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FOR THE FIBRE AND TEXTILE INDUSTRIESSince Danfoss invented the first mass produced electronic frequency converter in 1968

– and gave it the VLT name – we’ve striven to set new standards for quality and performance in the category. In terms of quality, we consider it a professional challenge to earn every quality

approval that matters, from ISO 9001 to CE certification.Our concern for quality and the environment is shared by everyone at Danfoss. Headquartered inDenmark, Danfoss is represented in more than 100 countries on six continents. What defines a quality drive? First, check the name if it says VLT, it says it all. Because there is only one VLT.

The one Danfoss invented, and gave the name. Application know-how and strong dedication to research and development has brought us to the technological forefront

– with a broad range of products, specifically designed to precise customer needs.

Danfoss Drives

FOR THE FIBRE AND TEXTILE INDUSTRIES

Danfoss Drives

VLT® is a trademark of Danfoss A/S

MAN MADE FIBRES AND FILAMENTSThe Spinning Unitprofits from the high output resolution ensuring an accurate pull of the fibres. Where more VLT drives are involved, interconnecting the DC links may solve the problems caused by mains dropouts.

Integrated wobble optionThe VLT drive achieves the wobble function by changing the output frequency either accordingto a fixed pattern or atrandom. This makes anytype of winding patternobtainable, and the windercontrol system may be greatly simplified. Furthermore installationcosts are reduced by avoiding a separate wobblegenerator. The integratedwobble option also handleselastic fibres.

Fieldbus Communicationis the ultimate answer to

process control and monitoring. By means of the fieldbus all stages of the process may be optimized. The VLT drivesupports a number of fieldbus protocols such as PROFIBUS, LonWorks, Modbus+, DeviceNet, Interbus-S and others, which makes full integration into the controlsystem an easy task.

Load sharingWhenever a motor is beingpulled by an overhaulingload such as when themotor speed is being rapidly reduced, energyfrom the load is fed back to

the motor which then actslike a generator. This surplus energy is in turn fedback to the AC drive whichmay absorb it by means ofa brake resistor, convertingthe energy into heat. In thisway the energy is wasted.With the load sharing feature the surplus energycan be harnessed by interconnecting the DC railsof more drives into asystem. In this way theenergy is conducted to theother drives where it maybe utilized.

External control power supplyKeeping the control system

alive during a power blackoutor brownout is the overridingconcern of a great many endusers of textile machines.

The VLT drive has an optionwhich allows connection of an external 24 V d.c. power supply to keepit´s control section poweredduring a mains loss. Thisallows continous operationof monitoring systems, fieldbus communication,encoders etc.

The Stretching and Texturizing Unitbenefits from the high accuracy of the VLT drive, which optimizes the process.The result is better productquality and less breaks, resulting in less costly downtime.

The Dryeroperation is optimized, saving up to 30-50 percentof the energy consumption. This is achieved by the VLT drive controlling the fan speed, instead of adjustingthe hot air flow with a damper.

The Cutting Unitmounted with a VLT driveis running with greateraccuracy, ensuring that the filaments are cut to exactly the length prescribed.

The Baling Pressprocess speed may be significantly increased with a VLTdrive to synchronize the movements of thecompression.

For more than 20 years Danfoss hasbeen a partner to the fibre and textile industries, supplying a vital

technology – safe, reliable and accuratefrequency converters for AC motors.This cooperation has given us a working knowledge about the technological needs of the industry. All along we have transformed our know-how and insights into stillbetter products, characterized by benefits like:• Energy savings• High reliability• Low downtime• Low cost of ownership• A global service and support

organisation with years of experience.

The Extruder runs with a high starting torque andhigh speed accuracy, ensuring smooth and trouble free operation.For pressure control the integratedPID controller of the VLT drive keeps the pressure constant.

The Windergets a higher winding speed, a better filling of the bobbin and thus a better quality of the fibre packages – all thanks to a specially developed wobble software, integrated in the VLT drive.

SPINNING OF NATURAL AND MAN MADE STAPLE FIBRES

Bale Opener and MixerWith a VLT drive installed onthe feed motor it becomeseasier to control the quantityof the material conveyed – and the process can run continuosly. Correspondingly the mixer capacity can be controlled. The whole processcan be adjusted to match the capacity of the carding machines.

Cleaner and FeederA VLT drive adjusts the speed of the cleaner according to themixer, thus optimising the process, ensuring better productquality and causing less wear.For the feeder drive, controlmeans optimum conveying offibres to the carding machine,contributing to better productquality.

Kinetic BackupA safety function to ensureundisturbed operation in spiteof minor power failures: The mechanical energy ofthe motor is transformedinto electrical energy, thusforming an emergency generator that keeps the drive powered until themains supply is restored.The function is ideal for the fibre and textile industries, where it reducesthe number of breaks all through the manufacturingprocess substantiully.

Synchronizing and Positioning OptionSynchronizing different

processes, positioningitems or markers, programming severalspeed curves, setting infinite gear ratios, programming a number ofsequences. Possibilitiesare numerous with the VLT SyncPos option. The performance ofSyncPos could make thePLC obsolete, or make its job a lot easier. The on-board computermakes the option card a high performance, highspeed and high resolutionextension of the drive, turning it into an intelligent stand-alone control system.

Automatic Motor Adaptation (AMA)Thanks to AMA the VLTdrive handles most motoradjustments itself. AMA works by automaticallyadjusting the drive to what-ever motor you use, withoutthe need to spin the motoror disengage the system.This makes the drive veryuser friendly – and at thesame time ensure optimummotor performance.

Automatic Energy Optimizer (AEO)Applying VLT drives to the processes of the textileindustry will very oftenmean a considerable energy

saving in itself. The recentgenerations of the drive,however, have added anintelligent feature that provides even furthersavings: The AEO function automatically monitors thepower requirement of theapplication and reduces thepower output to match theactual need.

VLT® software dialogA software tool is availableto up/download settingsand read all operationaldata. It communicates with all drives in a networkand makes commissioning a lot easier.

Carding MachineA VLT drive brings flexibility tothe carding process: Themechanical gear is replaced byelectronic control, making itquick and easy to change overfrom one type of fibre to another. With the incorporationof the SyncPos option allnecessary functions can beachieved within the VLT.I addition, the kinetic backupfeature protects the sliver against breaks during shortpower failures.

Speed FrameWith VLT drives you can implement your own optimised speed profile,resulting in a better bobbinbuild-up and allowing the process to run at maximumspeed. Experience shows thattypically a 10% increase inproduction is achieved andthe automatic flyer positioningsequence means there is noneed for the time consumingmanual inching during doffing.

Open End Rotor FrameA motor on each shaft, controlled by a VLT drive,replaces the mechanical gear.The benefits are less wear,minimum maintenance andnotable energy savings. The latter becomes very significant on the bottom line,as an open end rotor frame is responsible for the lion’s share of power in an openend spinning mill.

Ring FrameThe 0.95 power factor due tothe built-in DC link chokesmakes further power factor correction superfluous, savingcapacitors and maintenance.Low harmonic distortion is increasingly important – as the number of drives ineach mill is increasing – inorder to reduce the load of the mains. Last but not least considerable energy savingscan be achieved - extremelyimportant for the ring frame as the major power consumerof the mill.

Typical energy consumptiondistribution in ring spinningmillEnergy costs account for a substantial proportion of the manufacturing costs in the fibreand textile industries. Thepotential for savings is oftenunderestimated and generallydeserves more attention – notleast the ring spinning process.VLT frequency converters are avital part of the efforts to reduce energy consumption. Bymeticulously metering the load-dependent energy supply tothe motor they greatly reducethe amount of energy used inthe many processes – from feeder to air conditioning system.

Spinning of staple yarns is a key process for the fibre and textile industries. The efficiency of this process is decisive for the

profitability of your business. That is why youshould choose Danfoss as your partner for AC drives. Our VLT® frequency converters are specially designed to give you: • Higher product quality due to gentle

handling of the raw material. • High operational reliability due to robust

design and built-in EMC filters.• Less downtime due to stable and smooth

motor operation. • Add to this energy savings that can cut your

power expenditure by 10-20 percent. A reliability that brings new life to the phrase“set and forget”. Then you have the mostfavourable AC motor drives offered to theindustry today.

Air Conditioner and HumidifierThe speed of fans and water pumps in the a.c. system is controlled by VLT drives instead of being throttled by dampers and valves. This brings about energy savings of typically around 30 percent. At the same time better control of the relative humidity and temperature is achieved – improving the product quality.

Ring frame Other machinery

Humidifier

Speed frame

Cleaning and carding

WEAVING AND KNITTING TEXTILE TREATMENT AND FINISHING

Circular knitting machineEquipped with AC motors andVLT drives the machine is isnot affected by the dusty pro-duction atmosphere thanks tothe IP 54 enclosure rating.Typically this compares to anIP 20 rating associated withDC motors and drives – making the latter vulnerableand maintenance-demandingin the fibre and textile industries. Furthermore ACmotors are available as astandard,which adds attractive initial costs to the lower running costs. On top of this the bettersystem efficiency of AC solutions offers considerableenergy savings.

Torque Controlcontrols the torque of the motorshaft with similar performanceto a DC drive/motor system, butwith better profitability thanks tolower initial and running costs.By allowing for the frictional losses in the system the torqueis linear throughout the entire speed range.

High Starting TorqueThe VLT drive has a very highstarting torque, yielding a break-away torque of 180 percent.This enables the drive to evenstart up heavy and slow machines with a high degree ofinertia and friction.

High Impact LoadThis function makes the motor

immune to shock loads, thusensuring a constant speed, evenwith varying loads.

No deratingThanks to the patented VVC andVVCplus control principle operati-on with VLTdrives results in thesame motor conditions as withmains operation. No extra heat isgenerated and it is unnecessaryto buy bigger motors than prescri-bed.

Integrated filtersVLT drives come with integratedRFI filters. The filters offer maxi-mum Electro Magnetic Compati-bility (EMC) in “noisy” environ-ments, and they are built into thedevices, avoiding installation ofexternal filters.

Winding and UnwindingA VLT drive provides exactlythe right winding tension, so that the web is wound uniformly onto the cylinder.The web tension is usuallymeasured by a dancer with aposition sensor, acting asfeedback to the integratedPID controller.

PrintingThe accuracy of a printing process is greatly improved with a VLT drive. Mountedwith the SyncPos option, the drive coordinates theposition of the material and the printing unit, withextremely precise results.The versatile SyncPos optioncan be tailor-made to suitnumerous applications – andany programming is donewith user friendly Windows based PC software.

LoomsVLT drives increase the pro-duction of the looms as thespeed can be optimized forthe actual product. Anotheradvantage of the Danfoss drives over mains operation is the ability to compensatefor an insufficient power supply, that makes the loomsrun slower. The VLT drives maintain a steady motor speed by means of a preciseslip compensation and they are able to compensate for variations in mains voltage as well as mains frequency.

Dust and fluff in the air is a steadyfollower in all textile industries – not least when it comes to

weaving and knitting. Here a “hairy atmosphere” often means frequent maintenance of motors and drives and inworst case causes downtime. This is a good reason for choosing ACmotors and matching VLT® drives fromDanfoss. Their optional dust tight IP 54enclosure make them practically mainte-nance free and thus less expensive in run-ning costs. Space saving is a much askedquality in weaving and knitting applications. With a newly released combined drive and motor – integratingmotor and a frequency converter – Danfoss offers the most compact andefficient solution in this field to date.

Also the last phases of the textileproduction process require reliability, accuracy and

– preferably – a cost competitive technology. All these demands can bemet by installing VLT® drives in vitalfunctions, whether it be a winder, a washer/dryer, a dyer, a textile printingmachine or a cutter.Textile treatment and finishing applications often consist of complexsystems with a large number of drivesinvolved. The wiring and installationcosts are greatly reduced by using fieldbus communication. At the sametime it allows all drive parameters to be monitored – an important process optimisation tool.

Motor and Drive in OneThe VLT DriveMotor is anintegrated energy savingmotor and frequency converter, no larger than astandard motor with terminal box. It not onlysaves panel space but also removes the needs forexpensive shielded cabling.

The drive motor also comeswith a built-in PID controllerand the ability to be mountedin any position and direction.It is protected against ther-mal overload, missing phase,undervoltage and voltagetransients – all in all meetingthe needs of many textileapplications.

Poor Supply CompensationIn many textile producingcountries the power supply isvery unstable with fluctuatingmains voltage and frequency.With mains driven motorsinsufficient voltage may cause motor overheating.Insufficient mains frequency(e.g. 48 Hz instead of 50 Hz)lowers the actual rpm by 4percent – a loss that is neverregained: It makes themachinery 4 percent slower.A VLT drive compensatesboth, so that nominal voltage and frequency is supplied uninterruptedly.Mains voltages as low as15% below nominal can be compensated for.