What is polypropylene?
Polypropylene is part of the polyolefin family. It is produced when many propylene molecules are joined together by a process called polymerisation. Propylene is usually extracted from Crude Oil.
Polypropylene can be made into a film which :-
- Gives excellent moisture resistance
- Resists attack by the majority of acids, bases, salts, oils and fats
- Cost effective
What is biaxially oriented polypropylene film?
Biaxially oriented polypropylene (BOPP) film is produced when a polypropylene film is stretched in both machine and transverse directions directly following extrusion.
What are the effects of biaxial orientation?
The stretching process has the effect of orienting the polypropylene molecules.
What is the bubble process?
The Bubble (sometimes referred to as the double bubble) process is a technique for producing BOPP, the alternative being the Stenter process. The two methods give film with subtle differences in mechanical and physical properties.
Diagram of the 'Bubble' Process
What are the differences between Bubble and Stenter film?
Bubble film imparts a simultaneous orientation of 8x MD and 8x TD compared to Stenter film which imposses 5x MD and 10x TD sequentially. This leads to several property benefits for Bubble film such as:
- Higher machine direction stiffness for improved control in R2R processes
- Balanced MD/TD properties. Improved cuttability in label production. Balanced shrink properties for shrink overwrap applications
What is the structure of BOPP?
All BOPP films from Innovia are multilayer co-extruded films. Other functionality can be introduced by the application of various coatings.
When should a coated film be used?
Coatings are usually used when an improved barrier to oxygen, moisture or aromas is required. In addition some coatings have a low seal threshold which allows faster running on packaging machines. Many coatings also give superior gloss to enhance pack aesthetics.
What type of coatings can be applied?
PVdC coatings can be applied if a high oxygen barrier is required. Acrylic coatings give aroma barrier and superior gloss as well as a reduced heat sealing threshold. FFF coatings are used for a very low heat seal threshold. Films with differential coatings can be produced.
Can BOPP film be printed?
Yes. Our BOPP films are suitable for use with standard printing techniques with a wide range of different inks. Please consult our Technical Department for more details.
Why are the barrier properties of a film important?
The film’s barrier properties are vitally important as it is necessary to match the needs of your product to the most appropriate packaging film. This will ensure your product is kept in the best possible condition when packaged. We have a range of films that provide barriers to moisture, oxygen and UV light. Please consult our Technical Department if you require more information.
Does Innovia have films that are suitable for lamination?
Yes. We have a range of BOPP films that are suitable for lamination. Please consult our Technical Department for more details.
Why is the slip of a packaging film important?
The slip properties of a packaging film (Coefficient of Friction) are important as the film needs the correct slip levels to be able to run efficiently on a packaging machine.
Are the films food contact approved?
The majority of our BOPP packaging films are food contact approved. We are able to provide a Declaration of Compliance for each film which gives details of the film’s regulatory compliance. Please consult our Technical Department if you require a copy of these documents or if you require more information on the subject.
How can I select the best product for my application?
Matching the correct packaging film to the product application is essential, both to guarantee the functionality you require and to maximise potential shelf life.
The ‘Markets we Supply’ and the ‘Product’ sections of the website are designed to help you choose the correct product for your application. However, should you require further guidance, please do not hesitate to contact the Sales and Marketing Department in order to discuss your requirements.
What thickness BOPP can Innovia provide?
Innovia Films offer a choice of standard thicknesses ranging from 15 microns through to our collection of Labels films with thicknesses of up to 92 microns.
For more information about the grades available within the packaging field please refer to the B100 ‘BOPP Films Product Range for Packaging’ summary document.
What widths can Innovia provide?
Innovia Films has the capacity to provide slit reels in a variety of sizes, from a narrow 30mm up to reels with a width of 2600mm.
Please be aware that, although we endeavour to meet customer requirements wherever possible, the need to utilise the full width of the master reel must be considered.
Please contact your sales representative to discuss whether the widths you require are available in your chosen grade.
What are your minimum order quantities?
For BOPP films, the minimum order quantity is 500kgs to the nearest full pallet.
Because the film reels are packed securely on pallets, we do insist that only full pallet packs are despatched in order to reduce the chances of damage during transit. However, if you do require a smaller amount of film for trial purposes please contact your Sales Representative to discuss.
Is it possible to receive A4 samples of your film?
We maintain a stock of BOPP film grades cut to A4 sized sheets.
Please consult the ‘BOPP Films Product Range for Packaging’ summary and contact the Sales and Marketing department if you would like to receive any A4 samples.
What are the viable recovery options for OPP?
All Innovia Films OPP films are suitable for energy recovery, via incineration. In theory, our coextruded materials are also suitable for material recycling with other PP materials and we understand that it is now possible to recycle our coated materials. The ability to recover flexible materials still remains limited at this stage as the infrastructure is still developing.
Do Innovia Films’ OPP product contain any recycled content?
With waste minimisation in mind, Innovia Films recovers its coextruded material rejects and reprocesses those as standard procedure. This insures that we make the most out of our precious resources.