Latest trends in calender lines.Latest trends in calender CALENDER. An almanac. Julius Caesar ordained that the Roman year should consist of 365 days, except every fourth year, which should contain 366, the additional day to be reckoned by counting the twenty-fourth day of February (which was the 6th of the calends of March) twice. lines The demand for production lines at high output capacities with optimum product quality and short tooling times calls for ultra-modern calender lines for the manufacture of semifinished sem·i·fin·ished adj. 1. Made, treated, or sold to be used in a finished product: semifinished steel. 2. Partially finished: a semifinished basement. products. Recently, we delivered and comissioned calender lines in full compliance with the following demands: * One, four-roll calender line for the manufacture of textile conveyor belt conveyor belt One of various devices that provide mechanized movement of material, as in a factory. Conveyor belts are used in industrial applications and also on large farms, in warehousing and freight-handling, and in movement of raw materials. carcasses up to a production width of 2,300 mm. * One, four-roll calender line for the manufacture of textile conveyor belt carcasses up to a production width of 2,300 mm. * One, four-roll calender line for the double-sided coating of tire cord. * One, roller head line with a three-roll calender for the manufacture of covering sheets for conveyor belts made of steel ropes and for the manufacture of textile conveyor belt carcasses up to a finished width of 1,800 mm. Four-roll calender lines for conveyor belt carcasses Technical data and description of function Double let-off device - The production starts with the let-off device. The latter consists of two mobile let-off stands for each batch of fabric or carcasses. The maximum batch diameter is 2,800 mm. The tension is 1,000-3,000 N and can be adjusted in accordance with the type of fabric to be let off. If a liner is required, each let-off stand is provided with an appropriate wind-up stand. An expander roll and an edge control unit ensure a foldless and straight edge winding of the liner. Sewing machine sewing machine, device that stitches cloth and other materials. An attempt at mechanical sewing was made in England (1790) with a machine having a forked, automatic needle that made a single-thread chain. In 1830, B. - A special sewing machine connects in an overcast manner the front end of the material sheet to be let off with the rear end of either the thread in fabric or material batch. A belt conveyor, transporting the front end of the fabric or carcass carcass, carcase 1. the body of an animal killed for meat. The head, the legs below the knees and hocks, the tail, the skin and most of the viscera are removed. The kidneys are left in and in most instances the body is split down the middle through the sternum and the vertebral , is arranged between the let-off device and the sewing machine. A let-off accumulator A hardware register used to hold the results or partial results of arithmetic and logical operations. (processor) accumulator - In a central processing unit, a register in which intermediate results are stored. with a capacity of 40 m is located in front of the calender so as to have sufficient material available for the continous operation of the calender when the batches are changed. The dancer carriage of the accumulator is hydraulically actuated ac·tu·ate tr.v. ac·tu·at·ed, ac·tu·at·ing, ac·tu·ates 1. To put into motion or action; activate: electrical relays that actuate the elevator's movements. 2. . The maximum material tension is 3,000 N. Feed roll stand - The feed roll stand takes the fabric from the let-off devices and conveys it into the accumulator. The working speed for the filling of the accumulator is 50% higher than the rated line speed. Drive is effected by a four quadrant D.C. motor controlled by the lifting motion of the accumulator dancer carriage via a potentiometer. Holdback hold·back n. 1. a. The act of holding back. b. Something held back. 2. A device that retains or restrains. 3. stand - A holdback stand in front of the calender ensures a uniform fabric tension during the calendering calendering, a finishing process by which paper, plastics, rubber, or textiles are pressed into sheets and smoothed, glazed, polished, or given a moiré or embossed surface. process. The holdback stand is driven by a four quadrant D.C. motor and controlled by a load measuring bearing incorporated in the dancer roll system. The center control unit in front of the calender is used to center the fabric or the carcass before the latter runs into the calender roll gap. Photoelectric cells photoelectric cell or photocell, device whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is incident upon it. scan the material edges and give setting pulses to the guide rolls. The photoelectric cells adjust themselves automatically according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. new material widths. Calender - The four-roll calender is the most important and decisive component of the whole line. The rolls are arranged ranged in an S-configuration. Rolls 2 and 3 are arranged vertically one above the other, roll 1 at an angle of 45 [degrees] in front of roll 2, and roll 4 at an angle of 30 [degrees] in front of roll 3. The roll diameter is 750 mm, the roll face length of 2,500 mm. The operating speed The operating speed of a road is the speed at which motor vehicles generally operate on that road. The precise definition of "operating speed", however, is open to debate. of 2-40 m/min. is infinitely variable. Roll 2 is the fixed roll and rolls 1, 3 and 4 are adjustable. Rolls 3 and 4 are arranged on one sliding block bearing. In this way, rolls 3 and 4 can be adjusted in common at mean and quick speed without any change of the gap between rolls 3 and 4. Sliding block bearing - This design of the sliding block bearing is a Berstorff patent. The adjusting speed at quick speed is 1.5 mm/sec. and at mean speed 4 or 1 mm/sec. All other rolls can be adjusted by 4 mm, 1 mm and 0.4 mm/sec. The adjusting speed of 0.4 mm/sec. is provided for the connection of an automatic roll gap control. Axis crossing device - Rolls 1 and 4 are additionally equipped with an axis crossing device. The latter serves for the compensation of the roll deflection deflection /de·flec·tion/ (de-flek´shun) deviation or movement from a straight line or given course, such as from the baseline in electrocardiography. de·flec·tion n. 1. up to a maximum 0.3 mm. Thus, a uniform thickness of the rubber sheet over the whole working width can be ensured. Roll bearings - Ultramodern cylindrical roller bearings roller bearing One of the two types of rolling, or antifriction, bearings, the other being the ball bearing. Like a ball bearing, a roller bearing has two grooved tracks, but the balls are replaced by rollers. The rollers may be cylinders or shortened cones. in connection with preloading devices ensure an absolute concentricity and a backlash free bearing arrangement of the rolls. (Maximum tolerance 0.005 at operating temperature.) An oil circulation lubrication lubrication, introduction of a substance between the contact surfaces of moving parts to reduce friction and to dissipate heat. A lubricant may be oil, grease, graphite, or any substance—gas, liquid, semisolid, or solid—that permits free action of system supplies lubricant Lubricant A gas, liquid, or solid used to prevent contact of parts in relative motion, and thereby reduce friction and wear. In many machines, cooling by the lubricant is equally important. to the bearings of the rolls and preloading devices. Bearing lubrication - Safety devices prevent the bearings from running dry. In case of any disturbances of the lubrication system, the calender line is stopped automatically. Preloading device/bending device - The rolls 1, 2 and 3 are equipped with hydraulic preloading devices and additionally, roll 3 with a bending device. Gear unit/driving motors - Each roll is individually driven by a D.C. motor. Driving power is 4 x 110 kW. For the operation of "double-sided coating," the gear unit is additionally equipped with a synchronizing synchronizing, n a technique that a therapist uses to coordinate his or her breath with that of the client; builds trust and establishes relationship. step to be engaged by hand and arranged between rolls 2 and 3. Maintenance free, universal joint shafts transmit the torque onto the rolls. Control desk - The central control desk enables a quick recognition of the actual operating function due to the well arranged, high-precision indicating instruments on the vertical desk panel. The switches and potentiometers for control and regulation tasks are arranged on the horizontal desk panel. Roll gap control - The contactless measuring of the thickness of the material sheet from roll gap 1 and 3 is effected over the whole width according to the backscatter backscatter in radiology, radiation deflected by scattering processes at angles greater than 90 degrees to the original direction of the beam of radiation. Important in radiotherapy when estimating surface exposure dose. measuring procedure with strontium strontium (strŏn`shēəm) [from Strontian, a Scottish town], a metallic chemical element; symbol Sr; at. no. 38; at. wt. 87.62; m.p. 769°C;; b.p. 1,384°C;; sp. gr. 2.6 at 20°C;; valence +2. sources. Deviations from the rated value are corrected automatically by the adjusting devices of rolls 1 and 4. The same measuring system controls the axis crossing devices of the rolls 1 and 4 as well. overhead surfaces in either thin layers (minimum of 1/4 inch) or with relatively high rates of build-up build·up also build-up n. 1. The act or process of amassing or increasing: a military buildup; a buildup of tension during the strike. 2. . In addition, it cures rapidly to very high compressive strengths Compressive strength is the capacity of a material to withstand axially directed pushing forces. When the limit of compressive strength is reached, materials are crushed. Concrete can be made to have high compressive strength, e.g. . Because it is designed for gun application, hand labor is greatly reduced. In addition, it is a simple system - water addition to the mixing equipment is all that is required. No mixing of various ingredients. It has low rebound (a characteristic needed for the shotcrete shotcrete or gunite Concrete applied by spraying. Shotcrete is a mixture of portland cement, aggregate, and water conveyed by compressed air to a spray gun. For structural uses, shotcrete is usually sprayed over a framework of reinforcing bars and steel mesh. application) and it allows passage of water vapor in the same way as normal concrete. The shotcrete technique applies a layer of concrete to a surface by pneumatically "hosing" a layer of material onto the appropriate surface. Mixing of the concrete with water occurs at the nozzle as the material is applied, resulting in a continuous rather than a batch process. Mixing with water is done at a predetermined pre·de·ter·mine v. pre·de·ter·mined, pre·de·ter·min·ing, pre·de·ter·mines v.tr. 1. To determine, decide, or establish in advance: ratio at the mixing head. This allows for use of only the amount of material needed for the job as well as rapid application. There are several important factors in successful shotcrete application: * Distance of nozzle from surface (2-6 ft.). * Angle of nozzle to the surface (90 [degrees] optimal). * Consistency of the mortar (should be somewhat plastic). This method reduces the high labor factor required with normal mortar. Because of the high impingement impingement (impinj´m  nt),n the striking or application of excessive pressure to a tissue by food or a prosthesis. velocities, it is also able to fill cracks and voids to a much greater degree. Finally, the process also allows (and somewhat requires) use of a fast curing material. Prior to application of this type of material, the surface to which the new material will be applied should be thoroughly cleaned. This can be done using a high pressure water blast (6,000 psi) or sandblasting Sandblasting or bead blasting[1] is a generic term for the process of smoothing, shaping and cleaning a hard surface by forcing solid particles across that surface at high speeds; the effect is similar to that of using sandpaper, but provides a more even finish . With this material, no additional primer or surface preparation was needed. The Sikachem 103 is reported to behave very much the same as normal concrete except it is stronger and cures faster. Table 1 shows typical values for strength of the cured material. Reports indicate that there is no problem bonding to other cured concrete Curing is the process of keeping concrete under a specific environmental condition until hydration is relatively complete. Because the cement used in concrete requires time to fully hydrate before it acquires strength and hardness, concrete must be cured or to itself, whether cured or not. Table : Table 1 Comprehensive strength (ASTM ASTM abbr. American Society for Testing and Materials C-109) 2 days 6,000 PSI 7 days 8,100 PSI 28 days 9,000 PSI Flexural strength Flexural strength is also known as modulus of rupture, bend strength, or fracture strength. Flexural strength is measured in terms of stress, and thus is expressed in pascals (Pa) in the SI system. 7 days 1,000 PSI 28 days 1,400 PSI Tensile strength tensile strength Ratio of the maximum load a material can support without fracture when being stretched to the original area of a cross section of the material. When stresses less than the tensile strength are removed, a material completely or partially returns to its 7 days 600 PSI 28 days 750 PSI How did the material work? With the Sika material, it was possible to apply up to a 1-1/2 inch layer of material in one pass with no sag problems. Application was done using 300-400 psi air. All work was done in a closely confined space Confined space is a term from labor-safety regulations that refers to an area whose enclosed conditions and limited access make it dangerous. Description A confined space is any space: 1) that has limited or restricted means of entry or exit; 2) is large enough for a , requiring low dust material. With the shotcrete method, the material was applied and was able to be tooled right away on all surfaces. According to the applicator ap·pli·ca·tor n. An instrument for applying something, such as a medication. applicator, n a device for applying medication; usually a slender rod of glass or wood, used with a pledget of cotton on the end. , the material had the consistency of a firm jelly when applied. As the data in table 1 indicates, compressive strength develops to over 6,000 psi within two days. (Normal concrete has a compressive strength of 4,000 psi when fully cured). From the beginning, the work proceeded smoothly. In approximately one week, the work crew had cleaned and prepared a 20 foot by 12 foot by 12 foot chamber by cleaning to bare aggregate. Two inch by two inch wire mesh wire mesh, wire netting n → tela metálica was applied to floor, walls and ceilings. Then 1-1/2 inches of Sikachem 103 was applied, tooled and cured. After almost a year of use, the surface is reported to be in good shape. Good enough that Bridgestone/Firestone is planning on using the same material and methods to repair hot wells in other plants. Any potential problems? Virtually none. Minimum temperature for application is 45 [Degrees]F. Surfaces should be clean and free from deteriorated material. The surface to which the material is applied should be "saturated surface dry." As with normal concrete, pH extremes (particularly acid) should be avoided. No problems would be expected with use in the range of pH 5-9. Application is typically done by commercial applicators who are trained and approved by Sika. Shotcreting is done per standards established by ACI ACI American Concrete Institute ACI Arch Coal Inc ACI Airports Council International (formerly Airport Associations Coordinating Council) ACI Automobile Club d'Italia ACI American Competitiveness Initiative 506-R85. Finishing is done by normal methods. The surface can be broomed to a rough texture, wood floated to a granular texture or steel troweled to a smooth finish. Finishing should begin about 5-10 minutes after initial set of the material. If local conditions are likely to cause premature surface drying, a fine water mist spray, wet burlap or a curing compound should be applied. Conditions likely to cause this include high temperatures, low humidity and strong winds. The material is a microsilica filled cement. As such, normal safety procedures for handling dry and wet concrete need to be observed: use dust masks, safety goggles goggles, n the protective eyewear worn by dental personnel and patients during dental procedures. goggles see periocular leukotrichia. and rubber gloves rubber gloves rubber npl → gants mpl en caoutchouc . Skin and eye contact should be avoided. Summary Many of the maintenance functions and requirements go unnoticed by engineers and technologists who are busy making products. General maintenance is an unsung hero in our industry. Without attention to problems so mundane as hot wells, we wouldn't be able to make very many acceptable products. The report on this product looks very promising for one aspect of maintenance that certainly deserves attention. It obviously seems to be of benefit to Bridgestone/Firestone. After coating, the finished product (double-sided coated fabric) is checked by means of a transmission measuring device. The transmission measuring device is moved in transverse To cross from side to side. direction to the material sheet for the latter to be checked and corrected in an optimum way. The profile of the coated product is always visible on the control stand. The transmission measuring device also controls the bending device of roll 3 as well. Heating/cooling of rolls - A separate heating/cooling device is provided for every calender roll. All calender rolls are peripherally drilled. Heating/cooling is effected by hot water via electric controllers and continuous valves. The maximum roll surface temperature is 150 [Degrees]C. Heating up or cooling down Cooling down is the term used to describe an easy, full-body exercise that will allow the body to slowly transition from an exercise mode to a non-exercise mode. Depending on the intensity of the exercise, cooling down can involve a slow jog or walk, or with lower intensities, is effected by 1 [Degree]C/min. via a time-lag control. Hydraulic unit - The hydraulic unit is used for the generation of pressure and the hydraulic control of the cylinders of (a) the preloading device, (b) axis crossing device, and (c) the hydraulic pressure compensation unit (hydraulic cushion) for the automatic relief of the center roll gap when a splice passes through. Cooling unit - The cooling unit consists of four driven double-walled rolls, diameter 1,000 mm, with multichamber cooling system cooling system: see air conditioning; internal-combustion engine; refrigeration. cooling system Apparatus used to keep the temperature of a structure or device from exceeding limits imposed by needs of safety and efficiency. . A hydraulically actuated dancer roll with integrated load cell controls the drive of the cooling unit so that the preset preset Cardiac pacing A parameter of a pacemaker that is programmed permanently when manufactured material tension of maximum 10,000 N is ensured. Double wind-up device - The material sheet runs to the double wind-up device over a feed belt conveyor ascending by 25 [Degrees]. The wind-up device consists of two laterally movable stands with liner let-off above which a horizontally movable transfer belt conveyor is arranged. This design enables the automatic, continuous winding of even the most heavy carcasses without any manual operation by the personnel. When the batch in the first winder has reached its set length or the maximum diameter, the coated material sheet and/or the carcass is cut on the feed belt conveyor by the cross cutting device. The end of the material sheet runs over the feed belt conveyor into the winder. At the same time, the transfer belt conveyor moves forward and takes over the front end of the new material sheet. The second winder starts automatically to turn and the first meters of the material are found automatically on the winding shaft by means of the previously threaded and wound liner. The maximum wind-up diameter is 3,000 mm and the maximum tension 3,000 N. Surface winder - Rubber sheets are wound up according to the surface winding system without any tension. In this case, the belt conveyor serves as drive for the batch to be wound up. A hydraulic pneumatic system is provided for the automatic weight relief. Preheating of rubber - One pin barrel extruder GE 250 K8 x 12 D for each calendering roll gap is provided for the preheating of the rubber compounds to be processed. The extruded strip is fed via take-off belt conveyors and feeding devices into the calender roll gap. The extruder output capacity is regulated to controlling the rolling bank height by means of three ultrasonic ultrasonic /ul·tra·son·ic/ (-son´ik) beyond the upper limit of perception by the human ear; relating to sound waves having a frequency of more than 20,000 Hz. ul·tra·son·ic adj. 1. probes and a microprocessor, thus, a continuous and uniform roll gap feeding is ensured at every calender speed. Electrical equipment A piece of electrical equipment is a machine, powered by electricity and usually consists of an enclosure, a variety of electrical components and often a power switch. Examples of Electrical Equipment
Variants of production The calender line is rated for a continous operation. For this reason, it is necessary to use a thread-in fabric which runs through the line according to the material flow. Double-sided coating of fabric and one sided frictioning of fabric are shown in figure 1. Covering of conveying belt carcasses A conveyor belt consists of (1) the carcass of e.g. three layers of coated fabric, (2) a rubber sheet on the bottom side as the backing whereas a thicker one on the top side is the carrying side, and (3) the edge protection on the left and right sides. Figure 2 shows the production step "covering of conveyor belt carcasses." Compared with the conventional procedure, this working method is a considerable rationalization. While formerly, the backing, carrying side and edge protections had to be separately applied to the carcass in several steps, this ultramodern calender line renders it possible to carry out all three operating steps in one single pass. The carcass is guided below the calender and provided with the backing and edge protection into the lower roll gap. The carrying side is applied to the carcass in the upper roll gap after having been calendered cal·en·der n. A machine in which paper or cloth is made smooth and glossy by being pressed through rollers. tr.v. cal·en·dered, cal·en·der·ing, cal·en·ders in the center roll gap. Four-roll cord line for double-sided coating of tire cord Technical data of the machine is shown in table1. Equipment arranged in front of the calender includes: * Double let-off device, diameter range 200-1,200 mm, let-off tension 500-2,500 N. * Splice press, electrically heated up to 200 [Degrees]C, heating time 10-120 seconds, specific splice pressure 250 N/cm2 * Feed roll stand cord tension 500-2,500 N, operating speed 3.5-70 m/min plus 50% advance when filling the material accumulator. * Automatic center control hydraulic optically operated. * Material accumulator pretensioned hydraulically, tension 500-2,500 N, accumulator capacity 140 m. * Automatic center control. * Expander roll. * Roll liner. Equipment behind the calender (calender train) includes: * Dancer roll system with integrated load measuring unit Noun 1. measuring unit - a unit of measurement measuring block unit, unit of measurement - any division of quantity accepted as a standard of measurement or exchange; "the dollar is the United States unit of currency"; "a unit of wheat is a bushel"; "change for the control of the cooling unit. * Drum drying unit and/or pull roll stand for a cord tension of 2,000-20,000 N. * Pricking device. * Pick breaker breaker: see wave, in oceanography. . * Marking device. * Creel for cotton threads. * Material accumulator, pretensioned hydraulically, tension 500-2,500 N, accumulator capacity 70 m. * Automatic center control. * Pull roll stand, cord tension 500-2,500 N, operating speed 3.5-70 m/min plus 50% advantce when emptying the material accumulator. * Cross cutter and automatic threading unit for the double wind-up device. * Double wind-up device with two liner let-off stands, wind-up diameter 200-1,200 mm, wind-up tension 300-2,500 N. Used for rubber preheating are two extruders (GE 250 KS x 12 D, output 2,300 kg/h each), complete with all additional equipment, namely: * Extruder for the calender gap formed by rolls 1 and 2. * Extruder for the gap formed by rolls 3 and 4. Complete electrical equipment with a free-programmable control unit for the control and regulation part with a process master computer for the whole line including the automatic calender roll gap and rolling bank control. Three modes of operation are possible: * Manual operation. All rated values preset by personnel. * Semiautomatic operation. Rated values are partially programmed. * Automatic operation. All rated values are stored and the line is completely controlled by the process master computer. Roller head line for conveyor belt carcasses Technical data of the machine Extruder GE 200 KS x 18 D with wide extrusion head, output capacity 2,500-3,500 kg/h pending on the viscosity and permissible stock temperature. Screw speed 33 min-1, driving power 300 kW. Three-roll type calender 600 x 2,200 mm, with axis crossing device on the center and bottom rolls and preloading device on the top and/or center rolls. The rolls are driven by three D.C. motors via special gear units. The driving power on the top roll is 40 kW and on the center and bottom rolls 48 kW each. The operating speed is 0.5 - 20 m/min. Equipment behind the calender (calender train) for the production step "sheeting": * Take-off device * Roller train * Thickness gauge * Three daylight cooling unit for indirect water cooling Water cooling is a method of heat removal from components. As opposed to air cooling, water is used as the heat transmitter. Water cooling is commonly used for cooling internal combustion engines in automobiles and electrical generators. * Longitudinal cutting device * Cross cutting device * Conveyor belt and double surface winder with hydraulic weight relief Supplementary equipment for the coating of the fabric or carcasses: * Let-off device with liner wind-up stand * Expander roll * Edge trimming device * Pull roll stand with three rolls * Wind-up device with liner let-off stand * Electric drive for the D.C. and three-phase current section of the whole line Variants of production: Technical product data * Thickness of rubber sheet: 1.5-18 mm * Width of rubber sheet: 1,000-1,800 mm * Fabric tension: 2,500-7,500 N * Let-off diameter: 200-1,200 mm * Wind-up diameter: 20-1,500 mm Manufacture of rubber sheets for conveyor belts made of steel ropes or of sheets made of fiber loaded compounds for raw-edge v-belts, one-sided coating of fabrics for conveyor belts or v-belts and one-sided covering of conveyor belt carcasses made of several fabric layers are shown in figure 3. |
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