Everyone knows that plastic doctor blades are safer than steel. But why exactly is plastic a safer option?
The answer lies in the fundamental differences between the two materials: steel blades are harder and sharper than plastic blades. While this is commonly understood, the reason becomes clear when we examine the molecular structures of these materials.
Plastic vs Steel: What does it mean to be sharp?
Steel and plastic, like all materials, consist of small particles. As the doctor blade wears down over time, the material is removed in chunks. The chunks are at least as large as the material’s basic particle size. This means the finest tip on a blade can only be as wide as one particle.
Since plastic particles are larger than steel particles, a worn plastic blade will have a tip wider than that of a worn steel blade. Combined with the fact that plastic is inherently softer than steel, this results in a plastic blade edge that is less sharp and, therefore, safer to handle.
Plastic vs Steel: Which doctor blade is Better for Ink Metering?
Given this information, one might wonder how a plastic blade can meter ink as effectively as a steel blade. The answer is that not all plastics are suitable for high-precision applications. In many cases, UHMW plastic works well for ink metering, but steel performs better on high-line screen anilox rolls. UHMW blades lack the rigidity required to maintain a fine tip and small contact area with the anilox roll.
However, next-generation polymers such as Acetyl, Delrin, and Polyether Ether Ketone (PEEK) possess material compositions that provide the necessary rigidity. These advanced polymers offer a fine contact area similar to steel, they even outperform steel on the roll. These characteristics make new polymer blades superior to steel, as doctor blades are designed to wipe liquid from a roll, not to cut.
TruPoint plastic doctor blades, including innovative designs like TruPoint Edge, excel in liquid removal tasks without compromising safety or performance on high-resolution anilox rolls. Engineered for superior characteristics such as chemical resistance, temperature resilience, and operational speed, these advanced plastic blades outperform their steel counterparts in modern pressroom environments. Many pressrooms favor these advanced plastic blades over traditional steel for enhanced workplace safety and improved overall efficiency in pressroom settings.
Switching from Steel to Plastic: Safety Advantages in the Pressroom
Next-generation polymer doctor blades offer the performance of steel blades while providing the safety of plastic blades. The combination of advanced materials and innovative MicroTip edge design enables these safe doctor blades to perform in demanding applications previously dominated by steel. Substituting a next-generation polymer doctor blade for steel is a simple way to maintain a productive and profitable pressroom environment while keeping employees safe.
