Insulation Finishes—This Month’s Topic: Laminates
Product Characteristics of Weather Barriers, Vapor Retarders, and Finishes
Laminates are, in general terms, materials made by bonding (through the use of heat, pressure, adhesives, or any combination thereof) 2 or more layers of materials. The layers can be comprised of similar or dissimilar materials. Laminates used for protective jacketing may be comprised of metal foils, plastic films, papers, nonwovens, scrims, etc. and may or may not contain a topcoat of some kind for coloration or UV resistance. Laminates may also come in a variety of different configurations.
For vapor retarder applications, at least 1 component must be a material that offers significant resistance to vapor passage. Laminates may be classified into 3
- Laminated Foil Jacketing (ASJ/FSK/PSP/PSK)
- Synthetic Rubber Laminates
- Multi-ply Laminates
Laminated Foil Jacketing (ASJ/FSK/PSP/PSK)
A traditionally used pre-formed jacket for pipe, tank, and equipment vapor retarder applications is the lamination of white paper, reinforcing fiberglass scrim, and aluminum foil.
This laminate is typically called All-Service Jacket (ASJ). Variations on this structure, sometimes referred to as Next Generation ASJ, is a similar basic structure, with a white polymer film/substrate in place of the bleached paper. These products are generally referred to as ASJ or next generation ASJ and meet the requirements of ASTM C1136, Standard Specification for Flexible, Low Permeance Vapor Retarders for Thermal Insulation.
Traditional ASJ or next generation ASJ facings are commonly used as the outer finish in low abuse, indoor areas; elsewhere, they are covered by a protective metal or plastic jacket.
A similar facing material, foil-scrim-kraft (FSK) has the same basic structure except with the aluminum foil layer facing outward. Numerous variations, such as Poly-Scrim-Poly (PSP) or Poly-Scrim-Kraft (PSK), are also available. Many types of insulation products are supplied with factory-applied ASJ, FSK, or PSK vapor retarders.
Synthetic Rubber Laminates
Synthetic, rubber-based laminates typically consist of aluminum facing laminated to a synthetic rubber membrane and a peel-and-stick application. These laminates are used on pipes, ducts, and tanks for both interior and exterior applications, and may be used in direct burial applications. A variety of weights are available. Perm values of less than 0.02 are reported, and the materials are generally considered to be “self-healing” in that small
punctures and penetrations will re-seal.
Multi-ply laminates consist of multiple layers of aluminum with alternating layers of polyester or polyethylene film with a peel-and-stick adhesive system. These laminates are used on pipes, ducts, and tanks for both interior and exterior applications. They cut easily and install easily in the field. Perm values of 0 or near 0 are reported. They are available in smooth or embossed surface finish in a variety of thicknesses. Several colors and chemical-resistant films are also available.
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