In Mould Labelling (IML) is a groundbreaking technology that redefines packaging by fusing labels directly into product containers during the moulding process.
Unlike traditional labelling methods, which often compromise durability or recyclability, IML ensures labels become an integral part of the product container, so it can provide better resistance to scratches, peeling, moisture, and chemical.
Its compatibility with mono-materials like polypropylene (PP) and polyethylene (PE) simplifies recycling process, which is addressing one of the pressing issues of environmental pollution.
As seen in industries like dairy and personal care, companies are taking huge benefits by using IML technology, from lower logistics costs to stronger customer loyalty.
Beyond durability and aesthetic look, IML aligns with the goal of sustainability, as labels and containers are made from the same materials (e.g., polypropylene), which makes recycling process much easy and simple.
In this blog post, we will explore in-mould labelling technology in simple and engaging language by discussing its history, components, processes, benefits, challenges, applications, and future trends.
By the end of this post, you will have a comprehensive understanding of IML and its significance in modern packaging.
Introduction
Packaging serves as the first point of contact between a product and its consumer. It not only protects the product but also plays a crucial role in marketing and branding.
Traditionally, labels were applied to containers after the manufacturing process, requires additional labor, time, and cost.
In-Mould Labelling (IML) technology has changed this approach by integrating the labelling process directly into the molding process, making it faster, more efficient, and highly customizable.
History of In Mould Labelling (IML)
In-Mould Labelling technology was first introduced in the 1970s in Japan.
The concept pops up from the need for more efficient and durable labels for plastic containers, especially in industries like food, beverages, and consumer goods.
The early forms of IML involved applying labels to containers during the injection molding process.
The technology became widely used in the packaging industry in the 1980s. This was because of improvements in molding equipment and a growing need for stronger and more attractive packaging.
By the 1990s, IML began to see significant growth globally, particularly in Europe and North America.
The technology offered several advantages over traditional labeling techniques, including better durability, higher-quality graphics, and environmental benefits.
As a result, a few machine manufacturers are developing high-tech machines to support the growing adoption of IML for its cost-effectiveness and sustainability.
What is In Mould Labelling (IML)?
In Mould Labelling (IML) is a cutting-edge packaging process that involves inserting a pre-printed label into the mold cavity before the plastic is injected. The label becomes a permanent part of the product once the molding process is completed. Essentially, the label is fused with the container, providing a high-quality, durable, and aesthetic look.
The IML process is typically used for plastic containers, such as bottles, tubs, cups, and lids.
The label itself can be made from a variety of materials, including polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET), which ensures that it remains intact throughout the product’s lifecycle.
Key Components of In Mould Labelling (IML)
1. Labels: The label used in IML is pre-printed with graphics, decoration, branding, and other relevant information. It is made from a variety of materials, such as PP, PET, and PE. The label must be durable enough to withstand the molding process and remain attached to the final product.
2. Moulds: The mold is the core component where the label and plastic material come together. The mold is typically made from steel or aluminum and is designed to create the desired shape of the final product.
3. Plastics Substrate: PP and PE are the most widely used materials due to their compatibility with label materials, and recyclability. PET is also used for some specific applications.
4. The Injection Molding Machine: The injection molding machine is responsible for injecting the molten plastic into the mold. This machine is precisely controlled to ensure that the label is correctly positioned and fused with the product during the molding process.
5. The Robotic Arm or Automation System: A robotic arm or automated system is used to place the label inside the mold before the injection of plastic. This automation ensures high precision and reduces human error.
In Mould Labelling Process
The IML process involves several steps and each one is critical to achieve a high-quality, durable label that becomes part of the molded product. Below is a simplified step-by-step breakdown of the IML process:
1. Label Feeding
Pre-printed labels are automatically fed into the mould using robotic arms or pick-and-place systems. These labels are precisely held by using vacuum suction to get defect-free final products.
2. Mould Closure
The mould closes by securing the label in its place. Advanced systems are used (sensors or vision cameras) to verify proper label position. It helps to reduce production wastage.
3. Plastic Injection/Blowing Process
Injection Moulding: Molten plastic is injected into the mould under high pressure. The heat and pressure soften the label and allow it to bond chemically with the plastic material.
Blow Moulding: Compressed air inflates a plastic parison (hollow tube) against the mould walls and presses the label into the plastic surface.
The Science Behind the Bond
During moulding, heat (180–220 °C for PP/PE) softens both the label and plastic. Pressure forces the molten plastic into the label’s porous surface, creating a mechanical and chemical bond.
4. Cooling
After the plastic is injected, the mold is cooled to solidify the plastic and bond the label permanently. The cooling time depends on the material being used and the size of the product. Cooling channels within the mould ensure uniform temperature distribution.
5. Ejection
The finished product is ejected, revealing a seamless, durable label that resists peeling, moisture, and scratches.
6. Quality Check
The final product undergoes a quality check to ensure that the label is properly bonded, free from defects, and visually appealing.
Types of Moulding Techniques Used in In-Mould Labeling (IML)
Injection Moulding
In injection moulding, molten plastic is injected into a closed mould to form the desired shape.
Labels are placed inside the mould before injection, bonding the label securely to the product.
This technique is ideal for rigid containers such as caps, lids, and small components, offering fast production cycles (10-30 seconds) and high precision.
It’s commonly used for products like automotive parts, cosmetic jars, and food containers.
Blow Moulding
Blow moulding is used to create hollow plastic products by inflating a plastic parison inside a mould.
Labels are placed inside the mould and wrap around curved or complex shapes.
This method is perfect for lightweight items like bottles and jerrycans, providing 360° branding.
Blow moulding has slower cycle times (30-60 seconds) and is commonly used for products like shampoo bottles, detergent containers, and beverage bottles.
Thermoforming
Thermoforming involves heating a plastic sheet and forming it into a shape using a mould.
The label is applied to the mould before shaping. This technique is used for rigid containers with flat or slightly curved surfaces, such as ice cream tubs and yogurt cups.
Thermoforming has fast cycle times (10-30 seconds) and is ideal for products requiring high-volume production with smooth, durable labeling.
How to Choose the Right Printing Method for IML Labels?
The best printing method for IML labels depends on several factors such as design complexity, production volume, material type, and budget. Here’s a breakdown to help determine which method is best based on specific needs:
1. Flexographic Printing
Best for: High-volume production with vibrant colors and medium to complex designs.
Pros: Cost-effective for large runs, fast printing speeds, versatile with various materials.
When to choose: Ideal for large-scale production with consistent, high-quality graphics, especially when printing on non-porous surfaces like plastic films.
2. Offset Printing
Best for: Detailed and high-resolution designs requiring fine text and graphics.
Pros: High-resolution output, excellent color reproduction, and sharp images.
When to choose: Best for premium products where visual quality and intricate designs are important, such as cosmetic packaging or premium food containers.
3. Gravure Printing
Best for: Large runs requiring consistent high-quality prints and intricate designs.
Pros: Consistent quality, capable of fine detail, and ideal for long production runs.
When to choose: Best for industries like food and beverage where high-quality, long-lasting prints are essential. It’s ideal for large volume and intricate graphic work.
4. Screen Printing
Best for: Simple designs, logos, or large solid color areas.
Pros: Durable, long-lasting prints, excellent for solid colors and large areas, resistant to scratching or fading.
When to choose: Best for simple, durable prints, like logos and barcodes, especially when resistance to wear is important.
Ultimately, the “best” method depends on the specific requirements of the packaging project. For a balance of quality, speed, and cost, flexographic printing is often the most popular choice.
Materials and Design Considerations in IML
The success of IML is highly dependent on chemical bonding between the label and the plastic substrate.
Proper adhesion of the label to the plastic substrate is very important. Factors like label material, surface treatment, and mould temperature play a significant role.
PP Labels + PP Plastics or PE Labels + PE Plastics: Identical polymer structures and similar melting points allow molecular-level fusion during heating, which provides seamless adhesion without delamination.
Why Same Material and Compatibility Matter
Adhesion: Mismatched materials, like PP label on PET plastic substrate can cause poor bonding and delamination.
Recyclability: Mono-material packaging (e.g., PP label + PP container) is far better than multi-material packaging (e.g., PP label + PET container) in terms of sustainability.
1. Label Materials
The choice of label material is critical in IML, impacting durability, aesthetics, and recyclability. Key options include:
Polypropylene (PP)
– Properties: Lightweight, flexible, and chemically resistant.
– Advantages: Bonds seamlessly with PP containers, enabling mono-material recycling.
– Applications: Dairy tubs, microwave-safe food packaging.
Polyethylene (PE)
– Properties: Excellent moisture resistance and toughness.
– Advantages: Ideal for blow-moulded bottles (e.g., shampoo containers).
2. Plastic Substrate
The plastic substrate must be aligned with the label material for optimal bonding and recyclability:
PP (Polypropylene)
– Properties: Heat-resistant (up to 120°C), rigid, and lightweight.
– Use Cases: Food containers, automotive parts.
PE (Polyethylene)
– LDPE: Flexible (e.g., squeeze bottles).
– HDPE: Rigid (e.g., detergent bottles).
PET (Polyethylene Terephthalate)
– Properties: High clarity, strong barrier against gases.
– Challenges: It is Rarely used with IML due to incompatibility with PP/PE labels. Requires special labels or adhesives.
3. Mould Design
The mould must be designed to accommodate the label and ensure proper placement. This includes considerations for vacuum channels, cooling systems, and ejection mechanisms.
A well-designed mould provides precision and efficiency:
– Vacuum Systems: Tiny channels create suction to hold labels in place, which is critical for complex shapes (e.g., curved shampoo bottles).
– Cooling Channels: Strategically, channels are placed to ensure uniform cooling, which helps to prevent warping or label distortion.
– Texture Integration: Moulds can imprint textures (e.g., matte finishes for grip, embossed logos) directly on the product container during forming.
Example: Ice cream tub moulds often include cooling channels to handle rapid production cycles while maintaining label clarity.
4. Adhesion Science
– Label Adhesion: Proper adhesion of the label to the plastic substrate is very important. Factors like label material, surface treatment, and mould temperature play a significant role.
– Temperature Control: Too low → weak bond; too high → label degradation.
– Surface Treatment: Corona or flame treatment enhances label receptivity.
– Mismatched Materials: PET labels on PP containers cause delamination and recycling issues.
Benefits of In Mould Labelling (IML)
IML offers numerous advantages over traditional labeling methods, making it highly valuable. Some of the key benefits include:
1. Durability
Since the label is fused with the product during the molding process, it becomes highly durable and resistant to wear and tear. The label will not peel or fade, even with exposure to moisture, sunlight, or chemicals, for a longer time.
– Water Resistance: Ideal for freezer-to-microwave packaging, where condensation would cause glued labels to peel off.
– Chemical Resistance: It is good for storing harsh cleaning agents, typically used for household products (e.g., bleach bottles).
– Scratch Resistance: No fading or scratching during transportation or use, critical for automotive parts or tool packaging.
Real-World Example: Häagen-Dazs uses IML for its ice cream containers, ensuring labels stay intact even after months in freezing conditions.
2. Aesthetic Superiority
IML allows for high-quality, full-color graphics and intricate designs that make the product stand out on store shelves. The label is an integral part of the product, giving it a premium look and feel.
– High-Resolution Graphics: Digital and offset printing produce photorealistic images, gradients, and metallic finishes.
– 3D Effects: Embossed textures or raised logos (e.g., luxury cosmetic jars) add tactile appeal.
– Seamless Finishes: No edges or bubbles, which gives products a premium look.
Case Study: L’Oréal uses IML for its Lancôme skincare line, leveraging holographic finishes to enhance shelf presence.
3. Sustainability
IML technology can use recyclable materials, making it an eco-friendly choice.
Additionally, because the label is integrated into the mold, it reduces the need for separate label disposal, contributing to a reduction in waste.
This also helps to reduce waste from the release liners, which are made of paper and resin.
– Easy Recycling: PP labels and PP containers (or PE and PE) make sorting easier and comply with the EU’s Circular Economy standards. In contrast, traditional multi-material labeling systems are harder to recycle due to the use of adhesives.
– Reduced Waste: Eliminates adhesives and liner waste, PVC shrink sleeves, and secondary packaging.
Stat Alert: Mono-material IML packaging can boost recycling rates by up to 40% compared to multi-material alternatives.
4. Cost Efficiency
IML eliminates the need for additional labeling steps, such as applying stickers or heat-shrink labels after production. This reduces labor costs and increases efficiency in the manufacturing process.
– Reduced Waste: Precise label placement reduces material scrap by 15–20%.
– Faster Production: Integrated process eliminates post-moulding labelling steps, which increase speed by 30%.
– Lower Labor Costs: Automation reduces reliance on manual label application.
ROI Example: A European dairy company reduced annual packaging costs by 22% after switching to IML, thanks to faster production and fewer rejected units.
5. Tamper Resistance
IML technology makes it hard to tamper with the packaging because the label is fused with the product during molding, enhancing security and safety for consumers.
It also protects your products from counterfeiters, as IML requires significant investment and skilled labor to produce.
Technical Challenges and Solutions of In-Mould Labelling (IML)
While In Mould Labelling (IML) offers transformative benefits, its implementation isn’t easy.
This section explores common technical challenges, their root causes, and innovative solutions driving the industry forward.
1. Common Challenges
a. Label Misalignment
Cause: Mechanical faults during label placement.
Impact: Crooked labels, branding inconsistencies, and rejected units.
Solution:
Robotic Precision: 6-axis robots with vision-guided systems achieve placement accuracy within ±0.1 mm.
Static Charge Technology: Electrostatic pins hold labels in place during mould closure.
b. Air Entrapment
Cause: Air pockets trapped between the label and molten plastic.
Impact: Bubbles, wrinkles, or delamination.
Solution:
Vacuum-Assisted Moulds: Micro-channels evacuate air during injection.
Optimized Flow Rates: Adjusting injection speed to minimize turbulence.
c. Adhesion Failures
Cause: Mismatched materials (e.g., PET label on PP container) or insufficient heat.
Impact: Labels peel off during use or recycling.
Solution:
Material Matching: Strict adherence to compatible polymers (PP + PP, PE + PE).
Surface Activation: Corona or plasma treatment enhances label receptivity.
2. Quality Control
Robust QC protocols are critical to maintain IML’s output.
Vision Systems: High-resolution cameras inspect labels for defects (misalignment, ink smudges) at speeds of 10,000+ units/hour.
Adhesion Testing
– Peel Tests: Measure bond strength using standardized force (e.g., ASTM D903).
– Cross-Cut Tests: Check for flaking after scoring the label surface.
Environmental Stress Tests
– Thermal Cycling: Expose products to -40°C to 120°C to simulate real-world conditions.
– Chemical Resistance: Soak labels in acids, alkalis, or solvents to assess durability.
Example: Siemens’ SIMATIC Vision Systems reduce defect rates by 90% in IML production lines.
3. Cost Barriers
The machinery and equipment required for IML can be expensive. Small and medium-sized manufacturers may find it difficult to invest in the necessary technology.
High upfront costs for custom moulds ($50,000–$200,000) and automation systems.
Solutions
– Modular Moulds: Adjustable designs accommodate multiple product sizes, spreading costs across all SKUs, like 100ml, 200ml, 300ml, and so.
– Phased Automation: Start with semi-automated systems, then scale as demand grows.
– ROI Focus: Highlight long-term savings—e.g., Unilever cut packaging waste by 30% post-IML adoption.
Stat: Companies recoup IML investments in 12–18 months through reduced scrap and labor costs.
4. Material Innovation
To address sustainability and performance gaps, material science is pushing boundaries:
Compostable Labels
– PLA (Polylactic Acid): Derived from corn starch, compostable in industrial facilities.
– PHA (Polyhydroxyalkanoates): Marine-degradable, ideal for single-use packaging.
Barrier Coatings
– Nanocomposite Layers: Block oxygen/moisture to extend shelf life (e.g., for snack packaging).
– Recyclable Barriers: EVOH coatings compatible with PP recycling streams.
Challenge
– Biodegradable materials often require lower processing temperatures (~160°C vs. 200°C for PP).
– Higher costs (PLA labels are 2–3x pricier than PP).
Innovation Spotlight: Mondi Group’s BarrierPack Recyclable uses IML-compatible coatings to replace aluminum layers in food packaging.
Applications of In Mould Labelling (IML)
IML is used in a wide range of industries due to its versatility and ability to provide high-quality, durable labels. Some of the most common applications include:
1. Food and Beverage
IML is commonly used for packaging products like yogurt cups, snack containers, and beverage bottles. The high-quality graphics and durability of IML labels make them ideal for these industries.
Dairy Tubs & Ice Cream Containers: Labels withstand freezer temperatures (-20°C) and condensation without peeling, as seen in brands like Häagen-Dazs.
Microwaveable Packaging: PP-based IML labels tolerate high heat, ensuring safe reheating (e.g., ready-to-eat meal trays).
Example: Danone uses IML for yogurt cups, combining leak-proof seals with vibrant, food-safe graphics.
2. Personal Care
IML is also used for packaging personal care products. The technology ensures that the packaging is both attractive and durable.
Shampoo Bottles: Labels resist water, oils, and frequent handling (e.g., Pantene’s sleek, fade-resistant designs).
Cosmetic Jars: High-gloss finishes and tactile textures (e.g., L’Oréal’s embossed luxury skincare containers).
Toothpaste Tubes: Flexible yet durable labels survive squeezing and bathroom humidity.
Innovation: Chanel uses IML for perfume caps with metallic effects, enhancing shelf appeal.
3. Household and Industrial
IML excels in demanding sectors where labels face extreme conditions:
Detergent Bottles: Resistant to corrosive chemicals (e.g., Tide’s bleach-compatible containers).
Chemical Containers: Legible warning labels endure exposure to solvents and UV light.
Automotive Parts: Engine components use IML for heat-resistant (up to 120°C) identification tags.
Case Study: Henkel employs IML for industrial adhesive packaging, ensuring labels survive rough handling and storage.
4. Emerging Niches
IML is gaining traction in sectors requiring precision and innovation:
Medical Packaging: Sterile, tamper-evident labels for IV bags and pill bottles, compliant with FDA standards.
Electronics: Durable labels on circuit boards and devices, often integrating QR codes for traceability.
Future Trend: Smart IML labels with RFID tags are being tested for medical device tracking and anti-counterfeiting in electronics.
Innovations and Future Trends in IML
The future of IML technology looks promising with ongoing advancements in materials, printing techniques, and automation.
Additionally, the integration of smart technologies into IML labels is expected to open up new possibilities for interactive packaging and enhanced consumer experiences.
1. Smart Labels
RFID Tags: Embedded during moulding, these enable real-time supply chain tracking. For instance, Pfizer uses RFID-enabled IML labels to monitor COVID-19 vaccine vials globally.
QR Codes/NFC: Scannable codes link consumers to interactive content (recipes, loyalty programs). Luxury brand Johnnie Walker integrates NFC in whiskey bottles for authenticity verification.
Impact
– Anti-Counterfeiting: 30% reduction in counterfeit goods for pharmaceuticals.
– Consumer Engagement: 60% of millennials prefer brands with interactive packaging.
– Challenges: Higher costs (20–30% premium) and infrastructure requirements.
2. 3D and Tactile Effects
Embossed Textures: Moulds with laser-etched designs create grippy surfaces (e.g., Nivea’s anti-slip shower gel bottles).
Holographic Finishes: Light-reflective films for luxury appeal, as seen in Dior’s limited-edition perfume packaging.
Tech Behind It
– 3D Printing for Moulds: Enables rapid prototyping of intricate textures.
– Hybrid Films: Multilayer labels combine metallic sheens with tactile elements.
– Future Trend: “Scented” labels with micro-encapsulated fragrances activated by touch.
3. Sustainability Push
Biodegradable Labels: BASF’s ecovio® (compostable film) pairs with PLA plastics for soil-degradable packaging.
Closed-Loop Systems: Loop Industries partners with Coca-Cola to recycle IML containers into new food-grade packaging.
Circular Economy Wins
– Mono-material Magic: PP/PE-only IML packaging achieves 95% recyclability rates.
– PCR Chemical Recycling: Breaks down labels and containers into raw materials for reuse.
Challenge: Biodegradables require lower moulding temps (~160°C vs. 200°C), slowing production.
4. Digital Transformation
Defect Detection: Google’s Vision AI spots label misalignments with 99.8% accuracy, cutting waste by 25%.
Predictive Maintenance: IoT sensors on moulding machines forecast failures, reducing downtime by 40%.
Industry 4.0 Impact
– Digital Twins: Virtual replicas of moulds optimize designs before physical production.
– Data-Driven Production: Real-time analytics adjust parameters (temp, pressure) for peak efficiency.
Case Study: Procter & Gamble uses AI-powered IML lines to produce 1 million Tide bottles/day with near-zero defects.
Conclusion
In Mould Labelling (IML) technology represents a significant advancement in the packaging industry, offering numerous benefits in terms of durability, aesthetics, and efficiency. From basic applications to advanced innovations, IML continues to evolve, driven by the need for sustainable and smart packaging solutions. As technology progresses, we can expect even more sophisticated and versatile applications of IML in various industries.
Implementing IML isn’t just about upgrading equipment—it’s about transforming your packaging strategy to meet consumer, regulatory, and environmental demands.
Are you ready to shape the future of packaging?
Get a free consultation by leaving a comment or contacting us today. Position your brand at the forefront of durability, sustainability, and smart design. The next era of packaging starts now.
FAQs
Yes, IML is recyclable. The label and container are made of the same material, which simplifies recycling.
IML costs vary based on product type and design, but it can be cost-effective long-term due to durability and reduced waste. Contact us for a customized estimate.