Adhesive Properties 101: How to Read a Technical Data Sheet (TDS)

AJ Adhesives Blog – Adhesive Properties 101: How to Read a Technical Data Sheet (TDS)

April 22, 2026

In many packaging and manufacturing environments, adhesive selection often comes down to a technical data sheet (TDS). These documents are packed with numbers, ranges, and specifications—but for many operators and even purchasing teams, they can feel more confusing than helpful if you have never broken down adhesive properties before.

The reality is this: a TDS is not just a reference sheet. It is a performance guide. When you understand how to read it, you can better predict how an adhesive will behave on your line.

Understanding Adhesive Properties

Adhesives don’t fail randomly. When performance issues arise on the line, they are usually due to how the adhesive interacts with temperature, substrates, application methods, and environmental conditions.

A technical data sheet gives you insight into those interactions.

Instead of asking, “Will this adhesive work?” the better question becomes:

“Does this adhesive match how my line runs?”

Understanding the properties below helps answer that question with confidence.

Adhesive Type & Description

Every TDS begins with a basic classification of the adhesive. This tells you how the product is designed to perform.

Common types include:

Hot Melt Adhesives – Applied in a molten state and set by cooling. Ideal for high-speed applications where fast set and immediate handling strength are required.
Water-Based Adhesives – Form bonds through water evaporation or absorption into the substrate. Common in paper, labeling, and lamination applications where lower application temperatures are beneficial.
Metallocene Adhesives – A more advanced type of hot melt designed for improved thermal stability, cleaner running, and more consistent performance over long production runs.
Fugitive Adhesives – Designed for temporary bonds. These adhesives provide light tack and can be removed cleanly without damaging the substrate.
Epoxy Adhesives – Two-part systems that chemically react to form very strong, durable bonds. Often used in structural or high-strength applications rather than high-speed packaging.
Polyurethane (PU) Adhesives – Known for flexibility, durability, and resistance to environmental conditions. Common in assembly and specialty bonding applications.
PUR (Reactive Polyurethane) Adhesives – A moisture-curing polyurethane that starts as a hot melt and then chemically crosslinks. Provides very strong, heat- and chemical-resistant bonds after curing.
Pressure Sensitive Adhesives (PSA) – Remain tacky after application and bond with light pressure. Common in labels, tapes, and graphic applications where repositionability or instant adhesion is needed.
Cyanoacrylates – Fast-curing “instant” adhesives that bond quickly with minimal application. Typically used for small parts or precision bonding.

Each of these adhesive types is engineered for specific conditions. Understanding the category helps you quickly determine whether an adhesive is even a fit for your process before diving into detailed specifications.

Key Physical Adhesive Properties

Viscosity

Viscosity measures how thick or thin an adhesive is at a specific temperature.

Low viscosity → Flows easily, ideal for spray or fine bead applications
High viscosity → Thicker, better for controlled patterns or gap filling

On the line, viscosity affects how the adhesive pumps, applies, and cuts off. If viscosity is too low, you may see stringing or messy application. If it’s too high, you may struggle with poor flow or inconsistent coverage.

Open Time

Open time is the amount of time you have between applying the adhesive and bringing the substrates together.

Short open time → Best for fast-moving lines
Long open time → More flexibility for positioning or slower processes

If open time doesn’t match your process, problems show up quickly. Adhesive can set too fast before compression, or stay open too long and fail to bond properly.

Set Speed

Set speed refers to how quickly the adhesive develops holding strength after bonding.

Fast set → Immediate handling strength, ideal for high-speed packaging
Slow set → Allows repositioning but limits throughput

For most packaging lines, set speed directly impacts whether products hold together as they move downstream.

Application Temperature

This is the recommended temperature range for applying the adhesive.

For hot melts, this includes the tank, hoses, and application head. Running outside the recommended range can create major issues:

Too cold → Poor flow, weak bonds
Too hot → Adhesive breakdown, char, stringing, and buildup

Temperature consistency is one of the most important factors in maintaining stable adhesive performance.

Softening Point (Hot Melts)

The softening point indicates when a hot melt adhesive begins to transition from a solid to a softened state.

Higher softening point → Better heat resistance after bonding
Lower softening point → More flexibility at lower temperatures

This matters when products are exposed to heat during storage, shipping, or end use.

Solids Content (Water-Based Adhesives)

Solids content refers to how much actual adhesive material is present compared to water.

Higher solids → Faster bond formation, less drying required
Lower solids → Longer drying time and more sensitivity to the environment

Since water-based adhesives rely on evaporation or absorption, solids content plays a major role in how quickly bonds develop.

pH (Water-Based Adhesives)

pH measures how acidic or alkaline the adhesive is.

This can affect:

Stability over time
Compatibility with certain substrates
Interaction with coatings or inks

While not always a daily concern for operators, pH becomes important when evaluating long-term performance or material compatibility.

Tack & Bond Strength

Tack refers to the initial “grab” of the adhesive, while bond strength refers to the final holding power.

High tack → Immediate hold during application
High bond strength → Long-term durability

A strong adhesive needs both. High tack without strength can lead to failures later, while strong bonds with low tack can create issues during application.

Clean Machining & Film Properties

Some TDS documents refer to clean machining or film characteristics.

This describes how the adhesive behaves in equipment:

Clean cutoff vs stringing
Buildup on nozzles or components
Consistent film formation

Adhesives that run clean reduce maintenance, downtime, and operator adjustments. This often has a bigger impact on efficiency than bond strength alone.

Handling, Storage, and Shelf Life

Technical data sheets also include guidelines for proper storage and handling.

Typical recommendations include:

Store at consistent, controlled temperatures
Keep containers sealed to prevent contamination
Rotate stock (first-in, first-out)
Avoid exposing adhesive to extreme conditions

Ignoring these guidelines can lead to changes in viscosity, reduced shelf life, and inconsistent performance before the adhesive is even applied.

Safety, Cleanup, and Regulatory Information

A TDS also provides important operational details beyond performance:

Safety – Handling precautions and PPE requirements
Cleanup – How to remove adhesive from equipment or surfaces
FDA status – Compliance for food packaging applications
Toxicity considerations – Workplace and regulatory requirements

These details help ensure the adhesive fits both your process and your compliance needs.

The Most Important Takeaway About Adhesive Properties

A technical data sheet gives you the “expected behavior” of an adhesive—but it does not tell the full story.

Real performance depends on how that adhesive interacts with:

Your equipment
Your substrates
Your environment
Your line speed

Understanding the properties on a TDS allows you to make smarter decisions upfront and reduce the need for constant adjustments during production.

Final Thoughts: From Specs to Real Performance

When you know how to read adhesive properties, you stop reacting to problems and start preventing them.

Operators gain more control over application consistency.
Purchasing teams make decisions based on performance, not just cost.
Production teams see fewer disruptions and more predictable output.

At AJ Adhesives, we help teams translate technical data into real-world performance—so the adhesive you choose works the way your line needs it to.

Need more information about your adhesive properties or interested in something new? Contact your AJ Adhesives representative today!

To speak with someone immediately, call: (314) 652-4583

For more information or questions, email us at: info@ajadhesives.com

News

AJ Adhesives, Inc. – Holding North American Manufacturing Together.