Shirty/HOWTO: Unterschied zwischen den Versionen

(6 dazwischenliegende Versionen von einem anderen Benutzer werden nicht angezeigt)

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Notes from screen ~~printing testout~~ session 23.06.09:

== Notes from screen print test session 23.06.09 ==

* Material bought from Wöco:

** ~~FIXME~~

** Screen with frame

** Emulsion

** Sensitizer

** Paint

** "Squeegee"

** Cleaning agent to clean away hardened emulsion

* Sensitize emulsion:

** Fill up the small sensitizer bottle with water

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** Our printout was not very dense due to a broken/out-of-ink printer

* Expose the screen

** Place the screen with the flat side down on a horizontal surface

** Place the printed transparent foil onto the screen

** Mount a UV lamp lighting downwards with ca. 1 meter distance

** We used the IR+UV lamp from the Chemielabor. Note! The UV lamp won't work lighting downwards, for some reason. Alternative setup: tape the transparent foil to the screen with _transparent_ tape. Cover the backside with something non-reflective.

** Exposure time: 15-20 minutes. This depends on the thickness of the emulsion, too short and the opaque areas have not hardened, too long and thin lines in your design bleed together.

* Clean away the non-hardened emulsion

** Use warm/hot water with as much pressure as you can get from a shower head

** Since our print wasn't very dense, this had an effect on the exposure: Less well-covered areas had clear half-hardened emulsion. These areas, in addition to areas with small details were a lot harder to wash away. Using a dishwashing brush helped a lot.

** If some emulsion doesn't come off, use a small _plastic_ tool (e.g. a reprapped palm stylus) to _carefully_ scrape away the remaining emulsion.

** Now, let the screen dry. Shouldn't take long.

* Apply paint

** Line up a bit of paint just outside the motive

** Using the squeegee, carefully drag the paint over the motive so the whole motive is covered with paint

** If it's not fully covered, drag it back again

** Using a bit more pressure, drag the squeegee once over the entire motive

** Carefully lift the screen from the motive

** Every once in a while, clean away dried paint from the screen with water

* Drying

** Using a hair dryer, lightly dry the fabric

** At this point, to make the print permanent, an iron should be used on the fabric. We didn't have one available, so who knows what will happen now..

== Neue Erkenntnisse aus einer Session im August '09 ==

* Eine Belichtungszeit von fünf Minuten ist ausreichend

* Farben kann man mischen, aber Vorsicht, die dunkelere Farbe (zb. bei gelb und rot ist rot dominat) sollte nur ganz langsam und vorsichtig beigemischt werden

* Testdrucke auf t-shirts macht man am besten linksrum, auf der innenseite