Definition
The Printing Spreader Wheel is a specialized inspection instrument used for quality control in the printing industry. It simulates the printing process by evenly applying a layer of ink or varnish of known thickness on a specific substrate to form a standard color block for subsequent measurement and evaluation of physical and chemical properties such as color, density, and wear resistance. The instrument provides a reproducible means of standardized sample preparation for the parameter determination and material property comparison of the printing process.
How it works:
The core working principle of the printed color spreader is based on precise mechanical transmission and scraping action. The instrument typically consists of a metal roller that rotates at a uniform speed and a precision scraper. When the roller rotates, the scraper scrapes the ink on the surface of the substrate fixed on it with constant pressure and angle, forming a layer of ink film with uniform thickness and fixed area. Its film thickness can be controlled by formulah = V / ATheoretical estimation is made, where h represents the thickness of the wet film, V represents the volume of ink applied, and A represents the area covered by scraping. By controlling the roller speed, scraper angle, and pressure, repeatability and consistency of film thickness can be achieved.
Measurement method
After using the printed color exhibition wheel to prepare the sample, it is necessary to combine it with other detection instruments to quantify and analyze the sample. Common measurement methods include: measuring the density value of a color block using a density meter to evaluate ink coloring power; The color block Lab value and color aberration ΔE were measured by a spectrophotometer for color management. The abrasion resistance of the ink layer is evaluated by a friction tester. Use a gloss meter to measure the gloss of the ink layer. All measurements are performed under standard lighting and ambient conditions, and in accordance with the procedures specified by relevant industry standards (e.g., ISO 2834, ASTM D 4366, etc.) to ensure data comparability.
Influencing factors
The quality of the prepared samples of the printed color exhibition wheel is affected by multiple factors. Instrument factors include roller speed stability, surface finish, scraper hardness, edge straightness, and set angle. Material factors involve the viscosity and leveling of the ink, as well as the surface energy and smoothness of the substrate. Environmental factors such as ambient temperature and humidity can affect the rheological properties of inks. Operating factors include the amount of ink applied, the speed and uniformity of the scrape. The combined effect of these factors directly determines the uniformity, thickness and surface state of the final ink film, which in turn affects the accuracy of the subsequent detection data.
Applications:
The printing color spreader wheel is mainly used in the quality control and research and development process of the printing and related material manufacturing industry. In the field of ink manufacturing, it is used to evaluate the color strength, color spreadability and printability of different formulations of inks. In printing enterprises, it is used for proofing, determining standard printing parameters and incoming material inspection. In the field of packaging materials, it is used to test the performance of coating materials such as varnishes and composite glues. In addition, it is also commonly used in third-party testing institutions to conduct conformity testing of materials according to national or international standards.
Key points of selection
When choosing a printed color spreader, it is necessary to comprehensively consider multiple technical parameters and actual needs. Core parameters include roller width (determining maximum sample width), speed range and control accuracy, and fineness of scraper adjustment (e.g. fine adjustment of angle and pressure). In terms of materials, rollers and scrapers should be made of wear-resistant and corrosion-resistant materials. The instrument should have good running stability and repeatability. In addition, it is necessary to confirm whether the instrument meets the requirements of the standard method cited in the target testing project, and consider its compatibility and connection with other existing testing equipment in the laboratory. Ergonomics of operation and ease of maintenance are also aspects to consider.