Author Topic: Discharge and Our Vastex LED  (Read 8076 times)

Offline canucklehead

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Re: Discharge and Our Vastex LED
« Reply #45 on: November 01, 2015, 02:27:04 AM »
99% of our jobs are discharge. Never had a stencil breakdown. We use this combo: Aquasol HV with diazo. 1/1 coat with sharp edge, 6-10 sec blast with 10K single metal halide in 25 year old Richmond Graphics Solar Beam. S and LX mesh, counts from 135 to 225. Works like a charm.


Offline ABuffington

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Re: Discharge and Our Vastex LED
« Reply #46 on: November 02, 2015, 11:20:49 AM »
A couple of notes here:
SBQ pure photopolymers can be post exposed.  Dual Cures and Diazos don't benefit the same as SBQ from post exposure.  The initial light strength and exposure determines a lot more of the durability than post exposure or hardening which are band aids to fix exposure.  We never used hardener on most jobs using Aquasol TS, high res SBQ, since an 8K metal halide with true film maximizes the exposure.  That is a pet peeve I have about LED.  It's not how short you can expose for it's how well you expose the screen. Our tests show SBQ in the sub 10 second range, its the tenths of a second that can make the difference.
LED is applicable to many companies. However as noted it can have a hard exposure on print side and soft on squeegee side, so SBQ is better on LED for post exposure to harden the squeegee side.  Halftones on MH have better cure and side wall formation, but LED is fast, easy and convenient and works for most shops.  Once I hit huge volume though metal halide has stencil exposure advantages.  Like many pieces of equipment available what works for one shop may not work for another. 

Al
Alan Buffington
Murakami Screen USA  - Technical Support and Sales
www.murakamiscreen.com

Offline alan802

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Re: Discharge and Our Vastex LED
« Reply #47 on: November 03, 2015, 08:33:41 AM »
Damn, what a day.  After a few weeks of being able to manage instead of putting out fires, I'm now back to running around playing a fireman.

Our stencils are VERY consistent and over the years it's been one of the things we've excelled at and I've wanted to show off our screens against an auto coater if given the chance.  We've consistently been able to be within 2-3 microns from like mesh counts from screen to screen and also within 1-3 microns from top to bottom of all mesh counts.  So with all that bragging out of the way, our 150's are either 45 or 48 micron thread thickness are around 15% EOMR and right around 12 micron EOM.  There is the occasional 15 micron EOM on the 150's but I spend a stupid amount of time measuring our screens so I feel good about where our stencils are.

Now I do not feel good about going even lower on our stencils for the sake of our LED.  I feel like we've already sacrificed enough and I don't feel that there is much more to do but move on.   
I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it -T.J.
Those who expect to reap the blessings of freedom, must, like men, undergo the fatigues of supporting it -T.P.