Лако-красочные материалы — производство

Epoxy phenolic or PVC containing solvent based lacquers have traditionally been used for internally lacquering food cans. Not all food cans are internally lacquered, however, it is normal practice to lacquer the ends of three piece cans if they are made from TFS (tin free steel). Three piece can bodies are made from ETP because […]

The spray application of internal lacquers has many disadvantages with non-uniform distribution of the lacquer being a major factor. Due to the non-uniformity of the film a thicker than required film is applied over most of the can to ensure that the area where the film will be lowest in weight is sufficient to protect […]

This is normally evaluated using a wedge bend or T-bend test, with reference to ASTM test methods D3281-84 or D4145-83. A sample of applied and cured coating is bent through 180°, and evaluated for fracture using acidic copper sulphate, which shows a colour change where reaction with the metal has occurred. The sample can be […]

This tests the successful application of the can and the dry film integrity. The can is filled to the rim with a salt solution (1% NaCl, or NaHS04), an electrode is immersed in the solution, and a voltage is applied across the can, 6.3 V for 4 seconds, then the insulation properties of the cured […]

It is necessary to test the internal lacquer to ensure that it will withstand the demands placed upon it. A series of standard tests are undertaken to evaluate the quality of the application, and the dry film. (i) Film thickness A lacquer is applied to a can and cured. The coating thickness is tested using […]

Due to the taste contamination of beer by tiny concentrations of iron, it is necessary to protect beer cans against this form of spoilage. In order to guarantee protection of the packed product (beer, cola, etc.) from iron contamination (often referred to as iron pick up), the internal coating is applied twice, wet on wet, […]

For the last twenty years, waterborne coatings have been used for the internal spray lacquering of DWI beer/beverage cans, unlike externals. They are used for both steel and aluminium DWI cans. During that time they have progressively replaced solvent borne coatings throughout the world. As long ago as 1979, Robinson of Glidden, now part of […]

External coatings for the DWI 2 piece beer and beverage can market are moving away from solvent to water based systems. However the metal used to construct the can may influence whether the external coating is solvent based or waterborne. A further complication in Europe is that both steel (ETP) and aluminium DWI cans are […]

by Andrew Hoggan BSc, David Fone BSc, Peter Oldring PhD BA, Kevin O’Hara LRSC and R James 1. Introduction The principles of the manufacture of cans, caps, closures and other items generally coated with metal decorating products, have already been outlined in the solvent based application section. Many users of waterborne products expect to replace […]

Typical metal primer formulations are given below: (i) Metal Primer FORMULATION 7-19 Millbase butyl glycol 4.17 water 12.20 defoamer 0.10 surfactant 0.31 dispersant 1.34 red iron oxide 1.47 strontium chromate 1.36 talc 10.00 micronised barytes 13.84 Mill to Hegman 7 and let down with: Rhoplex WL-91 38.10 surfactant (35%) 0.90 butyl carbitol 2.37 dibutylphthalate 1.57 […]