Step by step: How Anduro manufactures BOPP Bags

Finished BOPP bags are palletized and ready for shipment by container from Honduras to Gulfport, Mississippi.

Every year, bag-makers like Anduro produce millions of woven polypropylene bags for pet food, animal feed, charcoal, seeds, and other heavy, bulky material.

You see the polypropylene bags throughout your daily travels, but did you ever think about what it takes to get that dog food bag on the shelf at the local pet store?

Here’s how it happens.

Is it a new or returning customer who needs the bag?

If it’s a new customer or a returning customer with a new or resized bag, the process will begin with some research and exploration. For example, these questions will be needed to be answered:

  • What size will the bag need to be? We’ll make test bags at the requested size to be sure that they can hold the volume of contents that’s expected
  • What type of closure is needed for the bag and what type of equipment will it be filled on?
  • What are the contents of the bag – are there specific ingredients (i.e., Poultry Fat) that will need to be considered when defining the specification of the finished bag?
  • What is the cubic density of the product being put into the bags – can we save the client money by reducing the amount of material used to make the bag?
  • Does the customer need samples of an identical finished bag for fill testing and for palletizing testing at their facility?
  • Is there specific artwork for the bags and can we obtain a high-quality original version of the files?
  • If not, should we expect to work with the customer to create art for their bags?
  • Have there been any issues with bags they have used previously that we should be aware of?
  • What are the logistical requirements in terms of shipping and storing finished bags?

If it’s an existing customer with a reprint of a previous job, the path is simpler at the beginning. We will have a conversation with that customer to confirm that the specs for the bags remain the same or, if not, work with them to reconfigure their bag design.

Next step: Price-quote the job

Once the specifications of the bag are set, then we have just a few more questions to help us price out the project.

  • How many bags need to be delivered?
  • What is the final Total Weight of the bag materials (i.e., GSM of the Fabric)?
  • Where will we be delivering the bag? Typically, we ship by container to our warehouse in Gulfport, Mississippi but we can make adjustments to suit the customer’s needs.
  • Will we need to store finished bags for the client and provide a Just in Time fulfillment process?
  • What are the payment terms going to be?
  • There may be incentives to the client for larger order quantities or rapid payment terms.
  • Are there any special requirements that need to be considered?
  • Has the customer approved the die-line and the associated artwork, which is a schematic showing the actual dimensions of the finished bag before final assembly?

It’s production time for our woven polypropylene bags

Before beginning actual production of the bags, we will work with the customer to get final approval of the art files. It’s important to make sure everything is exactly as expected here, as any changes beyond this point will incur unnecessary additional expenses and time because active production would need to stop in order to make those changes.

The customer delivers a purchase order outlining the quantity ordered, noting that all proofs and die-lines are approved and that payment is expected according to the terms agreed to.

At this point, we are ready to go with the printing of the woven PP bags.

Going on-press with the BOPP bags

The actual flexographic printing of the bags’ outer layer is what happens first. At Anduro, we can accommodate up to 10 colors on press. For most of our customers, this includes a four-color CMYK process build, along with additional Pantone “Spot” colors as needed.

We can also print extended gamut depending on customer needs.

We prepare the printing plates, start up the printer, and watch the magic happen.  The print quality of our bags is produced much in the same way that the photographs in a National Geographic magazine are done…. So you could say that we take great pride in the quality of our print for our clients.

Next step: lamination

The printed layer of the bags next needs to be laminated to the woven polypropylene fabric layer. This is what makes our bags good-looking on the retail shelf and super-durable on the journey there.

We always keep common woven PP sizes on hand and can manufacture more custom sizes right here in our Honduras manufacturing plant.

Forming the bags and preparing for shipping to the customer

Once the materials are laminated together into strong and attractive sheets, it’s time to cut and assemble them into the bags that get sent to the customer.

The bag-forming step (The conversion process) is the final step in manufacturing our BOPP bags. Customers can choose pinch-bottom bags or sewn closures. Each has its own specific process of bag-forming. Soon the finished bags are rolling off the lines at a rapid pace.

During bag-forming, we also sample-test the final product every few minutes to ensure the highest quality standards are consistently being met and that all customer specifications are intact on each and every bag.  Among the tests we run during bag-forming are:

  • Drop testing with full contents
  • Lamination bond strength testing
  • Peel force testing
  • Shear force testing
  • Size Verification
  • Print Color Validation with Photo Spectrometers
  • Uniform palletization and packaging of the finished bags

We have more than 250 people working on your bag project as it passes through our plant.

The final, and very critical, stage inside our walls is palletizing and preparing the bags for shipment.  We adhere to stringent procedures when it comes to packing the bags to ensure the client always gets a bag that is neatly packed, wrinkle free, and that will separate and run well in their filling machines. 

From Puerto Cortés to Gulfport: Your bags are on their way.

Many BOPP bags are manufactured in Asia and can take four weeks or more on the water, most often to a west coast USA port.

Our bags spend only three days on the water during the much shorter transit from Honduras to Mississippi. Our customers, especially in 2021 where our on-time delivery actually improved to a near-perfect 100% during a global shipping meltdown, tell us they love how quickly their bags get to the United States.

There are other timing elements that need to be calculated, of course, including time in customs. From the time the bags leave Honduras to the time they are ready to be delivered to their final destination in the U.S. is typically less than 7 days total!  Our team will work with you from the very first day to assure that you are fully informed of the expected timeline and of any unlikely deviations from that timeline during the entire process.

To be sure there are no surprises, we hold weekly Zoom or phone calls with you and your team. Additionally, we make online management tools, which are updated daily, available to any customer who wants them, so you can track the progress of your order in near-real time along with any inventory we may be managing for you.

Any issues or changes are addressed with urgency and professionalism. Our goal is to get your bags to you where you expect them, when you expect them and looking exactly as you expect them.