Polyurethane as a material is characterized by enhanced physical and mechanical properties compared to rubber. It has a wide range of hardness, elasticity, low abrasion, high strength, oil and petrol resistance, resistance to acids and alkalis, operating temperature range from -35 ° C to +80 ° C. Easily tolerates repeated mechanical dynamic impacts without compressive and shear deformations. It is not susceptible to surface cracking, scratches, has a low tendency to dirt and is easy to clean.
At the same time, of course, the cost of polyurethane is higher than rubber, but the long-term economic effect of using polyurethane instead of rubber analogs in the repair and operation of printing equipment is unambiguously high. Products made of polyurethane are more durable, retain their technical and geometric parameters throughout the entire operation. This not only has a positive effect on the quality of products manufactured on the equipment, but also reduces the overall cost of repair and maintenance of machines and machine tools.
Restoration of the coating of print rollers and rollers
To maintain print quality on high-speed printing presses, it is necessary to maintain consistent coating quality on the rolls of printing presses.
Replacing the entire shaft is a rather lengthy and costly undertaking. Today it is possible to remove the old layer of the shaft covering, replacing it with an identical new one made of polyurethane with the necessary allowances for machining, the so-called lining or shaft restoration. This increases the service life and improves the operational properties of the shafts. Lining / restoration of shafts with polyurethane is the most advantageous in terms of price / quality ratio.
During the lining, the polyurethane is firmly bound to the surface of the shaft, forming a protective layer. For the printing industry, where high frictional forces occur, the shafts are lined with a layer of polyurethane several centimeters thick.
The main applications for polyurethane coated rollers are inking, dampening and grinding rollers for offset printing machines, flexographic machine shafts, adhesives and rollers.
The polyurethane used to restore the print rollers has a high resistance to notches, elasticity and, accordingly, to mechanical stress. In addition, polyurethane is a chemically inert material. It has a low swelling parameter in paints, solvents and detergents (note: when using mixtures for cleaning shafts, we recommend checking the chemical resistance of polyurethane). Therefore, the roller coated with polyurethane stably retains the specified hardness for a sufficiently long time and requires minimal time to clean it.
Replacing the worn-out rubber layer of the printing roller with a polyurethane one allows maintaining a consistently high printing speed. The durability of the polyurethane coatings of shafts and rollers allows saving on the costs of shaft replacement and repairs by increasing the service life.
In each specific case, when restoring a shaft with polyurethane, we proceed from the technical conditions of its operation. Possible range of hardness of the polyurethane layer 55 – 95 Shore A. The maximum overall dimension of the shaft for restoration is 800mm, the working area of restoration with polyurethane is 600mm, diameter is 120mm.
Polyurethane covering of shafts of paper and cardboard cutting machines. Shafts and rollers of folding machines
In the process of intensive work under a hard load in machines for cutting and folding paper, the coating of shafts and rollers quickly wears out, and their technical characteristics deteriorate.
We offer the restoration of the worn layer of shafts for cutting and folding machines with polyurethane. To cover such shafts, polyurethane of hardness 70-80 Shore A is used.
The polyurethane coating of the shafts is uniform, resilient and elastic, resistant to cuts and abrasive wear. More wear-resistant than rubber, polyurethane-coated rollers provide the required level of material tension and are the best option for repairing and completing paper cutting and folding machines.
Rollers coated with polyurethane have good adhesion to the surface of paper, cardboard, are not subject to mechanical damage, deformation, chips, cuts, and the effects of chemically aggressive environments. They have greater durability and much lower abrasion than rubber ones, therefore they are effectively used in the operation of printing machines.
We remanufacture roll paper rolls, pinch rolls, feed rolls, feed rolls, conveyor rolls, printer rolls. Rollers for packaging lines. And also the rollers of warehouse stackers, which are so necessary in the work of the printing industry. Polyurethane hardness range for rollers 55–98 Shore A.
Polyurethane marzans for paper cutting machines
Marzans made of polyurethane are used in cutting machines as a support for the knife during cutting. Due to the properties of the material, they effectively retain the sharpness of the knife, preventing it from becoming blunt, increasing the productivity of the machine.
- Do not have a smooth surface without cracks, bumps, depressions
- elastic, after the first immersion of the knife, the groove remains in them
- not plane-parallel, which ensures high quality cutting to the last sheet
- provide a tight grip of the marzan due to the dimensional accuracy
- are made with specified parameters of hardness (viscosity and elasticity), which allows you to keep the sharpness of the blade for a long time, preventing the knife from chipping
- high strength, high resistance to cuts and mechanical damage
- universal for working with different types of knives
- Wear-resistant and durable polyurethane gussets improve cutting performance. They significantly increase productivity and knife life while reducing machine downtime, which positively affects the quality of the entire production process.
It is possible to manufacture polyurethane marzans in small batches according to an individual order of the given technical characteristics in the shortest possible time at competitive prices.
We can also make plastic stops for pushing the trimming foot, marzans in the form of plates and discs for rounding corners or punches, jigs for cutting and drilling holes.
Screen Printing Polyurethane Blades
Polyurethane is used as the most versatile material in the manufacture of silk screen squeegees. The properties of the material determine the high durability of polyurethane squeegees, even when exposed to extreme loads.
Polyurethane doctor blades are highly resistant to cyclic deformation without destruction, abrasion and have lower wear than rubber ones. Impervious to uneven substrates. The high mechanical resistance of the polyurethane squeegee reduces vibration during high speed printing.
Polyurethane blades are resistant to the damaging effects of printing inks and solvents, allowing for longer blade cycle times and reduced cleaning times. The smooth surface and the geometric shape of the polyurethane squeegee provide high quality when printing on substrates of any complexity, with inks of various viscosities and compositions.
Another advantage of the polyurethane blade is that it hardly changes its stiffness over time, which reduces the risk of blade warping (waviness of the blade) and increases the service life. The squeegee made of polyurethane does not cause abrasion of the stencil.
We manufacture squeegees from polyurethane of a given hardness in the range of 55 – 98 Shore A (determined during the manufacture of the product), elasticity and elasticity. Therefore, you can choose a squeegee blade for your needs – both softer for printing on fabrics, and harder for printing on dense surfaces, plastics, etc.
Polyurethane bands, rings for rotary die cutting equipment
The high quality of products cut by means of rotary die cutting is largely ensured by the quality of the band as a counterpart of the die cut. Polyurethane is an excellent alternative to rubber in rotary die cutting equipment.
We produce high-strength, wear-resistant polyurethane bandages of specified hardness, size and color for packaging lines, production of cardboard, corrugated cardboard (for cutting and extrusion of grooves at the places of folding of cardboard products)
Unlike rubber bands, which have a limited service life, polyurethane bandages have extremely high resistance to wear and friction, and are insensitive to temperature extremes. In addition, it is possible to manufacture polyurethane bandages in a wide range of stiffness, which is programmed at the stage of manufacturing the product itself.
The polyurethane bandage has a high elasticity parameter and recovers as quickly as possible after mechanical interaction with the stamp. This allows you to get high-quality clean cut and creasing and, as a result, high productivity of the punching equipment.
Polyurethane bandages are made to order, taking into account the characteristics of the equipment and operating modes.