NTU Prof Raju holding and flexing 2 pieces of wood bonded in the center by the magnetocuring glue, to show its strong bonding strength. Credit: NTU Singapore
A possible advantage to green production, the brand-new glue saves money on energy, time and area.
Scientists from Nanyang Technological University, Singapore (NTU Singapore), have actually established a brand-new method to treat adhesives utilizing an electromagnetic field.
Conventional adhesives like epoxy which are utilized to bond plastic, ceramics, and wood are normally created to treat utilizing wetness, heat, or light. They typically need particular treating temperature levels, varying from space temperature level approximately 80 degrees Celsius.
The treating procedure is needed to cross-link and bond the glue with the 2 protected surface areas as the glue takes shape and solidifies to accomplish its last strength.
NTU’s brand-new “magnetocuring” glue can treat by passing it through an electromagnetic field. This is extremely beneficial in specific ecological conditions where present adhesives do not work well. Also, when the adhesive is sandwiched in between insulating product like rubber or wood, standard activators like heat, light and air cannot quickly reach the adhesive.
Products such as composite bike frames, helmets, and golf clubs, are presently made with two-part epoxy adhesives, where a resin and a hardener are blended and the response begins instantly.
For producers of carbon fiber – thin ribbons of carbon glued together layer by layer – and makers of sports devices including carbon fiber, their factories utilize big, high-temperature ovens to treat the epoxy glue over lots of hours. This energy-intensive treating procedure is the primary factor for the high expense of carbon fiber.
The brand-new “magnetocuring” adhesive is made by integrating a normal commercially offered epoxy adhesive with specifically customized magnetic nanoparticles made by the NTU researchers. It does not require to be combined with any hardener or accelerator, unlike 2-component adhesives (which has two liquids that should be blended prior to usage), making it simple to make and use.
It bonds the products when it is triggered by travelling through an electromagnetic field, which is quickly created by a little electro-magnetic gadget. This utilizes less energy than a big traditional oven.
Assoc Prof Steele (left) and Dr. Richa treating the magnetocuring glue on a cotton mesh utilizing an electro-magnetic field. Credit: NTU Singapore
For example, one gram of magnetocuring adhesive can be quickly treated by a 200-Watt electro-magnetic gadget in 5 minutes (consuming 16.6 Watt Hours). This is 120 times less energy required than a conventional 2000-Watt oven which takes an hour (consuming 2000 Watt Hours) to treat traditional epoxy.
Developed by Professor Raju V. Ramanujan, Associate Professor Terry Steele and Dr. Richa Chaudhary from the NTU School of Materials Science and Engineering, the findings were released in the clinical journal Applied Materials Today and provide possible application in a vast array of fields.
This consists of high-end sports devices, automobile items, electronic devices, energy, aerospace and medical production procedures. Laboratory tests have actually revealed that the brand-new adhesive has a strength approximately 7 megapascals, on par with a number of the epoxy adhesives on the marketplace.
Assoc Prof Steele, a professional in numerous kinds of innovative adhesives, described: “Our key development is a way to cure adhesives within minutes of exposure to a magnetic field, while preventing overheating of the surfaces to which they are applied. This is important as some surfaces that we want to join are extremely heat-sensitive, such as flexible electronics and biodegradable plastics.”
How “magnetocuring” glue works
The brand-new adhesive is made from 2 primary parts – a commercially offered epoxy that is treated through heat, and oxide nanoparticles made from a chemical mix consisting of manganese, zinc and iron (MnxZn1-xFe2O4).
These nanoparticles are created to warm up when electro-magnetic energy is gone through them, triggering the treating procedure. The optimum temperature level and rate of heating can be managed by these unique nanoparticles, getting rid of getting too hot and hotspot development.
(Left to right) NTU Assoc Prof Terry Steele, Prof Raju V. Ramanujan and Dr Richa Chaudhary holding up numerous soft and difficult products bonded by their brand-new magnetocuring glue. Credit: NTU Singapore
Without the requirement for big commercial ovens, the activation of the glue has a smaller sized footprint in area and energy usage terms. The energy effectiveness in the treating procedure is essential for green production, where items are made at lower temperature levels, and utilize less energy for cooling and heating.
For circumstances, producers of sports shoes typically have problem warming up the adhesives in between the rubber soles and the upper half of the shoe, as rubber is a heat insulator and withstands heat transmission to the traditional epoxy glue. An oven is required to warm up the shoe over a very long time prior to the heat can reach the glue.
Using magnetic-field triggered glue bypasses this problem, by straight triggering the treating procedure just in the glue.
The rotating electromagnetic field can likewise be embedded at the bottom of conveyor belt systems, so items with pre-applied glue can be treated when they travel through the electromagnetic field.
Improving production effectiveness
Prof Raju Ramanujan, who is globally acknowledged for his advances in magnetic products, collectively led the job and forecasts that the innovation might increase the effectiveness of producing where adhesive joints are required.
“Our temperature-controlled magnetic nanoparticles are designed to be mixed with existing one-pot adhesive formulations, so many of the epoxy-based adhesives on the market could be converted into magnetic field-activated glue,” Prof Ramanujan stated.
“The speed and temperature of curing can be adjusted, so manufacturers of existing products could redesign or improve their existing manufacturing methods. For example, instead of applying glue and curing it part by part in a conventional assembly line, the new process could be to pre-apply glue on all the parts and then cure them as they move along the conveyor chain. Without ovens, it would lead to much less downtime and more efficient production.”
First author of the research study, Dr. Richa Chaudhary stated, “The curing of our newly-developed magnetocuring adhesive takes only several minutes instead of hours, and yet is able to secure surfaces with high strength bonds, which is of considerable interest in the sports, medical, automotive and aerospace industries. This efficient process can also bring about cost savings as the space and energy needed for conventional heat curing are reduced significantly.”
This three-year job was supported by the Agency for Science, Technology and Research (A*STAR).
Previous deal with heat-activated glue utilized an electrical current streaming through a coil, called induction-curing, where the glue is heated up and treated from outdoors. However, its downsides consist of getting too hot of the surface areas and irregular bonding due to hotspot development within the adhesive.
Moving forward, the group wishes to engage adhesive producers to work together on advertising their innovation. They have actually submitted a patent through NTUitive, the university’s development and business business. They have actually currently gotten interest in their research study from sporting items producers.
Reference: “Magnetocuring of temperature failsafe epoxy adhesives” by Richa Chaudhary, Varun Chaudhary, Raju V. Ramanujan and Terry W.J. Steele, 15 September 2020, Applied Materials Today.
DOI: 10.1016/j.apmt.2020.100824
