When taking a sealed bag from the shelf in the store, the consumer may assume that freshness is assured. The cookies or fruit or candy will only be at risk of getting stale after the bag is opened.
Qualities like freshness, crispness, and taste are high-priority functions of packaging, but in reality packaging protects the contents of a bag only to an extent. And that depends upon the right packaging for a given product. No ordinarily used packaging is entirely impermeable.
A teeth-cracking hard candy or a soggy cookie can scare your customers away from your brand, no matter how great is your food packaging design. There are two major villains that cause a food product to deteriorates inside the packaging.
MVTR and OTR for best food packaging
The Moisture Vapor Transmission Rate (MVTR)—also called the Water Vapor Penetration Rate (WVPR)--is a measure of how much moisture gets into a given packaging over a certain time interval. Depending upon the product and how long it is exposed, the result can range from mushiness or hardness.
The Oxygen Transmission Rate (OTR) is a measure of the product's exposure inside the back to oxygen. Oxidation of the product in the bag is the chief contributor to what we called staleness—a diminution of the qualities of texture and taste.
If these problems are not anticipated in planning the packaging to suit the product, then unfortunately the experience of the consumer might be that the freshness of what is in the bag cannot be counted upon. The consumer may or may not check for a use-by date on the bag—and the reliability of the freshness date, of course, will depend on appropriate packaging.
At Carepac, we are constantly alert to these issues when we plan the packaging of your product and when we go on to create and test the packaging. Fortunately, there are reliable standards for measuring MVTR and OTR and, in addition, accurate instruments for making those measurements.
International standards and accurate packaging testing
Both the vapor and gas are measured using tests defined by two standards:
ASTM International, as the name implies, is an international standards organization. It works out and publishes voluntary consensus technical standards for many products and services. (Formerly it was called the American Society for Testing and Materials.)
The International Organization for Standardization performs the same functions, bringing together representatives from national standards organizations to develop and publish worldwide technical, industrial, and commercial standards.
Referring to these organizations, Carepac can monitor international standards defined for tests that measure MVTR and OTR.
One leading provider of the specialized equipment needed to perform these tests is MOCON.
Calculating packaging's barrier against penetration
One useful and reliable calculator of the barrier against moisture or oxygen provided by a given packaging is the Norner Barrier Calculator (a free version can be accessed here: https://barrier.norner.no/).
The calculator allows you to select different package geometries such as film, cup, bottle, and cuboid. This simulates your target package's design. The calculating models then put out an estimate of the water vapor or oxygen transmission rate through various plastics, including, of course, packaging material.
Barrier properties of specific types of packaging can be studied by this means and changes in layers, geometry, and in-mold label can be tested and compared. The results make the calculator a highly useful tool for designing and developing packaging with reliable performance in protecting different products in different conditions of storage and exposure.
Typically, the tests measure the number of grams that are lost or gained through a barrier over a given period, such as 24 hours. Since transmission through a package (or penetration of a package) is to be controlled, the lower the readout, the better. A number lower than 1 gram is considered a high barrier.
The challenges: finding the barrier level required by a product
It is important to put this in context. Not every packaged product needs the highest achievable barrier. For example:
- A foil barrier is "highest": .0006
- Polyethylene (PE) (for example, bread bags): 14-20
- Polyethylene terephthalate/polyethylene (PET/PE): 3
Because creating packaging with a higher barrier sometimes increases manufacturers costs, the appropriate package is the one that protects your specific product under conditions it will face for the time required. The end goal, of course, is that in every package that is purchased and opened, the consumer finds a fresh and tasty product.
Finding your bag's design
When you work with Carepac on packaging (or repackaging) your product, our design team and manufacturers are experts and begin by understanding the nature of your product, how it is prepared for packaging, how it is shipped and stored, and for what period of time it should be able to remain fresh at the point of purchase. Part of that process for consumable products is testing them inside bags of different materials and manufacturing. That should direct selection of material with the required barrier properties but not redundantly high, which increases your budget. When there is a selection of comparable quality materials and designs, then budget considerations (and possibly your manufacturing deadline) become paramount.
At the same time, the Carepac teams addresses every aspect of your packaging, such as the shape for different types of display and the crucial decision on appearance of the label. That is because the package and its label are the prime point-of-purchase marketing features to close the sale. And naturally, your product's reputation with consumers for freshness is indispensable for repeat sales and word-of-mouth advertising.
Starting your supply chain
Your first step is as easy as visiting our website for information about every phase of creating a package that protects a product, helps to sell it at the crucial point of sale, and fits your budget. Our online estimator can give you an instant price estimate for your bag as you now conceive it. The choices you will make in consultation with us are explained in the relevant sections of the site, with many examples to clarify your choice and give you a picture of what your product will look like in the store—be it brick-and-mortar or online.
When you are ready to discuss a specific order, which can begin with a planning and design session with our range of experts, just get in touch with us.And check back here to see our regular blogs on challenges, opportunities, and solutions in packaging.
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