Line and Text is not same in consistency

[Christian29884974eq0g]

the project requires 550 x 550 pixels, my problem is I can't make the letters as crisp as the line and makes it blurry once exported.

[Ton Frederiks]

That is normal, you will always get pixels when exporting as an image. Your lines fall nicely on the pixelgrid, but text will be anti-aliased.

To make it a little crispier you can experiment with the anti-aliasing method in the Character panel.

[Bobby Henderson]

One thing I tend to do when creating text items to display in a pixel-challenged environment such as LED-based variable message sign is I'll size the letters according to capital letter height in whole pixel numbers and make sure the baseline of letters lines up with the pixel grid. The font height options in Illustrator allows for such an approach. The letters still aren't going to be "perfect," but it does make a pretty big difference visually when the baselines and cap height lines of letters are matching up to the pixel grid.