Adhesives and Sealants
Adhesive systems and sealants are of central importance in the development of new and innovative products for many key industries today. With an extensive range of applications, examples include UV curing systems in electronics to tapes in construction and hot melts in packaging.
Therefore, rheology is an important tool for formulating or characterizing an adhesive so that it performs in the desired manner. To ensure that adhesives and sealants perform as required during their application and end-use, the formulator must be able to control the flow and solidification properties of the product. The main challenge that the developer faces is that the adhesive or sealant may need different flow characteristics during production, application and use.
Different flow characteristics can be:
· Application, dispensing (trowel, brush, extrusion)
· Surface flow and wetting
· Penetration into surface topology, pores, and narrow joint gaps (no access penetration in substrates or bleeds)
· Diffusion over interfaces
· Solidification, curing, UV curing
· Resistance to internal and externally applied StressStress is defined as a level of force applied on a sample with a well-defined cross section. (Stress = force/area). Samples having a circular or rectangular cross section can be compressed or stretched. Elastic materials like rubber can be stretched up to 5 to 10 times their original length.stress (shear resistance, tack, peel strength)
Tack or TackinessTackiness describes the interaction between 2 layers of identical (autohesion) or different (cohesion) materials in terms of surface stickiness.tackiness in the context of material behavior is associated with stickiness and may result from adhesive forces between two materials in contact or cohesive forces in a material bridging two substrates.
For pressure sensitive adhesives including tapes and labels, tack is defined as the ability to form an adhesive bond to a substrate under slight pressure and brief contact and is an essential requirement for such products. For other materials and applications, tack may be an unwanted property, an example being bone cements, which must be tack-free, to allow the user to shape and apply the cement without adhering to gloves or application aids.
Which Rheometer suits your needs?
Rotational and Capillary Rheometers
From the entry level Kinexus Prime lab+ to the most sensitive Kinexus Prime ultra+, we have a range of rotational rheometers to meet your needs, suited to sample type and measurement requirements. Some examples of our extensive range of optional extras include the ability to perform UV curing measurements or torsional tests on solid samples.
A high-pressure capillary rheometer can replicate the higher shear rates of your processing or application conditions. The portfolio includes the bench-top Rosand RH2000 and the more powerful RH7 and RH10 models.
- Time to Spec Up? Top Five Reasons to Replace a Viscometer with a Rheometer
- Processing Non-Newtonian Products: Determining the Pressure Drop for a Power Law Fluid Along a Straight Ciruclar Pipe
- Determination of Pressure-Sensitive Tack and Adhesion Using Axial Measurements on a Rotational Rheometer – Blu-Tack
- Predicting the Compounding Performance of Pressure-Sensitive Adhesives (PSAs)
- Evaluating Product Spreading Characteristics on a Rotational Rheometer Using the Power Law Model
- Quantifying Viscosity Recovery Following Extrusion or Spraying Using Thixotropy Assessment on a Rotational Rheometer
- Monitoring Structure Rebuild (Thixotropy) Following Extrusion from a Bottle, Tube or Spray Head
- Predicting the Stability of Dispersions with a Yield Stress