From Lysis Technologies Ltd.
Konstantia Asteriadou, PhD, CEng
The flexibility and wide range of possibilities that Rotational moulding offers, has enabled the industry to develop and adopt technologies that can be applied at various stages during the process. This results in higher quality products with more attributes and potentially personalised. One of these technologies is the use of decorative graphics or functional coatings. These can be realised on the product and be permanent part of it.
Apart from our post mould label free graphics for polyolefin mouldings, at Lysis Technologies and Tesoplas, we have developed graphic systems that can be transferred on a moulding after being printed on the metal mould. This technique, commonly know as in-mould transfer, happens during rotational moulding, where the whole graphic/design is transferred and diffused in the polyolefin moulding, offering a perfect finish. The result is a permanent, chemical and flame resistant graphic.
The graphics can be applied via various methods such as coating, stencilling, screen-printing, stamping or just brush painting. Multicoloured items can be achieved with vibrant colours and innovative designs.
Decorative and functional coatings can also be introduced to the mouldings. Examples are light-blocking, antimicrobial, antistatic etc.
The ink can be colour-matched and is characterized by its high UV resistance as well as by its long shelf-life since it is a solvent free system.Some of the ways to achieve that are shown in the following pictures:
- graphics made with screen printing (fig.1)
- coatings applied with in mould spraying (fig.2)
- graphics made with gloss roller and multi-use stencil (fig.3)
- designs made with in mould brushing and painting (fig.4 &5)
Figure 1: In-mould Marking/Branding with screen-printing
Figure 2: Two coloured moulding with in-mould spray coating
Figure 3: In-mould marking/ branding with gloss roller and multiuse stencil
Figure 4: Customised leisure "cow" boat with in-mould brush painting
Figure 5: Two coloured Boat with in-mould painted branding done with brush painting
The herein described technology is an alternative to in-mould label systems. The in-mould decoration process using ink systems has the following benefits:
- Permanent graphics, since the graphic is encapsulated within the moulding while it is being formed.
- No air entrapment and bursting air bubbles on the graphic surface
- Economical with no minimum order quantities
- High quality graphics
- Easy & Flexible application
- Safe, as ink is solvent free
- Short lead times
- Long shelf life