Measurement of Different Yarn Materials by STA

Introduction

Yarns used in sewing and embroidery are made from a variety of materials, which can be broadly classified into natural fibers and synthetic fibers. The former consist of vegetable and animal fibers, such as cotton and hemp in vegetable fibers, and silk and wool in animal fibers. The latter are often synthesized from polyester and nylon. In this study, simultaneous thermogravimetry and differential thermal analysis (STA; TG-DTA) was used to identify the thermal behavior of hand sewing yarns made from cotton, silk, and polyester.

Measurements and results

Hand sewing yarns were cut into 2-3 mm in length, and then analyzed by STA with a heating rate of 20°C /min from 50°C to 500°C under a N₂ atmosphere. Results are shown in Figure 1.

In the TG curve of silk, a slight mass loss began at around 200°C, a rapid mass loss was exhibited due to decomposition at around 300°C, and then a gradual mass loss continued up to 500°C. In the TG curve of cotton, a slight mass loss began at around 300°C, and then a mass loss related to decomposition was observed from 350°C to 400°C. In addition, a mass loss of polyester associated with decomposition was shown from 400°C to 500°C.

In the DTA curve of polyester, an endothermic peak related to melting was exhibited at around 250°C. In addition, endothermic peaks of silk, cotton, and polyester were observed due to decomposition. This suggests that STA can be employed to elucidate the thermal behavior of yarns made from different materials.

Figure 1: Results for hand sewing yarns made from silk, cotton, and polyester

Recommended equipment and software

• Thermo plus EVO2 STA8122
• Vullios measurement and analysis software