Shrink wrap has become a vital component in the packaging process - especially in the food and beverage, pharmaceutical, and personal care industries. From wrapping multi-packs of bottled drinks to securing medical supplies for hygienic transport, shrink wrap packaging is ubiquitous.
But despite its wide usage, coding on shrink wrap presents unique challenges - particularly when applying variable data such as expiry dates, batch numbers, or barcodes. So, how do you ensure clear, durable, and compliant codes on such a tricky surface?
This guide breaks down the best technology for coding on shrink wrap, outlines key considerations, and offers expert insights for factory engineers, operations managers, and packaging professionals.
What Is Shrink Wrap?
Shrink wrap, also known as shrink film, is a plastic material that shrinks tightly over a product when heat is applied. It typically comes in rolls and is used in both primary and secondary packaging.
Common Types of Shrink Wrap:
- Polyolefin (POF) – Highly durable and FDA-approved, ideal for food packaging
- Polyvinyl Chloride (PVC) – Good clarity, but less environmentally friendly
- Polyethylene (PE) – Commonly used in bundling applications, such as multipack beverages
Shrink Wrap Applications Across Industries
Food & Beverage
- Multi-pack bottles and cans
- Fresh produce trays
- Frozen foods
- Meat and dairy products
Pharmaceutical
- Medical kits
- Carton bundles for transport
- Tamper-evident packaging
Household & Personal Care
- Cosmetics and toiletries
- Cleaning products
- Promotional bundles
In each of these sectors, traceability and compliance demand accurate and legible date coding, batch coding, or product identification - and that’s where the coding on shrink wrap becomes critical.
The Challenge: Why Coding on Shrink Wrap is Tricky
Shrink wrap creates a low-adhesion, high-gloss, and often flexible surface - all of which make it more challenging for traditional coding systems. Add to that:
- Heat sensitivity (especially during application)
- Condensation and dust in food factories
- Line speed variations
- Recyclability requirements
- Regulatory compliance (like GS1 barcodes or expiry date formats)
Not all coding technologies are up to the task. But some are.
Best Technologies for Coding on Shrink Wrap
When selecting a shrink wrap coding solution, it's vital to match the machine to your operational and environmental needs. Here are the leading contenders:
Thermal Transfer Overprinting (TTO)
Best for:
- Flexible shrink wrap on flow wrap lines or vertical form fill seal machines
- TTO systems use a heated printhead to transfer ink from a ribbon onto the film
Pros:
- High-resolution codes (barcodes, QR, text)
- Clean and precise
- Ideal for intermittent motion packaging
Considerations:
- Limited by print area size
- Requires smooth, flat surface
- TTO is a strong choice for food-grade shrink film, particularly where detail and clarity are essential
Continuous Inkjet Printing (CIJ)
Best for:
- High-speed lines and non-contact coding
- CIJ remains one of the most versatile coding technologies for printing directly onto shrink wrap as it moves through the production line
Pros:
- Fast drying inks available
- Great for curved or uneven surfaces
- Continuous operation with minimal maintenance
Considerations:
- Ink adhesion must be tested on slick surfaces
- Solvent-based inks may raise environmental concerns
- CIJ printers like the Markem-Imaje 9000 series are often deployed in beverage lines for coding multipacks
Laser Coding Systems
Best for:
- Permanent marks on specially treated shrink film
- Laser coders work by ablation, removing the top layer of material to expose a contrasting layer below
Pros:
- No consumables (ink or ribbon)
- Permanent, tamper-proof marks
- Environmentally friendly
Considerations:
- Requires laser-reactive film
- High upfront investment
- Safety and ventilation considerations
- Laser systems are ideal for high-output plants aiming to reduce operating costs and consumables
Thermal Inkjet (TIJ)
Best for:
- High-resolution coding on slower or stop-start lines
- TIJ systems use cartridges similar to those in desktop printers. They provide excellent resolution, ideal for data matrix codes and GS1-compliant barcodes
Pros:
- Easy to maintain
- Crisp code quality
- Compact for small spaces
Considerations:
- More expensive inks
- Limited to slower lines
Environmental & Factory Conditions
Your coding solution should be chosen with factory conditions in mind. Here are key environmental factors:
- Temperature Fluctuations: Ink must adhere even in cold-fill or hot-fill environments
- Humidity: Can affect drying time, particularly for CIJ and TIJ
- Dust & Condensation: Common in food processing plants, affecting sensor performance and print quality
- High-speed lines: Need robust print and data throughput
A good supplier should perform material compatibility testing before full deployment.
Sustainability & Shrink Wrap Coding
With increasing pressure to reduce plastic waste, manufacturers are shifting to:
- Recyclable shrink films
- Compostable alternatives
- Mono-material packaging
Coding technologies must adapt by:
- Using eco-friendly inks
- Avoiding excessive energy usage (laser vs inkjet)
- Maintaining code integrity on new materials
If you're trialling new sustainable shrink wrap, always revalidate your coding system for adhesion and legibility.
Integration With Packaging Lines
Efficient coding relies on more than the printer - it’s about seamless integration.
Key integration factors:
- Smart sensors to detect product position
- Automated print verification (vision systems)
- Coding redundancy checks
- Modular design to suit shrink tunnels, conveyors, or flow wrappers
Partnering with an experienced industrial printer integrator - like us at Industrial Printer Services Ltd to ensure you get a bespoke solution that fits your exact packaging workflow.
Expert Tips for Coding on Shrink Wrap
- Test before you invest: Different shrink wraps react differently to ink and laser
- Choose quick-drying, solvent-based inks for CIJ applications on glossy wrap
- Implement preventative maintenance to avoid downtime in humid or dusty areas
- Work with an expert partner who can conduct onsite trials and offer ongoing support
Final Thoughts: The Best Technology for Your Shrink Wrap Needs
There’s no one-size-fits-all answer to coding on shrink wrap. The best technology depends on your:
- Substrate type (POF, PE, etc.)
- Production speed
- Factory conditions
- Environmental goals
- Regulatory requirements
But with the right guidance and a tailored solution, you can achieve high-quality, compliant, and efficient coding - even on the most challenging shrink wrap applications.
Need Help with Shrink Wrap Coding?
Industrial Printer Services Ltd are experts in designing, supplying, and maintaining coding and marking systems across the UK. Whether you need a CIJ printer for bottled drinks or a laser coder for eco-friendly shrink film, we’ve got the experience to guide you.
Contact us today to discuss your shrink wrap coding technology options.
