PHP preg_replace all but letters and numbers
If you want to remove all characters from a string using ascii range, this is one setup you can use. To modify see the HEX ascii values in this ascii table.
$text = preg_replace('/[\x00-\x1F\x21-\x2F\x3A-\x40\x5B-\x60\x7B-\xBF]/u', '', $text); //ascii range keep characters and numbers
//these are the ascii ranges: