Comparative Analysis of Various Building Insulation Materials
Release Time:
2015-07-21
Source:
Comparative Analysis of Various Building Insulation Materials
The adoption of high-performance thermal insulation technologies and materials in the building and industrial sectors often yields twice the results with half the effort. Statistics show that for every ton of mineral wool insulation products used in buildings, as well as when appropriate insulation measures and materials are employed for industrial equipment and piping, energy consumption and production costs can be significantly reduced, the environment can be improved, and substantial economic benefits can be realized. For example, in industrial equipment and piping systems, optimal insulation conditions can reduce heat loss by approximately 95%, and the investment in insulation materials is typically recouped within about one year through energy savings. The development of building insulation materials has a long history, with a wide variety of types available; the following table provides a comparative overview of the main energy-saving insulation materials:
Mineral wool and its products are high-quality thermal insulation materials with a production and application history spanning more than 100 years.
In 1840, the United Kingdom was the first to discover that molten slag, when blown with compressed air, could be transformed into fibers, leading to the production of slag wool. By 1880, Germany and the United Kingdom had begun manufacturing slag wool, after which other countries gradually adopted its use and production; large-scale production and application commenced in the 1930s. From 1960 to 1980, mineral wool experienced its most rapid development worldwide. Since 1980, global production of mineral wool products has remained relatively stable, primarily due to the accelerated development of alternative insulation materials such as glass wool and foam plastics, coupled with a slowdown in the growth rate in developed countries. In recent years, annual global production of mineral wool products has hovered around 8 million tonnes. Mineral wool is most extensively used in construction: for example, it accounts for 85% of insulation applications in the United Kingdom, 70% in Germany, 92% in Japan, and over 90% in the United States.
In the early 1980s, Beijing introduced a 16,300-ton production line from Sweden, marking a major step forward for China’s thermal insulation materials industry toward larger-scale production, superior performance, and a more comprehensive range of product types and specifications. Subsequently, cities including Harbin, Taiyuan, Hohhot, Qiqihar, Urumqi, Dongguan, Yinchuan, Xining, Shanghai, and Beijing successively imported such lines from Sweden, Japan, Australia, Italy, the United Kingdom, and Poland, while Nanjing also built another production line. Today, there are 80 enterprises with an annual production capacity of 3,000 tons each, approximately 180 manufacturing firms in total, and a combined design capacity of 550,000 tons.
Rock wool production technology: Rock wool produced by small plants exhibits poor uniformity; in contrast, imported equipment features automatic adjustment of laying speed and thickness, with higher output and faster drive roller speeds, all operating in a proportional relationship. Consequently, rock wool from large-scale manufacturers boasts uniform bulk density and low slag ball content.
Glass wool and its products represent a lightweight, high-performance thermal insulation material that emerged after rock wool. In 1990, Japan’s production reached 205,000 tonnes; in 1985, the United States produced 1.925 million tonnes; and in 1984, France produced 115,000 tonnes. Prior to the 1980s, China had only a handful of small-scale ultra-fine glass wool plants, with a limited product range and poor quality. In the mid-1980s, Shanghai and Beijing introduced technology and equipment from Nitto Bosei, adopting the centrifugal blow-spinning process for production. The resulting products include boards, felts, shells, and decorative ceiling panels.
Characteristics: lightweight, typically 10–96 kg/m³; below 20 kg/m³ is felt, 24–48 kg/m³ is medium-hard board, and 48–96 kg/m³ is hard board, with 48 kg/m³ suitable for ceiling applications. The softening point is around 500°C, and thermal insulation performance is maintained up to 300°C. It is widely used in the United States, with a thermal conductivity coefficient of 0.9.
Calcium silicate insulation products were successfully developed in China in the 1970s. They feature high compressive strength, low thermal conductivity, ease of installation, and reusability, making them widely used in power systems.
By the end of 1994, nearly 50 manufacturers nationwide had a combined designed production capacity of close to 300,000 square meters; today, however, only slightly more than 30 remain in regular operation, with an annual output of approximately 150,000 square meters. Its market penetration has been undermined by competition from mineral wool, compounded by relatively high prices and insufficient marketing efforts, resulting in sluggish sales in recent years and constraining production.
Applications: It offers excellent high-temperature resistance and a relatively low cost; however, its major drawback is that thermal expansion can easily cause cracking and misalignment of the welds. The presence of gaps allows hot air to escape and cold air to enter, resulting in significant heat loss despite the relatively low surface temperature of the outer protective layer.
Aluminosilicate fiber, also known as refractory fiber, is primarily used as thermal insulation material for kilns. It was successfully developed in China in 1971. Currently, there are approximately 200 production enterprises, with a total production capacity exceeding 40,000 tons per year and an annual output of nearly 20,000 tons. A wide variety of grades are available: domestically, the main products include ordinary aluminosilicate fiber, high-purity aluminosilicate fiber, high-alumina fiber, and aluminum-containing fiber, along with a small number of finished products—all of which are mid- to low-end; higher-end products include polycrystalline mullite fiber, polycrystalline alumina fiber, and polycrystalline zirconia fiber.
Most domestic producers operate on a small, workshop-style scale. Subsequently, four production lines were introduced from the United States, featuring advanced process technology that enables rapid dissolution and spinning into fibers, as well as dry-laid needle-punched felts, with stable quality and temperature resistance ranging from 800 to 1,250°C.
Characteristics: acid resistance index of 2.0 or higher, high-temperature resistance—common chemical pipelines typically operate at temperatures above 1,000°C, necessitating the use of this material. Melting point is around 2,000°C.
Foamed plastics are plastic products made on the basis of synthetic resins and characterized by a multitude of tiny internal pores. They offer advantages such as low thermal conductivity and ease of processing and molding, and were initially adopted in the construction industry. Their primary applications include packaging (e.g., for refrigerators), thermal insulation for underground direct-buried pipelines, and cold storage insulation. The main products are polystyrene foam and polyurethane foam.
