Automatic printing.

[sben763]

I recently bought a old automatic. I have done ton of 1-2 color jobs and 1-2  plastisol transfers. I can't get the wet on wet printing on this thing. I can do wet on wet on my manual.  The ink is coming out rough on the previous color and where there is a underbase it spreads.  These are all spot color jobs.

My current job set up. Head 1  Underbase 166 double stroke flash. Head  3 light gray on 205. Head 5 red on 205 head 6 black on 205. The gray stays ok but gets a little rough.  The red spreads out and looks terrible. To get though this job I am turning on 1 head at a time and running them all the way around so that they flash in between and its coming out ok but seems rather thick but I am not concerned on this job about the thickness as they are hoodies. I just thought maybe the thickness may be part of the issue. Do my stencils have to be much thinner then the manual? 

I actually don't mind having to run the auto around but would like to figure out the wet on wet.  Its still helping with my arthritis not printing on the manual.

[Prosperi-Tees]

I run higher mesh counts for wet on wet, anywhere from 230 to 305 on white shirts and underbases.

[starchild]

Thread count tells you what ink deposit thickness to expect given the right conditions. The mesh diameter-thread thickness-and open area is what should be considered along with the inks personality to be able to identify if the conditions are met to achieve the required ink deposit for that count mesh.

Ink layer roughness could be caused by positive mesh lag where the screen does not immediately snap off the shirt as the squeegee passes over each parallel unit of mesh opening, also image stretch "spread" could occur by the mesh rolling beneath the squeegee. Both roughness and stretch happens with too low off contact screens, too low screen tension.. Indicating raising your off contact for this job but eventually match your screens to the ink behavior..

Thicker threads with smaller open areas coupled with high eom is not a good combination for inks that behaves badly.. You will have to print with softer squeegees at lower angles, higher pressure and slower speeds to achieve the required deposits.

Start with your inks and get the mesh specs to match it or get high performance mesh and fix the ink.

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[sben763]

Thanks for the responses.  I talked with Sonny on the phone.  With the responses here and talking to him I think I am using too low of mesh, too high squeegee pressure, too high flood pressure too high screen tension (40N) . I think my off contact maybe not enough.  I thought I was at 1/4 with shirts but I just went out and checked and with a shirt and its 1/8" and 0 with a hoodie.

I am going to lower the off contact a real pain on this old press and just run it around as its only 50 hoodie job and I would normally do these on the manual but just trying to get some automatic experience

[Frog]

Thanks for the responses.  I talked with Sonny on the phone.  With the responses here and talking to him I think I am using too low of mesh, too high squeegee pressure, too high flood pressure too high screen tension (40N) . I think my off contact maybe not enough.  I thought I was at 1/4 with shirts but I just went out and checked and with a shirt and its 1/8" and 0 with a hoodie.

I am going to lower the off contact a real pain on this old press and just run it around as its only 50 hoodie job and I would normally do these on the manual but just trying to get some automatic experience

With "0"on your fleece, aren't you going to raise your off contact?
Also, why would too high tension on your screens hurt your printing? (added fragility of mesh notwithstanding)

[sben763]

Yes you are correct but since my old machine doesn't have central off contact adjustment its done by the either the screen holders or the platens I was speaking of lowering the platens to increase the off contact. 

I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.  I'm going to play around some more. The plastisol transfers I have made off this machine are great. Better then any ones I've purchased or made off the manual.

I'm going to play around with some adjustments, off contact, squeegee pressure ,and up the mesh count on the next job.  My main printing is spring and fall. The jobs I'm doing now I would usually of have passed on as they are simple spot jobs and 50-60 piece jobs. I'd rather do simulated process higher paying jobs.

[Printficient]

Before lowering the platens I would raise the screen by putting washers under the screens in the screen holders.

[Frog]

Yes you are correct but since my old machine doesn't have central off contact adjustment its done by the either the screen holders or the platens I was speaking of lowering the platens to increase the off contact. 

I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.  I'm going to play around some more. The plastisol transfers I have made off this machine are great. Better then any ones I've purchased or made off the manual.

I'm going to play around with some adjustments, off contact, squeegee pressure ,and up the mesh count on the next job.  My main printing is spring and fall. The jobs I'm doing now I would usually of have passed on as they are simple spot jobs and 50-60 piece jobs. I'd rather do simulated process higher paying jobs.

I was pretty certain that that's what you meant by "lowering", but then, of course, you aren't lowering the off contact, and I wanted to eliminate any confusion to anyone else who may read this thread.
I am very interested in why high tension screens won't work properly on this old Lawson.

[Printficient]

Yes you are correct but since my old machine doesn't have central off contact adjustment its done by the either the screen holders or the platens I was speaking of lowering the platens to increase the off contact. 

I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.  I'm going to play around some more. The plastisol transfers I have made off this machine are great. Better then any ones I've purchased or made off the manual.

I'm going to play around with some adjustments, off contact, squeegee pressure ,and up the mesh count on the next job.  My main printing is spring and fall. The jobs I'm doing now I would usually of have passed on as they are simple spot jobs and 50-60 piece jobs. I'd rather do simulated process higher paying jobs.

I was pretty certain that that's what you meant by "lowering", but then, of course, you aren't lowering the off contact, and I wanted to eliminate any confusion to anyone else who may read this thread.
I am very interested in why high tension screens won't work properly on this old Lawson.

The chopper cylinders on the older smaller presses are not sufficient to evenly deflect high tension,  Think of it this way, your arm would tire sooner if you had to exert a great amount of force to complete a task as opposed to little or no force to do the same job.  The higher the tension or tighter the screen the more force needed to initially deflect it.  The off contact distance is not relevant to the equation.  Obviously once deflection of the screen is initiated then the off contact distance is relevant

[starchild]

I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.

I'm trying to figure out why higher tensions will have a negative affect on the press.

Let's say you want to print a 3 color, 65lpi image..

The first thing we consider is resolution so we pick a mesh with a thread count to hold those dots-that's in the stencil..

The second thing is to make sure we can hold the required registration tolerance of 65lpi, so now we consider a screen's tension because the screen's static tension (before squeegee pressure) together with your inkwell distance, will inform you of what off contact distance the print head needs to be set at to be within the 65lpi tolerance.

Now the higher the tension the screen is, the lower the off contact can be and still achive the 65lpi.. This high tension/low off contact is ideal for image tolerance/registration but comes at the expense of latitude for error.. (It's best that the press is dialed in and your squeegee's length does not push the limits of your screen's)

For more midrange tensions, you will still be able to achieve the desired 65lpi but with larger inkwells (shorter squeegees and therefore smaller images, be prepared to sacrifice 5"-6" of screen width to the inkwell) and higher offcontact distances.

Both scenarios should enable you to print with less pressure and faster stroke speeds-if you're using thin thread, high percentage open mesh areas and decent enough inks-with sufficient dynamic tension for ink transfer to occur without much issues.

So static tension is used to set image tolerances and dynamic tension feeds ink to the mesh openings.


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[TCT]

Actual quarters($.25) two on each side between the bottom of the screen and holder used to work wonders on our less capable press!

[Printficient]

I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.

I'm trying to figure out why higher tensions will have a negative affect on the press.

Let's say you want to print a 3 color, 65lpi image..

The first thing we consider is resolution so we pick a mesh with a thread count to hold those dots-that's in the stencil..

The second thing is to make sure we can hold the required registration tolerance of 65lpi, so now we consider a screen's tension because the screen's static tension (before squeegee pressure) together with your inkwell distance, will inform you of what off contact distance the print head needs to be set at to be within the 65lpi tolerance.

Now the higher the tension the screen is, the lower the off contact can be and still achive the 65lpi.. This high tension/low off contact is ideal for image tolerance/registration but comes at the expense of latitude for error.. (It's best that the press is dialed in and your squeegee's length does not push the limits of your screen's)

For more midrange tensions, you will still be able to achieve the desired 65lpi but with larger inkwells (shorter squeegees and therefore smaller images, be prepared to sacrifice 5"-6" of screen width to the inkwell) and higher offcontact distances.

Both scenarios should enable you to print with less pressure and faster stroke speeds-if you're using thin thread, high percentage open mesh areas and decent enough inks-with sufficient dynamic tension for ink transfer to occur without much issues.

So static tension is used to set image tolerances and dynamic tension feeds ink to the mesh openings.


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Ok here is my question.  At what tension do you lose registration on a 65 lpi screen 25 ncm, 30ncm, 35ncm, 40ncm?  I have held 65lpi halftone 4cp screens at perfect registration (ie. holding a rosette patern) viewed under a 45 power loupe on wood screens at 15 ncm.

[Binkspot]

First for off get some 1" wide alum flat bar 1/16" and 1/8" thick, cut to the width of the screen holders to use as shims or the M&R Rasta bars if still available.

This tension thing isn't making sence. Our roller frames are kept between 32-36 nm and print with less then 30 psi pressure usually between 22-28 psi, sometimes as low as 15 psi, off contact is about the thickness of a dime maybe a nickel at most.

IMO "off contact" is not necessarily a measurement between the bottom of the screen and the garment but the distance needed for the screen to pop off the garment on its own after the squeegee passes. You need more off contact with screen at 15nm then one with 35nm to make the screen lift off the garment and leave the ink behind. Yes I do know many printers that pull off amazing prints with statics in the 17-20 range. Please set me straight if this is wrong.

IMO the screens are fine for the job just add some off contact and back the pressure off on the squeegees sounds like you are squishing the red ink with the next screen. It could also be the ink has been modified and has a runny property. Or is the press not in parallel and needing excessive pressure to clear the screen from front to back.

[starchild]

I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.

I'm trying to figure out why higher tensions will have a negative affect on the press.

Let's say you want to print a 3 color, 65lpi image..

The first thing we consider is resolution so we pick a mesh with a thread count to hold those dots-that's in the stencil..

The second thing is to make sure we can hold the required registration tolerance of 65lpi, so now we consider a screen's tension because the screen's static tension (before squeegee pressure) together with your inkwell distance, will inform you of what off contact distance the print head needs to be set at to be within the 65lpi tolerance.

Now the higher the tension the screen is, the lower the off contact can be and still achive the 65lpi.. This high tension/low off contact is ideal for image tolerance/registration but comes at the expense of latitude for error.. (It's best that the press is dialed in and your squeegee's length does not push the limits of your screen's)

For more midrange tensions, you will still be able to achieve the desired 65lpi but with larger inkwells (shorter squeegees and therefore smaller images, be prepared to sacrifice 5"-6" of screen width to the inkwell) and higher offcontact distances.

Both scenarios should enable you to print with less pressure and faster stroke speeds-if you're using thin thread, high percentage open mesh areas and decent enough inks-with sufficient dynamic tension for ink transfer to occur without much issues.

So static tension is used to set image tolerances and dynamic tension feeds ink to the mesh openings.


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Ok here is my question.  At what tension do you lose registration on a 65 lpi screen 25 ncm, 30ncm, 35ncm, 40ncm?  I have held 65lpi halftone 4cp screens at perfect registration (ie. holding a rosette patern) viewed under a 45 power loupe on wood screens at 15 ncm.

You will loose registration at offcontact distances not set to hold the image tolerance for the screen tension being used..

So if you printed your image at 15n then an inkwell distance not less than 2.5 to 3 inches would have been required and a 1/8" or more of off contact to achieve that.. Otherwise at 15n and an off contact distance of say 1/16" or less would have caused image stretch in the stroke direction due to the mesh rolling under the print stroke.

You will not achieve 65lpi registration, due to inadequate off contact distance for the specific tension you decide to print with along with the inkwell being too shallow. The thing is you can achieve 65lpi at 1/16" off contact with total ease (shallow inkwell and all) but it must be at higher tensions to prevent image stretch.

Inkwell+tension+offcontact=image tolerance.



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[sben763]

I thought about washers or spacers but honestly I don't want to unregister the job. I am in a very tight space (too tight) and it honestly will be easier to lower the platens then to reset up

 I have Newman pin registration for my manual but I would have to get the pallet jig on my auto platens and I most likely wont have the press long enough to justify the expense plus I would have to modify the front clamps to use it. Next step is a M&R then I can use my same platen for reg system

for the manual I coat my screens 2/1 with CCI HV or Ryonet HI-FI (same stuff) with rounded edge.  On a 205 last time I checked It was about a 18 micron stencil. the 166 I could get as much as 22 micron.  So I have been using thick stencils.  Should I do a 1/1 or a 2/1 with sharp side of coater and go for a thinner stencil?

I have another job that I am going to make new screens for it.  I am going to use a 205 for underbase and 272 for top colors.  This one is a 55 LPI for 1 color the rest are spot. 

I got the squeegees with the machine and they felt somewhat sharp.  I have a sharpener so I am going to go sharpen them tomorrow.   

What about angle.  they were all set but I had to change 1 because it didn't allow it to chop correctly. they seem to be at a angle close to what I use on the manual when using push stroke. should they be more straight up since this is like a pull stroke on a auto.