PadPrintech – Manufacturers of pad printing machines based in Mumbai, brings to you guaranteed no stress pad printing machines. But why pad printing is beneficial and why does pad printing bring more value to your product branding and product marking.
If you are reading this post then you are already aware of the advantages of pad printing and the typical mistakes one can make while choosing the right pad printing machines. Let’s now understand the process of Pad Printing.
How does Pad Printing work? and What are the types of Pad Printing Inks?
Pad Printing is an indirect Offset-Gravure printing process, where an image on the Cliche is transferred, using a silicone rubber pad, onto the surface to be printed. So what are the steps involved when the image is being transferred onto the product?
Home position is where the pad is on top of the product and the image area is covered with ink.
This is where the doctoring ring (or doctoring blade) moves behind (suggest: “around the home position” instead of “behind”) cleaning the excess ink on the Cliche and leaving ink only in the etched areas (image area) on the Cliche. The position of the Silicone pad is now on the Cliche.
The Silicone pad now moves downwards and rolls against the cliche lifting the ink from the etched areas (image area) on the Cliche and then moves upwards and forward, now ready to transfer onto the product.
Note: After the Silicone Pad has picked the ink from the cliche, the ink gets exposed in the air and the thinner starts to evaporate.
The silicone pad now moves downwards again and rolls on the product to transfer the ink on the substrate.
Note: Here, the other side of the ink is exposed in the air and now the remaining thinner starts to evaporate. It is through this process that the ink starts to cure and adhere onto the product.
Inks are available in different grades depending on the substrate you want to printed. Mainly, there are two types of inks available:
Single component inks are the ones that are directly mixed with suitable thinners and used for printing on the product. These inks are usually suitable for substrates such as ABS, SAN, Acrylic, PVC, Polystyrene, Polycarbonate etc. and are normally cured by natural drying.
Two Component inks come in two parts i.e. Ink + Hardener. To be used, they need to be mixed in a certain ratio (according to company specifications) along with a thinner or a retarder to achieve adhesion and durability. These inks require a post-curing process such as Infrared Drying, Hot Air Drying, Baking or Flame treatment and are best-suited for substrates such as Polypropylene, Thermoplastic Elastomers, Rubber, Glass and Ceramics, Metals etc.
Thinners and retarders are available with different rates of evaporation. Thinners are fast evaporating in nature whereas retarders are slow evaporating. These must be used depending on ambient temperature.
Certain substrates and specifications require hardeners to achieve adhesion and durability of the Print.