • Small three-phase centralised systems: the conveying mechanism becomes more articulated and involves a vacuum system with centralised self-cleaning filter and bypass valve, side channel blowers and a 4.0 control system of the different stations. The material flow is unlimited and the system can handle up to 2, 2,4 +4 or 9 stations.

Vismec also designs and manufactures large centralised conveying systems. They are more articulated feeding systems that allow the rapid, efficient and controlled conveying of dried plastic granules.

These systems represent the evolution of the smaller systems we have presented so far and incorporate some of the most innovative solutions developed by Vismec:  

  • FW50 control system manages up to 48 transport stations per vacuum line, with possible emergency stock system. Now it is also available in a touchscreen version with remote control and with three different solutions: magnet, table-top and wall-mounted.
  • integrated Vismec Dryfeed dehumidifier delivers dry air to prevent moisture absorption during transport;
  • the system can be integrated with a vacuum unit or an emergency blower to avoid the risk of downtime machine;
  • receivers of the different stations are made of stainless steel, in different sizes and equipped with an optimised filter system and discharge, inspection and cleaning mechanisms.

Vismec large centralised conveying systems can be integrated with various accessories and provide several advantages to the companies that choose them. In particular, they make it possible to control and optimise the logistics of plastic granules thanks to integrated supervision and management systems, and they concentrate the filtration phase in one point, keeping the production environment clean. They also reduce energy consumption, and time and costs for maintenance, resulting in savings for the company.

Do you want to know how they work in detail? Contact our technical team.

Deumidificatore per plastica come sceglierlo

Plastic dryer: how to choose it

Choosing the right plastic dryer (also called plastic dehumidifier) is crucial for plastics processors. In this article, we will explore the elements that influence the drying process and look at the different types of dehumidifiers. Then we will present the innovative Vismec rotor dryers.

Plastic dehumidification: the criteria

Effective plastic granule drying preserves material properties, improves aesthetics, reduces processing time and the risk of faulty production.

However, the result of dehumidification may vary according to different elements that depend on the characteristics of the plastic material, external factors and the conditions under which the drying process takes place.

When subjected to heat, thermoplastics, including plastic granules, become malleable. They are divided into hygroscopic thermoplastics, with both internal and external moisture, and non-hygroscopic thermoplastics, with moisture limited to the surface. This is an important first distinction when choosing the most suitable dryer for a plastics processing company.

However, there are other factors that affect the process result. Here are the main ones.

  • Dew point: the temperature at which the air becomes saturated with moisture. Accurately measuring the dew point prevents condensation during drying.
  • Set temperature: affects the performance of the dehumidifier and can also have an impact on material properties, e.g. for advanced materials such as bioplastics.
  • Drying time: when it is too long, it carries the risk of thermal, physical or chemical degradation of the material. In addition, it has an impact on process organisation.
  • Air flow rate: when it is adjustable according to material specifications, it allows a more accurate and efficient drying.
  • Material type and shape: influence the specific drying used strategies.
  • Initial and final humidity. To correctly set the drying parameters, it is important to both measure the moisture present in the material at the beginning of the process and to determine the desired final moisture content.

The choice of the ideal plastic dryer has to be determined by the balance between these factors.

Characteristics of different types of plastic dryers and Vismec solutions

We will now very briefly present the different drying methods. Then, we will focus on the features and advantages of the rotor dryers designed and manufactured by Vismec compared to other solutions.

Let's see what systems are available to companies that process plastic materials.

  • Hot air ovens: an expensive manual system, which allows small quantities of material to be dehumidified, provides a limited control over the process and ultimately does not guarantee optimal results.
  • Hot air dryers: they provide continuous drying and can be installed either on board or beside the machine. However, they have high energy costs, are influenced by environmental conditions and are only suitable for non-hygroscopic materials.
  • Compressed air dehumidifiers: they also allow continuous drying, can be installed beside the machine and require little space. However, they are only effective for small production runs, generate high indirect costs and process control is limited.
  • Microwave plastic dryers: they expose plastics to risks related to material degradation. They are not suitable for industrial use.
  • Infrared dehumidifiers: they permit continuous drying and accelerate the process. However, they are only applied to large production runs and involve high costs and consumption. In addition, their control is complicated and there is a risk of contaminating the material.
  • Vacuum dryers: the continuous drying process reduces process time and does not subject the material to any harmful stress. In addition, energy consumption and maintenance time are limited. However, this system is only suitable for small production runs and has high purchase costs.
  • Molecular sieve dryers: they also allow a continuous drying process, can be installed on board or beside the machine, and are not subject to limits on production quantities. However, their dew point is inconstant, and the molecular sieves degrade very quickly, so they must be often replaced.

Vismec rotor dryers have different and innovative features compared to the solutions described so far. The wheel, the pivotal element of the system, rotates thanks to a stepper motor and air passes through it in the 3 phases that we will see below.

  • Dehumidification: the air is dried and then passes into the heating chamber, which enables it to reach the desired temperature. Next, the hot, dry air dries the plastic granules.
  • Regeneration: The second section of the wheel is crossed by hot air generated by a chamber and a dedicated blower.
  • Cooling: the wheel is cooled and then returned to the first drying section.

The advantages of the Vismec rotor dryers are many, starting with the efficiency of the process. The machine is more compact and has reduced maintenance requirements. In addition, the traditional molecular sieves are replaced by a wheel with a special honeycomb structure that is much stronger.

Other advantages include:

  • drying temperature of up to 180°C without using cooling water;
  • constant and adjustable dew point down to-50°C;
  • energy consumption reduced by 40 % and monitoring from display;
  • air flow regulation;
  • preset and adjustable reference parameters with Smart mode system;
  • MPM - Material Protection Management, a system to protect material from over-wetting and degradation;
  • SLS - Safety Loading System, a safety system to prevent non-dehumidified material from reaching the processing machine.

The features and benefits of Vismec rotor dryers are many more than we have presented. This makes them effective and adaptable to the different companies needs. Contact our team to learn more.

Stoccaggio industriale granuli plastici Vismec

Industrial storage of plastic granules

In the plastics processing sector, accurate industrial storage of granules helps to maintain efficient production processes. In fact, storage integrates effectively with transport and receiving systems, optimising material management.

Furthermore, a good storage system, especially in particular situations, helps to preserve the physical characteristics of the raw material. This element is important, especially when its characteristics have an impact on the quality of the finished product.

In this article, we will talk about the main needs that companies have to face in industrial granule storage. Then we will present the solutions that Vismec proposes, highlighting their added value.

Industrial storage of plastic granules: challenges and solutions

Plastics processing companies are facing more than one challenge in the storage of plastic granules.

The common need is for solid storage containers that can adapt to different load volumes and weights. As we will see in more detail in the next section, the solutions proposed by Vismec for industrial storage are flexible in terms of:

  • Size and capacity. They range from small 100-litres cylindrical containers to large external silos whose volume can reach up to 200 m3.
  • Manual or automatic loading systems.
  • Other structural elements. Like the loading and unloading systems we mentioned above, these can differ in type, diameter and capacity, as well as in the additional mechanisms available to facilitate operations.

Having versatile solutions is a key element in aligning the characteristics of industrial granule storage systems with the different needs of companies. This is precisely why, among its products, Vismec offers modular containers or other types of adaptable structure, including options and accessories.

As mentioned at the beginning, plastic processing companies must also consider the need to preserve the characteristics of the material. We have already covered this topic from several points of view in various articles on our blog. For example, when we explained what dew point is and how it applies to drying systems, or when we talked about bioplastics. 

In the context of industrial storage, the topic becomes relevant when talking about the large outdoor silos used to contain plastic granules. In this case, it is important that water does not condense inside the silo, in order to avoid a contamination of he material. Vismec answers to all these needs with efficiently and strategically designed solutions.

Vismec systems for industrial storage

Each of the containers that our company offers for the industrial storage of granules is designed to meet different and flexible needs. Here are the main solutions we offer:

  • Cylindrical storage bins: designed to collect and transport bags of plastic granules without risk at the company's production site. They are solid storage systems, entirely made of stainless steel and available in different sizes. They can be integrated with one or two suction probes and with a bag-breaking grid on request.
  • Square storage bins: more sophisticated and performing than cylindrical containers, they are already designed for mounting a receiver on each of the two sides. In this way, the product facilitates integration with Vismec granule transport systems. In addition, the suction valve with adjustable air flow simplifies the unloading of the container.
  • Big Bag Station with integrated big bag emptying system: its telescopic structure makes it suitable for emptying bags of different sizes. The bag is inserted into the frame of the big bag station via a suitable lifting system. Then the stored plastic granules are conveyed to the big bag emptying system designed by Vismec, connected to a suction valve with one or more outlets available in different diameters.
  • Indoor silos: silos with variable volume, from 10 to 80 m3, made of aluminium or steel. They can be filled using a standard vacuum conveying system or with a pressurised mechanism, which is much faster.
  • Outdoor silos: large silos for outdoor use, with a volume that can reach 200 m3, also in the double silo solution. All silos have a filling pipe, a discharge filter and access and inspection mechanisms that guarantee maximum safety for operators.

In the last case, as already mentioned above, use in an outdoor environment makes it necessary to prevent moisture build-up in the silo. For this reason, Vismec provides a drying system on request: the dry air produced keeps the granules dry, preventing the material from deteriorating.

Each of the solutions proposed by Vismec for the industrial storage of plastic granules meets specific requirements in terms of sizing, material handling mechanisms, and integration with other systems. Contact our team: we will be able to advise you on the most suitable storage system for your company.

Dew point significato e applicazioni

Dew point: meaning and applications to plastic dehumidifiers

In various industrial fields, including plastics dehumidification, the concept of dew point and its meaning are important. In fact, the dew point is a physical condition to be carefully considered for companies operating in sectors where humidity can influence the quality of processes, the material used and results.

In this article, we will go into the technical meaning of the term, presenting the impact of dew point in the industrial sector and highlighting its applications in plastic granules drying process.

Dew point: meaning and general applications

To better understand the meaning of dew point, let us start from its basic definition. Basically, the dew point is the temperature at which the air becomes saturated with water vapour, resulting in the condensation of moisture in the form of water droplets.

The quantity of water vapour that the air can retain before becoming saturated and initiating the condensation phenomenon increases with increasing temperature. Consequently, a cubic metre of air at a lower temperature requires less water to reach saturation. For example:

  • 1 kg of air at 20°C becomes saturated with 14.7 g of water;
  • 1 kg of air at 3°C becomes saturated with 36.6 g of water.

Thus, the temperature at which the air reaches the saturation point corresponds to a certain quantity of water present in it. Consequently, this temperature, known as “dew point”, in turn becomes an indication of how much water is contained in the air when water vapour condenses.

What are the practical implications? In industry, dew point has a direct impact on production processes, the quality of materials used and final products. In fact, humidity-sensitive materials such as plastics can undergo undesirable changes.

For this reason, an accurate control of the dew point is very important: the careful measurement and management of this parameter allows preventing condensation by activating drying processes when necessary. In this way, processed and transformed materials can comply with the required parameters regarding the tolerated quantity of humidity.

The dew point finds application in various industries. For example, monitoring it in the food and pharmaceutical sectors is crucial to preserve the quality and integrity of products. The same goes for electronics, where humidity can affect devices performance.

Looking specifically at the plastics processing sector, the issue is similar: keeping plastic granules within the expected humidity parameters prevents defects in the appearance and properties of the plastic product. We will see this in more detail in the next section.

Applications in plastic granule drying

Understanding the meaning of dew point and the correspondence between temperature and the amount of water in the air has significant practical implications. It is particularly important in the processes used to maintain polymers at the right humidity level by drying.

Plastics naturally retain humidity. However, depending on the type of material, the methods are different:

  • in non-hygroscopic plastic materials, humidity stops at the surface;
  • in hygroscopic plastic materials, on the other hand, humidity is present on the surface, but also penetrates inside the plastic granule.

If the humidity is not removed or kept within the allowed tolerance limits, the final product resulting from the granules processing could be opaque or streaked, smudged or bubbled. Then, from a functional point of view, the presence of residual humidity could worsen the mechanical properties of the object, deform it or lead to uneven wear over time.

To avoid problems of this type, the plastic granule is passed through a stream of hot air during the drying process. The initial explanation about the meaning of the terms “dew point” and how the phenomenon works makes us understand why.

In fact, the air can retain humidity until it becomes saturated. As we have seen, this capacity increases with increasing temperatures. Therefore, the humidity and temperature of the air used to dry the plastic granules in the drying process can be adjusted according to the result to be achieved.

When we design drying systems, we take all these parameters into consideration. In addition, our systems have a further advantage: they allow for very significant energy savings which reach up to 40 per cent and more.

This element makes the process more efficient and sustainable in terms of consumption and use of resources. In other words, Vismec dehumidifiers ensure excellent performance: top quality results and reduced energy costs.

Our drying systems include:

  • Drycube, which enables perfect drying and efficient transport of the technical plastic granule. Drycube can reach a drying temperature of 180°C and a constant dew point, adjustable down to -50°C.
  • Drywell, a compact high performance dehumidifier. Again, drying temperature and dew point are adjustable up to 185°C and -50°C respectively, depending on the type of material and its condition.
  • Dryplus, a floor standing dehumidifier used mainly in on-board installations.

In this article, we have presented just a few of Vismec's solutions for the drying of plastic granules. 

Nevertheless, we can provide you with a much wider range of machinery and accessories, according to your company's needs. 

Want to know more? Contact our team.

Deumidificatore plastica Vismec caratteristiche funzionamento e applicazioni

Plastic dehumidifier: what it is, what it is used for, Vismec dehumidifiers

The plastic dehumidifier plays a fundamental role in the production processes of companies involved in transformation of plastic materials.

But what exactly is it and what role does it play in this field? We will see in this article, exploring its characteristics, operation and practical applications. Finally, we will discuss the advantages of the dehumidifiers offered by Vismec.

Plastic dehumidifier: operation and applications

Plastic dryers are machines designed to eliminate the moisture in plastic granules. In fact, the presence of moisture can compromise the material features and, as a consequence, the quality of the result of plastics transformation processes.

Therefore, the use of a plastic dehumidifier becomes essential to ensure the efficiency and reliability of the production process and the quality of the final result.

The operation of dehumidifiers is based on a condensation process, which can be summarised as follows:

  • Initially, the moist air contained in the plastic granules is sucked into the device. Then, the air flow passes through a series of heat exchangers, where it is cooled below its dew point.
  • In this way, the moisture present in the air condenses into liquid form and can be eliminated. This process returns the granule perfectly dry, that is, in an optimal condition to be used in plastic processing.

In this production process, the use of a high-performance and reliable plastics dehumidifier brings several advantages.

  • First, it helps to maintain the stability of the physical and mechanical characteristics of the polymers, avoiding alterations due to humidity.
  • Consequently, it reduces the risk of defects or deformations in the finished product and the possible negative impacts on performance when such a product is used.

In some fields, such as medical, food or bioplastics, these characteristics are particularly important, because they are also linked to consumer health, safety of use, and maintenance of high performance standards.

Similarly, the use of optimally dehumidified polymers as raw material contributes to the good aesthetic of the finished product. This element is significant in sectors such as design, construction, production of components for consumer electronics, automotive sector.

In the next section, we will present wheel dehumidifiers produced by Vismec, and explain their features and advantages.

Vismec plastic dehumidifiers

The plastic dehumidifiers we produce provide efficient dehumidification combined with great flexibility. In addition, they save energy, reducing consumption and costs.

These advantages arise especially from the possibility of adjusting the dew point of the air flow. In fact, the operating mechanism of our machines allows calibrating the dew point, keeping it constant over time, regardless of any external ambient condition.

Each Vismec plastic granule dehumidifier adds to this feature additional adjustment, like temperature monitoring and control mechanisms. Let’s see them in particular.

  • Smart Mode, that controls the temperature of the return air, automatically adapting the process to the production needs of the client company.
  • MPM (Material Protection Management), that guarantees the integrity of the material, protecting it from excess dehumidification. This achievement is important to ensure maximum quality and is possible by monitoring the loading mechanism and the return air temperature.
  • SLS (Safety Loading System), that prevents still wet plastic granules from reaching the production machinery, thanks to accurate control of the dehumidification time.

The latest proposal in the range of Vismec wheel dryer for plastics is Drycube. Drycube combines the efficiency of a rotor dehumidifier with an integrated pneumatic conveying system, a receiver for the dehumidification hopper, a receiver for IMM and all related accessories.

The conveying of hot materials takes place in a closed circuit: hot dry air is used to transport the material to the processing machine, and this particular technology allows the polymer to be kept stable away from changes in temperature and humidity from the outside air.

DryCube enables the automatic setting of the parameters of the drying process and continuously monitors the operations to achieve the ideal conditions and protect the material from over-dehumidification. It is particularly suitable as a stand-alone flexible dehumidifier to be placed on the side of the processing machine. 

When the dehumidifier is positioned next to a plastics processing machine (usually a press), this mechanism allows a greater flexibility and speed of use, reducing processing times. 

However, the Vismec product range for dehumidification is much broader and includes machines, control and measurement systems, and accessories. If you want to learn more and choose the most suitable solution for your company? Contact our team: we will be happy to support you.

Valvola proporzionale: funzionamento e vantaggi nel trasporto dei polimeri e dei granuli plastici

Proportional valve: operation and advantages in conveying plastic polymers

A proportional valve is a simple mixing element. It is used in industrial automation and engineering applied to system for conveying bulk materials by means of an air flow, generally called pneumatic conveying systems. In this article we will have a closer look at what it is, its applications and the advantages of Vismec proportional valves for the conveying plastic granules.

Proportional valve: general operation

The name “proportional valve” comes from the fact that it is used to create a proportion between two different types of material. This name is improper in this field, because in engineering it is usually referred to as being a valve that is able to change the flow rate of different types of flows proportionally to the control signal received.

Thus, proportionality is understood as the relationship between the control signal which varies in a certain range of values, and the opening position which is variable in a certain range too. These devices find application in various sectors, including the automotive, aerospace, chemical and energy industries. In these areas, for example, they can be used to:

  • control pressure and flow rate of fluids in hydraulic systems;
  • ensure precise dosing of liquids in chemical processes and other processes;
  • regulate the speed in automatic transmission systems of vehicles.

In the case of proportional valves used in pneumatic conveying, the proportion between two different materials is not achieved through a continuous variation of a valve body that continuously modulates two flows. It is, instead, achieved by the proportion between the conveying time of a first material and the conveying time of a second material.

Thus, the proportional valves produced by Vismec allow the alternating suction, in a specific proportion, of two different plastic materials through the action of an air flow.   For example, it may be a virgin polymer and a regrind polymer, or two primary materials. The proportion between the two is simply set by indicating the percentage of one material compared to the other.

The versatility and precision of proportional valves make them very useful in various applications where handling of two materials belonging to the same granule receiver is required. For this reason, they are an essential component of the Vismec feeding systems for plastics processing companies

As we will see, the valves that we design and integrate into products for conveying plastic granules have specific characteristics that make them extremely functional. However, let’s start from the beginning by briefly explaining how this type of device works in general.

The proportional valve for bulk materials operates by means of two shutters which are able to block the flow of granules and hermetically seal the duct, in response to a command or control setting. This command controls the alternating opening of the valve stems, making it possible to create a ratio between two materials arriving at the same bulk receiver.

As we have mentioned, in the case of Vismec proportional valves, the material in transit consists of polymer granules sucked alternately according to an adjustable proportion. Looking at their use in conveying polymers for plastic processing, let’s focus on the proportional valves designed by our company.

Advantages of Vismec proportional valves for conveying plastic granules

The Vismec proportional valve, installed before or in correspondence with the plastic granule receiver, allows two different types of plastic materials to be sucked in alternately thanks to an air flow produced by the same vacuum generator. The valve switches the vacuum from a main pipe to a secondary one.

From the point of view of the process control, it is sufficient to set the percentage of the second material to manage the entire process. Through the control, it is possible to vary the percentages of the two components to obtain a loading proportion. To increase homogeneity, the materials can be alternated several times during the same loading cycle.

Let's have a look at the features that make VISMEC proportional valves unique on the market.

  • The extremely clean one-piece precision-cast stainless steel design avoids the presence of stagnation areas. Therefore, the passage of granules is fluid and without interruptions or deposits. The stainless steel body greatly reduces wear due to abrasion caused by sliding granular materials.
  • The inspection window is made of borsilicate glass that can withstand temperature changes and is wear-resistant to impacts of granules. The window has gaskets made of elastomers and noble polymers with high temperature resistance that are not in contact with the granules .
  • The valve is controlled by a Vismec receiver and does not need a separate stand-alone control. Once the receiver has been properly parameterised, the valve is also adjusted accordingly, without the need for additional control points.
  • The shut-off system consists of two stainless steel double-stage shutters, in which the first stage stops the granules and the second stage seals the pipe to enable the perfect transfer of vacuum into the second pipe. There are also moulded elastomer wear-resistant gaskets without frontal impact, to allow a perfect seal.
  • The proportional valve is part of a pneumatic conveying system for polymer granules or for granules dehumidification and conveying. This plant is controlled by a system that uses the standard OPC UA protocol, allowing the automated management of processes with an advanced and intuitive human-machine interface. 

Let’s now see the advantages of the proportional valve.

  • Simple adjustment. The device allows you an easy adjustment of two different materials to be used on the same polymer processing machine. This element is particularly useful when it comes to ensure an accurate proportion of materials in transit, as in the case of Vismec proportional valves.
  • Wear-resistance. This type of valve is designed and manufactured to withstand wear and weather conditions. Consequently, it ensures a long operating life and reliable operation over time.
  • Presence of control and signalling systems that facilitate the use of the device.
  • Perfect closure of the valve and connecting components to avoid inefficiencies.

As we have seen, the Vismec proportional valves allow you to manage different functions and passages within the systems in a simple, rapid and automated way by a single control point. So, they allow companies that use them to simplify operations, optimise time and reduce consumption.

If you want to know in detail how they work and the other Vismec proposals for feeding and conveying plastic polymers, contact our team. We will be happy to evaluate with you the most suitable solutions for your company.

Dosatore volumetrico e gravimetrico: differenze e applicazioni

Gravimetric doser and volumetric doser: features and applications

The gravimetric doser and the volumetric doser are devices used in the industrial sector for the precise measurement and dosing of powders or granules. 

The two tools differ significantly in their measuring methods and in  their possible applications. We are going to talk about it in this article, also presenting the solutions proposed by Vismec for gravimetric and volumetric dosing.

Gravimetric doser and volumetric doser

So let’s start by trying to understand what the two devices are and presenting the differences between the gravimetric and volumetric dosers.

In the dosing process, the gravimetric doser measures the quantity of material by weight, thanks to an integrated scale that continuously measures the weight of the material. 


  • doser weighs the material in real time and in a highly accurate way;
  • device compensates for any variations in the density of the weighted material or environmental conditions;
  • this precision is crucial in sectors such as the chemical, pharmaceutical and food industries, where the correct dosing of ingredients is essential for the quality of the final product.

Even in applications in the plastics processing sector which requires a high precision, the gravimetric blender ensures quality results. An example? The dosing of additives.

Instead, the volumetric dosing unit doses the material based on the occupied volume. This type of doser often uses a system of measuring chambers or tanks that fill and empty cyclically, dispensing a pre-established amount of material. 

Volumetric dosers are often faster than gravimetric dosers, but can be less accurate because they do not take into account variations in material density. As we will see in the next paragraph, the volumetric dosers that our company offers, on the other hand, allow the dosing of plastic granules while maintaining precision. 

A further difference between the two dosing systems concerns the calibration of the instrument:

  • the gravimetric doser requires accurate initial calibration to ensure the accuracy of results over time;
  • in the case of the volumetric doser, adjustments must be more frequent because the density of the material may vary. 

Additionally, gravimetric blenders are more suitable for materials that may compact or have a significant change in density during production.  

Thus, the two types of blenders have different operating methods. Vismec offers advanced and effective solutions for gravimetric and volumetric dosing, calibrated according to: 

  • type of application;
  • supported plastic processing;
  • characteristics of the use environment.

We will present them more thoroughly in the next paragraph.


Products offered by Vismec for volumetric and gravimetric dosing

As we were saying, Vismec volumetric and gravimetric dosers allow accurate dosing of plastic granules and any additives. Each product has its own specific features, designed to best meet the needs of customer companies.

  • The MGF gravimetric doser accurately measures the quantity of blended additive with the plastic material. The dosing unit features a high-precision automatic recalibration system, without the need for additional configurations.
  • The WSB series doser is equipped with advanced control technology that allows accurate and real-time monitored mixing of the granules. The device fits on any moulding machine, even allowing the loading time of the plastic material to be adjusted.  
  • Vismec volumetric dosers are also designed to support plastic injection or extrusion moulding machinery. The device is designed to withstand mechanical stress and vibration without compromising the precision of operations. In addition, the loss-in-weight volumetric dosing system allows the weight of the polymers to be constantly monitored, ensuring the optimum quality of the end result.

All products offered by Vismec for gravimetric and volumetric dosing, in addition to precision, have a common ability to facilitate machine maintenance and cleaning. Furthermore, the integrated control devices optimise dosing operations and allow the customer company to reduce material waste and associated costs.

Would you like to learn more about the dosing systems and other products Vismec offers companies in the plastics sector for polymer dehumidification, conveying and storage operations? Contact our team and tell us what you need. Together we will find the most effective solution for your company.