Industrial Sealants: A Selection Guide

Selecting the Best Industrial Sealant for Your Needs

When picking a sealant, consider its end-use environment. In general, a quality industrial sealant has the following traits:

1. Excellent bond strength: A good industrial sealant should provide excellent adhesion to the materials you are using such as ceramics, glass, wood, plastics, and metals. Bond strength will vary with the chemical composition, the permeability and surface finish of the substrate, curing method, and other factors. For certain hard-to-bond surfaces primers may be necessary to achieve high bond strengths.
2. Stability over a wide temperature range: High-quality sealants maintain their integrity across a wide range of temperatures once cured. Many sealants should perform at temperatures between -65 and 125°C, for higher and lower temperatures more specialized sealants may be required. It is important to understand the range of temperatures that your application may encounter to ensure satisfactory sealant performance through the final assembly's useful life.
3. Chemical and weather resistance: UV radiation, weather, and pollutants can damage sealants over time leading to cracks and brittleness. Some chemistries are more resistant to UV and other outdoor conditions and would be preferred for applications exposed to sunlight, chemicals, and weather.
4. Low flammability: Some sealants are more fireproof than others and may even be qualified to or conform to UL standards for flame retardance. For some building and consumer devices, a UL or other 3 party recognition may be desirable for the sealant.
5. Electrical properties: If the electrical properties of the sealant matter to your application, it is important to take that into consideration. Some sealants produce vapors during curing that may cause corrosion during curing or may have poor electrical insulation values, while other chemistries do not off-gas during curing and provide excellent electrical insulation values.

Types of Industrial Sealants

Sealants come in several forms, including liquids and pastes, and can be sprayed into the space between mated parts or applied to the surfaces before joining. Many industrial sealants permanently seal and adhere parts, while other industrial sealants remain flexible after application, meaning that components are not permanently locked together. In these cases, mechanical fasteners help to join the mated parts.

Today, more than 40 types of industrial sealants exist on the market. Here are five of the most common industrial sealants:

1. Phenolic industrial sealants: Phenolic sealants are typically created from phenol and formaldehyde. This sealant forms strong bonds on top of sealing joints and is known for its heat resistance. It is the only sealant available in liquid, powder, or film form. Phenolic sealants are ideal for adhering plywood, construction components, and appliances.
2. Epoxy sealants: Epoxy sealants are good when you need toughness and durability. They are usually supplied as two-component systems made of a hardener and resin. These industrial sealants can cure at ambient temperature, although sometimes extra heat may be required. Due to their strength, epoxy sealants are common across automotive, aviation, and marine industries. SP&S’s Liquidweld™ and EpoPro® product lines include several dozen epoxy sealants for a variety of applications.
3. Polymer-based sealants: Polymer-based sealants include vinyl, polyester, polysulfide, polyamide, and polyurethane sealants. They are usually cured at ambient temperature or with anaerobic and thermal curing. These sealants create permanently flexible seals, so they are best for joints that move. SP&S Ultralane® and Liquidweld™ sealants include polyurethane, polysulfide, and hybrid sealants and cover many applications.
4. Silicone-based sealants: Silicone-based sealants are extremely popular because of their adaptability, strength, and affordability. They have a long lifespan (10 to 20 years). They are available in two main types: acetoxy and neutral cure. SP&S’s Sil-Pro™ and Liquidweld™ sealants include about dozen one and two component silicone sealing and bonding materials.
5. Acrylic industrial sealants: Acrylic industrial sealants are created from a catalytic reaction involving acrylic acid. Thermal curing takes the shortest time, but other curing methods are also available. These strong industrial sealants are impermeable by foreign particulates and are paintable, flexible, and odorless. SP&S manufactures several high quality, low cost acrylic sealants under our Liquidweld™ trade name.

Our Sealant Capabilities

Industrial sealants are good for filling gaps and sealing joints to prevent foreign materials like water, dirt, and gasses from infiltrating a system. Sealants are applied to ensure that gaps between mating components are void-free.

At Specialty Polymers & Services (SP&S), our objective is to maintain or increase efficiency. We understand that industrial sealants must perform perfectly each time they are used. Our industrial sealant solutions provide reliable performance in critical applications and rapid fixture times to ensure complete customer satisfaction. We offer a variety of sealants for various applications, including:

• Car & Truck Bodies,
• Industrial sealants
• Agriculture Equipment
• Hot melt sealants
• HVAC Equipment
• Construction sealants
• Metal Sealants
• Primers
• Pumpable sealants
• Sealants for coolers, display cases, dispensers
• Refrigeration sealants
• Heat & Chemical resistant Applications.