Structural Properties of Nylon 66 Carpet Yarns Observed with Near Infrared Analysis

Abstract

Heat significantly influences the supermolecular structure of nylon, which results in changes in the fibers' chemical and physical properties and the morphological re sponse of the yam systems during further processing. The near infrared analysis (NIR) technique has been used extensively to measure the heat-set temperature of nylon yams. Previous investigations have studied the effect of changes in heat history on the NIR spectrum of nylon carpet yams from a spectroscopic approach, in which the wavelength assignments and the rationale for specific wavelengths used on the heat set temperature NIR calibration equations were presented. In this paper, a crystallo graphic approach is used to examine the effect that changes in the heat history of Suessen heat-set nylon 66 carpet yams have on the NIR spectrum and the heat-set temperature NIR calibration equations, and various crystalline, thermal, and laser light scattering parameters of the Suessen heat-set nylon 66 yarns are measured. The NIR spectrum is responding to changes in the crystalline perfection of the nylon 66 polymer with changing temperature, specifically to changes in the C—H stretches in the Van der Waals plane. Agreement between the results of the various measurement techniques (crystalline, thermal, light-scattering, NIR) is excellent. A definite change in morphological response occurs at ∼190°C, which coincides with the Brill transition of nylon 66. The slight deviation from linearity in the NIR response below the heat set temperature of 190°C is due to the Brill transition.

Get full access to this article

View all access options for this article.

References

Baeder, J. , Operation Techniques on Continuous Heat Setting Machines, Part II: Early Detection of Process Upsets, presented at 2nd Symposium on Solving Tufted Textile Problems, Textile Engineering Dept., Auburn University, Auburn, AL, 1981 .

Bell, J. , and Dumbleton, J. , Relation between Melting Behavior and Physical Structure in Polymers, J. Polym. Sci. Part A-2 7, 1033 (1969).

Brill, R. , Relationship Between Hydrogen Bonds and Several Properties of Polyamides , Makromol. Chem., 18/ 19, 294 (1956).

Ghosh, S. , and Roy, R. , Quantitative Near-infra-red Analysis of Reducing Sugar from the Surface of Cotton, J. Textile Inst. 79 (3), 504 (1988).

Ghosh, S. , and Rodgers, J. , Determining Heat Set Temperature by Near Infrared Reflectance Spectroscopy , Textile Res. J. 55 (9), 556 (1985).

Gosline, K. , An Overview of the Carpet Yam Twist Setting Process, presented at Carpet Manufacturing Technology Conference, Clemson University, Clemson, SC, 1984.

Instruction Manual for the 500C InfraAlyzer, Bran + Luebbe Analyzing Technologies (Technicon Industrial Systems), Elmsford, NY.

Itoh, T. , Change with Temperature in Crystal Structures of Nylon 6, 66 and 610 , Jpn. J. Appl. Phys. 15 (12), 2295 ( 1976 ).

Roberts, R. , The Melting Behavior of Bulk Crystallized Polymers, Polym. Lett. 8, 381 (1970).

10.

Rodgers, J. , Specific Applications of NIRA in the Textile Industry, presented at 7th International NIRA Symposium, Technicon Technical Center , Tarrytown, NY, 1984.

11.

Rodgers, J. , NIRA Potential for the Process Monitoring of Heatset Temperature, presented at 10th International NIRA Symposium, Technicon Technical Center, Tarrytown, NY, 1984.

12.

Rodgers, J. , and Lee, S. , NIRA Primary Wavelength Investigations of Nylon Yams, Textile Res. J. 59 (9), 513 ( 1989).

13.

Starkweather, H. , and Jones, G. , Crystalline Transitions in Powders of Nylon 66 Crystallized from Solution, J. Polym. Sci. Polym. Phys. Ed. 19, 467 (1981).

14.

Tincher, W. , and Luk, A. , NIRS Analysis of Cotton/ Polyester Yams, Textile Chem. Color. 17 (10), 200 (1985 ).

15.

Tincher, W. , Casey, P. , Mayfield , A. , Characterization of Heat Set Nylon Carpet Yam, Textile Chem. Color. 18 (2), 25 (1986).