Commercial Printer Research Articles

Sustainable and Recyclable Acrylate Resins for Liquid-Crystal Display 3D Printing Based on Lipoic Acid.

The development of renewable vinyl-based photopolymer resins offers a promising solution to reducing the environmental impact associated with 3D printed materials. This study introduces a bifunctional lipoate cross-linker containing a dynamic disulfide bond, which is combined with acrylic monomers (n-butyl acrylate) and conventional photoinitiators to develop photopolymer resins that are compatible with commercial stereolithography 3D printing. The incorporation of disulfide bonds within the polymer network's backbone imparts the 3D printed objects with self-healing capabilities and complete degradability. Remarkably, the degraded resin can be fully recycled and reused for high-resolution reprinting of complex structures while preserving mechanical properties that are comparable to the original material. This proof-of-concept study not only presents a sustainable strategy for advancing acrylate-based 3D printing materials, but also introduces a novel approach for fabricating fully recyclable 3D-printed structures. This method paves the way for reducing the environmental impact while enhancing material reusability, offering significant potential for the development of eco-friendly additive manufacturing.

Facile fabrication of degradable, serrated polyethylene diacrylate microneedles using stereolithography

Microneedles have the potential for minimally invasive drug delivery. However, they are constrained by absence of rapid, scalable fabrication methods to produce intricate arrays and serrations for enhanced adhesion. 3D printing techniques like stereolithography (SLA) are fast, scalable modalities but SLAs require non-degradable and stiff resins. This work attempts to overcome this limitation by utilizing a poly (ethylene glycol diacrylate) (PEGDA, F3) resin and demonstrating its compatibility with a commercial SLA printer. FESEM images showed high printing efficiency of customized bioinks (F3) similar to commercial resins using SLA 3D printer. Mechanical endurance tests of whole MNA showed that MNs array printed from F3 resin (485 ± 5.73 N) required considerably less force than commercial F1 resin (880 ± 32.4 N). Penetration performance of F1 and F3 was found to be 10.8 ± 2.06 N and 0.705 ± 0.03 N. In-vitro degradation study in PBS showed that MNs fabricated from F3 resin exhibited degradation after 7 days, which was not observed with the commercial F1 resin provided by the manufacturer. The histology of porcine skin exhibited formation of triangular pores with pore length of 548 μm and efficient penetration into the deeper dermal layer. In conclusion, PEGDA can be used as for fabricating degradable, serrated solid MNs over commercial resin.

Carbon dot-loaded Fe3O4 as photonic pigments for multilevel anti-counterfeiting

Amorphous arrays assembled from colloidal microspheres are a way that obtains angle-independent structural colors. In order to obtain additional properties, colloidal microspheres, which are constituent units, can be modified with other materials. Here, we utilized the silane-functionalized carbon quantum dots (SiCDs) by incorporating them into the Stöber reaction to fabricate Fe3O4@SiO2/SiCDs nanospheres with a core-shell structure. Amorphous colloidal arrays (ACAs) were constructed on commercial printing paper using Fe3O4@SiO2/SiCDs nanoparticles as structural units by a simple permeation assembly. Macroscopically, the prepared ACAs exhibit the magnetic properties of Fe3O4, while under sunlight, they display bright, angle-independent structural colors. Under ultraviolet light, the array shows significant fluorescence. This enables the presentation of multidimensional information under varying magnetic and lighting conditions. By adjusting the thickness of the outer SiO2/SiCDs composite layer, the optical properties and magnetism can be controlled easily. Moreover, due to the strong light absorption capability and high refractive index of Fe3O4, the digital patterns constructed with Fe3O4@SiO2/SiCDs nanospheres demonstrate excellent multi-level anti-counterfeiting characteristics, even under water exposure. The magnetic properties of Fe3O4@SiO2/SiCDs nanospheres, along with their distinct display characteristics under different optical environments, suggest their wide applicability in the fields of multifunctional anti-counterfeiting pigments, bioimaging, and sensing displays.

Characterization of Commercial and Custom-Made Printing Filament Materials for Computed Tomography Imaging of Radiological Phantoms

In recent years, material extrusion-based additive manufacturing, particularly fused filament fabrication (FFF), has gained significant attention due to its versatility and cost-effectiveness in producing complex geometries. This paper presents the characterization of seven novel materials for FFF and twenty-two commercially available filaments in terms of X-ray computed tomography (CT) numbers, as tissue mimicking materials for the realization of 3D printed radiological phantoms. Two technical approaches, by 3D printing of cube samples and by producing cylinders of melted materials, are used for achieving this goal. Results showed that the CT numbers, given in Hounsfield unit (HU), of all the samples depended on the beam kilovoltage (kV). The CT numbers ranged from +411 HU to +3071 HU (at 80 kV), from −422 HU to +3071 HU (at 100 kV), and from −442 HU to +3070 HU (at 120 kV). Several commercial and custom-made filaments demonstrated suitability for substituting soft and hard human tissues, for realization of 3D printed phantoms with FFF in CT imaging. For breast imaging, an anthropomorphic phantom with two filaments could be fabricated using ABS-C (conductive acrylonitrile butadiene styrene) as a substitute for breast adipose tissue, and ASA-A (acrylic styrene acrylonitrile) for glandular breast tissue.

Tuning the Mechanical Properties of 3D-Printed Objects by Mixing Chain Transfer Agents in Norrish Type I Photoinitiated RAFT Polymerization.

Photoinduced 3D printing via photocontrolled reversible-deactivation radical polymerization (photoRDRP) techniques has emerged as a robust technique for creating polymeric materials. However, methods for precisely adjusting the mechanical properties of these materials remain limited. In this study, we present a facile approach for adjusting the mechanical properties of 3D-printed objects by adjusting the polymer dispersity within a Norrish type I photoinitiated reversible addition-fragmentation chain transfer (NTI-RAFT) polymerization-based 3D printing process. We investigated the effects of varying the concentrations and molar ratios of trithiocarbonate (BTPA) and xanthate (EXEP) on the mechanical properties of the printed materials. Our findings demonstrate that increased concentrations of RAFT agents or higher proportions of the more active BTPA lead to a decrease in Young's modulus and glass transition temperatures, along with an increase in elongation at break, which can be attributed to the enhanced homogeneity of the polymer network. Using a commercial LCD printer, the NTI-RAFT-based 3D printing system effectively produced materials with tailored mechanical properties, highlighting its potential for practical applications.

3D Printable Materials Based on Renewable Polymers from Terpene Alcohols and Calcium Carbide

AbstractThe transition to a sustainable future requires the use of waste‐free technologies for production. Potentially, additive technologies can be a promising approach for accessing circular economy due to the precise amount of feeding materials and the absence of molds. However, the initial feeding materials for additive approaches are often based on non–renewable hydrocarbon sources. This work focused on the use of polymers derived from terpene alcohols to develop a filament suitable for 3D printing. Initially, the vinylation of menthol using calcium carbide was optimized and scaled up, then a series of terpenyl–based vinyl ethers were obtained under optimal conditions. The cationic polymerization of vinyl ethers was also scaled up and resulted in 99 % yield of the polymers, which was subsequently subjected to hot extrusion. The initial terpenol was used as an additive to increase polymer flexibility. The addition of menthol (30 wt %) to polyvinyl menthol led to the suitable filament. Using the filament, a series of objects were 3D printed at 125 °C. The material demonstrated good sinterability and adhesion to glass and shrinkage comparable to that of commercial 3D printing filaments. Furthermore, the polymers obtained were used as additives to enhance the adhesion of commercially available filaments.

A heterogeneous pore design algorithm for material extrusion additive manufacturing

Material extrusion additive manufacturing offers great potential for customizing matters with complex external contours, and filament diameter-adjustable 3D (FDA-3D) printing strategy provides fresh impetus to create heterogeneous porous structures inside these complex matters. However, the absence of supporting algorithms to implement FDA-3D printing severely hinders its widespread use. In this paper, we develop a heterogeneous pore design (HPD) algorithm aimed at advancing the development of FDA-3D printing for producing heterogeneous porous matters. The HPD algorithm consists of three sub-algorithms: model design, collapse compensation, and fabrication file (G-codes) generation. As proofs of concept, we utilize this algorithm to 3D print radial gradient and letter-embedded gradient materials following specific steps: (1) designing the heterogeneous porous models with collapse compensation in Grasshopper® and displaying them in Rhinocores®; (2) customizing and writing the corresponding G-codes files by following the material extrusion 3D printer's control rules; (3) upgrading a commercial extrusion printer to FDA-3D print the design models via the customized G-codes. Micro-computed tomography-based 3D reconstruction and quantified pore size maps for the fabricated objects demonstrate the high capability of this HPD algorithm. Overall, the HPD algorithm holds the potential to revolutionize material extrusion 3D printers cost-effectively, creating new possibilities for material extrusion of heterogeneous materials.

Preparation of Pulp, Microfibrillated Cellulose, and Paper Hand Sheets from Bakong (<i>Hanguana malayana</i> (Jack) Merr.)

Bakong (<i>Hanguana malayana</i> (Jack) Merr.) is a perennial herbaceous plant that grows abundantly in certain parts of the Philippines. This study investigates Bakong fibers' potential as a pulp source for papermaking. Furthermore, microfibrillated cellulose (MFC) produced from the fibers was used as an additive in the Bakong fiber-based hand sheets at 2%, 6%, and 10% w/w, and their effects on their strength properties were observed. The soda pulping method produced Bakong pulp with a total yield of 47.36%. Proximate chemical analysis showed that the method reduced the lignin content from 13.19% to 8.76%, and the resulting pulp was successfully formed into paper hand sheets. The strength properties of the hand sheets were tested, and the resulting burst index, tear index, tensile index, and folding endurance values were 5.98 kPa/m2∙g, 6.41 mN∙m2/g, 105.97 N∙m/g, and 626 double folds, respectively. Aside from the tear index, the Bakong hand sheets' strength properties were much higher than that of locally produced commercial printing paper. The addition of MFC on the hand sheets negatively affected the burst and tensile index values of the Bakong hand sheets but significantly improved the tear index up to 6% w/w. These results show that the pulp produced from the Bakong fibers can potentially be used as an alternative source of pulp for papermaking, but further optimization of the pulping process is recommended to increase the yield, lower lignin content, and improve compatibility with the MFC.

Design of FDM fabricated poly-lactic acid parts with forced-air cooling speed as the new control parameter to tune its shape memory effect

Poly lactic acid (PLA) as one of the shape memory polymers has extensively been used as the material in the 3D printing by fused deposition modeling process. In this study, we introduced the forced-air cooling speed as new control parameter in the fabrication process. A commercial material extrusion printer was retrofitted with a control module of forced-air cooling system. The shape memory effects of the PLA printed in different cooling speeds from 0–5 m s−1 were first measured by submerging the printed coupon specimens into water bath at recovery temperature. It is found that the changes in dimensions were mainly anisotropic and dependent of the raster angle in printing, in addition to the controlled cooling speed. The shape memory strains were roughly in linear trend with the magnitude of cooling air speed. In other words, the shape memory effect of the PLA can be easily controlled by the cooling air speed in fabrication. X-ray diffraction measurement on the specimens before and after recovery treatment confirmed the shape memory effect was related to the partial crystallization of molecular structure. Moreover, the different cooling air speeds also induced different thermal stresses in the printed specimens which manifest its important role in the total shape memory strain. Finally, the proposed theoretical beam formulation for the recovery bending deflection was shown to have good prediction accuracy comparing with experimental measurements.

Stereolithography 3D Printing of Stimuli-Responsive Spin Crossover@Polymer Nanocomposites with Optimized Actuating Properties.

We used stereolithography to print polymer nanocomposite samples of stimuli-responsive spin crossover materials in the commercial photo-curable printing resins DS3000 and PEGDA-250. The thermomechanical analysis of the SLA-printed objects revealed not only the expected reinforcement of the polymer resins by the introduction of the stiffer SCO particles, but also a significant mechanical damping, as well as a sizeable linear strain around the spin transition temperatures. For the highest accessible loads (ca. 13-15 vol.%) we measured transformation strains in the range of 1.2-1.5%, giving rise to peaks in the coefficient of thermal expansion as high as 10-3 °C-1, which was exploited in 3D printed bilayer actuators to produce bending movement. The results pave the way for integrating these advanced stimuli-responsive composites into mechanical actuators and 4D printing applications.

Cold Laser Sintering of Medicines: Toward Carbon Neutral Pharmaceutical Printing.

Selective laser sintering (SLS) is an emerging three-dimensional (3D) printing technology that uses a laser to fuse powder particles together, which allows the fabrication of personalized solid dosage forms. It possesses great potential for commercial use. However, a major drawback of SLS is the need to heat the powder bed while printing; this leads to high energy consumption (and hence a large carbon footprint), which may hinder its translation to industry. In this study, the concept of cold laser sintering (CLS) is introduced. In CLS, the aim is to sinter particles without heating the powder bed, where the energy from the laser, alone, is sufficient to fuse adjacent particles. The study demonstrated that a laser power above 1.8 W was sufficient to sinter both KollicoatIR and Eudragit L100-55-based formulations at room temperature. The cold sintering printing process was found to reduce carbon emissions by 99% compared to a commercial SLS printer. The CLS printed formulations possessed characteristics comparable to those made with conventional SLS printing, including a porous microstructure, fast disintegration time, and molecular dispersion of the drug. It was also possible to achieve higher drug loadings than was possible with conventional SLS printing. Increasing the laser power from 1.8 to 3.0 W increased the flexural strength of the printed formulations from 0.6 to 1.6 MPa, concomitantly increasing the disintegration time from 5 to over 300 s. CLS appears to offer a new route to laser-sintered pharmaceuticals that minimizes impact on the environment and is fit for purpose in Industry 5.0.

3D printable and biocompatible PEDOT:PSS-ionic liquid colloids with high conductivity for rapid on-demand fabrication of 3D bioelectronics

3D printing has been widely used for on-demand prototyping of complex three-dimensional structures. In biomedical applications, PEDOT:PSS has emerged as a promising material in versatile bioelectronics due to its tissue-like mechanical properties and suitable electrical properties. However, previously developed PEDOT:PSS inks have not been able to fully utilize the advantages of commercial 3D printing due to its long post treatment times, difficulty in high aspect ratio printing, and low conductivity. We propose a one-shot strategy for the fabrication of PEDOT:PSS ink that is able to simultaneously achieve on-demand biocompatibility (no post treatment), structural integrity during 3D printing for tall three-dimensional structures, and high conductivity for rapid-prototyping. By using ionic liquid-facilitated PEDOT:PSS colloidal stacking induced by a centrifugal protocol, a viscoplastic PEDOT:PSS-ionic liquid colloidal (PILC) ink was developed. PILC inks exhibit high-aspect ratio vertical stacking, omnidirectional printability for generating suspended architectures, high conductivity (~286 S/cm), and high-resolution printing (~50 µm). We demonstrate the on-demand and versatile applicability of PILC inks through the fabrication of 3D circuit boards, on-skin physiological signal monitoring e-tattoos, and implantable bioelectronics (opto-electrocorticography recording, low voltage sciatic nerve stimulation and recording from deeper brain layers via 3D vertical spike arrays).

Advantages of stereolithographic 3D printing in the fabrication of the Affiblot device for dot-blot assays

In stereolithographic (SLA) 3D printing, objects are constructed by exposing layers of photocurable resin to UV light. It is a highly user-friendly fabrication method that opens a possibility for technology sharing through CAD file online libraries. Here, we present a prototyping procedure of a microfluidics-enhanced dot-blot device (Affiblot) designed for simple and inexpensive screening of affinity molecule characteristics (antibodies, oligonucleotides, cell receptors, etc.). The incorporation of microfluidic features makes sample processing user-friendly, less time-consuming, and less laborious, all performed completely on-device, distinguishing it from other dot-blot devices. Initially, the Affiblot device was fabricated using CNC machining, which required significant investment in manual post-processing and resulted in low reproducibility. Utilization of SLA 3D printing reduced the amount of manual post-processing, which significantly streamlined the prototyping process. Moreover, it enabled the fabrication of previously impossible features, including internal fluidic channels. While 3D printing of sub-millimeter microchannels usually requires custom-built printers, we were able to fabricate microfluidic features on a readily available commercial printer. Open microchannels in the size range 200–300 μm could be fabricated with reliable repeatability and sealed with a replaceable foil. Economic aspects of device fabrication are also discussed.Graphical abstract

Vat photopolymerization of olefinic elastomers from sulfonated ethylene-propylene-diene monomer (EPDM) latexes

Ethylene-Propylene-Diene Monomer (EPDM) rubber is recognized for elasticity over a wide temperature range and exceptional resistance to UV light and oxidative degradation. In this study, sulfonated EPDM (sEPDM) latex serves as an innovative platform for 3D printing olefinic elastomers through vat photopolymerization (VPP). The sulfonation of EPDM and subsequent neutralization with potassium hydroxide enabled the production of water-dispersible sEPDM (K-sEPDM), yielding a stable latex with an average particle diameter of 125 nm. The inherent low viscosity of the latexes allowed the direct application of elastomeric polymers during the VPP process. The photopolymerization of a scaffold precursor composition, which consisted of n-vinylpyrrolidone (NVP) and poly(ethylene glycol) diacrylate (PEGDA) in the aqueous phase of K-sEPDM latex, solidified the latex as a particle embedded hydrogel. Post-processing for removing water from the 3D printed green body facilitated coalescence of the K-sEPDM particles throughout the scaffold network, generating a second ionically crosslinked network together with scaffold as an interpenetrating polymer network (IPN). Tensile testing demonstrated tunable elastomeric properties with an ultimate strain from 315±11–453±37 % and ultimate stress from 7.6±0.5–8.2±0.3 MPa with excellent thermal recoverability. VPP of photocurable K-sEPDM with a commercial printer showcased high-resolution printing capabilities with controllable isotropic shrinkage for the printing of olefinic elastomers.

Evaluation of DTP Package using WPM Method

DTP Package. Pamphlets, brochures, and newsletters are among the types of papers that can be produced using desktop publishing software (DTP). The fundamental capabilities of DTP software are included in contemporary word processors, but features like templates and frames make DTP software excellent for intricate page layouts. Examples based on your document in templates. You can achieve this with the aid of five of the most well-liked desktop publishing programmed: Adobe PageMaker, Adobe InDesign, Quark Express, Adobe FrameMaker, and Corel Ventura. Naturally, no one application has all the resources required to satisfy the needs of every publisher. Adobe FrameMaker, Adobe InDesign, Corel Ventura, CorelDraw, Microsoft Publisher, Page Stream, and QuarkXPress are typical examples of desktop publishing software. Although desktop publishing software includes some templates, it is still easy to produce subpar designs that can impair a media message's effectiveness or transmission. Microsoft Publisher, QuarkXPress, Adobe InDesign, and Adobe FrameMaker are examples of common desktop publishing software. DTP operators have enough of work because they are in charge of both new work and a sizable volume of old data that needs to be converted to digital format. A DTP operator may work for a big company or a tiny grocery store. Desktop publishing software includes applications like Adobe InDesign, Microsoft Publisher, QuarkXPress, and Scribus. While office employees, teachers, students, small company owners, and non-designers utilize some of these, professional graphic designers and commercial printing technicians use others. She is a print and web designer as well as a writer, artist, and graphic designer. Graphic designers and desktop publishers frequently employ four different kinds of software. The designer's toolkit is primarily composed of these projects. Two key pieces of hardware are required for desktop publishing (DTP): 1) a computer with additional input devices like scanners and cameras, and 2) a printer with the ability to generate high-quality typographic and visual content. This paper is the weighted product for solving the routing decision problem Model (WPM) used. Every dynamically assign weight to criteria this proposed scheme considers the relevant valuation method for the Disk Operating System, Desktop publishing, Miscarriage, Scan, Spying alternative, and Count of occurrences across the entire dataset, % of total data, % of anomalous data evaluation. Disk Operating System, Desktop publishing, Miscarriage, Scan, Spying. Count of occurrences across the entire dataset, % of total data, % of anomalous data. The scan is got the first rank whereas Miscarriage has the lowest rank.

Fully 3D-Printed Miniature Soft Hydraulic Actuators with Shape Memory Effect for Morphing and Manipulation.

Miniature shape-morphing soft actuators driven by external stimuli and fluidic pressure hold great promise in morphing matter and small-scale soft robotics. However, it remains challenging to achieve both rich shape morphing and shape locking in a fast and controlled way due to the limitations of actuation reversibility and fabrication. Here, fully 3D-printed, sub-millimeter thin-plate-like miniature soft hydraulic actuators with shape memory effect (SME) for programable fast shape morphing and shape locking, are reported. It combines commercial high-resolution multi-material 3D printing of stiff shape memory polymers (SMPs) and soft elastomers and direct printing of microfluidic channels and 2D/3D channel networks embedded in elastomers in a single print run. Leveraging spatial patterning of hybrid compositions and expansion heterogeneity of microfluidic channel networks for versatile hydraulically actuated shape morphing, including circular, wavy, helical, saddle, and warping shapes with various curvatures, are demonstrated. The morphed shapes can be temporarily locked and recover to their original planar forms repeatedly by activating SME of the SMPs. Utilizing the fast shape morphing and locking in the miniature actuators, their potential applications in non-invasive manipulation of small-scale objects and fragile living organisms, multimodal entanglement grasping, and energy-saving manipulators, are demonstrated.

3D printed anatomical models for preoperative planning of complex orthopaedic surgical operations of the lower limb

Complex multifragmentary fractures of the pelvis and lower limb are a major challenge for operative orthopaedic surgery. The successful metallic osteosynthesis of the fractures requires an extensive planning process, which can be dramatically improved with the 3D printed anatomical models – replicas of the bones with high fidelity generated from CT and MRI imaging studies. The models represent the spatial properties of the skeleton with a dimensional error of approximately 8 μm/mm. They can be manufactured easily and with high reproducibility with commercial or open-access software and FDM 3D printing. Orthopaedic surgeons use the preoperative models as a highly accurate physical model of complex fractures and allow them to choose and prepare the optimal operation window, surgical tools, metallic implants, and as a template for recontouring (pre-bending) of fixation plates, which will be used during the surgery. The approach provides a new level of personalisation in operative orthopaedic surgery and significantly reduces the duration of the operation, the amount of blood loss and the intraoperative X-rays. The proper anatomical repositioning of the fracture is achieved at a higher rate in the surgeries, which are planned with 3D-printed anatomical models. The planning of surgical operations with 3D-printed models increases the overall effectiveness of the surgery, reduces the rate of post-surgical complications, and allows for a patient-specific approach.The paper will describe the methods for manufacturing accurate 3D-printed anatomical models representing complex fractures and their application for preoperative planning of orthopaedic operation.The anatomical 3D models were generated from CT datasets with open-access medical informatics software (3D Slicer) and 3D printed on an FDM 3D printer with minimal thermal deformation (Polylactate, PLA). The finished models were used for preoperative planning of complex orthopaedic operations, including high-energy multifragmentary hip, knee and ankle fractures. The preoperative planning included selecting surgical access, preparing tools and implants, and contouring (pre-bending) metal plates for metallic osteosynthesis. Several parameters, such as operation time, blood loss, intraoperative X-rays, and the achievement of anatomical reduction of the fractures, were observed in order to measure the quality of the operations.Accurate anthropomorphic 3D models representing the spatial properties of the bones can be generated from tomographic imaging studies easily and accurately, even with open-source software. They can be utilised as a tool for preoperatively planning complex orthopaedical operations of the lower limb. Using 3D-printed models allows a patient-specific approach, which leads to good anatomical reduction and favourable functional results in complex surgeries regarding the pelvis, acetabulum, tibial plateau, and calcaneus.The methods described in the paper are routinely used for the preoperative planning of complex orthopaedical operations regarding the lower limb. In the future, they will be combined with the implementation of 3D-printed personalised titanium implants to achieve good anatomical reduction even for the most challenging multigragmental fractures.In the paper, we described the technical aspects and clinical considerations for the preoperative planning of complex orthopaedical operations, which can assist engineers and clinicians alike in implementing the useful method in clinical practice.

A new approach for effective productivity management of newspaper printing press

Within the modern commercial printing press, a common problem is the ef-ficient management of the maintenance of different machines of newspaper printing press. If Effective Maintenance Management is applied, productivity of the machines can be increased by reducing breakdown time of the ma-chine. Productivity Management is an organizational framework that helps machines to improve productivity. Productivity of a machine is dependent on the failure probability which can be controlled by technical and management actions. The present investigation is established by the analysis of productivi-ty, effectiveness and failure probability on the basis of Pareto Analysis. Pareto chart is also developed to understand the actual scenario where highest prior-ity events are sequentially arranged. It has been observed that the web-offset printing machine has the highest productivity and effectiveness with less failure probability while the exposure unit has the highest failure probability having low productivity and effectiveness. Based on the reduction of proba-bility of failure to meet the acceptable criteria, further maintenance planning can be suggested. This approach confirms that productivity and effectivity of the machines of newspaper printing press can be increased by considering consequences of the machines and their corresponding failure assessments.

Flexible and Free-Standing Metal-Organic Framework Nanowire Paper.

Beyond traditional paper, multifunctional nanopaper has received much attention in recent years. Currently, many nanomaterials have been successfully used as building units of nanopaper. However, it remains a great challenge to prepare flexible and freestanding metal-organic framework (MOF) nanopaper owing to the low aspect ratio and brittleness of MOF nanocrystals. Herein, this work develops a flexible and free-standing MOF nanopaper with MOF nanowires as building units. The manganese-based MOF (Mn-MOF) nanowires with lengths up to 100 μm are synthesized by a facile solvothermal method. Through a paper-making technique, the Mn-MOF nanowires interweave with each other to form a three-dimensional architecture, thus creating a flexible and free-standing Mn-MOF nanowire paper. Furthermore, the surface properties can be engineered to obtain high hydrophobicity by modifying polydimethylsiloxane (PDMS) on the surfaces of the Mn-MOF nanowire paper. The water contact angle reaches 130°. As a proof of concept, this work presents two potential applications of the Mn-MOF/PDMS nanowire paper: (i) The as-prepared Mn-MOF/PDMS nanowire paper is compatible with a commercial printer. The as-printed colorful patterns are of high quality, and (ii) benefiting from the highly hydrophobic surfaces, the Mn-MOF/PDMS nanowire paper is able to efficiently separate oil from water.

Thermo-Mechanical Behavior and Strain Rate Sensitivity of 3D-Printed Polylactic Acid (PLA) below Glass Transition Temperature (Tg).

This study investigated the thermomechanical behavior of 4D-printed polylactic acid (PLA), focusing on its response to varying temperatures and strain rates in a wide range below the glass transition temperature (Tg). The material was characterized using tension, compression, and dynamic mechanical thermal analysis (DMTA), confirming PLA's strong dependency on strain rate and temperature. The glass transition temperature of 4D-printed PLA was determined to be 65 °C using a thermal analysis (DMTA). The elastic modulus changed from 1045.7 MPa in the glassy phase to 1.2 MPa in the rubber phase, showing the great shape memory potential of 4D-printed PLA. The filament tension tests revealed that the material's yield stress strongly depended on the strain rate at room temperature, with values ranging from 56 MPa to 43 MPA as the strain rate decreased. Using a commercial FDM Ultimaker printer, cylindrical compression samples were 3D-printed and then characterized under thermo-mechanical conditions. Thermo-mechanical compression tests were conducted at strain rates ranging from 0.0001 s-1 to 0.1 s-1 and at temperatures below the glass transition temperature (Tg) at 25, 37, and 50 °C. The conducted experimental tests showed that the material had distinct yield stress, strain softening, and strain hardening at very large deformations. Clear strain rate dependence was observed, particularly at quasi-static rates, with the temperature and strain rate significantly influencing PLA's mechanical properties, including yield stress. Yield stress values varied from 110 MPa at room temperature with a strain rate of 0.1 s-1 to 42 MPa at 50 °C with a strain rate of 0.0001 s-1. This study also included thermo-mechanical adiabatic tests, which revealed that higher strain rates of 0.01 s-1 and 0.1 s-1 led to self-heating due to non-dissipated generated heat. This internal heating caused additional softening at higher strain rates and lower stress values. Thermal imaging revealed temperature increases of 15 °C and 18 °C for strain rates of 0.01 s-1 and 0.1 s-1, respectively.