L 260, L26500 wide rectangles are bent ?

[Ian Stewart-Koster]

Today I needed to make 4 black rectangles, 48" wide x 5-1/2" deep.
They had a bit of yellow text on them.
I printed them OK, on self-adhesive oracal vinyl, allowing 1/4" bleed all round, thank goodness!

When I went to trim them, despite the 48" being left to right on 54" vinyl, the edges had a pronounced curve to them- nearly 3/8" curvature. Lucklily they trimmed OK, but it was amazing to see that the substrate had grown>

(I'd really appreciate any ideas on stopping this in future.)
Thanks

 

[bigben]

If you take a vinyl that have a #90 liner, you will have no or very minimal bending. There is also a curve correction in the rip, but from my experience you have to adjust it frequently depending of the size of your print and roll.

 

[Ian Stewart-Koster]

Thanks for the reply - what's #90 liner? This was a silicone/paper liner the same looking as most...
Onyx is the rip we use, but I've not seen a curve correction.
I wondered if it was the quantity of black ink in the print - but still it was a banana shape, forwards in the middle- yet it must have printed straight, suggesting the heating caused the growth or stretch that then did not reset itself back...?

 

[AF]

Heaters heat the part of the media in the print zone. The media expands. The ink is laid down on the distorted media. The media cools and goes back to straight. Now the print is distorted. You can take most of this out in the rip.

 

[Ian Stewart-Koster]

Thanks very much