The low-temperature toughness of the substrate is a key factor in determining smooth unwinding. Traditional PVC or standard BOPP substrates tend to become brittle at low temperatures, leading to breakage or delamination during unwinding. Switching to copolymerized polypropylene (CPP) or thermoplastic elastomer (TPE) substrates can significantly improve low-temperature ductility. These materials, through their molecular chain structure, maintain elasticity at temperatures between -10°C and -20°C, reducing stress concentration during unwinding. For example, biaxially stretched TPE substrates achieve a 30% increase in elongation at break compared to conventional materials, effectively reducing the risk of breakage during low-temperature unwinding.
The low-temperature adaptability of the adhesive formulation directly impacts the separation performance of the tape from the substrate. Acrylic pressure-sensitive adhesives are prone to glass transition at low temperatures, resulting in a decrease in viscosity and cohesion. By introducing long-chain alkyl modifiers or nano-silica toughening agents, a dynamic cross-linking network can be created, enabling the adhesive to maintain moderate fluidity at low temperatures. For example, a certain brand of personalized adhesive tape uses a low-temperature acrylic emulsion with a glass transition temperature (Tg) as low as -15°C, 10°C lower than traditional formulations. This ensures no adhesive transfer or residual adhesive during unwinding at -5°C.
Innovations in coating technology offer a new path to improving unwinding performance. The uniformity and low-temperature stability of the release coating are crucial. Traditional silicone release coatings are prone to migration or crystallization at low temperatures, resulting in fluctuations in release force. Fluoropolymer release coatings, chemically bonded to the substrate surface, achieve consistent release force over a wide temperature range of -30°C to 80°C. Furthermore, microstructured release coating technology creates a nanoscale concave-convex structure on the substrate surface, reducing the contact area between the tape and the release layer, further reducing unwinding resistance.
Temperature control during storage and use is critical to ensuring unwinding performance. Low-temperature storage can cause the substrate to shrink and the adhesive to harden. Therefore, it is recommended that tapes be stored in a constant-temperature warehouse between 15°C and 25°C and with a relative humidity of 50%. Before use, the tape should be preheated in the operating environment for two hours to allow the material temperature to equilibrate with the ambient temperature. For automated packaging lines, an infrared heating module can be added before the unwinding device to locally heat the adhesive layer and soften it, reducing initial unwinding resistance.
Precise control of process parameters is crucial for smooth unwinding. During the coating process, the adhesive solids content must be strictly controlled between 45% and 50%. A higher solids content can lead to brittle adhesive layers, while a lower solids content can cause insufficient cohesion. The drying temperature profile should be designed in stages, with a high temperature of 80°C in the first stage for rapid solvent removal and a lower temperature of 50°C in the latter stage for curing to avoid stress accumulation within the adhesive layer. The rewinding tension should be dynamically adjusted based on the elastic modulus of the substrate, typically within a range of 0.5-1.2 N/mm width, to prevent excessive tension from causing springback during unwinding.
Customized structural optimization can indirectly improve the unwinding experience. For example, guide grooves or dotted cuts can be designed on the tape edge to guide the unwinding direction and reduce edge friction. The pattern printing process must avoid excessively thick ink layers, as this will alter the substrate's surface energy and affect smooth unwinding. High-precision gravure printing technology allows the ink thickness to be controlled within 3μm, ensuring interfacial stability between the substrate and the adhesive.
In practical applications, improving the unwinding smoothness of personalized office tape cans depends on the specific application. For warehousing and logistics in cold regions, a combination of a low-temperature-resistant TPE substrate and a fluorine-based release coating can be used. For office document packaging, room-temperature unwinding can be achieved by optimizing the adhesive formulation and winding process. Through systematic optimization of materials, processes, and the environment, the personalized office tape can has evolved from a single-function product to an intelligent, environmentally adaptable one, providing an innovative solution for efficient office work in low-temperature environments.
