How to create csv comma separated list from an array in PHP

I need to place every category in a separate category column.

Like Category_1, Category_2, Category_3…..

        $categoryIds = implode('|', $product->getCategoryIds());//change the category separator if needed
        $cat_name = array();
        $cat_array = $product->getCategoryIds();
        for($k = 0; $k < count($cat_array); $k++)
        {
            $id =  $cat_array[$k];
            $cat->load($id);
            $cat_name[] =  $cat->getName();
        }
        $_cate_name = implode(',', $cat_name);

Full code

< ?php
ini_set('memory_limit','2048M');
ini_set('max_execution_time',3600);
error_reporting(E_ALL | E_STRICT);
define('MAGENTO_ROOT', getcwd());
$mageFilename = MAGENTO_ROOT . '/app/Mage.php';
require_once $mageFilename;
Mage::setIsDeveloperMode(true);
ini_set('display_errors', 1);
Mage::app();
    $products = Mage::getModel("catalog/product")->getCollection();
    $products = Mage::getModel("catalog/product")->getCollection();
    $products->addAttributeToSelect('mgs_brand');
    $products->addAttributeToSelect('manufacturer');
    $products->addAttributeToSelect('qty');
    $products->addAttributeToSelect('category_name');
    $products->addAttributeToSelect('name');
    $products->addAttributeToSelect('description');
    $products->addAttributeToSelect('short_description');
    $products->addAttributeToSelect('url_key');
    $products->addAttributeToSelect('price');
    $products->addAttributeToSelect('ean');
    $products->addAttributeToSelect('sku');
    $products->addAttributeToSelect('category_ids');
    //$products->addAttributeToFilter('status', 1);//optional for only   enabled products
    //$products->addAttributeToFilter('visibility', 4);//optional for   products only visible in catalog and search
    $fp = fopen('exports.csv', 'w');
    $csvHeader = array("Visible", "Brand", "Supplier", "NL_Title_Short", "NL_Title_Long", "NL_Description_Short", "NL_Description_Long", "NL_URL", "NL_Variant", "Price", "Price_Old", "Price_Cost", "Price_Unit", "Unit", "Tax", "Stock_Track", "Stock_Disable_Sold_Out", "Stock_Level", "Stock_Min", "Stock_Alert", "Article_Code", "EAN", "SKU", "Category");
    fputcsv( $fp, $csvHeader,",");
    $cat_name = array();
    $cat_array = array();
    $cat = Mage::getModel('catalog/category');
    foreach ($products as $product)
    {
        $brand = $product->getMgs_brand();
        $supplier = $product->getManufacturer();

        $qty = $product->getQty();

        $sku = $product->getSku();
        $name = $product->getName();
        $desc = $product->getDescription();
        $shortDesc = $product->getShort_description();
        $urlKey = $product->getUrl_key();
        $price = $product->getPrice();
        $ean = $product->getEan();
        $categoryIds = implode('|', $product->getCategoryIds());//change the category separator if needed
        $cat_name = array();
        $cat_array = $product->getCategoryIds();
        for($k = 0; $k < count($cat_array); $k++)
        {
            $id =  $cat_array[$k];
            $cat->load($id);
            $cat_name[] =  $cat->getName();
        }
        $_cate_name = implode(',', $cat_name);

        fputcsv($fp, array(
            'Y',
            $brand,
            $supplier,
            $name,
            $name,
            $shortDesc,
            $desc,
            $urlKey,
            'Product',
            $price,
            '0',
            '0',
            ' ',
            ' ',
            '21',
            'Y',
            'Y',
            $qty,
            '0',
            '5',
            ' ',
            $ean,
            $sku,
            $_cate_name

        )
        ,
        ","
        );
    }
fclose($fp);

?>