What is BOPP exactly?
BOPP stands for biaxially-oriented polypropylene. It’s a variant of polypropylene (PP). Polypropylene a thermoplastic polymer, alternately known as polypropene. It’s an ideal printing surface and can be made into labels and stickers, as well as textiles and a host of different plastic parts and materials.
BOPP is essentially polypropylene that’s stretched flat. BOPP is oriented with a system that stretches it in two directions. This is where the “biaxially-oriented (BO)” part of BOPP comes from. The three most common processes for making BOPP are the tenter frame sequential process, simultaneous tenter frame orientation, and the double bubble process. This technical document from Brueckner-Maschinenbau, one of the oldest BOPP manufacturers, explains these processes in more detail.
BOPP parent material, PP, is the world’s second most produced synthetic plastic, after polyethylene (PE). It’s economical to produce while offering incredibly useful performance characteristics.
Common applications for polypropylene and BOPP include:
- Packaging labels
- Food containers
- Plastic ropes
- Medical-grade plastics
- Laboratory items
- Performance textiles
What are BOPP film’s qualities?
BOPP shares the properties of other PP plastics, including ruggedness, fatigue resistance, moisture resistance, very low toxicity, flexible finishing options, as well a controllable transparency (manufacturers can make BOPP clear, opaque, or any translucency in between). Also, while they make long-lasting labels and stickers and easily printable, most off-the-shelf adhesives have trouble attaching themselves to the material. These qualities are perfect for long-lasting, food-safe labels and other common BOPP film applications.
Why is BOPP such a great material for labels?
BOPP film can be white, metal-colored, or clear. The ability to make clear BOPP film allows the creation of transparent labels to show off the contents of clear containers. With the appropriate inks and adhesives, BOPP labels can also be waterproof. BOPP labels immersed in ice-water or subjected to high-humidity without deteriorating. Labels made from BOPP are extremely tough. The material offers exceptional resistance to fatigue compared to other common label materials and has an unusual resistance to common solvents, bases, and acids.
For food labels, BOPP film offers significant advantages. It’s non-toxic. The material’s also resistant to solvents and acids. Many food and beverage items, such as those containing tomatoes, citrus, or coffee, are quite acidic. Even when the items don’t directly touch the labels, there can be some off-gassing or limited contact during the manufacturing process that can stain or cause deterioration in other label materials. Using BOPP film for your labels can help mitigate this issue. These same properties make BOPP well-suited for bottle labels, jar labels, and canning labels.
Check out these other posts on labels:
- A Simple Guide to Making Better Stickers and Labels
- A Visual Guide for Printing Custom Labels
- 25 Caliente Hot Sauce Labels to Inspire Your Label Designs!
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Arthur Piccio is a feature writer and subject matter expert for theUPrinting Blog.