Download this free, 140-page Flexible Packaging Playbook jam-packed with strategies for success, best practices, and pitfalls to avoid.  Learn more »
Glenroy invites you to download this playbook.
Article |

Exopack Addresses Woven Polypropylene's Impact on Consumer Shipping Sack markets

Exopack, historically a manufacturer of multiwall and plastic packaging, has recognized the need to manufacture and provide Woven Polypropylene (WPP) packaging due to the performance advantages and impact this has on our customers and markets.
FILED IN:  Machinery  > Inspection

In addressing this need, the company has created a separate business unit focused solely on manufacture and sale of WPP materials. WPP bag manufacturing is currently in progress at several of Exopack's manufacturing facilities and will include both WPP and paper-laminated WPP packaging materials. And to further expand production capability, capital for new equipment is also being committed. Exopack will continue to approach the market as one offering multiwall paper and plastic finished bags and FFS packaging from a single source.

The History of the Woven Polypropylene Shipping Sack

The North American shipping sack market is experiencing a large impact by bags constructed from WPP. Historically seen in IBC bulk sacks, WPP is making inroads into retail and smaller format shipping sacks due to greatly enhanced graphics. The key performance characteristic of a WPP bag is outstanding strength when compared to other materials. In addition to having very high puncture resistance, it also has excellent tear resistance as a hole will not turn into a large slit or lead to total bag failure.
WPP is formed by weaving polypropylene strands or threads into a cross-mesh fabric pattern. The fabric is then coated or laminated to create a smooth surface for both printing and binding the fibers together. For consumer applications, the WPP fabric is usually laminated to an Oriented Polypropylene (OPP) film that is reverse printed. Various types of bags can then be converted with sewn-open mouth and valve styles being the most popular. Globally, WPP is the primary package option and has the leading market share for dry goods in Asia, South America, and Africa. Although generally seen with rudimentary surface printing and manufactured by hand, superior strength makes it the bag of choice. WPP bags have been in the US for years but were used in commodity grade dry goods applications where graphics and presentation played a negligible role. But now that it is gaining acceptance due to performance and improved appearance, many companies using WPP Sewn and Valve packaging have found that it can be utilized on existing equipment with little modification. A recent product addition has been a bag constructed of paper laminated to WPP which provides the appearance and stackability of paper, but with the added strength benefit of the WPP substrate.

What is driving WPP?

The current proliferation of WPP bags can be traced to two key drivers.
First, the addition of a reverse-printed BOPP outer layer laminated to the WPP material. This enables a WPP bag to have the same high-quality graphic appearance and shelf-appeal as multiwall and other plastic packaging with high gloss, a smooth surface, and resistance to ink abrasion.
Second, retailers have identified a significant potential cost savings by cutting down on bag loss and improving cleanliness resulting from excessive and preventable breakage. Hard-cost savings include a reduction of broken bags that are either unsaleable or sold at a deep discount, reduced waste, and reduction of customer returns. Soft cost savings include a significant labor reduction in the need to clean and restack displays and aisles, lower insurance, and a reduction in overhead costs associated with customer and supplier returns. Fill-product manufacturers have enjoyed similar cost savings as well as a reduction in damage pay-back to their retailers and in the need to rebag product due to damage.
Market applications that are currently evaluating and utilizing WPP bags include pet foods, animal feed, cat litter, building materials such as concrete and grout, sand, fertilizer, resins and chemicals. These items are often subject to harsh conditions throughout their lifecycle and may be handled multiple times before use. It is not uncommon for a retail item to travel in 3 to 4 separate vehicles, be restacked, slid or dropped into a vehicle and left unprotected by the end-user for days at a time. Additionally, export bags may be handled 8-10 times and travel in an open small truck or even a bicycle. Automated pallet handling may be unavailable so the bag may be moved and stacked multiple times manually.

Source of Supply


The largest issue to date facing users of WPP bags has been a lack of reliability in the source of supply. Distribution channels have been dominated by importers and resellers who have been unable to duplicate the service that has been available from domestic bag and packaging manufacturers, lead times from Asia average 10 to 12 weeks so demand needs to be forecasted with a high degree of accuracy, there is difficulty in obtaining small run orders, and quality and consistency from bag to bag and run-to-run have presented major issues. Also adding to the problems have been importers who switch suppliers without informing customers and a distribution channel that does not always stand behind or support it's products. Technical support and assumption of responsibility for problems have been in short supply. There have been several noted examples of offshore manufacturers copying confidential information and products, as well as copying incorrect information. Service has been inconsistent and often riddled with a series of hidden costs associated with importing, such as product delivered to only a single location leaving the user to perform his own quality inspection, sorting, inventorying and distribution of bags to their own packing locations.
But these issues are now being addressed as more domestic bag manufacturers such as Exopack and other high-end suppliers are now entering the market. These groups will bring the same level of service, quality and support that has characterized the multiwall bag and packaging markets for years. Several manufacturers are installing equipment for making WPP bags in the US. They are also applying their knowledge and experience to create a WPP supply-chain that will provide the same level of 2-4 week service that packaging users require. Production processes will be automated;  end-users can expect bags made to the same world class standard of quality that they have become accustomed, including manufacturing environments that meet FDA and AIB standards.
Long-term, WPP users should expect manufacturers to offer a dual sourcing strategy. Major WPP bag suppliers will be manufacturing in the US and Canada to guarantee service and availability. But these same domestic manufacturers will also invest and partner with offshore manufacturers. This will enable them to control costs, but more importantly will assure that customers get the quality and service they require.
It is important to keep in mind that WPP is still in the early stages of use in North American markets. While the product performance and appearance are good, an effective supply-chain program designed to meet the user's needs is still in development. Improvements in quality and service are still to be expected as well as new products such as heat-seal or other sealable type WPP bags are on the horizon. Today, the key to utilizing a WPP package is as much finding the right supplier as it is finding a good product. Partnering with a source that will support needs through quality and service is critical.


Related Sponsored Content

44 Best Package Designs: 2015
Sign up to receive timely updates from our editors and download this e-book of our editors’ selections for most innovative package designs of the past year.


Don't miss intelligence crucial to your job and business!
Click on any newsletter to view a sample. Enter your email address below to sign up!
Each newsletter ranges in frequency from once per month to a few times per month at most.