The main component of sandwich board is commonly known as sandwich core, which is the common name of sandwich composite. The sandwich core is divided into metal sheet, styrofoam or corrugated paper, which is the fixed form. All kinds of honeycomb core have the structural characteristics of transverse expansion, which can reduce the volume and facilitate storage and transportation. There are many forms of sandwich core, from the early development of corrugated paper to honeycomb or various geometric core. The main materials are metal materials and non-metal materials. The metal materials include stainless steel plate or light aluminum plate, and the non-metal materials include styrofoam, paperboard, asbestos or glass fiber.
Sandwich board features
In addition to the high stiffness weight ratio, sandwich composites can also achieve different functions by choosing different core materials and panels.
Flame retardant, low smoke, non-toxic (FST)
In places where buses, train and aircraft are highly concentrated, the special functions of sandwich sandwich composites can be achieved by selecting suitable core materials, such as AIREX PET foam, etc. - flame retardant, low smoke and non-toxic. Some structural core materials have special structure and raw material characteristics, so they can realize self extinguishing function on the basis of non-toxic; while thermal insulation polymer core materials are usually composed of microporous structures, which are filled with air to achieve thermal insulation and cold insulation effect.
Based on the same microporous structure, when the core material is suitable, the sandwich composite can achieve good sound insulation effect. It has been widely used in high-speed rail, aviation and other fields.
Sandwich sandwich structure composite panel usually can choose some relatively poor rigidity but has good impact resistance, corrosion resistance materials, such as FRP. Taking yacht shell as an example, the sandwich sandwich structure composite material with glass fiber reinforced plastic as the panel, AIREX PET foam or Bashan light wood (BALTEK wood) as core material can not only make the yacht shell have good life expectancy under the condition of high salt and high corrosion, but also achieve various performances such as heat insulation, impact resistance, fire prevention and so on. This makes sandwich composites ideal for ship and subsea structural applications.
Some core materials have excellent dielectric properties. This allows them to block radio interference - a feature that can be used to design and build radomes, spherical shields for radar equipment, or X-ray equipment.