TYPES OF FOOD-PACKAGING PLASTICS

There are two general types of food packaging plastic materials, fossil-based plastics and bio-based and biodegradable plastics. Fossil-based plastics are derived from petroleum. Bio-based and biodegradable plastics are derived from natural materials that readily break down in the environment.

Bio-based and biodegradable plastics is a phrase representing two differing attributes, but the two terms, bio-based and biodegradable, are often used in conjunction with one another. When the terms are paired as modifiers with the term plastics, the phrase bio-based and biodegradable plastics denotes
a composition deriving from mainly natural substances that break down over time, with the environment, the materials’ composition, and the time-frame all factoring in how quickly the break-down occurs.

FOSSIL-BASED PLASTICS

Fossil-based plastics have been around for many years and have provided tremendous benefits to the food packaging and food services industries in terms of food preservation and food shelf-life. But fossil based packaging plastics have negative environmental impacts and for this reason packaging industries,
including the food-packaging and the food service industries, have been working to reduce the use of fossil-based packaging materials.

Since the 1960s, packaging industries like the food-packaging and the food service industries extensively used petroleum-based synthetic polymers, commonly termed plastics—such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), poly(ethylene terephthalate) (PET),
polyurethane (PUR).

These fossil-based plastics have become the most tenacious polluters of the environment worldwide. The main environmental impacts are these: 1) they leave a high carbon footprint, thereby contributing to global warming; 2) they damage the air, becoming toxic when combusted; and 3) they have detrimental effects on wildlife, waterways, and other natural spaces. In addition, they can take decades to thousands of years to decompose.

BIO-BASED AND BIODEGRADABLE PLASTICS

Bio-based and biodegradable plastics are relatively new plastic materials used by the food packaging and the food services industries. As these newer bio-plastics degrade, they emit a very low amount of carbon, so they leave a very low carbon footprint. They are overall much more environmentally friendly
than conventional plastics. Because these materials are much less harmful to the environment than fossil-based plastics, their use has been on the rise.

Small amounts of fossil-based plastics are still used in making some bio-based and biodegradable plastics, but the amount of fossil-based plastic used in making bio-based and biodegradable plastics continues to be reduced with the invention of new material compositions (polymers). As a result, bio based
and biodegradable plastics leave significantly less plastic waste to damage the environment than do fossil-based plastics and their time to decompose is reduced to three to six months instead of decades to thousands of years. Some bio-based and biodegradable plastics are made without using any
fossil-based plastics. Their usefulness to the food packaging and the food services industries is dictated by their material composition, which consists of blended substances and are called called polymers.

Types of bio-based and biodegradable polymers are polylactic acid (PLA), biodegradable starch-based plastics, cellophane, biodegradable and bio-based polyesters, drop-in bio-based materials, polyethyline furanoate (PEF) and others. New bio-based and biodegradable polymers are under development.

Like conventional fossil-based plastics, bio-based and biodegradable plastic packaging products are made up of various physical configurations with varying properties, and, as a result, it is not always simple to compare one type’s sealing and packaging benefits with another type’s. Likewise, their
biodegradability varies depending on the ratio of their blends (polymers) of bio-based and fossil-based derivatives, the environment surrounding them, and their own condition.

Though their compositions vary, bio-based and biodegradable plastic polymers are generally made up of cellulose, starch, sugar, vegetable oils, and other materials that are mostly renewable in nature. Organisms in the environment—like bacteria, algae, and fungi—act on the bio-based plastics, degrading
or decomposing them when certain environmental conditions are met and working in conjunction with the polymers’ chemical composition and the polymers’ condition.

BIO-BASED AND BIODEGRADABLE PACKAGING APPLICATIONS

Some concerns arise in the food industry with regard to bio-based and bio-degradable packaging plastics. These concerns have to do with the bio-based plastics’ uses, packaging attributes, shelf-life, food protection and safety levels.

We offer a selection of biodegradable plastic material options for use with creating biodegradable packaging, and compostable packaging. Below is a table of the most commonly used bio-based plastics, their uses, their packaging attributes, their shelf-life, and their established safety levels.

Works Consulted
Greene, J. P. (2014). Sustainable Plastics: Environmental Assessments of Biobased, Biodegradable. John Wiley & Sons.
Moura, Isabel Gonçalves de and Arsénio Vasconcelos de Sá, Ana Sofia Lemos Machado Abreu, Ana Vera Alves
Machado (2017) Bioplastics from agro-wastes for food packaging applications. Food Packaging, Alexandru Grumezescu, Editor. Academic Press: Pages 223-263,
Oever, Marien van de, Karin Molenveld, Maarten van der Zee, and Harrietter Bos (2017). Bio-based and biodegradable plastics—Facts and figures. No. 1722. Wagneingen Food & Biobased Research.

Polylactic acid (PLA) is one of the primary alternatives to traditional oil-based plastics. Polylactic acid is highly popular as a plant-based polymer because its general performance characteristics are similar to many non-compostable polymers and can be processed in similar ways. There are some distinct performance trade-offs that must be considered when using polylactic acid as a laminate element in flexible barrier packaging, but with continued technological advancements many of these are becoming moot. Initially we will give a brief overview of both biodegrable and compostable material classes, then explore polylactic acid in more detail.

Biodegradable Materials

These are materials that can undergo biological anaerobic and aerobic degradation thereby creating water, carbon dioxide, mineral salt, biomass and methane as the product depending on the environmental factor that caused the decomposition.

Compostable Materials

These are materials that can create compost when microbial organisms act on organic waste. In order to claim that a product is fully compostable, the product must meet all the requirements of a recognized testing standard, in the US, the Standard ASTM D6400 is applied. In general, the tests are designed to review the specification requiring that biodegradable/compostable products completely decompose in a composting setting in a specific time frame, leaving no harmful residues behind.

Biodegradable and compostable barrier packaging materials are highly needed in today’s modern world to keep our foods, drugs and some other valuable substances safe, while also reducing the amount of waste that clogs our landfills and oceans.  It is very important that foods, drugs and other perishable substances should be properly packaged and kept so they can have a long shelf life.  These packaging materials offer protection to products against the influence of light, water,  air and other environmental factors that might affect it. 

However, bearing the rate at which our environments are polluted, the material that should be used to packaging goods should be biodegradable, compostable or easily be recycled. In the process of biodegradation, the packaging material turn into compost and decay after use.

Another movement in flexible barrier packaging is the advancements in active an intelligent packaging. Barrier technology continues to improve, and so-called active and intelligent packaging is becoming a reality. Active packaging is a means of maintaining the optimum desired barrier conditions to which a food is exposed, while intelligent packaging detects the status of foods e.g. quality, maturity inside the package.

Polylactic Acid Composition

PLA Poly (lactic acid) or polylactic acid is a biodegradable and bioactive thermoplastic aliphatic polyester derived from renewable resources, such as corn starch. This is unique and ground-breaking material. Polylactic acid can be made from: Sugarcane, Cassava, and corn, among other sugar rich plants. Polylactic acid can readily decomposes and biodegrades into biomass, water and co2 at ambient temperature conditions in open air landfills and requires no specialized compositing facilities. Let’s quickly brush up some of the important benefits barrier packaging material and how they’re made.

How is polylactic acid made?

Polylactic Acid is principally made through two different processes I.e condensation and polymerization. The most common polymerization technique is known as ring-opening polymerization. This is a process that utilizes metal catalysts in combination with lactide to create the larger polylactic acid molecules. The condensation process is similar with the principal difference being the temperature during the procedure and the by-products (condensates) that are released because of the reaction.

You might not know the extent of the usefulness if this material until you try. Here are some the reasons why biodegradable and compost barrier packaging made of polylactic acid is the best and some of the features.

polylactic acid as a film membrane

Polylactic acid is very clear, can be processed into either a COEX or Biaxially oriented film (BOPLA). BOPLA is the most common form of film used for flexible packaging. Polylactic acid can specifically replace PET, and biax PP film layers. When polylactic acid is laminated to a paper it can create a more durable packaging solution than when PLA is cross laminated to itself.

Liquid Storage and Moisture Vapor Challenges

Polylactic acid must be further processed or coated for use with liquids or products that require a high MVTR rating because uncoated PLA has a high water vapor permeability. The primary solution to these limitations is to coat the PLA layer with additional elements. The most common MVTR boosters are

• Aluminum Oxide
• Silicon Oxide
• PVDC

They are certified compostable by the Biodegradable Products Institute (BPI), petroleum-free and registered as USDA Bio-based Products. It is a cost-effective barrier that has been used for granola, candy, chips, cosmetics, jerky, pharmaceuticals, powders, and many other products.

Benefits

Packaging that incorporates polylactic acid into its material composition has several unique features that makes it a great choice for many food and drug manufacturing companies.

• 100% biodegradable
• Made from plant based material.
• When polylactic acid is used as an inner barrier liner it is food safe PLA and can be used with paper to create appealing easy-view window.
• Common applications of polylactic acid packaging: coffee, pasta, cookies, and more.
• Most of these products weigh less than 13 pounds.

Polylactic Acid Pros

• Heat Sealable
• anaerobic diestable
• Disallows that penetration of air
• Resistant to grease and oil
• Prolongs products lifespan

Polylactic Acid Cons

• Supply Chain issues, and availability.
• Poor MVTR performance without additional coatings.

Application of polylactic acid barrier packaging

These material that is made of PLA has so many applications and have been approved for use for food, medical, and general industrial purposes. Since the interior of packaging made with polylactic acid PLA are often coated with other materials always coated with LDPE sealant layers which enables it to be heat sealable.

Want to explore packaging your product in Compostable PLA? Contact Us to Discuss.

The measurement of laminated plastics and coex films can be a little unusual for people who have not worked with these materials before. A few notes, gauge is usually reserved for thicknesses below 1 mil. Microns measurements are usually rounded to the nearest whole integer. Mil to Micron conversion is usually the most important conversion to make when working with flexible barrier plastics. Mils being a US unit of measure and Micron (um or Micrometer) being a metric system measurement of thickness. Blow film thicknesses are controlled by the size of the “bubble” that forms when extruding the plastic. Laminated plastics usually are at a minimum 2 mil (50.8um), but can range anywhere from 2 mil to 5.5mil for most commercial applications. Some Mil-Spec materials can be as much as 10mil or 20 mil in thickness. Gauge to micron conversion is important to ensure that your film thickness is correct.

When you need flexible barrier plastics, call PouchWorth 949-336-1541

Gauge to Microns Conversion Table

Mil	Micron (um)	Millimeter (mm)	Gauge (ga)	Inch (“)
.20	5.08	.0051	20	.0002
.30	7.62	.0076	30	.0003
.40	10.16	.0102	40	.0004
.50	12.7	.0127	50	.0005
.60	15.24	.0152	60	.0006
.70	17.78	.0178	70	.0007
.80	20.32	.0203	80	.0008
.90	22.86	.0229	90	.0009
1.0	25.4	.0254	100	.0010
1.5	38.1	.0381	150	.0015
2.0	50.8	.0508	200	.0020
2.5	63.5	.0635	250	.0025
3.0	76.2	.0762	300	.0030
3.5	88.9	.0889	350	.0035
4	101.6	.1016	400	.0040
4.5	114.3	.1143	450	.0045
5	127	.127	500	.0050
5.5	140	.140	550	.0055