A Comparative Study on the Felting Propensity of Animal Fibers
The felting propensity of different animal fibers, particularly alpaca and wool, has been examined. The Aachen felting test method was employed. 1 g of each type of fiber was soaked in 50 ml of wetting solution and agitated in a dyeing machine to make felt balls. The diameter of each ball was measured in nine directions and the ball density was calculated in g/cm3; the higher the density value of the ball, the higher the feltability of the fibers. The effects of fiber diameter and fiber length on the felting propensity of these fibers were investigated. The results show that the alpaca fibers felt to a higher degree than wool fibers, and short and fine cashmere fibers have lower felting propensity than wool fibers at a similar diameter range. There is a higher tendency of felting for bleached and dyed alpaca fibers than for untreated fibers. Fiber length has a remarkable influence on the propensity of fiber felting. Cotton and nylon fibers were also tested for felting propensity to verify the mechanism responsible for the different fiber felting behavior.
The structure and properties of wool treated with a reversed-phase microemulsion containing aqueous alkali
In order to limit modification to the surface of wool fibers and decrease pollution caused by conventional chemical treatments using chlorine, a water-in-oil-type reversed-phase microemulsion with decamethylcyclopentasiloxane as the external phase was prepared containing very small amounts of an aqueous solution of alkali. The edges of the wool cuticle scales were modified by the alkali in aqueous solution contained in the reversed-phase microemulsion. The external phase decamethylcyclopentasiloxane can be recycled after application. In this paper, the solubility of water in the reversed-phase microemulsion and its stability were first studied and then it was applied in the treatment of wool. The results showed that surfactant sodium alcohol ether sulfate/NaOH aqueous solution was quite stable. Felting shrinkage of treated wool was reduced and the initial dyeing speed was higher than that for untreated wool. The corroded scales of treated wool were observed by scanning electron microscopy and the bromine Allwörden reaction with bromine water was reduced or eliminated after treatment. This adsorbable organohalogen-free modification should be useful in improving the manufacturing properties of wool, such as hydrophilicity, and as a pretreatment for wool printing.
Researches on Structural Factor Involvement in Oral Tribology
This study is focused on two ceramic materials, D.SING (Ivoclar) and VM13 (emphasis the VITA TN), frequently used in restorative dentistry practice and it comes to complete a full set of results obtained by the authors over several years of research on oral tribology with main influence on oral health. In this way there are involved more specific structural aspects of dental restorative ceramic materials quality as is shown in [1].