The Use of FTIR Analysis in Adhesive Manufacturing

By Craig Hirsh | February 21, 2022

FTIR stands for Fourier Transform Infrared Spectroscopy. It is a versatile technique used to identify the quality of the adhesives’ raw materials and the finished product. It helps to point out any organic, inorganic, or polymeric features which could cause inconsistencies in the final product.

We cannot underestimate the importance of adhesives in today’s world. Manufacturers commonly use adhesives in many industries thanks to their many applications, from aerospace engineering to medicine.

Adhesives come in many types, hence their varied applications. Manufacturers use resins, plasticizers, fillers, solvents, emulsifiers, thickeners, fire retardants and many more ingredients during the adhesive formulation process to ensure the final quality is excellent. With such complex mixtures, it can be hard to maintain consistency in the quality of raw products and the final product- and this is where the FTIR analysis comes in.

When using this technique, adhesive manufacturers can quickly identify any defects or changes that might affect the adhesive’s overall quality.

What Is Adhesive Coating?

Adhesive coating refers to applying an adhesive covering to a material’s surface. The covering can have functional purposes such as protection, aesthetics, or both. Also, the manufacturer can partly or wholly do the coat.

What Are The Characteristics Of Adhesives?

The ideal adhesive should have the following properties:

It should wet the substrate
It should increase the strength of the substrate after application
It should have rapid bonding, which can be accelerated by temperature increase
It should have a good environmental resistance

What Are The 7 Types Of Adhesives?

Adhesives can be classified into the following categories:

1. Pressure-Sensitive Adhesives (FSA)

Pressure-sensitive adhesives can easily stick on the surface of a material when you apply slight pressure on them. They are made of silicone, acrylics, and rubber.

When using a pressure-sensitive adhesive, you don’t need water or heat to have the adhesive stick because you can easily achieve that by applying a little force. FSAs are commonly used in floor lamination and cartons.

2. Polymer-Based Adhesives (PBAs)

PBAs are used in many forms, including resins, epoxies, urethanes, and methacrylates. These products are strong, versatile, and highly resistant to environmental conditions; hence they are the most popular. PBAs are primarily used to seal oil tanks, fuel tanks, piping, and other chemical equipment.

3. Hot Melt Adhesives

Commonly known as hot glue, hot melt adhesives are sold in cylindrical sticks and are applied using the hot glue gun. The gun comes with a heating element that melts the plastic glue and then squeezes it out of the nozzle.

Hot melt adhesives work best for woodworking projects, although you can still use them to bond cardboards, glass, fabrics, and metals.

4. Electrically Conductive Adhesives

Electrically conductive adhesives are primarily used for the assembly of electrical components. They are incredibly durable, biocompatible, and long-lasting. Electrically conductive adhesives are compatible with medical sensors; a common example is electrodes on a heart monitor.

5. Casein Adhesives

Casein is a special type of glue made from milk protein. It is one of the oldest and strongest glues used to create and bond picture frames since the renaissance period. Today, casein is used in furniture creation, bottles, musical instruments, and more.

6. Solvent-Based Adhesives (SBAs)

SBAs are produced by blending an adhesive material with a suitable solution to create an adhesive polymer solution. Solvent-based adhesives come in a solution form and are used in areas that need high resistance to temperature, water, and harsh environmental conditions.

7. Water-Based Adhesives

Water-based adhesives cure through evaporation. They have a similar texture to cement and are mostly used for decorative purposes. Nevertheless, they still work best in bottling and packaging.

FTIR Analysis: What Is It, And What Is It Used For?

fourier transform spectroscopy applications

FTIR analysis is a technique used to reveal the real identification of solids, gases, and liquids. In adhesive manufacturing, this technique helps identify any unknown materials (defects) in the incoming materials (raw materials), affecting the production process. The process also examines the final output to ensure consistency and confirm that the products meet the minimum quality requirements.

The information content for analysis is very specific, meaning that it helps manufacturers identify any defects no matter how minor they are.

The main applications of FTIR analysis:

Examination of thin coatings and films
Quality verification for both the incoming and outgoing materials
Microanalysis to identify contaminants that could be the cause of a malfunction
Failure analysis

How Do You Prepare A Sample For FTIR Analysis?

One good thing about FTIR analysis is that it does not require the hefty preparation of extra accessories. Also, a very small sample can be used for the analysis with little preparation.

The user simply places a sample of the materials to be tested directly into an infra-red beam. The sample should be strategically located at the center such that the infra-red beam passes through it well. However, analysts should prepare the sample well into a film, mull, or pellet before the process, and an expert should only do the preparation.

How Do You Analyze Data On FTIR?

FTIR measures the absorbance of infrared to a sample at different wavelengths to determine the structure and composition of the sample. The Fourier Transform spectrometer covers data from the infra-red to gain useful insights about the sample’s structure.

When the sample testing and spectrum collection processes are done, the interpretation starts immediately. The analysts start with the high-frequency area to know the active groups present. After that, the analysts study the fingerprint area to know the compound’s presence. In most cases, the data analysis and interpretation processes require a team to minimize mistakes.

Want To Know More About FTIR In Product Development?

FTIR is an incredibly useful tool to manufacturers across all industries. The technique is fast, effective, and provides excellent spectral information, making it ideal for qualitative measurements.

The Lamart Corporation team has extensive knowledge of adhesives, coating, and substrate and how to design them according to users’ specific needs. We also offer a wide range of products such as pressure-sensitive tapes.

Posted in Adhesives