shipping-notifications/ShippingNotifications/Block/ShippingCategory.php

<?php 

namespace Cpcommerce\ShippingNotifications\Block;

use Magento\Catalog\Block\Product\View\Description;
use Magento\Catalog\Model\Product\Attribute\Repository;
use Magento\Framework\View\Element\Template;
use Magento\Framework\View\Element\Template\Context;

class ShippingCategory extends Template
{
    public function __construct(
        Description $description,
        Repository $attribute,
        Context $context,
        array $data = []
    ) {
        $this->description = $description;
        $this->attribute = $attribute;
        return parent::__construct($context, $data);
    }

    public function getAttributeData($attribute_code){
        return $this->attribute->get($attribute_code);
    }

    public function getShippingCategory(){
        $_product = $this->description->getProduct();
        $shipping_category = $_product->getResource()->getAttribute('shipping_category')->getFrontend()->getValue($_product);
        return $shipping_category;
    }
}