<?php
$str=  'This is some example text , I want to print this variable in 3 lines, also.';
$x = '12';
$array = explode( "\n", wordwrap( $str, $x));
var_dump($array);
?>

array(7) {
  [0]=>
  string(12) "This is some"
  [1]=>
  string(12) "example text"
  [2]=>
  string(11) ", I want to"
  [3]=>
  string(10) "print this"
  [4]=>
  string(11) "variable in"
  [5]=>
  string(8) "3 lines,"
  [6]=>
  string(5) "also."
}