Technical Comparisons of Foams Using Various Blowing Agent Blends Containing HCFC-141b, HFC-245fa, Solstice~R Liquid Blowing Agent, and Hydrocarbons in Domestic Appliances.

摘要

This paper presents a technical comparison of the most common blowing agent blends as alternatives to HCFC-141b, in Article V countries. Basic criteria for blowing agents are not only physical data of pure compounds, but their measured physical properties in mixtures simulating the real gas mixtures in the foam, e.g gas thermal conductivity and vapor pressure. The interactions of blowing agent in foam matrix are in certain ranges adjustable by formulation like: absorption of blowing agent by the polymer, plasticizing of the polymer by the blowing agent and permeation rates. Besides the evaluation of the physical properties of the foams made with different blends we will also be discussing the consideration of advantages of Cyclopentane (95%)/HFC-245fa blends. In an attempt to find an alternate solution for HCFC-141b which is required to be phased out by Montreal Protocol in Article V countries, and the changing more stringent energy standards in coming years Honeywell Labs in India tested a number of different blowing agents as blends in appliance application. These included HCFC-141b, HFC- 245 fa, Cyclopentane (95%), Cyclopentane (95%)/HFC-245fa, Solstice LBA/Cyclopentane (95%), HCFC-141b/HFC-245fa, etc. These differ in boiling points and physical properties, and solubility characteristics and have never been considered to be drop in. A number of in-depth studies of correlations were undertaken in lab and at production levels, to understand the mechanism by which different blowing agent impact the end use and the physical properties. The blowing agents have strong impact on the flow ability properties which in turn contribute to insulation behavior and compressive strength and demo Id behaviors besides density distributions. Initially lab level work was conducted which was followed by trials on a lab Cannon type high pressure foam machine and then subsequently selective few combinations were tested at customer end on actual refrigerator cabinet and door moulds . This was tested for all physical properties and energy and comparative data was generated.