Adhesion is the force that resists the separation of two bodies in contact. An adhesion test measures the force needed to separate a product from a test surface. Adhesiveness or stickiness is commonly measured with a cylinder probe, which is pressed onto the surface of the sample after which the force to pull the probe off it is measured. The higher the force to separate these surfaces, the more adhesive is the product. The distance the probe needs to be pulled away from the product indicates its viscoelastic behaviour and, depending on the product, its ‘tailing’ or ‘stringiness’ as well.
Measurement success depends on the ability to hold the sample in order to pull away from it and measure the withdrawal. Texture Technologies has many solutions for this. The operator can control the data acquisition rate, probe separation rate, probe material and a controlled force to apply to the sample.
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Related Attributes
Perform an adhesion test to measure...(what should these link to?)
Adhesive properties can be the most desirable characteristic of a product (e.g. adhesive pastes, tapes, confectionery products) and thereby their salient feature. Adhesion can be a major issue for a product (i.e. dough) and can cause production stoppages and product failures. The ability to measure this property will allow manufacturers to control the quality of a product or assess stages in production so as to avoid downtime.
In our software there is a special ‘Adhesive Test’ that measures this property. It allows the probe to approach the sample at a chosen speed, then apply a chosen force for a chosen period of time to allow a good controlled bond between the two surfaces. The probe then withdraws to a chosen distance at a chosen speed, thereby measuring the force to separate the two surfaces and quantifying stickness/adhesiveness.
Example graphs resulting from an adhesion test.
The maximum force is usually taken as the measurement of stickiness. Area under the positive region of the curve is termed 'Work of Adhesion' and the distance travelled away from the sample before separation is often used as a measure of 'cohesiveness'. In the case of mozzarella cheese or caramels, for example, this distance has been termed 'stringiness' or ‘tailing’. For adhesives and paints it is called 'peaking' or 'legging'.
Adhesion Accessories
P/1S
Spherical Probe
Analyze the entire stress-strain behavior of a probe test.
P/1S
Spherical Probe
Analyze the entire stress-strain behavior of a probe test.
P/1S
Spherical Probe
Analyze the entire stress-strain behavior of a probe test.
The Future of Adhesives
The value of the world market for adhesives and sealants is set to expand at an annual pace of around 4.5% over the next few years, reaching $40 billion and $9.5 billion, respectively, by 2023.
Opportunities abound across an array of industries, from packaging, construction to medical development and electronics manufacturing.
Global automobile production is likely to cross 100 million units by 2018. Increasing plastic and polymer use in vehicles to reduce weight and enhance efficiency will most likely drive adhesives and sealants market size.
Pressure sensitive applications dominate the glue demand with valuation over USD 6.2 billion in 2015. These are most commonly used with no water or heat treatment in applications such as pressure sensitive tapes, labels, note pads and automobile trim.
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There is a strong R&D focus to develop and commercialise the bioadhesive market using novel feedstock such as soybean polyols, vegetable oil polyamides, polyisoprenes and epoxies. This could result in a paradigm shift and change the product matrix significantly.
Proven high performance, consistent manufacture quality and the development of new adhesives will allow adhesive manufacturers to compete successfully.
However, as pressure on quality control and R&D labs increases, it is essential to accurately assess adhesive properties and strength to determine its ideal components and optimise its performance. Quality is the key factor for success—there is little room for guesswork.
The fact that there are so many industry-approved test methods for adhesives and adhesive tapes indicates the increasing emphasis on product standardisation, quality and performance. This is particularly important because of the diversity of applications with strict requirements in the adhesive industry: UV resistance, waterproof, fireproof, and human body safe, to name a few.
