Wood-plastic composites (WPCs) are one of the fastest growing construction components in the wood composites industry. Their popularity is due to low maintenance, high durability, and resistance to termites and other insect attacks. However their widespread usage has been limited due to their high cost in production and in some instances low strength.
Kenaf (Hibiscus cannabinus), is a plant in the Malvaceae family. Kenaf is cultivated for its fibre in India, Bangladesh, United States of America, Indonesia, Malaysia, South Africa, Viet Nam, Thailand, parts of Africa, and to a small extent in southeast Europe.
The present study focused on assessing the suitability of kenaf core fraction (about 65%of the whole stem of the plant) in powder form as filler material. Kenaf powder, processed from its core fibre, has been shown to offer one potential solution to the increasing scarcity of traditional filler materials. Kenaf stems contain two distinct fibre types, bast and core. Dosing with maleic-anhydride-modified polypropylene (MAPP) in the right amount displayed not only to bridge the interface between the ground kenaf core (GKC) and plastic in the present WPCs, improving stress transfer and increasing their strength and stiffness, but also allow a higher filler loading. Reducing the amount of plastic and increasing the amount of GKC, without sacrificing strength, stiffness or durability, would result in greener WPC products.Researchers examined the possibility of replacing sawdust with GKC and measured the mechanical properties of the resulting composites. They also looked at the effect of increasing maleic-anhydride-modified polypropylene (MAPP) dosage. Material preparation included GKC drying followed by high intensity blending with polypropylene (PP), coupling agents (MAPP) pellets, and feeding this into a counter-rotating twin-screw extruder for compounding. Compounded blends were then fed to an injection-moulding machine to produce boards of dimensions 153mm x 153mm x 3mm. Specimens were cut from the boards for tensile and bending tests in five replicates. GKC formulation gave the highest average tensile strength, modulus of rupture and modulus of elasticity.
New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State
Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy