Winding Rewinding Machine with Inkjet Printer
A winding rewinding machine runs a reel from an unwind shaft to a rewind shaft at controlled speed and tension, so that something useful can be done to the web on the way: a batch code printed, a defect cut out, a badly wound reel corrected. The KEW winding rewinding machine carries an inkjet printing system with hot air ink drying and handles web widths from 100 mm to 1500 mm.
Krishna Engineering Works builds the machine in Ahmedabad, India, in more than 25 types to suit different industries. This page covers the construction, the specification, the options and how to choose them.
What is a winding rewinding machine used for?
A winding rewinding machine is used for three jobs: printing variable information on a finished reel, correcting reels that were wound badly, and inspecting or doctoring printed material. Krishna Engineering Works describes the machine as suited to all three, and as a substitute for online coding or batching.
- Batch coding off the line. Batch number, dates and other variable data are printed on pre-printed film or laminate reel to reel, before the reel goes to the packing machine. This is an alternative to fitting a coder on every form fill seal machine.
- Correcting badly wound reels. A reel with telescoped layers, uneven edges or the wrong winding direction is rewound straight and tight.
- Doctoring and inspection. The web is run slowly past the operator, stopped at a fault, and the faulty length is cut out and spliced.
Why code reels offline instead of on the packing line?
Offline coding moves the printer to a machine built for steady web speed, which is the condition an inkjet printer needs for a clean code. On a packing machine the film moves in steps, the print position is hard to reach, and a printer fault stops the whole line.
On a winding rewinding machine the web runs continuously, an encoder tells the printer the exact web speed, and the hot air dryer sets the ink before the web is rewound. One rewinder can prepare coded reels for several packing machines. The trade off is that the batch data must be known before the reel is coded, so the method suits planned production runs.
The specialist site on rewinders for inkjet printers explains web path and print registration in more depth.
How the KEW winding rewinding machine is built
The KEW machine is a cantilever design with a movable unwind stage, built on an MS channel frame with a clutch and brake system. Each part of that sentence matters to the operator.
- Cantilever design. Both shafts are open at one end, so reels are loaded and unloaded from the front without lifting gear over the machine.
- Movable unwind stage with hydraulic web aligner. The unwind stand moves sideways under the control of a web aligner, so the web edge stays on one line and the rewound reel has a straight face. KEW makes the web guiding system itself.
- Clutch and brake system. A brake on the unwind and a clutch on the rewind set the web tension. A tension controlled magnetic powder brake is available as an option for finer control.
- Inkjet printing system with hot air drying. The frame carries the print head over a supported part of the web, followed by the dryer.
- Variable speed, double drive. The machine has a variable speed drive and a double drive arrangement, a compact layout and a comfortable operating height.
Technical specification of the winding rewinding machine
The table gives the published specification of the KEW winding rewinding machine with inkjet printer. Different models cover different reel weights.
| Item | Specification |
| Web width | 100 mm to 1500 mm |
| Maximum unwind weight | 100 to 1000 kg, by model |
| Maximum parent reel diameter | 400 mm |
| Maximum rewind reel diameter | 400 mm |
| Rewind core diameter | 76 mm |
| Motor | 2 HP DC or AC (3 HP and 5 HP also available) |
| Speed | 100 to 150 metres per minute |
| Frame | MS channel frame, cantilever design |
| Guiding | Movable unwind stage with hydraulic web aligner |
| Printing | Inkjet printing system with hot air ink drying |
Optional features and when to choose them
The options turn the basic rewinder into a coding, inspection or light slitting machine. Choose them by the job the machine will do most often.
| Option | What it does | Choose it when |
| Line guide system | Electronic sensing of the web edge or a printed line for straight winding | Reels must have accurate edges, or the print must track a printed line |
| Air shaft on unwinder and rewinder | Grips the core by air pressure for quick reel changes | Reels are changed many times per shift |
| Automatic tension control system | Holds unwind tension constant as the reel empties | Thin or stretchy films are run |
| Reverse and forward system | Runs the web back to a fault that has passed | The machine is used for doctoring |
| Stroboscopic inspection equipment | Freezes the moving print to the eye | Print is inspected at running speed |
| Techno feed system | Keeps web speed constant from the start to the end of the reel | Code spacing must be uniform |
| Encoder for the inkjet printer | Gives the printer the true web speed | Any inkjet coding job |
| High capacity blower with 800 W heater | Dries the ink quickly | Coding on films and foils |
| Slitting arrangement | Slits the web during rewinding | Coded reels must also be cut to width |
A stroboscope flashes in step with the print repeat, so the image appears to stand still. The powder brake works as a magnetic particle clutch in reverse: torque follows the coil current, which makes it easy to control electronically. KEW lists both brake types on its pneumatic brake and powder brake page, and shafts on the air shaft page.
How is the inkjet printer synchronised with the web?
The printer is synchronised by an encoder that measures web travel and by a constant web speed. Inkjet printing places drops in time, so if the web speeds up, the code stretches, and if it slows, the code shrinks. The encoder corrects for this by clocking the printer from the web itself.
Three more points decide print quality on a rewinder.
- Web support under the head. The web should run over a roller or plate at the print point, so the distance from head to web stays constant.
- Drying length. Films and foils do not absorb ink. The hot air blower must dry the code before the web touches the next roller or the rewound reel, or the code will set off on the back of the next layer.
- Print position. For codes that must land in a fixed panel of each pack, the printer is triggered from the printed eye mark, and the line guide keeps that mark under the sensor.
Other coding methods can be mounted on the same kind of machine. The doctoring range from KEW includes rewinders with a multi head inkjet printer and with a thermal transfer overprinter.
Winding rewinding, doctoring or inspection rewinding?
The three machines share one frame concept and differ in what they are equipped for. The KEW specification tables show the same web width range and speed for the winding rewinding and doctoring machines, and larger reel diameters for the inspection machine.
| Machine | Main purpose | Typical equipment |
| Winding rewinding machine with inkjet printer (this page) | Batch coding and reel correction | Inkjet printer, encoder, hot air dryer |
| Doctoring rewinding machine | Removing defects and rejoining the web | Reverse and forward run, optional slitting system |
| Inspection rewinding machine | Checking printed material | Stroboscope, top and bottom illumination, slitting assembly |
If the reels must be cut into many narrow widths at production speed, a slitter rewinder machine is the right machine, and the winding rewinding machine then codes or corrects its output. The group’s site on winding rewinding for coding, inspection and salvage looks at these uses one by one.
Setting up a coding run step by step
A coding run is set up in the same order every time. Change one thing at a time when adjusting.
- Load the parent reel on the unwind shaft and an empty 76 mm core on the rewind shaft.
- Thread the web through the aligner sensor, under the print head and past the dryer.
- Set the web aligner so the edge runs at the middle of the sensor.
- Set unwind tension low, start the machine slowly and raise tension until the web runs flat without stretching.
- Enter the batch data in the printer and check the encoder signal.
- Print a few metres, stop, and check code position, size and dryness.
- Raise the speed in steps, checking the code and the reel edge at each step.
- Record the tension, speed and dryer settings for that material.
Industries and materials
Winding rewinding machines are used in flexible packaging, paper, textiles, tyre cord and technical textiles. In flexible packaging the usual materials are printed films and laminates for pouches and wrappers. In paper and labels the machine corrects reels that were wound unevenly. In textile and tyre cord plants it rewinds liners and narrow fabrics.
Tension and ink drying depend on the material, so state every material and its thickness when you enquire.
Installation, spares and service
Krishna Engineering Works supplies spare parts and after sales service for the machine. A trial is run before dispatch, and installation, commissioning and operator training are given on site for customers in India and abroad.
Brake linings, shaft bladders and rollers are the usual wear parts. Rollers come from the company’s own rubber roller range, and the service scope is on the repairing and servicing page. The whole catalogue is on the products page.
What to send for a winding rewinding machine quotation
The machine is configured from your reel and printing data. Send:
- Material and thickness range
- Web width, maximum and minimum
- Parent reel diameter, weight and core size
- Rewind reel diameter and core size
- Speed required
- What is to be printed, on which side, and where on the repeat
- Whether you already have the inkjet printer, and its make and model
- Options needed from the table above
Send these through the contact page, and KEW will propose the model.
Frequently Asked Questions
What is the web width range of the KEW winding rewinding machine?
The KEW winding rewinding machine is built for web widths from 100 mm to 1500 mm, depending on the model. The published specification also gives a maximum parent and rewind reel diameter of 400 mm, a rewind core diameter of 76 mm, unwind weights from 100 to 1000 kg by model, and a speed of 100 to 150 metres per minute.
Can an inkjet printer be fitted to the winding rewinding machine?
Yes, the machine is designed to carry an inkjet printing system with hot air ink drying. An encoder for the printer and a high capacity blower with an 800 W heater are listed among its options. The printer is mounted over a supported part of the web so the head to web distance stays constant.
In which industries are winding rewinding machines used?
Winding rewinding machines are used in flexible packaging, paper, textiles, tyre cord and technical textiles. Packaging converters use them to print batch codes on reels and to correct or inspect printed film. Paper and label plants use them to rewind and correct reels, and textile and tyre cord plants use them for liners and narrow fabrics.
What is the advantage of a cantilever winding rewinding machine?
A cantilever winding rewinding machine has shafts that are supported at one end and open at the other, so the operator slides reels on and off from the front. No shaft has to be lifted out of bearings at each change. This shortens reel changes and suits a machine that handles many small reels per shift.
How is tension controlled on a winding rewinding machine?
Tension is controlled by a brake on the unwind shaft and a clutch on the rewind shaft. On the KEW machine a tension controlled magnetic powder brake is optional, and an automatic tension control system can hold unwind tension constant as the reel diameter falls. Steady tension keeps the web flat under the print head and the rewound reel even.
Can the machine slit the web while rewinding?
Yes, a slitting arrangement is listed as an option on the KEW winding rewinding machine. It allows a coded or corrected reel to be trimmed or cut into a few widths in the same pass. For slitting into many narrow reels at high speed, a dedicated slitter rewinder is the better choice.
Does Krishna Engineering Works supply spares and service for the machine?
Yes, Krishna Engineering Works supplies spare parts and after sales service for its winding rewinding machines. The company installs and commissions the machine at the customer’s site and trains the operators. Technical support continues after commissioning, and wear parts such as brake components, shaft parts and rollers are supplied as spares.
