Polypropylene honeycomb core exhibits a unique cell structure. The core has 3 orientations vs. the 2 orientations common with other honeycomb, making its properties more uniform. Each cell has a tubular form and is inherently stable. Features include high strength to weight ratio, corrosion, fungi, rot chemical and moisture resistant, sound and vibration dampening, energy absorbing and recyclable.
Phenolic impregnated honeycomb is coated with a heat resistant phenolic resin, creating a high strength to weight ratio that is corrosion resistant and thermally insulating. Phenolic impregnated has excellent creep and fatigue performance.
The interior cavity of the FRP door is completely filled with a corrosion-resistant material. The type of core that is used, such as Polypropylene Honeycomb, Phenolic Impregnated Honeycomb, Polyisocyanurate Foam, or Gypsum Mineral, is determined either by application or specification.
Gypsum mineral cores are available if the application requires a fire rated door. Gypsum is a sustainable product.
Polyisocyanurate foam provides the highest degree of insulation efficiency available, plus it is known for sound abatement, low permeability and helps to prevent mold and mildew growth. Polyisocyanurate is typically preferred in pharmaceutical applications.