Development of Thermal Insulation for Textile Wet Processing Machinery Using Needlepunched Nonwoven Fabrics

Abstract

In textile manufacturing, many fiber manufacturing, dyeing and finishing processes require temperatures in the range of 100^oC to 200^oC. A substantial amount of energy is needed to produce the desired temperature, and part of this energy is wasted when heat from the process escapes to the environment. Many of the processes are batch processes requiring frequent reheating and restarting. Most process equipment is constructed from stainless steel, which is a good conductor of heat. In addition to this, because of the cost involved in installation and regular maintenance of insulation, many manufacturers do not insulate their process equipment.

The heat and moisture loss to the environment makes the manufacturing facilities environmentally uncomfortable for employees. This reduces their productivity and is a health risk. Due to the energy wasted in the textile wet processing industry, there is a need to develop suitable insulating materials specifically for these applications. For commercial applications, both the cost of the insulating material as well as its effectiveness, ease of installation and durability are important.

Needlepunched fabrics have the potential to meet these demands [1]. Since low density needled felts with good heat blocking capacity can be made from durable fibers, they are ideal for heat insulation applications [1,2]. This research focuses on identifying suitable fibers and the manufacturing technology which will yield the desired results. After testing of prepared samples, the data was analyzed to determine the fabric and fiber parameters which influence heat transfer. An economic analysis was also conducted to optimize both cost and effectiveness.

The important factors contributing to the transfer of heat through needlepunched nonwoven fabrics were found to be the bulk density of the batt and the surface area of the fibers. Incorporation of low denier fibers (meltblown web) in the needlepunched structure led to a significant decrease in the apparent thermal conductivity of the batt. A cost analysis of this insulation (incorporating the meltblown web) determined the optimum thickness of such an insulation to be 10.1 mm.

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