211 | Page THERMO-INSULATION PROPERTIES OF CROSS- LAID NONWOVEN FABRICS MADE OF PET AND PP WASTE FIBERS E. R. Mahmoud Spinning, Weaving and Knitting dept., Faculty of Applied arts/ Helwan University, Egypt ABSTRACT Thermal properties are among the most important features of textiles that are used for personal protection and protection of objects. This research deals with thermal insulation properties of cross-laid nonwoven fabrics made of waste fibers (polyester and polypropylene fibers). In this research 72 samples were produced with cross-laid nonwoven technique and bonded using needle punching method using two groups of waste fibers ,waste blend (1) composed of polypropylene / polyester waste fibers of 50/50 blend and the waste blend (2) composed of polypropylene / polyester /polyester hollow waste fibers of 15/50/35 blend. Four fabric weights were produced 300, 600, 900 and 1200 g/ m 2 with three number of beats 600, 800 and 950 beats/min. and three puncture depths 12, 16 and 20 mm. Different parameters including fiber type, puncture depth, fabric weight and number of beats per unit area were studied and their influence on the performance of the end-use fabrics were also studied. The results demonstrated that thermal insulation properties of fabrics are increased by adding hollow fibers and increasing fabrics weight and both puncture depth and number of beats/min. Keywords: Nonwoven Fabrics, Solid Waste Management, Recycling Of Textile Wastes, Technical Textiles, Thermal Protective Fabrics, Thermal Insulation Properties Of Textiles, Waste Fibers. I. INTRODUCTION The rate of growth in consumption of fibers designed for technical applications , however , is now faster than those going to traditional clothing and furnishing sectors. Much of this growth will depend on greater realization of technological and functional benefits that fiber-based structures could bring to the traditional and unyielding sectors of engineering. [1] The increasing emphasis on human protection and the continued introduction of health , safety and environmental legislation means that the technical textiles market continues to be buoyant and thrive. [2] Protective and safety textiles are technical textiles with high-tech character in many cases, as it includes protection against cuts, abrasion, ballistic and other types of severe impact, fire and extreme heat, hazardous dust and particles, biological and chemical hazards, extreme cold, static electricity, etc. [2]& [3] Issues such as environment, recycling and biodegradability, which are increasingly subjects of concern for the public, will further encourage and benefit the growth and use of technical textiles. [1] Thus this paper aims at effective usage of waste polyester and polypropylene fibers into useful nonwoven products used in thermal insulation applications . 1.1 Thermal Insulation Properties of Fabrics