In order to discuss the properties of the so-called Combination FRP plastic indices of their work-done have been studied. The behaviors of Combination FRP can be known from the variation in elastic indices of work-done at various strains.
The types of glass-cloths used as main reinforcing elements were roving cloths and nonwoven cloths. Plastics used as the matrix were unsaturated polyester.
In plastics reinforced by combination of the above glass cloths, the behaviors of the elastic index of work-done showed elasto-plastic properties with different patterns depending upon the type and quantity of their reinforcing materials. The elastic index of the work-done at small strain is remarkably decreased by the influence of roving cloths, but this phenomenon was not so dangerous as it was “fail safe”.
Generally their tensile strength increased in proportion to the content of roving cloths.

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Dancer rollers are widely used in the textile, paper and other industries to detect the difference in running speed of a material between the let-off and take-up rollers.
If the running speed of a material increases, and if a material processed is more stretchable, then use of dancer rollers as a detector of the speed difference in a control loop is accompanied by these unfavorable phenomena described below: (1) The amplitude of variations in the tension of the running material and in the dancer roller
displacement increases due to the roller mass and the elasticity of the running material. (2) The running material slackens and the dancer roller jumps. (3) Slippage occurs between the dancer roller and the running material, resulting in variations in speed and tension of the running material.
Such phenomena are inexplicable by considering the static characteristics alone of dancer roller, but call for inquiry into their dynamic characteristics also. Assuming the deformation property of the running material to be linearly elastic, the phenomena mentioned above can be analyzed theoretically. The theoretical results are described and compared with experiments. A fairly good agreement between them is proved.

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Looped pile carpets having different pile structure were woven by a tufted machine using Nylon-6 textured pile yarns. Two different groups of model cut-pile carpets were made by using an attachment; one group consisting of the same apparent density in pile part and the other group of the different apparent density.
Apparent values of complex dynamic modulus have been measured of both the looped pile and the cut pile carpets at various given compressive strains by means of Hysteresis loop method at a fixed frequency of 0.5Hz. Their complex elastic modulus may be calculated on the assumption that the mechanical model of these carpets is similar to that of Voigt.
The viscoelastic property of the carpets under compression depends on various factors, and especially in this experiments on two factors: deformed mode of a pile yarn and volume fraction of fiber phase in pile part.

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