Flexography is a high-speed printing technique used for many packaging and label jobs. It allows for fast, inexpensive, and high-quality labels for a wide range of mass-produced products. End seals are necessary for the operation of a flexographic printer and provide uniformity to a finished product.
What Are End Seals?
End seals are foam adhesive strips applied to the end of paper rolls used in flexography printing. These seals ensure that ink does not bleed to the next sheet and prevent print defects such as silver streaks or blotches. End seals made with foam adhesive are superior to other types because they stick better and are easier to remove. End seals are applied by hand after the roll unwinds from the paper reels.
Prints are not supposed to bleed onto subsequent sheets, so end seals are necessary to prevent this. It is essential to follow all manufacturer’s instructions when applying end seals, or they may not function properly. Seals should be stored at thirty-five to sixty-five degrees Fahrenheit and fifty percent relative humidity, but not above eighty degrees Fahrenheit for more than forty-eight hours. In addition to foam, some seals contain oil-based rubber, C2S paper with pressure-sensitive adhesive, and film-laminated kraft paper.
What Options Are Available When Purchasing End Seals?
Many new end seals for flexo printing are available with coatings and various material combinations (two-part and three-part). End seals come in a few different thicknesses and remain in place with pressure-sensitive adhesive. Seals should be removed within twenty-four hours of application at room temperature with a hand puller or within ninety minutes if placed under the nip of a roll. End seals should not be stretched over a sharp edge, as this may damage the adhesive strip.
Different compression ratios are available for flexo end seals. Seals with a high compression ratio are difficult to remove. You can remove seals made with a low compression without tearing the paper. Check that the seal is not too tight when put into the chamber, as this might distort it. You should apply end seals to keep the paper level and flat in the rollers. Seals use with different types of adhesives, such as rubber, acrylic, or silicone-based.
As you can see, end seals are an essential part of flexo printing. Seals prevent leaks, add moisture resistance, and stop ink bleeds. End seals are available in different thicknesses and colors and can save money long-term if the fit is correct and used as intended by the manufacturer.