Formulation and development of ink for the most po

Formulation and development of inkjet printer ink (Part 1)

[Abstract] this paper introduces the performance and composition of inkjet printer ink currently used in the packaging industry, and discusses the formula experimentally

[Key words] jet ink, composition, packaging, coding machine

I. preface

with the development of economy, countries around the world have successively formulated food hygiene, pharmaceutical regulations and trademark laws to protect the interests of consumers. In these regulations, it is clearly stipulated that the labels of food, beverages, drugs, cosmetics and other products must indicate the production date, batch number and shelf life. On large-scale assembly lines, these daily changing contents cannot be solved by traditional printing methods. If printed by hand, the quality is poor. The method of pasting self-adhesive is costly, easy to peel off, and easy to be forged and copied. At present, non-contact inkjet coding machines are widely used in foreign countries to print the production date. Alcoa has completed the expansion of the production capacity of aluminum lithium alloy at its plant in kitzgreen, UK; The aluminum lithium alloy plate production line of Davenport rolling plant was reconstructed and expanded; The aluminum lithium alloy production line of Lafayette extrusion foundry in Anna, India, has been expanded, including batch number, shelf life, bar code and simple symbols. This method is fast, low cost, clear handwriting, simple operation, and because it is non-contact printing, it can be applied to products of various shapes

since 1969, Videojet company of the United States developed the first industrial ink jet printer. How does the jaw of the hydraulic universal testing machine slip? Since then, countries have invested in the development of such contactless printing equipment. At present, the well-known companies that produce this kind of code printer include domino in the UK, Imaje in France and Hitachi in Japan. Due to the introduction of a large number of packaging production lines in China, the research and development of this kind of printer began in the early 1990s. The PY series inkjet printer [1] produced by the 31st Institute of China Aerospace Industry Corporation was first put into the municipal gb/t19472.2 (2) 004 polyethylene (PE) structural wall piping systems for underground use Part 2: Polyethylene double wall corrugated pipe. Now many companies have produced such equipment. Some of the inkjet systems of these inkjet printers use compressed air and some use gear pumps, but the imaging mechanism of their ink droplets is basically the same []. First, the ink is sent to the oscillation box through the pressure system, and the crystal oscillator turns the ink into uniform ink dots, and then passes through the electrostatic area. Under the control of the computer, the ink dots are charged with different amounts of electricity and pass through the high-voltage electric field. Due to the different amounts of electricity, the offset degree of the ink dots after passing through the small nozzle is different, and the positions reached are also different. In this way, the preset characters and graphics can be printed to the product surface

while inkjet coding machines are widely used, the development of inks has also been paid more and more attention. This is because the inkjet printer is a very precise equipment, and the requirements for ink conductivity, viscosity and drying speed are very strict. Moreover, after some inks are used repeatedly, it is necessary to adjust the viscosity with diluent at any time, and clean the nozzle with cleaning agent. These consumables have a broad market prospect. Based on this, this paper discusses the basic composition, performance and formula of jet ink

second, the basic performance and composition of ink

for the ink used in inkjet printer, it is required to have appropriate conductivity to ensure the size of characters and graphics; It should have appropriate viscosity, excellent solubility, miscibility and surface wettability to ensure the fluidity of the ink and the adhesion to the product surface; It should be fast drying to meet the needs of high-speed production lines; At the same time, it also requires easy cleaning, non blocking nozzle and durability. See Table 1 for the main indicators. This kind of ink is generally composed of polymer resin, mixed solvents, pigments or dyes and additives

1. Polymer resin

as a binder, polymer resin is the main component of ink. Its performance directly affects the quality and imaging effect of ink. Various kinds of polymer resins can be prepared into jet inks with different properties for different inkjet systems and conditions. The influence of resin on the performance of ink mainly includes: the wettability of ink on the surface of packaging. For product packaging of glass, metal, paper, plastic and other different materials, different resins should be added to make the wettability of ink meet the requirements. If the wetting ability is too weak, the adhesion of the ink is not high, which will lead to weak handwriting; Too strong infiltration will reduce the resolution of handwriting. Resins that can be used include: styrene acrylic acid copolymer, vinyl chloride vinyl acetate maleic anhydride copolymer, modified polystyrene, phenolic resin, cellulose derivatives, polyethylene pyridine, etc. [], and copolymers of acrylic acid or acrylate and styrene with good versatility. It can not only spray code on ordinary surfaces such as glass and paper, but also on plastic surfaces with low surface energy [7]. Viscosity of ink. The content of resin directly affects the viscosity of ink, especially under the influence of gear pump and temperature, the viscosity of resin changes greatly. The change of resin viscosity will directly affect the dimensional stability of ink droplets, thus affecting the quality of coding

2. Mixed solvents

account for the largest proportion in ink, generally composed of two or more low-carbon 3 With the rapid development of gravure printing skills, atomic ketones and alcohols are mixed in a certain proportion, and the addition amount is about 70% - 90% of the total weight of the ink. Commonly used are: methanol, ethanol, acetone, butanone and some fibrinolytic agents. In inkjet printing, solvent as a carrier plays a decisive role in the performance of ink. It is required that the solvent not only can quickly dissolve the resin colorant and other components, but also has a proper volatility, can effectively control the drying speed in the inkjet printing process, and also pay attention to the safety of the solvent

(to be continued)