Post on 25-Mar-2020
Gerhard Passenegg (ex SCHEKOLIN AG)Technical DirectorSalchi Metalcoat S.r.l.Viale dell’Industria 3/A – 3/B20875 Burago di Molgora (MB)Italy
UV-curable packaging coatings for aluminiummonobloc cans
Agenda
1. Introduction Salchi Metalcoat
2. Technology in general
3. Process flow Aerosol-cans
4. Status of development
5. Outlook
Salchi Metalcoat
▪ Established in 1993
▪ Complete portfolio of coating solutions
▪ Coil coatings, including inks and adhesives forcolamination
▪ Packaging coatings, including metal decorationinks
▪ 130 employees in Burago Molgora, Italy
▪ 30% in R&D and Quality Control
▪ Production capacity of 27 000 tons/year liquid paints, inks and adhesives Burago di Molgora Plant 20 kms from Milan
Salchi Metalcoat and Schekolin
▪ Acquired metal packaging business of Schekolin AG in 2017▪ Metal Sheet▪ Aluminium Tubes and Monobloc▪ Complex Objects▪ Powder coatings
▪ Foundation of SMBB – Salchi Metalcoat Bendern Branch▪ 5 employees in Gamprin-Bendern, Principiality of
Liechtenstein▪ Focusing on R&D UV coatings for metal application
▪ SMBB acts as a service lab for customers, especially for thegerman speaking DACH-region
Sägastrasse 34, 9485 Nendeln, FL
TechnologyUV-curing coatings – Free radical curing technology
The photoinitiator decays intoradicals starting a chain reactionpolymerization with the doublebonds of the resins (acrylates)and monomers due to UV-radiation.
TechnologyUV-curing coatings – UV-cationic technology
The photoinitiator (a salt andblocked strong acid) decays intoan acid which starts the reaction(polymerization) due to UV-rays.This acid-curing reaction isstrongly influenced bytemperature.
TechnologyUV-curing coatings – Advantages and Disadvantages
+ Wide process window for application, curing and post-processes not time limited
+ No post-cure effect
+ Compatibility with UV printing inks
+ Fast curing
- Smell after curing
- Oxygen inhibition in thin layers
Free radical curing technology UV-Cationic technology
+ suitable for post-processes
+ Highly flexible
+ No smell after curing
+ Hot water resistant
- Post cure effect and overcuring can limitthe post processes
- Limited range of raw materials
- High raw material prices
Process flow Aerosol-can decoration
1. Impact-process, cutting, washing
2. Internal protection lacquer 8-12 µm
3. Stoving 5‘/260°C
4. Base coat clear, white 12-18 µm 6-9 µm
5. Stoving 5‘/100°C (pre drying) i.e. UV-Omega (10-12’’)
6. Printing UV-Inks
7. Stoving 5‘/150°C i.e. UV-Omega (10-12’’)
8. Overprint varnish, clear 6-9 µm 3-6 µm
9. Stoving 10‘160°C i.e. UV-Omega (10-12’’)
10. Necking and shaping
Significantchange
Thermal versus UV
Status of development
▪ UV-Basecoat, colourless cationic
▪ UV-Basecoat, white cationic
▪ UV-Basecoat, white-tinted cationic
▪ UV-Overprint varnish, semi-matt cationic
▪ UV-Overprint varnish, brilliant cationic
OutlookLED-curing coatings – Advantages and Disadvantages
Advantages Disadvantages
+ Pure UV-Light, low thermal stress
+ No warm-up period, energy efficient
+ No mercury, ecologically friendly
+ Long life span, approx. 20 000 h
- Small selection of functioning lacquers, expensive materials
- Only a few working initiators, danger ofyellowing
- Lacquers are extremely light sensitive
- Difficult to cure completely
Thank youfor your attention
Gerhard PasseneggSalchi Metalcoat s.r.l. Burago di MolgoraBendern-BranchIndustriestrasse 3FL 9487 Gamprin-Bendern
Mail: Gerhard.Passenegg@salchirh.itTel: 00 423 794 04 62