Paper‐Derived Bioactive Glass Tape

Abstract

Porous bioactive glass (BaG) structures were manufactured applying novel preceramic paper process. Preceramic papers were produced for aqueous suspensions loaded with different contents of pulp fiber and BaG filler. Pressure loading was applied in order to increase the packing density in the paper sheets. The paper sheets were sintered at 630 °C for 1 h. The porous glass–ceramic specimens were characterized for density, porosity, composition, microstructure, and mechanical properties. A pronounced volumetric shrinkage was observed, but no surface flaws or inhomogeneous areas were detected. The mechanical strength using the ball on three balls test and elastic modulus of sintered specimens vary between 21 and 33 MPa and 0.30–0.85 GPa, respectively.

Highly Filled Papers, on their Manufacturing, Processing, and Applications

“…As for the pulp fiber composition, the shorter, non‐refined hardwood pulp fibers made‐up a portion 60 vol% of the total pulp fiber content and the rest of the longer softwood pulp fibers. In previous studies on preceramic papers, the shorter pulp fibers were indicated to have an average diameter of 15 µm and an average fiber length of 657 µm, while the longer pulp fibers were indicated to have an average diameter of 22 µm and an average fiber length of 1665 µm. To obtain more precise values for the pulp fiber lengths and pulp fiber diameters, the pulp fiber dimensions were measured by the optical QIPIC/MIXCELL measuring system, carried out by the company Sympatec GmbH (Clausthal/Zellerfeld, Germany).…”

“…For highly filled papers, particulate or fibrous fillers are expected to accumulate at positions surrounding the pulp fibers and within voids of the pulp fiber network. When heat‐treating highly filled papers, the porosity of paper‐derived ceramics, ceramic‐ and metal‐based composites is mainly determined by the intricate structure of the pulp fiber network . Spaces in between individual filler particles can contribute to the total porosity of the paper‐derived sintering products, as well.…”

“…An overview of the different process routes for the heat treatment of highly filled papers is shown in Figure . The final sintering products or reaction products generated can be divided in the following groups: Oxide Ceramics Non‐Oxide Ceramics Ceramic‐Based Composites Metal‐based Composites …”

“…This can be achieved by compressing the highly filler papers. So far, two processes have been tested to compress the highly filled papers prior to heat treatment: pressing and calendering . Both processes were proven to increase the density and to flatten the surfaces of preceramic papers and paper‐derived ceramics.…”

“…When the oven reaches a sufficiently high temperature, the filler materials either undergo a sintering process or chemical reactions are initiated, yielding paper‐derived ceramics, ceramic‐, or metal‐based composites. Optionally, the green body can be infiltrated by a hot melt, such as liquid silicon or a liquid Cu–O alloy …”