Lohman Adhesive Tapes
Lohmann has introduced an extensive range of plate mounting adhesive tapes designed to meet the needs of increasingly difficult Letterpress and Flexo print jobs. Lohmann tapes not only secure printing plates, but also optimize cylinder rolling and printing pressure adjustment.
Duplofol ® vinyl adhesive tapes are mainly used in letterpress printing where compressibility and pressure adjustments are performed via the impression cylinder, and is suitable for fixing thin printing plates on an existing compressible plate.
The textured and siliconised liner leaves a scarcely measurable impression on the adhesive, and facilitates bubble free mounting.
Duplofol fixes Flexographic printing plates with exactly adjusted bond strengths. The rubber based adhesive is firmly anchored to the dimensionally stable film carriers so that the adhesive tapes can be demounted without leaving residues. Available in a range of thicknesses, from 0.1mm to 0.38mm.
DuploFLEX ®
The Compressible range of DuploFLEX plate mounting tapes from Lohmann feature a unique flexible PE-layer to reinforce the foam on both the plate and cylinder sides.
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Applied Pressure is spread across a larger area of the foam, effecting print quality. |
Applied pressure is focused on each particular dot, ensuring a smoother higher quality print. |
This highly flexible PE-layer ensures that any pressure exerted on the relief is focused on that particular area of the dot, and transferred to the compressible layer of the foam, this is in contrast to traditional foam tapes where the pressure is spread across a larger area, impacting on the print quality
As a result, the Lohmann tapes exhibit better print quality as the screen dot is not compressed, and keeps its original size eliminating uncontrollable dot gain.
Machine vibrations are effectively reduced, allowing for significantly higher press speeds without negative impact on print quality.
The second PE-layer on the cylinder side allows for the easy removal of the tape from the cylinder avoiding de-lamination and foam residue on the cylinder.
Benefits Include:
Mounting: No shellacking necessary.
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Mounting:
- Distortion free film liner avoids over expansion of the adhesive tape
- Smooth, slippery surface of the film liner for easy rub down of the tape on the cylinder during mounting
- Good adhesion (tack) between tape and cylinder
- Easy removal of the film liner from the adhesive tape, without lifting the tape from the cylinder.
- Embossed orange skin film liner leaves dimples on the adhesive surface assists with:
- avoids air being trapped under plate during mounting
- ensures that in the beginning the plate is mounted on the peaks of the adhesive film
- Repositionability – the special properties of the adhesive’s surface allows for easy repositioning of the plate without lifting the adhesive tape from the cylinder
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Printing: Reliable Bond
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Printing:
The Lohmann adhesive tapes offer a safe, reliable bond during the printing process:
- no “plate lifting”
- reliable bond, even during long and fast print runs
high resistance against solvents |
Easy Demounting |
Demounting:
- Easy removal of the adhesive tape from the plate:
- No adhesive residue on the plate
- No plate deformation
- Film layer on plate side of adhesive tape avoids tape delamination
- Easy removal of the adhesive tape from the cylinder:
- No adhesive residue on the cylinder
- Second film layer on cylinder side of adhesive tape avoids tape delamination
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Mounting Instructions
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1. Ink Residues must be removed with a suitable solvent |
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8. A hard leading edge may cause vibration marks, and reduced printing speeds. This can be overcome by mounting the Halftone part of a plate nearer the leading edge |
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2. The adhesive tape is applied to the cylinder first, avoiding the problem of the edges of the plate lifting. |
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9. Multi yield prints should be staggered on the cylinder |
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3. Remove the protective liner from the tape |
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10. To avoid plate edges lifting during longer runs or plate washing, the plate edges should be sealed.
The easiest way is to bond the edges with single sided tape. |
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4. Mount the printing plate immediately after removing the liner from the tape |
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11. Hot-melt or a liquid adhesive can be used if the space between the edges is not sufficient. |
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5. Excess adhesive tape is removed so that it does not come into contact with the substrate. |
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12. The printing plate should be removed at an angle of <60O This reduces the risk of adhesive / foam residue |
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6. Use a rubber roller to remove any air bubbles between the plate and the adhesive. |
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13. The adhesive tape should be removed from the printing cylinder accordingly |
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7. Particular care is required using the roller, to ensure correct contact between the plate edges and the adhesive |
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All Lohmann tapes are made from specialty adhesives, optimized for the highest efficiency in mounting, printing and demounting, and offer high resistance against solvents and cleaning agents.
The film liner resists high distortion, avoiding over expansion of the adhesive tape. The smooth slippery surface allows for easy manual rub down when applying the tape on the cylinder. The liners orange skin structure in the adhesive surface helps avoid air bubble entrapment between the adhesive tape and printing plate.
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