According to Google, there are over half a million items on the web on the topic of reclaiming screens, so it is little wonder there is so much confusion. We hope that we can bring some clarity to this important subject, so here are some of our top tips:
1. Don’t delay it - surprisingly obvious, but if you neglect your screens and let the inks dry out you will make it harder, if not impossible, to reclaim them successfully. Discarding any excess inks is the first step of the reclaiming process, do so in an environmentally sensitive manner and recycle ink if possible.
2. Do more than one. It always makes sense to reclaim more than one screen at a time, as you can progress through the various steps much more efficiently – remove, scrub, spray and so on.
3. Think about reclaiming when you are coating the screens. If you work carefully and cleanly from the start, the job of reclaiming your screens will be made a lot easier. A good tip from one of our contributors “When you are coating the emulsion, right after you complete one screen, take a pallet knife or piece of cut cardboard and scrape the thick edges up quickly. Just takes a second to do and saves you scrubbing time during reclaiming”
4. Don’t under expose. Under exposure of the emulsion is one of the most common mistakes. As well as compromising durability, it can also make it virtually impossible to reclaim screens. Why? – an underexposed stencil is vulnerable to hardening from on-press and post-print cleaners which means that stencil removers cannot penetrate the stencil. At best, you will be left with haze / stains which will require additional cleaning steps.
5. Don’t leave reclaiming screens to the rookies. This part of the process is sometimes given to the new starters to get on with. Well, don’t expect brilliant results if this is what you do and you haven’t provided them with appropriate training, checklists and equipment.
6. Don’t stinge on chemicals. It’s definitely false economy to think that you can get away with cheap stuff. Use ‘generic’ industrial cleaning products and solvents at your peril; you may be interfering with some of the chemical components of inks or other products, end up with ruined screens and even non-compliance with your waste water authority.
7. The jury’s out on dip tanks. Use them appropriately and only in specific conditions. Be careful as you could end up with some nasty chemical cocktails that may be very difficult to dispose of, as well as lots of sludge.
8. Follow the manufacturer’s instructions. Yep, more really basic stuff, but if you don’t read the instructions you have only got yourself to blame if things go wrong. Always check the recommended dilutions for economical use. A tip from one of our community users is to slightly increase the strength of the stencil remover in order to break the bond of highly water resistant emulsions more easily.
9. Don’t let stencil removers dry on the screen - you’ll say goodbye to your screen!
10. Check for haze and stains. Poor removal of the emulsion and under exposure can result in staining / haze being left on the mesh. Where possible use low caustic haze removers as these can safely be left on screens overnight. High caustic haze removers are much more aggressive and can damage your expensive mesh rather than preserving it. Again, read the instructions carefully!
11. Pressure washers at the end of the process can really help - but use them properly. One post neatly summed it up by saying, “it does a majority of the work and makes things much easier.”
12. Follow the law and best practice. Dispose responsibly and in keeping with local regulations. Provide a safe and clean working environment in the reclaim room. This includes properly cleaning all your equipment and in particular the pads and brushes. A well encrusted brush won’t be of much use to you next time…
Finally, here is a quote about screen reclaiming: “Screen reclaiming is a function of performance, cost, risks and regulatory affairs.” We debated this in the Screen Printers of the World Unite community and performance of the stencil remover came out top, but the other variables can be optimised by closely following the above tips.
Would you like to share your thoughts on this and more? Come and join the debate at the Screen Printers of the World Unite Community.
This 'How To Screen Print' guide was orignally printed on page 41 of the March edition of Printwear & Promotion as part of our Screen Print Column.
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Name: William Shorter
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