One of the primary interests of forensic sciences is the study of traces, better conceived as silent witnesses to criminal activity whose existence is attributable to Locard's principle. Thus, textile fibers are commonly exploited as they are easily transferred during contact which can vary in intensity depending upon the type of activity that occurred. Regardless, current knowledge pertaining to fiber transfer mechanisms, particularly in regards to blended textiles, is limited. It is recognized that the intensity of the contact, the type of textile as well as the size and type of fibers composing it have a significant influence on the amount of fibers transferred. However, when the donor textile is blended (eg. 50% cotton, 50% polyester), it often happens that one of the two types of fibers is transferred in greater proportion to the receiving surface (eg. 80% cotton and 20% polyester). The percentages indicated on the manufactured label are however not representative of the respective proportions (based on the number of fibers) of each type of fiber composing the fabric, but rather the weight of each respective type of fiber used to fabricate the garment. Therefore, the amount of collected fibers (traces) cannot be easily correlated to the proportions indicated on the manufactured label used to describe the textile. The objective of this study was to test the transfer capacities of blended textiles of different cotton and polyester proportions by performing several simulations under controlled conditions (i.e. contact between two textiles with a constant force and speed). The results were then correlated to the fiber type, morphology, and size. Overall, the project contributes to improving the comprehension of fiber transfer mechanisms, and provides insight on the quantity and the proportions of fibers capable of being transferred between the donor and the recipient textiles following a specific type of action and contact (legitimate or otherwise).
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.forsciint.2020.110181 | DOI Listing |
Materials (Basel)
December 2024
College of Civil Engineering, Tongji University, Shanghai 200092, China.
In recent years, steel-fiber-reinforced concrete (SFRC) has been increasingly applied in shield tunnel engineering. However, most research on SFRC segments focuses on the load-bearing capacity, while the tunnel deformation is an equally critical indicator that decides if the tunnel can operate safely during service conditions. Therefore, it is essential to also study the stiffness variations in SFRC segments, which is closely connected to the serviceability limit state (SLS).
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Micron School of Material Science and Engineering, Boise State University, Boise, ID 83725, USA.
Carbon-fiber composites with thermoplastic matrices offer many processing and performance benefits in aerospace applications, but the long relaxation times of polymers make it difficult to predict how the structure of the matrix depends on its chemistry and how it was processed. Coarse-grained models of polymers can enable access to these long-time dynamics, but can have limited applicability outside the systems and state points that they are validated against. Here we develop and validate a minimal coarse-grained model of the aerospace thermoplastic poly(etherketoneketone) (PEKK).
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Chemical Engineering, Materials, Environment, Sapienza University of Rome, 00184 Rome, Italy.
Cleavable bio-based epoxy resin systems are emerging, eco-friendly, and promising alternatives to the common thermoset ones, providing quite comparable thermo-mechanical properties while enabling a circular and green end-of-life scenario of the composite materials. In addition to being designed to incorporate a bio-based resin greener than the conventional fully fossil-based epoxies, these formulations involve cleaving hardeners that enable, under mild thermo-chemical conditions, the total recycling of the composite material through the recovery of the fiber and matrix as a thermoplastic. This research addressed the characterization, processability, and recyclability of a new commercial cleavable bio-resin formulation (designed by the R-Concept company) that can be used in the fabrication of fully recyclable polymer composites.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Key Laboratory of State Forestry Administration for Silviculture of the Lower Yellow River, College of Forestry, Shandong Agricultural University, Tai'an 271018, China.
Paper-based packaging materials have gained attention from academia and industry for their outstanding environmental sustainability advantages. However, they still encounter major challenges, such as low mechanical strength and inadequate functionality, hindering the replacement of unsustainable packaging materials. Inspired by the remarkable strength of trees provided by cellulose fibers and the water and heat protection of trees provided by bark, this study developed a new biomass-based packaging material (SNC-C) that combines strength, thermal insulation, and water resistance.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Hubei Key Laboratory of Biomass Fibers and Eco-dyeing & Finishing, School of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430200, PR China. Electronic address:
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!