Effects of Suessen Heat Setting Variables on Streaks in Finished Nylon Carpet

Abstract

The effects of dry heat setting conditions on streaks in finished carpets made from nylon 66 staple yams are considered. Two different polymers were subjected to controlled variation in heat-set temperature, residence time, and chamber steam pressure on a Suessen machine according to a factorial design. Yarns from some of the items were made into finished carpets, and other items were implanted into these carpets using two adjacent creel positions. Streak intensity grades were assigned to these implants, and then an empirical model was fit to the data relating streak intensity to the differences between the background and implant items in heat setting conditions. Streaks caused by variation in heat setting conditions are associated with differences in dye uptake rather than with physical or textural differences between tuftlines. If the Suessen is operated at a nominal temperature of 200°C, then surprisingly large differences in heat setting conditions are required in order to cause an objectionable streak. Furthermore, the effect of heat-set temperature differences on carpet streaks depends on the dyeing system used. For a continuous dyeing system, which has a dye uptake minimum at 200°C, any tuftline-to-tuftline heat-set temperature variation from 200°C causes dark streaks. On the other hand, the Beck system has a linear rather than a U-shaped dye response to heat-set temperature, and increases considerably above 200°C cause light streaks when that tuftline is implanted within a group of tuftlines having experienced a 200°C temperature.Prevention of streaks in finished carpets has long been a primary concern in the carpet industry as well as for nylon fiber producers. LeGault [ 8,9 ] discussed the wide variety of causes of streaks and concludes that differences in dry heat setting conditions are an important factor. Miller and Southern [ I I ] have recently shown that bulk-related streaks can be induced before heat setting. Several authors (Peters and White [ 13 ], Holfeld and Shepard [ 4 ] , Seu [ 14 ] , Kobsa el al. [ 7 ] , and Murthy et al. [ 12 ] ) attributed the effect of dry heat setting conditions to morphological changes in the fiber, but also suggested that increasing heat-set temperature causes an oxidative degradation of the dye sites. Ghosh [5] ] conducted a prior study of the effects of heat-set temperature differences on carpet streaks for both Suessen ( dry ) and Superba ( wet ) heat setting.He found that temperature differences of 4°C on the Superba caused severe streaks, but the Suessen required a larger temperature difference for streaking, and there was. less agreement between the panel members regarding streak intensity. At Monsanto (Gibson et al.[ 4 ] ), we conducted a factorial experiment to study the effects of Suessen heat setting conditions on fibcr properties under the standard process configuration and with an energy conservation package. We found effects of temperature and residence time on fiber structural and dyeing properties and observed more fiber vanability ...

Comparison between artificial neural network and response surface methodology in the prediction of the parameters of heat set polypropylene yarns

“…Additionally, the time-temperature relationship in the heat setting process varies depending on the polymer type, the fabric weight and its construction (Horrocks, Anand, & Anand, 2000). Of course, besides decreasing the yarn stress, better appearance is another desirable outcome (Baxley & Miller, 1991). Heat setting is categorized into three types, temporary, semi-permanent, and permanent (Gupta, 2002).…”

“…As an example (group a), several attempts have been made to investigate the effects of the heat setting process on yarn structural properties (Baxley & Miller, 1991;Cullerton, Ellison, & Aspland, 1990;Everaert, Vanneste, & Ruys, 1999;Lindberg, Køpke, & Fløisand, 1964;Pal, Mehta, & Gandhi, 1989;Shishoo & Olofsson, 1969;Vasanthan, 2004). These researches are generally based on the analysis of DSC, XRD and FTIR results.…”

Evaluation of the pinpoint effect on carpet appearance

“…Kish, Shoushtari, and Kazemi (2000) tried to draw a formula between elongation, load, and draw ratio after cold drawing and heat setting of polypropylene filaments. Other researchers (Baxley & Miller, 1991;Cullerton, Ellison, & Aspland, 1990;Everaert, Vanneste, & Ruys, 1999;Gupta & Kumar, 1981a;Lindberg, Kopke, & Floisand, 1964;Pal, Mehta, & Gandhi, 1989;Shishoo & Olofsson, 1969;Vasanthan, 2004) worked on the effect of heat setting on the yarn properties. They worked on structural changes and characterized the structural changes after heat setting via DSC, XRD, FTIR.…”

Influence of Suessen and Superba Heat Setting on Optical Streak Intensity in Finished Nylon Carpets

“…Each item, two of which were used as backgrounds, was heat set through a commercials Superba continuous heat-set unit equipped with a steam prebulker and a six meter heat-set chamber held at tunnel temperatures of either 129.4 or 137.8°C, and through a commercial Suessen, continuous heat-set unit held at 200°C. The Superba chamber provided a wet heat-setting environment [3}, the Suessen chamber a dry one [ 1,4 ] . In the dry environment, the nylon 66 glass transition and melt temperatures were greater than 100 and 250°C, respectively, while in the wet environment, the glass transition temperature fell below 30°C and the melt temperature below 190°C [ 5 ] .…”