Thermal Printing Overview
Thermal printing is a digital printing technology where a thermal printhead uses heat to apply a mark or print to a surface. There are two different thermal printing methods: thermal direct and thermal transfer.
Wax ribbons are suitable for general purpose printing on paper stocks, making it ideal carton labellingapplications. The high ratio of wax in the formulation means these ribbons have a lower melt point, so a lower heat setting can be used on the printer and high print speeds are achievable. Wax ribbons are the most economical ribbon.
Wax/Resin ribbons provide a finer image on very smooth, coated and gloss paper labels and some synthetic stocks (e.g. polypropylene, polyethylene, polyolefin). The printed image is more durable than wax, ensuring excellent resistance to scuffing or rubbing which can be a common problem for freight.
Full Resin Ribbons
Full resin ribbons provide excellent performance in harsh conditions including high temperatures, corrosive or UV applications. They are suitable for synthetic and specialty label stocks.
Thermal Ribbon rolls are available with the carbon-side (ink side) facing in or carbon facing out. Different printer makes and models will specify which style of ribbon they require. Also, the roll length of the ribbon needs to match the printer model.
It is important to match the appropriate ribbon to the label material and also ensure correct label printer settings for best results.
Label Material Considerations
There is a wide variety of facestock and adhesive combinations. Understanding the conditions and processes the label faces during its life is crucial when choosing label materials, ensuring the best outcome for the label and product.
Labels can be manufactured from paper or a variety of synthetic facestocks. The choice of facestock will depend on the expected service life of the product and the conditions it is expected to withstand. Synthetic stocks (polyethylene, polypropylene and polyolefin) offer properties that can lengthen the life of the label.
Acrylic or Hot Melt adhesives are commonly used. Factors affecting adhesive choice are temperature (both at the time of application and for the service life of the label), the nature of the product's surface, and other conditions likely to occur within the supply chain environment. Adhesives react differently depending on the surface energy of the product, for example carton vs glass vs different types of plastic.
A die or dies are used to cut the shape of the label. Rectangles, squares, circles, special shapes, perforations, undercuts (die cuts in label liner) are all options available to suit the application. This is a vital part of the manufacturing process as exact pressure is required for clean cutting, while not cutting too deep, causing die strike, and compromising the integrity of the liner.
For thermal printing applications, labels can be supplied on rolls, fan-folded into bundles or even supplied as continuous stock.