Virtual Reality: Acid-Etch Containers with Glass Enamels
The imitation of hydrofluoric (HF) acid- etch effects for glass containers has been an enormous challenge for many years.
Whilst it has been possible to simulate the frost-like appearance with a variety of coatings, it has not been possible to copy the total combination of smooth texture, quality feel and appearance, and durability that is typified by the "real thing".
Today, the environmental pressures and consequently the costs of producing HF-acid etched bottles are increasing hugely. The acid etching process itself also has a tendency to weaken the bottles, which can lead to increased breakage and higher costs for the bottle producers.
For these reasons, the Glass Industry is continuing its search for a viable alternative, which can perform not only for cosmetic and perfume bottles but also for wines and spirits bottles and glass tumblers.
The beverage bottle market is especially interested to replace the traditional HF-etch effects with glass enamel coatings, in view of the higher mechanical resistance demanded by this segment, necessary to survive both transportation and the filling lines.
Ferro's R&D team have now met this challenge with the successful development of a new range of smooth feel, lead-free glass enamel etches – branded AcE.
AcE delivers a smooth texture and appearance that is indistinguishable from the real thing, with enhanced abrasion resistance compared to organic coatings.
Characteristics of AcE Imitation Acid Etch Coatings and Inks
Ferro's AcE formulation is based on a lead-free and cadmium-free glass, combined with a novel processing approach to create the final imitation etch enamel system.
Good resistance to attack by mild acids, alkalis, alcohol and water, as well as good resistance to abrasion and filling-line scratching.
Coefficient of Thermal Expansion
83(+/-4) x 10-7K-1
Typical Firing Conditions
560-630°C with a cycle time of 1.5-2.5 h, with good ventilation and extraction of the combustion gases. Good control of temperature is always recommended.
Especially with this range, the final texture and visual effect are influenced by the firing conditions. Ferro technical teams are available to advise on specific products and cycles.
Coatings of various textures and handle can be supplied, either as plain semi-opaque or opaque. In addition, the screen-printable and wet coating systems can also be supplied in several color-ways.
Methods of Application
AcE can be supplied ready-to-use as cold paste, as thermoplastic (TP) flakes, or prepared for application by traditional wet spraying or wet electrostatic coating techniques.
AcE can also be prepared for application by electrostatic dry powder coating.
Wet Electrostatic Coating
For AcE all-over bottle coatings, wet electrostatic technology is an ideal method of application because this process can deliver:
- Increased transfer efficiencies, up-to 90%
- Reduced waste
- Energy efficient
- Low maintenance cost
- Homogenous deposit
- Flexibility - different article shapes can be handled by simple modification of the chuck design
- Can be used for glass stemware, vases, tumblers, food jars, cosmetic and beverage bottles
- Fast color changeover
- Closed loop conveyor system
- Optimum cost effectiveness, compared to real HF-etch coating
- Optimal environmental-friendliness compared to real HF-etching
- Relative low cost investment
Using this technology, AcE can be applied using one or other of either aerobell or turbodisc (standard or tilted configuration) applicators.
The market potential is huge. Today, millions of vodka, cognac, water and wine bottles are waiting to be decorated with AcE imitation acid etch glass enamels. Ferro imitation acid etch systems are specified more and more by leading glass bottle producers and premium drinks brands around the globe to add value to their products.
Archer's Peach Schnapps, Smirnoff vodka, Arbor Mist wines, Badoit sparkling water, Kriska vodka-flavoured beer are just a few examples.
AcE coatings are cost-effective, and used in combination with efficient application techniques – either wet or dry – offer an environmental-friendly, low cost substitute for traditional HF acid etching.