Edge overflow of adhesive is a persistent headache for label printing workshops, often triggered by a combination of factors-climate variations, transportation and storage conditions, and the inherent quality of the self-adhesive stock itself. This article shares a practical, on-site solution developed by Boniron to tackle this common challenge.
The Problem
When self-adhesive materials are ordered, multiple variables can contribute to adhesive bleeding at the roll edges: compression during transit, temperature swings, suboptimal storage, or even inconsistencies in the raw material itself. If left unaddressed, this overflow can cause matrix web breaks or edge tearing during die-cutting. Moreover, once the self adhesive material is fed into the press, the exuded adhesive tends to stick to guide rollers, registration guides, and rubber rollers, leading to production disruptions and equipment contamination (see Figure 1).
Figure 1: Adhesive overflow from the raw material edge, causing adhesion to guide rollers and registration guides during operation.
The most common countermeasure adopted by printing plants is the application of a release agent-typically a silicone oil-based spray, which acts as a low-energy chemical solvent. Spraying this onto the material edges reduces the tackiness of the adhesive and temporarily alleviates the oozing issue. However, silicone-based release agents are expensive, and prolonged use significantly drives up operational costs. In addition, these chemical sprays raise environmental concerns and are increasingly incompatible with eco-friendly production standards. While returning or exchanging the defective material remains an option for some customers, tight delivery schedules often make such recourse impractical. In these situations, a cost-effective, hands-on solution is urgently needed.
Given that edge overflow can damage equipment-and in severe cases, even cause machine stoppages-how can this problem be resolved effectively on the shop floor?
The Solution
Let us begin with a simple experiment. Apply a self-adhesive label to the surface of a desk lamp shade, then peel it off; adhesive residue will remain on the shade (see Figure 2a). Using materials coated with both hot-melt and acrylic adhesives for testing, apply white shoe polish to the residue and leave it for approximately 20 minutes. When wiped off with a cloth, the residue is completely removed from the shade surface (see Figure 2b). This demonstrates that a chemical interaction occurs between the shoe polish and the pressure-sensitive adhesive-specifically, the oils in the shoe polish penetrate and dilute the adhesive, softening it and reducing its cohesive strength. Consequently, white shoe polish proves effective for removing adhesive or label residue from various surfaces.
Figure 2: Comparison of the lampshade surface before and after treatment
Building on this principle, we conducted a trial at a printing facility, where the self-adhesive materials were suffering from noticeable overflow of adhesive, as shown in Figure 3(a). We prepared an oil-based mixture composed of 80% butter and 20% machine oil, and applied it evenly to the oozing edges using a cloth. After about half an hour, the adhesive had softened and lost much of its tack, allowing the equipment to resume normal operation, as depicted in Figure 3(b). It is important to note that this method only softens the adhesive rather than removing it completely; therefore, the paper transport path on the machine must still be thoroughly cleaned afterward.
Figure 3: Comparison of the material edges before and after treatment with the oil mixture
This approach not only alleviates sticking during unwinding but also reduces adhesion between the softened adhesive and machine components such as guide rollers and side baffles, making subsequent cleaning easier and effectively preventing web breakage. Although the edges of the material become contaminated with the oil mixture, these sections are removed during the waste matrix stripping and slitting processes. As a result, there is no adverse effect on the quality of the finished labels, as illustrated in Figure 4.
Figure 4: Contaminated edges removed during waste stripping and slitting
