# Screen printing problems



## WayOut (May 25, 2010)

Ok so I tried for the first time to screen print the oter day and im having a few problems.

Firstly, the ink seemed to be smudging on some text at the edge of the print, it looks like when back filling the screen some ink was protruding through these areas of the print causing a build up of ink on the shirt side of the screen.

I tried back filling very gently but this kept happening.

Secondly, not much ink seems to be depositing on the shirt, mainly in the middle of the image (apart from where the ink was protruding through the screen) even with a well flooded screen. Could this be due to the screen emulsion thickness?

Thirdly, when i tried to do a second pass on the print to thicken it up, the two images were slightly out of line.

The screen im using i think was a 33t, (i have some 55t and this looks much finer.

The ink is while plastisol and is of out of the tub consistency.

the squegee seems EVER so slightly rounded in the middle, but not so much as i would suspect it to cause issues?

The off contact distance was set to a bout 4 - 5 millimetres, and the screen is snapping off the image well.

Any help appreciated

Dave


----------



## alvin6661 (Dec 17, 2009)

*Re: screen printing problems*



WayOut said:


> Ok so I tried for the first time to screen print the oter day and im having a few problems.
> 
> Firstly, the ink seemed to be smudging on some text at the edge of the print, it looks like when back filling the screen some ink was protruding through these areas of the print causing a build up of ink on the shirt side of the screen.
> 
> ...


what kind of press, are you flash curing in between colors, and it should not be "snapping" if your hearing a snap noise then your screen is to loose.


----------



## WayOut (May 25, 2010)

*Re: screen printing problems*

Its just a standard clamp type press in which the screen is secured in the clamp and lowered over the platen. 

I am not using colors, just white. havent had a decent enough print to try and bother curing yet.

There is no snapping noise, I was just using that analogy to the screen pulling away from the garment when printing.

Cheers

Dave


----------



## bigphat (Jul 23, 2010)

WayOut said:


> Ok so I tried for the first time to screen print the oter day and im having a few problems.
> 
> Firstly, the ink seemed to be smudging on some text at the edge of the print, it looks like when back filling the screen some ink was protruding through these areas of the print causing a build up of ink on the shirt side of the screen.
> 
> ...


Hello Dave, I think most of us have the same problems when we start doing this, so I'll try to be very specific with my answers  

1.- Check for the off contact of your screen, it should be the same from the top to bottom of the pallet.
Try to keep your squeegee pressure steady while you travel trhu the screen.

2.- If there's not enough ink on the shirt when you printing it could be water in the middle of your image make sure that when you are preparing your screen is completely dry and water free.

3.- If your image looks like is not line up with the first pass, the press that your using is not tight enough and when you lift the screen from the first pass it doesn't hold your registration right.

4.- make sure your squeegee have a nice fine cut on the edges, and remember when you are printing you have to print with the edges of your squeegee not with the middle. If you just start in this I will recommend a 70(durometer) squeegee 

5.-The off contact should be fine at that distance but make sure is evenly 4mm from the pallet.


----------



## moe_szys1ak (Jun 16, 2008)

*Re: screen printing problems*

How wide is the image and how wide is your squeegee? Also, how close to the edge of the screen does your image get?

I've found that if I use a squeegee that's only slightly wider than the image, or if my image is too close to the edge of the screen, details in the image along the sides end up a little smudged or not as solid an imprint. If the squeegee is too short, you don't get the pressure on the edges that you do in the center, and if your image is too close to the edge of the screen, then a similar thing happens where those sides do not get pressed down close enough to the shirt and ink gets pulled beneath the screen, causing smudging or blurring.

I recommend either increasing the distance between the screen edge and the image, using a wider squeegee, or, if those options cannot be done for some reason, you might try decreasing the off-contact as a last resort.


----------



## macumazahn (Jan 11, 2007)

I have been having the same types of problems. I will put this to good use.


----------



## Solmu (Aug 15, 2005)

WayOut said:


> The screen im using i think was a 33t, (i have some 55t and this looks much finer.


33T is actually quite coarse. The standard for textiles is 43T, and it goes up from there (the higher the number, the finer the mesh).


----------



## Markolis (Jun 10, 2010)

wow, seems we newbs all get similar problems. I'm getting a clogged screen on the ends (like the squeegee is not pushing through there) with that same build up Dave is talking about on the print side of the screen. Doesn't seem to make a difference what off-contact I use and I just could not figure out the problem. I burned a new screen and still same issue - I realized that the common denominator is then the image itself - but I couldn't figure out why. But now, after reading this thread, It occurs to me this image is wider than others I've done....thanks!!!


----------



## WayOut (May 25, 2010)

Thanks for this info guys, it has helped a lot. Getting satisfactory print results now.

One thing i noticed the other day tho was i burnt a new stencil onto a screen, and when printing, some areas of the image were not laying ink down properly.

Upon inspection of areas of the screen concerned, i noticed the screen has a certain reflective shine or shimmer to it different to the other areas. 

I tried cleaning these areas with screen cleaner and even delicately cleaning with stencil remover but to no avail. There didnt seem to be any physical blockage in the screen, it just seemed to be retaining ink when printing.

Screen was new and was always cleared of any residual ink before printing.

Any ideas?

Cheers agen

Dave


----------



## InkedApparel (Mar 18, 2009)

when you use a new screen , do you degrease before coating with emulsion? always degrease before coating...this will emsure no grease or dirt , dust or any foreign matter is on the screen.......

Inked


----------



## WayOut (May 25, 2010)

Ive got some organic screenwash. will this do?

Dave


----------



## InkedApparel (Mar 18, 2009)

no... a screen wash is for washing the ink out of the screen...you need a degreaser.....go to walmart and pick up some simple green degreaser.....or any degreaser will do...

Inked


----------



## Markolis (Jun 10, 2010)

btw, I just had this problem like I said before and I finally figured out my issue. What was happening was the screen was getting clogged in a few places every print. Instead of the ink going through on those places it would stay in the image. Then when I tried more passes, it would just build up in those places and make a mess. Here's what I did after doing some research on this forum and it worked great. 

First thing was my off contact was not exactly even (ie the screen was slanted). By using a piece of cardboard I was able to get the top end of the screen (the end closest to me when printing) to be the same exact height as the bottom end. This helps to not get ink trapped under the screen and also helps to not get shadowing. 

Also I realized when I was doing squeegee passes, I was not clearing the screen completely. In other words after my pass there was still some ink left on the screen behind it. This could also happen if your squeegee is old and doesn't have sharp edges, but mine are new so it was my pressure and angle I had to work on. I concentrated on making sure that there is NO ink left behind the squeegee the whole width of the print and I stopped having that problem.

Hope this helps others having the same issue.


----------



## sweetts (Apr 4, 2010)

Make sure you shirt is staying stuck to the platen are you using an adhesive? 


Sent from my iPhone using TShirtForums


----------



## WayOut (May 25, 2010)

Using adhesive, the shirt dosent lift from the platen

Dave


----------



## Markolis (Jun 10, 2010)

Just a follow up on what I said before - try a push stroke instead of a pull stroke. After everything I did above I was still having trouble with the white ink which is very thick. More often than not I was not clearing the screen so I tried a push stroke and it does way better at getting completely clear. Also here's a vid I watched that helped know what to do if ink is left in the screen - the presentation is nothing to write home about but the info helped me tremendously [media]http://www.youtube.com/watch?v=_gXUXyAascE[/media]


----------



## Intrudair (Aug 18, 2010)

Hello everybody,

We use waterbased ink with a mesh 46. The problem is that the ink sometimes goes through and sometimes no on the same mesh. If we use diluent then too much ink goes through. Someone any idea about the solution?


----------



## InkedApparel (Mar 18, 2009)

Intrudair said:


> Hello everybody,
> 
> We use waterbased ink with a mesh 46. The problem is that the ink sometimes goes through and sometimes no on the same mesh. If we use diluent then too much ink goes through. Someone any idea about the solution?


 
sounds like the waterbased ink is drying in the screen....try to keep the image area covered with ink when not printing......and spray the image area with water before you flood it.

Inked


----------



## Intrudair (Aug 18, 2010)

We have some other problem too. The first one is, we cannot wash out the dry ink from the mesh. Do anyone has some idea what could we do? 
The second thing is, after the exposure we washed out the emulsion from the mesh, and the water got it out not only from the image, around it too. 

We thought maybe the pressure of the water was too strong, or the exposure time was too long...what do you think about it?


----------



## Intrudair (Aug 18, 2010)

InkedApparel said:


> sounds like the waterbased ink is drying in the screen....try to keep the image area covered with ink when not printing......and spray the image area with water before you flood it.
> 
> Inked


Thanks for your help


----------



## BroJames (Jul 8, 2008)

Intrudair said:


> We have some other problem too. The first one is, we cannot wash out the dry ink from the mesh. Do anyone has some idea what could we do?
> The second thing is, after the exposure we washed out the emulsion from the mesh, and the water got it out not only from the image, around it too.
> 
> We thought maybe the pressure of the water was too strong, or the exposure time was too long...what do you think about it?


Clogged inks are often impossible to remove by washing. You need a "screen opener". Ask you supplier about it. It won't work magic though so the best is to keep it from clogging in the first place. 

An alternative is to use medium to longer drying inks. Medium drying inks should start clogging in 5 minutes so that will give you enough time to move to the next colors without having the first screen clogged up.

As to the emulsion, if you are using household pressure then chances are your emulsion is underexposed meaning your exposure time is too short. What is you UV source, its distance from the image, and what is your exposure time?


----------



## Intrudair (Aug 18, 2010)

Another question... What kind of film and printer are the best for this purpose? we think that maybe these two things can be the reason of our problems...Anyone some idea?


----------



## BroJames (Jul 8, 2008)

I heard the epson 1900 prints good opaque black. (Edit: Sorry for the wrong comment. I thought you meant capillary but it seems you mean transparency film).


----------



## InkedApparel (Mar 18, 2009)

I use the Epson r1900 max print size is 13x19 , it has 8 ink carts...prints very dark films...I also have Accurip ...Accurip tells the epson to print from all 8 carts at once for a super dark film......I also use Ryonet waterproof rFilm.

Inked


----------



## DEE SIGN (Aug 23, 2010)

jst wnt 2 knw...wt r dey puting on the board b4 dey put da shirts..


----------



## BroJames (Jul 8, 2008)

Do you mean the platen?

Table adhesives.


----------



## DEE SIGN (Aug 23, 2010)

Tnx bro james.... Can make my own adhesives?


----------



## BroJames (Jul 8, 2008)

You can with elmers glue but must mix with water to get the desired "adhesiveness". Pero hindi desirable ang kumapit sa damit ang dikit after taking the shirt off the platen. Most just buy table adhesives either in bottle (cheaper) or spray (more expensive).


----------



## DEE SIGN (Aug 23, 2010)

sir bj salamat poh....andito poh ako sa south africa.meron poh kaming silk screen printng...ang problema kpo ehh..pag multi color na ung ginawa ko nag shi shift ung design after drying,,,rotary po gamit ko...water base ung mga pintura,,ahh anong klaseng glue poh ung elmers glue...snsya npo sa mga makulit na tanong...MARMING SLAMAT POH.. SIR


----------



## BroJames (Jul 8, 2008)

Elmers glue is regular white glue found in bookstores. Pero bakit ka nagtitipid sa glue o gustong gumawa ng sarili? Yung sprayway spray adhesive (# 84 yata iyon) is more heat resistant than their regular #82. 

Ako regular table adhesive na nabibili sa mga suppliers gamit ko pero kung medyo nababawasan na ang tamang adhesiveness during printing either #82 or #82 gamit ko. Hindi ko naman problema ang "shifting" after drying. Ano pala gamit mo ngayon?


----------



## Intrudair (Aug 18, 2010)

Hy Everybody ,

Im Trying to make my first T-shirt with screen print , i did read this forum and it did help a lot .

I did some experiments with the screen itself (exposing time , drying , cleaning ,degreaser , but now im out off ideas about my problem 

I did the test about the exposing calculator , and i got the time 5,15 s . so i get the designe , and i burn it to a screen 61 ( european unit so i think in the USA is 2,54 time more 154 mesh) 

The problem is that i can not wash out the soft lines , and when i use more water the emulsion starts to come off , i use a garden was head , I water the screen first and let it wait about 5m , than with normal shower setting i wash it out , the big parts are coming out about in a few secends , but the thin lines they dont want.

I check the foil with a 50 x microscope and i could not see through 

I have a self made exposer , i tape the foil to the screen i put carton paper on the top , then wood, and 6 kilos more weight . 

That is the test 
[media]http://www.smrsoftware.com/ftp/step_wedge.pdf[/media], and i dont understand that the straight line dont wash out 100 % ( 0,5 pt ) and the squares are looking fine after washing .

Any Idea will be aprechiated 

Thank Peter


----------



## BroJames (Jul 8, 2008)

Intrudair said:


> ...
> 
> The problem is that i can not wash out the soft lines , and when i use more water the emulsion starts to come off , i use a garden was head , I water the screen first and let it wait about 5m , than with normal shower setting i wash it out , the big parts are coming out about in a few secends , but the thin lines they dont want.
> 
> ...


What is the foil?

The soft lines not coming off suggest overexposure like if your print is not opaque enough. I would also try to use a black fabric with foam instead of just carton.


----------



## DEE SIGN (Aug 23, 2010)

sir bj..salamat,, sa mga sagot,,,,rotary poh ung gamit ko..nsa south africa poh ako ngayn at dto ko ginagawa ung silk screen printing


----------

