Toshio Matsuoka

Improvement on the freeze–thaw stability of corn starch gel by the polysaccharide from leaves of Corchorus olitorius L.

Effect of the polysaccharide from leaves of Corchorus olitorius L. (PLC) on the freeze-thaw (FT) stability of corn starch gel was studied. PLC was incorporated into the starch gel at 0.7% and total solid was adjusted to 6.0%. The syneresis was measured by the centrifugal-filtration method and, as a result, addition of PLC reduced effectively the syneresis of the starch gel even after 5 FT cycles, which was less than one third that of the normal starch gel. The rheological changes of the starch/PLC gel during the FT treatments were evaluated while the gel remained on the rheometer plate. The starch/PLC gel had less significant changes in the rheological parameters during the FT cycles than starch/guar gum or xanthan gum gel systems. SEM images showed that PLC stabilized the gel matrix surrounding pores, which would contribute to both a lower syneresis production and a higher stability in the rheological behavior at FT.

Identification of Principal Factors of Fabric Aesthetics by the Evaluation from Experts on Textiles and from Untrained Consumers

One of the important end-use performance measures of fabrics and other textile products is the handle, which measures the quality of fabrics as evaluated by reactions obtained not only tactilely but also visually. The well-known Kawabata Evaluation System includes both an objective evaluation and a prediction method of the handle. However, objective evaluations of the handle based on a visual perception of fabric aesthetics have not been investigated systematically. Thus, as the first step of a systematic study, we attempted to carry out a sensory evaluation of fabric aesthetics by experts on textile and untrained consumers using worsted and spun silk woven fabrics, which have different material effect and structural effect. Thereafter, the mean preference scores were examined by factor analysis to identify the principal factors of fabric aesthetics. From the result, it was found that two common factors—‘luster and depth sensation’ and ‘surface roughness sensation’—were identified tentatively as the principal factors of fabric aesthetics.

Characteristics of Novel Triplet Spun Yarns Made from Fibers of Differing Fineness

In order to reduce the hairiness of ring spun yarns and to develop novel multilayered spun yarns, we investigated the properties of triplet spun yarns made from the same size of three rovings with different fiber fineness using an experimental ring spinning frame. The results were: (1) different fiber fineness triplet spun yarn, a new yarn made by combination staple fibers of three different fineness into one twisting process; (2) although triplet spun yarn had a side-by-side structure in the cross-section, the central angle made by the assembly of finer fibers was smaller than that of coarser fibers; and (3) in comparison with single yarn, triplet spun yarn had less hairiness and greater strength because of the lower spinning tension of each strand and the twist propagation in each strand.

Backrest Designs in Meeting Chairs

Our purpose was to design the backrest of meeting chairs. We investigated how a backrest structure influenced the sitting comfort of a meeting chair. Sensory values of sitting comfort were measured through a paired comparison method and body pressure distributions. Subjects were selected from a consumer group and an expert group who worked at an office furniture company. Body pressures and contact areas between the human body and the chairs were measured. As a market test, 663 people sat on the sample chairs. The sensory evaluation results were examined through a factor analysis. The results were as follows: (1) The sitting comfort evaluated by the consumers had a positive correlation with those of the experts. (2) Two factors were common and significant in evaluating sitting comfort of meeting chair in both groups: “soft at back” and “not tiring.” (3) The adjectives related to “sitting comfort” had a relationship with the body pressure distribution and the bending properties of the backrest. (4) The “sitting comfort” of the meeting chair could be predicted by its physical properties. (5) The results of the market test conform with the results of the sensory test.