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ISO-C1/2.0 Datasheet


ISO-C1®/2.0 Polyisocyanurate Insulation

2.0 lb/ft³ (32.1 kg/m³) Density Foam (for higher density ISO-C1, click here)

ISO-C1/2.0 is Dyplast’s cornerstone polyisocyanurate rigid foam insulation within its broad ISO line of products. ISO-C1/2.0 is independently tested and audited, and is listed with FM as a Specification Tested Identified Component - Combustible Core for Insulated Building Panels under FM 4880. ISO-C1 has higher thermal efficiency than competing polyiso, EPS, XPS, fiberglass, or cellglass insulation, offering exceptional performance in both piping and panel applications from -297 to +300°F (-183 to +149°C). ISO-C1 physical properties are superior in other areas, achieving code compliance plus levels of dimensional stability, closed cell content, and moisture resistance otherwise unattainable. ISO-C1/2.0 meets the demanding requirements of ASTM C591-17, including thermal conductivity measurement down to -200°F (-129°C). [Dyplast's ISO-C1/2.5 meets CINI Standards (the International Standard for Industrial Insulation), often required for LNG (Liquid Natural Gas) facilities.]

ISO-C1 is produced as a continuous foam bunstock with the ability to custom size the bun in order to provide for fabrication to virtually any shape or size, thus reducing waste. For specific stock bun sizes contact the sales department at 1-800-433-5551 or click Contact Us on this website. Our proprietary production process utilizes hydrocarbon blowing agents creating a portfolio of ISO-C1 products with physical properties superior to prior generation formulations.


With its high R-factor, ISO-C1/2.0 can achieve the same insulating value with as little as half the thickness required by alternative insulating materials. Less insulation leads to thinner walls, less weight, more space, and fewer and tighter energy-losing seams - - further enhanced by the availability of larger pieces (for example, 24-foot panels or blocks). Less insulation in mechanical applications also equates to reduced quantities of expensive vapor retarders, jackets, and mastics. The lighter weight of ISO-C1/2.0 compared to cellular glass (roughly one-third) reduces structural support requirements.


High thermal insulation efficiency is achieved by infusing cells with gases having low thermal conductivity. All such rigid foam insulation (including polyurethanes and extruded polystyrene) thus lose a small amount of their insulating value over time as air displaces insulating gases. ISO-C1’s smaller, stronger cell structure and our proprietary cell-gas formulation work together to impede gas transfer across cell boundaries, thus reducing loss of thermal efficiency. It is important to note that ISO-C1/2.0’s service temperatures are normally well below 75°F, and that thermal aging is reduced considerably at lower operating temperatures. Thicker insulation, vapor barriers, and metal jacket constraints also limit gas diffusion. Long Term Thermal Resistance calculation standards were designed for faced polyiso sheets and are not accurate for ISO-C1/2.0 bunstock, particularly as-installed in low temperature applications.


Water absorption by insulation can degrade thermal insulating performance. ISO-C1/2.0’s excellent resistance to water absorption (0.47%) as measured in accordance with Test Method ASTM C272 helps ensure long-term thermal performance. Proper installation of vapor barriers can further improve performance of the complete ISO-C1/2.0 insulating system. Note that WA for different insulants is often measured by different ASTM Test Methods, making comparisons challenging. For instance, ISO-C1’s WA of 0.47% was based on C272’s 24 hour period of immersion; the comparable cellular glass test per ASTM C240 yields a <0.2% WA from a 2 hour immersion period.


For optimum performance and longevity, insulation systems for low temperature applications must be designed to control condensation. One primary design strategy is to specify high insulation effciency since if the surface temperature of the insulation system can be maintained above the dewpoint, condensation will not occur. Since a minimal amount of condensation may be acceptable (or unavoidable) in humid environments, a secondary design strategy is to also demand insulation with low water vapor transmission. In this regard, no other insulation alternative offers ISO-C1/2.0’s combination of superior R-factor and low permeability of 2.49 perm-inch.


The International Mechanical Code defines Class 1 insulation as meeting the 25/450 flame spread/smoke development rating. ISO-C1/2.0 performs well within this range with a 25/250 rating. When comparing surface burning characteristics of alternative products, care must be taken to consider the installed insulation system as a whole. For example, a well-designed ISO-C1/2.0 insulation system can improve overall fire/smoke performance of the polyiso insulation system. On the other hand, cellular glass’ fire/smoke ratings may be compromised by the use of the sealants or jacketing often recommended by suppliers. There is also the matter of insulation system integrity during a fire. ISO-C1/2.0 may be charred by flame, but maintains its integrity and continues to protect the insulated system.

ASTM C591-17 and CINI 2013

Compliance with the latest revisions of ASTM C591-17 specifications is critical to the success of low-temperature applications, particularly cryogenic projects such as Liquid Natural Gas (LNG). The most recent ASTM C591-17, for instance, puts limits on thermal conductivities (k-factors) across a range of low temperatures. Additionally, product certification entities including Factory Mutual (FM) and Underwriters Laboratories (UL) now require physical properties from each location of manufacture to be tested in order to remain certified. This ensures the product delivered is the same as the product specified. Dyplast's ISO-C1/2.5 has been tested, and meets CINI 2013 requirements.