You are not invisible, just "virtually invisible." A search on "'laser fume' 'fume extraction'" returns your URL at 188, which is a good news-bad news situation.
Good news: you're in there--Bad news: it's a very competitive field. Others here may be able to spot something you're doing wrong, I just thought I'd chime in with that to let you know you
are visible on
http://www.google.com/ie which is at least a start. Set your Google "Results per page" at 100 and it will be easier to check your visibilty (or lack of it) from that URL.
I waited well over a year to get listed in DMOZ in my category, I think the more competitive the field the longer the wait. DMOZ waiting times are uneven since each category has its own unique editorial situation. I can't see anything wrong with your site. Though as I said there are people here with more expertise than I. Maybe there is an undiscovered keyword that some people are searching on that your competitors have missed.
Best of luck.
Andi