Distributor / authorized representative that deals with supply & delivery of roll mills (calenders) to industrial enterprises of Russia
Engineering company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), Russia, has been successfully working with a number of Russian industrial enterprises at the local market for more than 20 years. Since the company’s founding, it has acquired immense engineering experience, market reputation, and has realized more than a hundred large-scale projects at the industrial plants in Russia. Our company is continuously in search of new business partners, who consider Russian market investment-attractive and want to boost their sales in the region, as well as expand their field of activities and enter a new international level.Contents:
We are interested in cooperation with the manufacturers of roll mills (calenders), who are looking for an official and reliable distributor to deal with supply & delivery of their equipment to the industrial plants in Russia.
The company’s top management and sales team are well acquainted with the Russian market, its mentality and laws; they also understand industrial specifics of the financial and economic activities of the Russian customers. All our sales managers have a large customer database, extensive experience of successful sales and well-established connections with the potential buyers of your roll mills. This allows our managers to promptly set out the most promising directions for promotion and to ensure a rapid entry of the products into the promising Russian market. Our employees, who are fluent in English and German, are focused on working at the international market with the supplies of foreign equipment.
Our team of experienced engineers, who can handle the most serious technical problems, constantly keeps in touch with the Russian customers, holds meetings and delivers presentations regarding the latest achievements of our manufacturing partners. They point out the engineering challenges and actively communicate with all the departments at Russian plants. That is why the specifics of doing a business in the Russian Federation are well-known to us, and we also know the equipment of the local industrial plants and their up-to-date modernization needs.
Once we become your authorized representative in Russia, our marketing staff will carry out a market research in order to check the demand for roll mills (calenders), will submit a market overview for roll mills that you offer and evaluate the needs for this type of equipment at local plants. Our specialists will also estimate the potential and capacity of this market at local industrial plants. Our IT-team will start developing a website for your products in Russian. Our experts will assess the conformity between your roll mills (calenders) and customer needs as well as analyze the common reaction to the new goods in general. We will look into the categories of potential customers, and pick out the largest and the most promising plants.
Upon becoming your authorized agent on the territory of Russia, ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), will obtain certificates, if required, for a batch of the goods, for various types of roll mills (calenders) in compliance with Russian standards. We can also arrange the inspection in order to obtain TR TS 010 and TR TS 012 Certificates. These certificates provides permission to operate your equipment at all industrial plants of the EAEU countries (Russia, Kazakhstan, Belarus, Armenia, Kyrgyzstan), including the hazardous industrial facilities. Our company is eager to assist in issuing Technical Passports for roll mills as per Russian and other EAEU countries’ requirements.
Our engineering company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), collaborates with several Russian design institutes in various industrial segments, which allows us to conduct preliminary design as well as subsequent design works according to the standards, construction rules and regulations that are applicable in Russia and other CIS countries. It also enables us to include your roll mills (calenders) into the future projects.
The Company has its own logistics department that can provide packing service, handling as well as the most efficient and cost effective mode of transportation of the goods (incl. over dimensional and overweight goods). The goods can be delivered on DAP or DDP-customer’s warehouse basis in full compliance with all the relevant regulations and requirements that are applicable on the Russian market.
Our company has its own certified specialists who will carry out installation supervision and commissioning of the delivered equipment, as well as further guarantee and post-guarantee maintenance of roll mills. They will also provide necessary training and guidance for the customer’s personnel.
Roll mills (calenders). A brief overwiew
Roll milling is a method of processing polymers, in which a raw material passes through the gap between contra-rotating heated metal rollers for several times. The polymer transition of a solid to a viscous-flow state occurs under applying temperature and mechanical forces. After the polymer becomes soft, it is intermixed and eventually homogenized under applied deformational forces. Roll milling involves material compression that is accompanied by shear strain and subsequent macromolecules’ decrease in molecular mass.
As a result of mechanic and chemical processes, macroradicals are formed. During roll milling, these macroradicals are affected by the temperature. Macroradicals can:
- Deactivate, resulting in polymer’s decrease in molecular mass.
- Recombine, resulting in formation of block polymers or graft copolymers. This phenomenon is commonly used in plastics processing technology.
A diagram, illustrating roll milling and calendering processes, is presented below.
Roll milling is used for:
- Mixing of required components with polymers (as a result, sheets and films are manufactured);
- Heating and softening of finished polymeric materials;
- Producing of block polymers and graft copolymers.
The rollers rotate at different speeds in order to increase deformation intensity. Moreover, the speed of the rear roller (w2) is higher than of the front one (w1). The differential speeds of the front and rear rollers are called friction (or friction ratio). Typically, this ratio varies from 1.1 to 1.4. The rollers can operate in two modes: intermittent or continuous.
Calendering and its major differences from roll milling
Calendering is a method, in which the raw polymer is being continuously processed. This technology is used in the following areas:
- Manufacturing of sheet or film products;
- Application of textured materials onto the sheets’ surface;
- Duplication of prefabricated belt blanks;
- Reinforcement of the raw polymer with fabric or mesh at a temperature above the flowing or melting point.
Calendering is performed on the machines that can operate continuously, and the main element of such machines is a multiple-roller calender. During calendaring, the polymer is fed through the gap only once as opposed to roll milling. To manufacture the film of calibrated thickness, the polymer needs to pass through several gaps, formed by the calender rollers. Calenders are equipped with three or more rollers, which rotate significantly faster than during roll milling. First, a hot homogenized and plasticized material is fed into the gap between the first pair of rollers. The layers of material move along the rollers’ surface at a speed equal to the rollers’ linear speed. When the movement starts, the inner layers of material are influenced by the buoyancy force, and then they are drawn into the gap between the rollers by the friction forces. The differential speed of the material layers provides for better plasticization of the material and causes shear strain. The speed of the middle layers increases sharply as the material gets closer to the gap. The speed reaches its maximum when the material passes through the gap. Afterwards, the speed gradually decreases and goes down to the rollers' speed.
Thus, the molten material flows through the rollers gap at various speeds and pressure gradient. A significant flow velocity gradient along the channel’s depth promotes high shear stress. This shear stress enhances homogenization, but leads to b orientation of macromolecules along the flowing direction. This effect is enhanced by the fact that the molten material has a low temperature at the rollers and it quickly cools down after passing through the calender. Therefore, the strain release is unlikely to happen.
The channeled flowing of a high-viscosity polymer through the rollers causes orientation of macromolecules along the calendering direction. This process leads to anisotropy of mechanical properties as well as to shrinkage of the film, i.e. “a calender effect”. This effect as well as a highly elastic strain id decreased by preliminary plasticization of the compound and by temperature rise of the rollers.
The temperature during calendering influences the molding’s quality and determines the degree of polymers’ orientation. The temperature should be within the range of the flow temperature of the polymer being processed. The film, taken off the calender, should not stick to it and should keep its form. One should note that when the molten material goes through rollers, the separating forces are exerted, and these forces can cause the rollers’ bending. In the result of the rollers’ bending, the film of irregular thickness is manufactured.
Several methods are used to solve the thickness variation problem.
- Rollers with increasing thickness along the axis towards the center;
- Location of rollers using criss-cross arrangement;
- Combined method.
Today, roller machines are used for manufacturing of films and sheets out of vinyl chloride plastic, PVC plasticizer, phenolic molding compounds and cellulose acetate molding compounds. Depending on a product to be manufactured, the rollers’ surface can be smooth or textured. At the same time, the roller’s surface should be wearproof and have low roughness. The upper layer of the roller is made of high-strength steel, thus providing for its long live.
Roller machine. Overview and principle of operation
Roller machines are equipment used for polymers processing and products manufacturing. Roll milling is a group of processes involving processing of raw polymers. The equipment, manufacturing finished or semi-finished polymer products, is known as calenders, and a corresponding group of processes is called calendering.
Rollers and calenders are exposed to mechanical impact at the gap between the rollers. In this case, mechanical processes are the main technological effects.
Roller machines are one of the most widely used types of equipment that is used for processing of rubber compounds and plastics. Roller machines and calenders are subtypes of roller equipment. Calenders are used for manufacturing of films and sheets (including ones with patterns), as well as for application of polymer coating onto textile or other substrate. Roller machines are widely used for mixing and homogenizing of components, plasticization, crushing, milling, and other manufacturing operations. Processing of polymers using calenders and roller machines are similar in many ways.
Two hollow cylindrical rollers are the main operating parts of roller machines. These rollers rotate towards each other and move at different peripheral speeds. The rollers’ axes are located in the horizontal plane. The number of roller may vary from 2 to 5, and rollers, rotating in the opposite directions, form pairs.
The polymer being processed is drawn by the coupling force from the rollers’ surface into the gap, and then it is deformed or broken up.
Roller machines can perform numerous manufacturing operations, though they have simple construction and are equipped with the following elements:
- Cast baseplate with stiffening elements;
- Two frames tied together by tie-bars;
- Two hollow cylindrical rollers;
- Fixed bearing case of the rear roller;
- Mobile bearing case of the front roller;
- Mechanisms for gap adjustment, restricting pointers;
- Rollers cooling/heating system;
- Lubrication system for brake and emergency device.
The polymer passes through one gap in the machines, which are equipped with a single pair of rollers. The polymer sequentially passes through several gaps between the rollers in the machines, which are equipped with more than two rollers.
Main units (parts), design and operating parts of roller machines
Rollers are the main operating parts of the roller machine. Roller machines are equipped with two cast frames (located on the fundament) and two rollers. There are two openings in the frames, where two cases with bearings for rollers are installed. The bearing cases of the front roller are movable, while the bearing cases of the rear roller are fixed. The frames are covered with beams from the upper side. The front pair of bearings is moved by two lash adjusters, which enable creating an operating gap between the rollers.
Parts of a roller machine:
1 – electric driving motor;
2 – bearings;
3 – emergency stop device;
4 – lash adjuster;
6 – frame;
7 – restricting pointer;
8 – tray;
9 – base plate;
10 – rollers.
Separate electric motors activate pressure (adjusting) screws by two-stage worm gearboxes (automatically) or by a hand wheel (manually). The lash adjusters are located on the frame at the side of the front roller. The limit switches restrict separation of the rollers and turn off the electric motor drives in case of emergency. Restricting pointers keep the milled compound within the rollers operating surface. The tray under the rollers collects chips of the material.
A kinematic diagram of a roller machine is shown in Figure 6. The transmission shaft consists of standard links, which are interconnected by disk couplings, and is located under the missing mill. The electric motor and gearbox transmit the torque to:
- the transmission shaft;
- the rear shaft;
- the front shaft (through friction pair).
The common drive is equipped with asynchronous low-speed electric motors.
The kinematic diagram of the heating rollers unit, consisting of three machines:
The drive for the roller machine is selected according to economic aspects. If it is a separate drive, the power of the electric motor should correspond to the maximum load at the beginning of the rollers’ operation. Afterwards, the motor operates with underload. In order to prevent the motor overload, its power should exceed the average consumption by 1.5 – 2 times at the moments of maximum electricity consumption. The motor load equalizes if the roller machine is equipped with a double or commonly used motor. The reason is that the beginning of the raw material loading onto one rollers differs from the time of loading of the other ones.
The rollers’ surface can be smooth or rubbed. The rollers are hollow. Cooling or heating liquid is fed into inner cavity. It is necessary to cool the rollers, using water, during operation with rubber compounds. Contrary to this, rollers should be heated by superheated steam during operation with plastics.
The heating circuit can also be used for cooling of the rollers. A gland sealing is installed in the annular gap of the guiding bushing and pressure plate. The heat medium is fed through the pipe, which is installed inside the roller. The cooling circuit supplies water by the pipe, which passes through the roller’s inner cavity. Nozzles are located on the operating part of the roller to discharge water on the pipe’s inner section. The water is sprayed from the nozzles at a speed of 6-12 m/sec. Then it is collected at the bottom and fills the roller cavity. The water passes through the openings in the guiding bushing and is collected in the drain funnel, then it is drained into the sewer system.
The bearings of the rollers for processing of elastomers are equipped with a central lubrication system. A manual grease station feeds the lubricant into the units using automatic feeders. The lubrication system is a circulating one (the oil moves in the circulation system with a filter-cooler and cools the bearings). A special mechanism adjusts a gap between the rollers of the roller machine. The mechanism consists of a screw pair (the nut is rigidly fastened into the frame, the screw rests against the bearing case of the front roller).
Rollers gap adjusting mechanism
To provide for a uniform gap along the rollers length, some adjusting mechanisms are equipped with a block, which also enables movement of the bearings.
A safety washer is installed between the screw and the supporting bushing of the bearing case in order to prevent breakage of the rollers. In case of overloading, the washer is cut and the gap between the rollers increases sharply.
Operation options of a roller machine with a single pair of rollers
Rollers are the main operating parts of roller machines. A roller machine can be equipped with two or more rollers. The rollers’ axes are located horizontally or parallel to each other. The rollers rotate in opposite directions and form pairs.
The processed compound is drawn from the roller’s surface into the gap and deforms. If a roller machine is equipped with a single pair of rollers, there are following operation options:
- The polymer is fed into the gap between the rollers. Then the polymer is removed, after it had passed through the gap once. The material feeding can be continuous or intermittent. (Figure 9a).
- After passing through the gap, the polymer sticks to the rollers (to one or both of them), and then returns into the feeding area. The material feeding is intermittent. The processed material is removed, after it had passed through the gap for several times.
- The polymer passes through the gap for several times, but the material is fed continuously. The areas for feeding and removal of the raw material are displaced in respect of each other in the direction of rollers’ axes.
Types of raw material processing on roller machines
The following types of materials processing are performed during the polymers processing on roller machines:
- Plasticization – increase of material’s fluidity level caused by its deformation;
- Mixing – increase of material’s homogeneity;
- Dispersing – elimination of large solids;
- Material heating prior to its loading into other processing machines;
- Refining – elimination of small size solids;
- Application of polymer coatings onto the substrate;
- Blanks profiling – surface finishing or pattern embossing on film materials.
Main processes performed on roller machines
Roller machines are widely used in the following processes:
- Components homogenization;
- Other processes.
The methods of polymers processing on calenders and roller machines are similar in many ways.
Roller machines and calenders application
Roller machines can produce sheets and films (including multilayered ones), block polymers and graft copolymers, apply images and embossing onto a surface, as well as reinforce polymer materials with fabric and mesh. This equipment is widely used in chemical and rubber-processing industries.
Gearboxes and polymeric equipment
Casting machines, injection molding machines
Extruders, extrusion lines
Gearboxes. Main description
Polymer substance press, preforming machines
Upon becoming the official distributer of roll mills (calenders), our company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), carries out the following: finds the buyers of your products on the market, conducts technical and commercial negotiations with the customers regarding the supplies of your equipment, concludes contracts. Should a bidding take place, we will collect and prepare all the documents required for the participation, conclude all the necessary contracts for the supply of your equipment, as well as register the goods (roll mills (calenders)) and conduct customs clearance procedures. We will also register a certificate of transaction (Passport of Deal) required for all foreign trade contracts in the foreign currency control department of the authorized Russian bank so that currency transaction could be effected. If required, our company will implement an equipment spacing project in order to integrate your equipment into the existing or newly built production plant.
We are convinced that our company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), will become your reliable, qualified and efficient partner & distributor in Russia.
We are always open for cooperation, so let’s move forward together!