Get Posts Category name outside of a Loop

The following pulls all category from a custom taxonomy that has a slug as 'product-type'

function getcategoryname_forproduct($postid){

	$categorys = get_the_terms($postid,'product-type'); 

	foreach ($categorys as $category) {

		$categor .= $category->name.', '; 

	}

	return rtrim($categor, ', '); 

}

The following pulls all categories a post belongs to default post

function getcategorynameallinpost($postid){

	$categorys = get_the_category($postid); 

	foreach ($categorys as $category) {

		$categor .= $category->name.', '; 

	}

	return rtrim($categor, ', '); 

}

Following Pulls all the tags (Custom Taxonomy in this case) of the post (custom post type in this case)

<?php 

$tags =  get_the_terms( get_the_ID(), 'content-type');

?>

<div class="link-sec">

   <?php

     if(is_array($tags)){

         foreach ($tags as $tag) {      ?>

            <a href="<?php echo get_term_link($tag->term_id,'content-type') ?>"><?php echo strtoupper($tag->name); ?></a>

  <?php      }

    }

?>