Custom Array to CSV function.

array2csv.php

<?php

 /**
   * create CSV file from address data
   *
   * @var array Address Data
   * @return  string formated CSV file
   */

  function createCsv($address) {

    // build array with headlines
    $lines = array(
      array('BestellNr', 'Bestelldatum', 'EndKdNr',
          'LieferName', 'LieferAnsprech', 'LieferStrasse', 'LieferLand',
          'LieferPlz', 'LieferOrt', 'Pos',
          'ArtikelNr', 'Menge', 'Einzelpreis', 'Währung')
    );

    $i = 1;
    foreach ($this->Bestelldaten as $Produktdaten) {
      $Pos = $i;
      $lines[] = array($this->BestellNr, $this->Bestelldatum,  $this->EndKdNr,
              trim($this->LieferName), trim($this->LieferAnsprech), trim($address['LieferStrasse']), $address['LieferLand'],
              trim($address['LieferPlz']), trim($address['LieferOrt']), $Pos,
              $Produktdaten['ArtikelNr'], $Produktdaten['Menge'], number_format( $Produktdaten['Einzelpreis'] , 2, ',', '' ), 'EUR');
      $i++;
    }
    unset($i);

    // put array to csv
    $outstream = fopen("php://temp", 'W+');
    foreach ($lines as $fields) {
      fwrite($outstream,implode(';',$fields) . "\r\n");
    }
    rewind($outstream);
    $csv = stream_get_contents($outstream);
    fclose($outstream);

    $this->logger->logWrite("CSV-Datei generiert");
    return $csv;
  }

Has to get a definition of utf-8 as chartset to work with Integralis

Maybe start the $csv with "\xEF\xBB\xBF" solves the problem, that the generated file is not UTF-8 by default.
As suggested: http://stackoverflow.com/questions/4839402/how-to-write-file-in-utf-8-format

Have to wait for feedback of Integralis...