Industrial and OEM Solutions

Handling Properties

Handling properties refer to its pre-cured properties—i.e., what it is like before it is cured. Some of the key handling characteristics to consider when choosing an epoxy or urethane are:

Viscosity

Viscosity is the tendency of a fluid to resist flow. This characteristic affects the material’s thickness and consistency, which, in turn, influences how well it permeates a substrate. The units used for viscosity measurements are Centipoise (cps) or millipascal-second (mPa-s). 

Epoxies and Urethanes are Non-Newtonian fluids, meaning their viscosity changes depending on the shear rate. Their viscosities are normally measured using a Brookfield viscometer, which calculates viscosity by considering the relationship between shear rate, time, and temperature. Epoxies and Urethanes can be classified into three categories based on their viscosity: 

• Low-viscosity: Low-viscosity systems have viscosities less than 2,000 cps. They have the thickness and consistency of water to detergent, meaning they have excellent flow, penetration, fill, and air release properties. Typical industrial and OEM applications include coatings, ignition coils, and insulation varnish. 
• Medium-viscosity: Medium-viscosity systems have viscosities between 2,000–50,000 cps. They have the thickness and consistency of honey to ink, meaning they offer less flow and penetration and better mechanical strength and thermal conductivity than their low-viscosity counterparts. Typical industrial and OEM applications include electrical potting and encapsulation, filter end caps, switches and connectors, and transformers.
• High-viscosity: High-viscosity systems have viscosities greater than 50,000 cps. They have the thickness and consistency of ketchup to shortening, meaning they exhibit non-sagging and non-drip characteristics. Other key properties include excellent resilience, adhesion, heat and shock resistance, and thermal conductivity. Typical industrial and OEM applications include adhesives for chillers and filter end caps. 

Mix Ratio

As indicated above, these systems are a mixture of a resin and a hardener. The proportion of resin to hardener required to cure or hardened and in turn perform properly is referred to as the mix ratio. This relationship depends on the exact chemical formula of the two compounds. It can be indicated in several ways: 

• Weight ratios (e.g., 10 grams of resin and 10 grams of hardener)
• Volume ratios (e.g., 1 cup of resin and 1 cup of hardener)
• Non-fractional ratios (e.g., 2 parts resin to 1 part hardener)
• Fractional ratios (e.g., 2.3 part resin to 1 part hardener)

Color

The color of a system can be tailored to the needs of an application by adding different fillers and pigments. Unfilled resin systems have no fillers added, so they maintain the natural color of the resin. Filled resin systems have fillers added, so they take on the color(s) of the filler(s). Some systems are naturally clear. They can be used as-is or mixed with pigments to achieve a specific color. 

Cure Requirements

Curing is the chemical process by which an epoxy or urethane hardens and develops its full strength. The time it takes to cure fully—i.e., the cure time—depends on several factors, such as formulation and temperature. Some systems cure at room temperature once the resin and hardener are mixed, while others require elevated temperatures (generally between 200° to 350° F) to achieve a full cure. 

The curing process occurs in stages. The initiation stage is the period of time in which the resin and hardener are mixed, but the mixture remains flowable and workable. The mixture must be applied before this stage ends. The gel time, or initial cure stage is the first point in time at which the mixture begins to transition into a solid.  The final stage, or full cure stage is when the product has had enough time and or temperature applied for the chemical reaction to reach its full potential. 

Cured Physical Properties

Ultimately, the type of system you choose should demonstrate the physical properties required for your application. Some of the characteristics you may consider include: 

• Adhesion
• Durability
• Thermal conductivity
• Flame retardance
• Flexibility
• Mechanical strength
• Electrical conductivity

How these properties are prioritized affect which resin and hardener formulation best suits your application. A knowledgeable and experienced solutions partner can formulate a system to suit your project needs. 

Contact Copps Industries for Industrial and OEM Epoxy Solutions Today

Epoxy and Urethane systems play a critical role in countless industrial and OEM applications. If you’re looking for a reliable solutions provider, turn to the experts at Copps Industries.  For additional information about our custom epoxy and urethane solutions for industrial and OEM applications, contact us today. To discuss your application with one of our representatives or receive a tailored recommendation or custom formulated product, request a quote.