Polymers and plastics play big roles in modern construction. Plastics and polymers in construction are used throughout our homes and offices, from basement to roof, offering a diverse range of solutions to modern construction challenges.
Like these versatile materials, borates are also multifunctional, offering a variety of benefits that make them the flame retardant of choice for increasing fire safety in plastics and polymers—and helping manufacturers keep costs in check.
Promoting fire safety in polymers, plastics
Building codes, such as the International Building Code (IBC) and International Residential Code (IRC), regulate polymers and plastics in construction—including requirements related to fire safety. Traditionally, plastics manufacturers have used antimony oxide (or other high-cost flame retardants) as a synergist to enhance the fire retardancy of halogen-containing polymers.
However, as manufacturers look for continuous improvement in the performance of their products—and continuous reduction in the cost of producing them—they have sought cost-effective alternatives for improving smoke suppression and fire retardancy in many of the polymers, plastics, and rubbers that are found in modern homes and offices:
- Foam insulation
- Roofing membranes
- Interior finish and trim
- Caulks, sealants, and epoxy resins
- Wiring and cables
- Electrical connectors and bobbins
- Circuit breakers and housings
- Fabric and upholstery
- Carpet backing
- Wall coverings
- Light covers and wall panels
Borates, alone or in combination with other substances, provide an improved solution. One of the best substitutes for antimony oxide is zinc borate, which answers manufacturers’ needs for better performance and improved cost. In contrast to antimony oxide, zinc borate is a smoke suppressant in halogen-containing polymers.
In addition to being an economical additive, 20 Mule Team® Borax Firebrake® products
have attributes that help manufacturers manage their overall production costs. For example, they have a refractive index that is similar to most polymer systems. That means that when they are added to the polymer formulation, they help retain translucency, enabling low pigment loading while maintaining true color.
The products are also ideal in high processing temperatures required for many modern applications. Firebrake
ZB is recommended for temperatures as high as 554°F (290°C). Firebrake
500—an anhydrous form of Firebrake
ZB that is stable up to 1112°F (600°C)—is designed for applications that don’t permit water evolution.
How do borates improve fire safety? Let’s count the ways
Borates like those in Firebrake
and ammonium pentaborate
products provide increased value to manufacturers because they improve fire safety in multiple ways. They display synergistic effects with halogen or a variety of halogen-free systems, such as metal hydroxides, nitrogen and phosphorus compounds, and silicon-based flame retardants.
Borates produce three significant effects that help enhance fire safety in plastics and polymers
products and ammonium pentaborate work to protect polymers, plastics, and rubbers across a wide spectrum. The products can often be used interchangeably, but each provides specific benefits as well. For example, Firebrake
ZB combines the benefits of zinc and boron and can be used with silica, ammonium polyphosphate, or expandable graphite in halogen-free silicone elastomers and thermo-plastic urethanes.
Smoke and afterglow suppression
products suppress smoke and retard fire in a multitude of materials used throughout homes and offices, including:
- Polyetherketone: PEEK—used in electrical cable insulation
- Polysulfone: PSU—found in electronics, appliances, and plumbing as well as automobile components
- Fluoropolymer: used in a variety of fabrics and cookware
- Polyester nylon
Borates promote the formation of char, which helps to reduce the spread and duration of fire and helps to protect wiring and prevent short-circuiting and sparking.
Ammonium pentaborate promotes char formation in epoxies, urethane foam, and thermoplastic polyurethane (TPU—a common adhesive and textile coating). By inhibiting oxidation, ammonium pentaborate solutions can work alone or as part of other formulations.
Firebrake for fire retardancy across industries and applications
The multifunctional nature of fire retardant effects in Firebrake
products makes them highly useful in a variety of polymer and plastics applications.
Sealants: Flooring, trim, cables, piping
products can be used in sealants to help prevent the spread of fire by providing intumescence.
That means that when the sealant is heated in the type of temperatures produced by a fire, it expands into openings between doors, cables, and pipes.
Epoxy: Flooring, trim
helps to retard flame and suppress smoke and afterglow in epoxy adhesives—both those that contain halogen and those that do not. Both Firebrake
products can replace a portion or all of the antimony trioxide in halogen-containing formulations; Firebrake
ZB can suppress smoke formation even when antimony oxide is present. The product displays synergy when used with ammonium polyphosphate, alumina trihydrate, or silica in halogen-free epoxies.
Polyvinyls and polyesters: Wiring and cables, piping, flooring, roofing, trim
helps to protect wires, cables, flooring, roofing membrane, and foamed insulation made from polyvinyl chloride, nylon, epoxy, polyethylene, polypropylene, polyesters, thermoplastic elastomers, and rubbers.
Other plastics: Insulation, carpet, roofing
has multifunctional fire-retardant applications in plastic and rubber compounds. For maximum fire-test performance and for film forming and adhesion, the products are available in fine and extra-fine formulations as well as in standard grade. The extra-fine grade has no particles greater than 12 microns (as determined by laser diffraction) and is suitable for more critical flame-retardant applications.
Using materials that meet fire safety standards—not to mention impart benefits such as energy efficiency or resistance to fluctuations in temperature and humidity—is a smart move for builders. Effective products, proven performance, a reliable supply chain, and outstanding customer service all provide value and improve ROI.
Want to learn more? Our experts are available
to answer questions and help you find the right borate formulations.