Лако-красочные материалы — производство

The manufacture of Twist-off style closures requires the application of an internal sealing compound for good vacuum retention after sealing onto glass jars. To ensure good compound adhesion, the internal lacquer must be the final application, thus requiring the external system to show minimal discoloration when subjected to this re-bake. For this reason acrylic and […]

Closely allied to the general line business is that of tubes and aerosols. The majority of aerosols are made from welded tinplate. The coatings used are very similar to those alkyd, acrylic and polyesters from the general line section. Varnishes used need to have additional properties of product resistance from spillages during filling. This is […]

It should be noted that for internal applications compliance with FDA 175.300 and local regulations are required. This limits the types of materials which can be used for internal coatings. External coatings will only be considered here, because solvent based acrylic resins have little usage in internal lacquers other than PVC organosols. In the following […]

By contrast to the now extensive use of acrylics in waterborne coatings for DWI beer/beverage can coatings, this is the only other sector where acrylics find significant use (Table 4-1). This coatings sector still uses mainly solvent borne coatings with some use of UV cured coatings. The main function of the coating on the outside […]

A number of additives are included in metal decorating enamels, the most important of which are slip flow additives (silicone and non-silicone types) and polyolefine wax dispersions. Incorporation of waxes into the formulation aids the forming and tooling operations and promotes mar resistance.

Compared with conventional paints, white basecoats are formulated with high loadings of pigment. Pigment/binder ratios as high as 1.2/1.0 w/w are not uncommon. This is necessary to achieve the required opacity at low film thicknesses of around 8 microns. (ii) Solvents Both sheet fed and DWI type end uses rely upon rollercoating as the method […]

These products have acid values in the region of 60-80mg KOH/g and can be crosslinked with either — a) an epoxy resin catalysed with a metal soap such as zinc octoate (0.5-1.5% metal base on acrylic resin solids) or b) up to 20% of a hexamethoxymethyl melamine and acid catalysed with p-toluene sulphonic acid. Up […]

Thermosetting acrylic resins can be formulated to achieve the balance of properties required for sheet fed and DWI application. The base acrylic resins contain high levels of plasticising monomer such as ethyl or butyl acrylates combined with a hard comonomer, such as methyl methacrylate or styrene. Levels of functional crosslinking monomers are kept low in […]

Vinyl coatings based on polyvinyl chloride (PVC) or modified PVC’s are also used as coatings for some internals. There are three main classes of PVC based resins: a) vinyl solutions (vinyls) b) organosols c) plastisols Vinyls are low solid coatings because reasonably high molecular weight resins are necessary to achieve the required mechanical and resistance […]

Some of the metal decorating applications which commonly use acrylic resins, remembering that there may be large geographic variations, include: TABLE 4-3: POLYMERS USED IN METAL DECORATING COATINGS DWI Beer/beverage Three piece (welded) food DRD Food Caps closures General line Internal Epoxies, acrylics, phenolics, aminos, vinyls Epoxies, phenolics, ‘organosols’, oleresinous ‘Organosols’, epoxies, phenolics Epoxies, phenolics, […]