What Does a Sealant Manufacturer Do?

A sealant manufacturer creates products to meet a specific application’s needs. They manufacture and market a range of joint sealing products, adhesives, encapsulants, and specialty polymers.

They design these products to meet the performance requirements established by industry standards and for specific and unique customer needs. However, the physical properties of these products must be understood and correctly designated for use.

Physical Properties of Sealants

The physical properties of sealants are based on the material they are formulated from, additives added to the base polymer and the various physio-chemical properties that the sealant undergoes in the forming process. The physio-chemical properties of a sealant include elasticity, hardness, flexibility and the ability to expand or contract with changes in temperature and other environmental factors.

Adhesion, which is the ability of a sealant to adhere to a substrate, is another important physical property that determines sealant performance. A sealant that does not have adequate adhesive strength will not be able to bond to the substrate and will be subject to adhesive failure when applied. The adhesive strength of a sealant can be improved by adding a primer to the formula.

Modulus, which is the degree to which a sealant can be stretched or deformed, is also an important physical property that affects sealant performance. This property is a function of the polymer used in the formulation and the thixotropic agents and other additives.

Low-unsaturated polyols such as those used to reduce the level of unsaturation in a polyurethane elastomer or sealant can significantly improve the physical properties of these products. This reduction in unsaturation can be accomplished by the use of a specialized catalyst, such as a cesium hydroxide (CsOH) or a double metal cyanide (Zn3 [Co(CN)6 ]2) catalyst.

These catalysts can produce a reduction in the degree of unsaturation that can result in a dramatic improvement in physical properties such as tensile strengths at break, modulus of elasticity and elongation. This means that the sealant can withstand greater amounts of stress at break, and can elongate to larger lengths when subjected to a higher degree of pressure.

The physical properties of sealants are a critical part of the selection and application processes for all types of sealant. It is the job of the manufacturer to provide test data that proves the sealant has the properties necessary for the specified application.

Adhesion

Adhesion, the ability of a material to bond or hold together with another, is an important property that manufacturers should consider when evaluating sealant performance. This property can determine which type of adhesive is most suitable for an application given the technical requirements and specifications.

There are several different mechanisms that contribute to adhesion between materials, each of which has its own unique characteristics and properties. These include adsorption, interdiffusion, and mechanical interlocking.

The most common mechanism of adhesion is adsorption, which involves the adsorption of adhesive molecules onto the surfaces of adherend materials. The molecules adsorb to the substrate and form a chemical reaction that forms an adhesive bond. This process is sometimes referred to as surface reaction.

It is also possible for the adhesive to flow into pores or projections on the surface of the adherend material, which leads to physical bonding. This may be accomplished in the case of some liquid adhesives or may occur through a chemical reaction.

Finally, adhesion may be caused by the development of electrostatic forces between two materials that have differing electronic band structures. In this case, the attraction forces resist separation–if only temporarily–which then enables the adhesive and substrate to bond together.

In addition to these four common adhesion mechanisms, there are many other factors that can influence the strength of adhesive bonds between two materials or objects. These factors include the surfaces’ surface energy, the interfacial tension between them, and other variables.

For example, the presence of certain types of ultraviolet radiation and oxygen gas on some polymer-on-polymer surfaces can lead to hysteresis–a reorganization of the interface that makes it more difficult for the materials to bond. Over time, hysteresis can weaken the glue bond between the two surfaces.

These processes may also be affected by environmental factors such as moisture, heat, and abrasion. sealant Manufacturer The most effective way to determine how these factors will affect the adhesion of a sealant is to review its manufacturer’s data sheet.

In most cases, adhesive manufacturers will provide information on the appropriate values for adhesion force in terms of modulus (i.e., a stiffer sealant needs a higher adhesion value than a softer one). However, this value is not a fixed value. The proper values are dependent on the specific modulus of the sealant and will vary depending on the application.

Durability

Sealants are designed to make a tight, watertight bond between different materials. They work best when they are able to adhere to various substrates, which may include wood, metal, glass, and fiberglass, as well as other non-porous material.

Durability is a property of a sealant that indicates its ability to perform under expected conditions such as temperature, moisture, light, and movement over the product’s design life. This property can be influenced by many factors including UV radiation, movement, moisture and the chemical composition of the sealant.

A manufacturer’s data sheet and other documentation should indicate a sealant’s durability properties and the ability of the sealant to perform under these conditions. The information should be based on input from the user or specifier as to what the specific applications and environments are that they expect the sealant to operate in.

There are several test procedures that can be used to determine a sealant’s tolerance for environmental strains such as moisture, heat, light and movement. These tests are usually referred to as weatherproofing or durability testing, and they involve the application of fresh sealant on an exposed joint in a controlled environment. The sealant is tested under specified conditions for the duration of the test (for example, 28 days post cure) and the results are analyzed to determine the extent of any changes in the joint due to movement or exposure.

The most important short term test for sealants is ASTM C719 Durability of Adhesion and Cohesion of Elastomeric Joint Sealants Under Cyclic Movement, which consists of exposing the joint to movement over a period of time. If the sealant passes the test, but it cannot survive cyclic movement in use in a field application, it is likely that the sealant will not be able to sustain joint movements over the design life of the product.

This is why it is so critical to know whether a sealant can handle cyclic movement in an application and what the degree of cyclic movement will be over the design life of the product. This is especially true when looking for a sealant that will be used in a building that experiences frequent movement.

Compatibility

Compatibility is the ability of a sealant to work with other construction materials without compromising its performance. This could be in terms of adhesion, cure profile or both.

The best way to evaluate this is to consult the manufacturer’s data sheet for the sealant you are considering using on a job. They may be able to provide information that will save you time and money in the long run.

One of the more popular compatibility tests is ASTM C794 which measures adhesive strength in peel. A number is generated and this is usually compared to the manufacturers minimum acceptable value.

This test is used on most of the sealant industry’s liquid-applied products to demonstrate the strength of a given sealant. It is also a good indicator of the quality of the product when it comes to performance and longevity.

A compatible sealant is one that is able to withstand the demands of a busy job sealant Manufacturer site. For example, it has to perform in a wide range of temperatures.

In addition, it must withstand the rigors of movement. For this reason it is often applied to exterior joint assemblies that experience the most heat and movement.

For this reason it is important to choose a sealant that can stand up to the jobsite challenges, whether they be thermal stress, UV exposure, or water intrusion.

Choosing the right sealant is not easy. It is important to consider the needs of the project and the goals of the contractor and architect before making a purchase decision.

If you are looking for the best sealant to suit your project’s needs, you should make sure it carries the best possible reputation and is backed by the industry’s leading manufacturer. You should also make sure it has the ability to withstand the weather and humidity conditions in your area. This will save you from costly repairs down the road.