This white paper addresses frequently asked questions from narrow web converters starting out in the pouch making market. It provides a variety of technical considerations and recommendations to clarify the pouch process, and as a result, helps assess the viability of adding pouch making to their capabilities.
Narrow web printers are well positioned to produce smaller quantities of flexible packages (pouches) at very competitive costs. This allows consumer product goods companies to cost-effectively emulate the packaging and graphics of larger competitors and make a real head-to-head challenge for shelf appeal.
The ability to run most structures on narrow web presses and cost-effectively service short-run requests with quick turnaround times enables brand owners to execute speed-to-market strategies that can effectively take advantage of consumer demand and trends. The fact that narrow web printers, with added pouch making technology with built in front back print registration allowing them the ability to run, roll/over roll allowing for full size pouches to be made from narrow webs. This includes the ability handle quick changeovers, with a lower plate-to-press and lower set-up and change over times in the pouch making operation reduces cost ratio versus wide web presses, creating a compelling value proposition.
Once a converter understands the pouch making process, it’s fairly easy to add it to the current mix of pressure sensitive tags and labels. As a guide, the following frequently asked questions will help converters better understand the technical challenges that come into play:
1. How hard is it to convert flexible packaging pouch materials?
Flexible packaging typically uses a combination of materials—paper, film and foil. Each material has production characteristics that impact the converting process. The combined properties of these materials are designed to protect the package contents—powder, liquid or solid. The majority of these structures will run on narrow web presses, so integrating the various materials into the existing production mix is easy. Pouch materials that are thicker in caliper, such as PPFP (Paper/Poly/Foil/Poly) or cosmetic webs—PET (Polyester/Poly) sealant film—have been found to run very well on standard narrow web presses.
2. General considerations for pouch making
Pouches in general are usually made from single rolls of film that are either slit in half and turned in on top of itself to make a top and bottom web, or they are made from a single web that is folded and formed, to make the pouches.
These pouch making methods require wider width equipment that has not been conducive to narrow web manufacturers.
This has limited the pouch making entry to narrow web converters by not allowing them to print and process the wider films generally needed to capture their fair share of the market.
The a added capability on a Modern manufacturing pouch machine, has opened up the pouch making capability to the narrow web markets by providing the ability to make pouches from two separate printed webs, and aligning the top and bottom printing together with a special registering system to allow efficient production for narrow web printers and label makers.
This capability to print two separate webs versus wide width quickly reduces the barrier to entry for the pouch making market allowing the capacity to make full height pouches without the need for a wide web press.
Without this capability the narrow web printer will be limited in the size pouches that can be produced, and will limit their market share.
3. Will my Press work for Pouch Material?
Pre-laminated materials designed to be surface printed and used to create side-sealed or stand-up flexible packaging pouches. Due to the thickness and material make-up of these pouch materials, standard unwind and rewind tensions used for converting pressure sensitive materials will work well.
Pre-laminated materials are designed to be surface printed. There are two categories of film-faced pouch materials. One is a very thin film that contains either a single layer of film, or two or more layers of film laminated together. The second is a multiple-film lamination that often contains a barrier layer. The multiple-layer laminations utilize similar web tensions as the paper-faced pouch materials, and are similar to pressure sensitive material tensions.
All of these film configurations can be run on a Modern dual roll pouch machine, giving you the ability to go after a large share of the pouch markets
4. What FDA requirements are involved?
All pouch materials used in food-market applications must be FDA compliant. It is in the converter’s best interest to determine FDA needs and requirements for each application. It is also recommended that narrow web converters work with their ink and varnish suppliers to meet the FDA requirements of their end-user customers. FDA-compliant varnishes are available. Another way to improve the FDA compliance of the end-user product is to over-laminate.
There are many existing film suppliers to help you gain knowledge and expertise in this expanding market.
Surface printing leaves the graphics exposed to handling and environmental degradation. As a result, some method of protection is required, such as a varnish or over-laminate, to keep the graphics intact.
• Digitally top coated products enhance toner adhesion and are available for surface printing.
• Inks are specific to film versus paper. Film inks are recommended, and are more expensive than paper inks due to the resins used.
• Post-cure happens with film printing (water-based and UV), meaning the ink will adhere better over time.
• Films demand lower heat levels, as excessive heat will cause the material to soften or stretch; in addition to higher airflow, chill rolls can be used to keep the web temperature low.
• Inks must be suitable for the flexible packaging process. During the pouching process, inks will see temperatures up to 375-400º F and, therefore, must be able to withstand that level of heat.
• Most flexible packaging inks are water-based, but UV and solvent-based inks are available.
• If using UV adhesives, proactively checking and maintaining UV lamps is recommended to ensure the material is receiving proper light exposure to promote full ink adhesion.
• Converters must specify layout and package design parameters and guidelines based on printing technique, material construction and final package form.
• It is in the converter’s best interest to determine FDA needs and requirements for each application.
Varnish considerations for surface printing
• Paper laminates are almost always varnished.
Flexible packaging typically uses a combination of materials—paper, film and foil. Each material has production characteristics that impact the converting process. The combined properties of these materials are designed to protect the package contents—powder, liquid or solid.
Varnish can be water-based or UV, and must meet the end-user needs for FDA requirements.
• Varnish must be heat resistant to 400º F when cured.
• Varnish must be crack-resistant.
• Varnish must be low-odor when cure-dried.
• Converters should contact the varnish manufacturer for brand-specific application profile specifications.
• Sub-surface printing refers to printing below the surface of a substrate. Many end users require the graphics to be “buried” or protected to avoid scratching or scuffing during shipping and handling.
• Graphics are reverse printed on the backside of the face stock, which is then laminated to the rest of the structure.
• During sub-surface printing, the inks come in direct contact with the laminating adhesive and, therefore, must be compatible with the adhesive.
• Most narrow web printers will use UV adhesives for the base stock, so the inks must be compatible.
• Inks should not contain high amounts of wax or slip additives, as these will affect the ultimate bond.
• Converters must specify package layout and design parameters and guidelines, based on printing technique, material construction and final package form.
• Converters should contact the ink manufacturer when beginning to work on a base stock project, and provide them with the specifications and requirements of the application to ensure they receive proper ink recommendations.
Adhesive considerations for laminating sub-surface printed components
• Most narrow web printers use UV adhesives because they offer a short learning curve, good initial and ultimate bonds, and good heat resistance.
• The adhesive bond should be high-strength, to withstand running through packaging machines.
• Converters should contact the adhesive manufacturer for brand-specific application profile specifications.
In conjunction with material selection, it is important to establish a good manufacturing process, one that ensures proper drying and the right combination of ink, varnish and adhesive. For example, here are three different treatments for film to consider during the manufacturing process:
• A proprietary chemical alteration of the surface by the film manufacturer, done during the filmmaking process, and unique to polyesters.
• A chemical coating applied to the surface to improve ink and toner adhesion.
• Various types of coatings are available, and are dependent on the ink system being used.
• Specific coatings may be necessary for UV flexo, UV screen, digital, offset or solvent inks.
• Altering the surface characteristics by exposing the surface to a high-voltage discharge (corona), resulting in an increase in surface energy (dyne level).
• Usually requires 38-42 dynes to print and achieve good ink adhesion.
• Corona treaters also help rid the film surface of many contaminates (oils and silicones). The ability to in-line treat is an advantage for flexible packaging materials.
7. What are some fit-for-use product recommendations?
It’s essential that converters use the appropriate flexible packaging material for the application at hand. For example, if a converter is looking to package a dry or wet food, powder ingredient, lotion, oxygen-sensitive product, etc., the
There are two categories of film-faced pouch materials. One is a very thin film that contains either a single layer of film, or two layers of film laminated together, (Laminated Films are Required for most all pouch applications) The second is a multiple-film lamination that often contains a metallic barrier layer or foil. The multiple-layer laminations utilize similar web tensions as the paper-faced pouch materials, and are similar to pressure sensitive material should be engineered to meet the needs of the specific packaging application. In addition, the flexible packaging substrate should offer excellent surface printability for flexo and digital applications.
A good place for converters to start is by contacting flexible packaging material suppliers to obtain general product and application information, which will provide a starting point for making product recommendations. The key is to test, test, and retest.
8. What are the testing requirements for pouches?
It’s strongly recommended that end users conduct testing on any flexible packaging materials to ensure the material will work in their application
Pouch making has its own general test methods, which are accepted standards, bell jar testing is acceptable form of leak checking, by sealing the pouch closed with an ample amount of air the pouch is then sealed closed and immersed in water with a vacuum being pulled inside the tank.
This will cause the pouch to inflate with a negative pressure surrounding allowing the operator to visually check for leaks.
Another method is an Instrom test that will test the seal integrity; this is usually done by a destructive testing method of cutting a strip out of the seal area and attaching them to the pull clamps on the Instrom.
The Instrom will then pull the seal apart, and the tensile strength will be then reviewed and recorded.
There are many film types and the tensile strength of the seal varies with the film, it is recommended to visually examine the seal to look for peeling or (creep) as well as fracturing along the edges.
For larger pouches drop tests are part of the testing practices, which usually are customer driven testing methods.
The drop height and frequency of drops will be generally determined by the end customer.
9. How do I find customers that need narrow web flexible packaging services?
With Pouches in North America pushing an 8 billion dollar market growing at a rate of over 7% per year, the customer base is continually growing. Converters should first mine their existing customer base. It’s likely that if a converter is already doing work for a larger customer the customer may also be using pouches or be in need of the converter’s services in the future to do affordable short-run pouching projects.
Another way for converters to find customers is to join industry associations to further expand their network within the market.
The pouch making process can be easily integrated into narrow web operations for pressure sensitive tags and labels by following the technical considerations and recommendations outlined in this white paper. Pouches not only delivers innovative package design, but it also offers the form, function and convenience demanded by today’s grab-and-go lifestyles. Its printing and performance characteristics deliver the recognition brand owners want and consumers trust. Pouches are expanding, and narrow web printers have the opportunity to expand their role and business in delivering a broader range of packaging solutions.