The Magical Layers of a Stand Up Pouch--Part One

Stand up pouches are made with multiple layers of barrier film specifically designed based upon the product going into the bag.  To those of you who are saying, "Duh, I knew that already," please allow me to explain further.  So many people tend to equate a stand up bag, because it is made from flexible film just like other common types of packaging, that it is made just like a ziplock sandwich bag or even a trash bag.  Sure, people can tell that a stand up bag, also known as a stand bag or a Mylar stand bag, is thicker, but what they don't understand is they are completely different bag styles and made in different ways.

Common bags such as ziplock sandwich bags and trash bags are known as mono or single layer bags, meaning they are made from a single layer of film adjusted to different thicknesses based upon what that bag will hold...thinner if holding a sandwich and thicker if a contractor bag used at a construction site, make sense so far?  Imagine a huge piece of bubble gum that starts out as tiny little beads or pellets (see picture above) being melted and then filled with air, this is called extruding the film or film extrusion.  This is how single or mono layers of film are made.  Again, a huge big bubble is blown 2, 3 or even 4 stories high and ultimately formed into rolls of film that will be cut to particular size.  Now, just like a chef would have a recipe to create a cake, the plastic extruder also has a recipe for the type of film he or she is making at this point.  Will it be food grade, will it be industrial plastic that will be made into trash bags, how will this film be used?

The goal here is to explain the basics of creating film, the single layer film, the down an dirty stuff.  Tomorrow, I will discuss other "recipes" of film extrusion that can create stronger, more robust film structures, known as co-extrusion and then finally I'll wrap up with the 3rd installment on how all of these layers can be joined or sealed together to create incredibly strong, durable, and puncture resistant pouches that can be made and sealed in a certain way that allow them to stand erect on a store shelf, also known as a stand up pouch.

Can't wait to learn more?  See video below.  Why is this important?  An interesting article caught my eye this morning.  Overseas governments are wanting to trace and know the origin of packaging from start to finish to determine if something is compostable, recyclable, etc.  If they are doing this overseas, the US cannot be far behind.  I'm going to use this soap box for the next few days and weeks to hopefully provide some info on how stand up bags are made, starting at the very beginning.