Hardcoats| Enabling Plastics, Enabling Innovation

Discover how innovative hard coatings can significantly enhance the durability and functionality of plastic materials, paving the way for new applications and designs.

Types of Hard Coatings We Utilize

Uncoated foam can often be fragile for many applications. Therefore, we formulate our coating products to provide robust protection against impact and abrasion. These coatings safeguard against environmental factors like wind, rain, snow, moisture, humidity, and sunlight, which could otherwise compromise the integrity of the surface. They effectively offer a protective layer that extends the product's lifespan.

There are numerous hard coating options available today. In our practice, we utilize Epoxy, Polyurea, Rubber-Latex, and both soft and hard Polyurethane coatings.

What distinguishes each of these materials? What are their respective advantages and disadvantages? Our decision on which to employ hinges on these considerations.

Epoxy Hard Coating Over Styrofoam

We opt for Epoxy hard coating when we need a thin protective layer on foam products, particularly when they will be outdoors for limited durations (up to two months, for example) or submerged in water (like pool letters). Epoxy is widely available and provides a glossy finish, although it’s relatively thin and typically won't last indefinitely. Some applications may require sanding and patches after coating and before painting to achieve a smoother texture.

Application involves brushing or rolling the epoxy onto the foam, usually requiring 1-2 coats, and sometimes a third for enhanced protection. After allowing it to dry completely for up to 24 hours (optimal conditions are around 75°F, though it can cure in a range between 60°F-90°F), we can proceed to sand, prime, or paint using acrylics.

This system typically involves mixing resin and hardener in a precise ratio. Epoxy is widely used to protect signs, logos, letters, props, architectural facades, and precast molds. However, it can crack or break upon impact, making it a cost-effective yet somewhat delicate option.

Polyurea Coating

For projects needing a thicker and stronger layer, we turn to Polyurea, ideal for long-term outdoor use, projects subject to frequent handling, or those necessitating a long lifespan. This material can serve as an effective replacement for fiberglass coatings due to its robust and watertight properties.

Polyurea is pricier than epoxy and demands a more complex application process, usually accomplished with a plural component sprayer system. Successfully employing this method requires significant skill and training to avoid clogs in the equipment which could hinder the flow of coating material.

This material cures in seconds, achieving a hard surface while maintaining flexibility throughout its service life. Polyurea has numerous variations, from rigid and brittle to soft and rubbery, and is excellent for applying to large surfaces. We even utilize it for industrial applications, such as spraying airplane hangars and flooring. Its waterproof nature and fire retardant options enhance its versatility.

The primary drawback consists of the cost and the necessity for ongoing machine maintenance, but it can be sprayed on a variety of surfaces, including foam, plastics, cardboard, wood, cement, and metals.

Other Coating Types

Within the polyurea category, StyroSpray provides a finer application that can be sprayed, brushed, or rolled, offering a more economical yet drippy finish requiring additional sanding, particularly effective in humid conditions.

Additionally, we utilize Polyurethane much in our industrial, artistic, and hobbyist projects, providing both rigid and semi-rigid options. One notable variety is the Rubber-Latex coating.

This flexible, impact-resistant coating is applied with a brush, forming almost a bouncy texture that adheres well to various substrates, including EPS foam, fabric, metals, plastics, and wood. This coating provides UV resistance alongside surface protection and chemical durability, setting quickly and often taking up to 24 hours to fully cure, yet it cannot be sanded.

Other coating options include gel coat, fiberglass, plasters, cement, among others. The choice of hard coating depends on several factors: the material and texture, the object's geometric characteristics (like grooves and indentations that need coverage), the desired finish (smooth versus semi-smooth), and the budget and timeline set by our clients.

For additional insights, visit HumenChem.