Construction Materials, Building Supplies, Construction Industry,
Carbon fiber the secret weapon that makes precast concrete as strong, light and tough as Transformers
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As the wave of prefabrication sweeps the world, the "excessive strength and insufficient toughness" of precast concrete (PC) components has always been a pain point in the industry. The emergence of carbon fiber, the "black magician", is making beams, plates and columns evolve from "fragile sharks" to "seismic iron men".

 

Pain point: Why can't traditional PC components "hold up"?

Brittle failure: Ordinary concrete is resistant to compression but not tension, and it is easy to break instantly when bent or impacted.

Steel bar corrosion: Chloride ion erosion in coastal areas or chemical plants has caused the "internal injuries" of traditional steel bars to increase.

Weight shackles: Increasing the cross-section to increase the bearing capacity will increase the transportation and lifting costs.

Post-earthquake repair is difficult: Once the node area is cracked, the on-site wet operation repair cycle is long, delaying the resumption of work.

 

Carbon fiber

 

Four disruptive roles of carbon fiber

Internal addition of "short fiber" - "ligament reconstruction" for concrete

• Mechanism: 0.2%-0.8% volume addition of short-cut carbon fiber forms three-dimensional random support in the matrix. When cracks appear, the fiber "bridges" to transfer stress, and the impact toughness is increased by 2-4 times.

• Scenario: Prefabricated stairs, subway pipe segments, anti-collision guardrails and other components that need to be impact-resistant.

• Data: Prefabricated beams with 0.4% carbon fiber added have a 35% reduction in mid-span deflection and a 50% reduction in crack width in the drop hammer test.

 

External "CFRP cloth" - "invisible armor" with 10 times the strength of steel bars

• Mechanism: CFRP cloth with a tensile strength of ≥3000 MPa is glued to the tensile surface of the component with epoxy glue to form a secondary force system, which can increase the bending bearing capacity by 30%-50% without increasing the cross section.

• Scenarios:

– Rapid reinforcement of old prefabricated hollow slabs;

– Seismic upgrade of prefabricated bridges (such as CFRP cloth wrapped around the plastic hinge area of piers).

• Case: After two layers of CFRP cloth were attached to the bottom of the prefabricated box girder of a certain overpass, the ultimate bearing capacity was restored to 1.45 times the original design.

 

Prefabricated "CFRP bars/grids" - "super steel bars" that never rust

• Mechanism: Using CFRP bars to replace traditional steel bars has a density of only 1/5 of that of steel, but a tensile strength of 10 times that of steel, and is resistant to chloride ion corrosion.

• Scenarios:

– Prefabricated exterior wall panels for coastal docks and LNG storage tanks;

– Prefabricated bridge panels that need to be protected from salt corrosion in high-altitude cold areas.

• Economical: The cost of the entire life cycle is reduced by 30%, eliminating the need for later anti-corrosion coating.

 

Intelligent "perception layer" - let the components have their own "health checkup"

• Mechanism: The evenly dispersed short carbon fibers make the resistivity of concrete change linearly with strain, realizing self-diagnosis of cracks.

• Scenarios:

– Prefabricated integrated pipe corridors, real-time monitoring of settlement;

– Prefabricated building exterior wall panels, rapid assessment of damage levels after an earthquake.

 

How much has the durability of prefabricated components improved after being "armored" with carbon fiber? We have obvious data comparisons, which are mainly reflected in two aspects;

1. Quantitative indicators of improved durability

Crack width: After CFRP cloth reinforcement, the crack expansion rate decreased by 60%-75%; after 120 dry-wet cycles, the stress intensity factor at the crack tip decreased by 50%.

Rebar corrosion: After CFRP bars/grids replaced steel bars, the chloride ion permeability coefficient decreased by one order of magnitude, and the steel bar corrosion rate was <0.01 mm/year.

Freeze-thaw cycle: After 300 rapid freeze-thaw (F-T) tests, the CFRP-concrete interface bond strength retention rate was ≥85%, while the unreinforced specimens only had 50%.

Ultraviolet aging: After continuous irradiation with UV-A 340 nm lamp for 1000 h, the tensile strength attenuation of CFRP cloth was <5%, which is much better than the 20% attenuation of epoxy-coated steel bars.

2. Environmental adaptability: Performance under extreme working conditions

High temperature and high humidity (40 ℃, RH 95%)

After 3000 h, the shear strength of the CFRP-concrete interface decreased by <8%, meeting the 30-year equivalent requirements of JTG/T J22-2011 for hot and humid environments.

Salt spray + dry-wet cycle (NaCl 5%, 120 cycles)

The bond strength of traditional reinforced concrete decayed by 50%, while the CFRP reinforced specimen only decayed by 12%.

Freeze-thaw + deicing salt (-18 ℃↗+5 ℃, 300 cycles)

The ultimate load of the CFRP cloth specimen decreased by <10%, while that of ordinary concrete decreased by 35%.

 

Therefore, carbon fiber is not simply "more expensive steel bars", but the key to the evolution of precast concrete from "passive load-bearing" to "active sensing". Whoever masters this key first will be able to open up a high value-added blue ocean in the red ocean of prefabricated buildings.

Magnetic Materials in Food Processing Invisible "Guardians", How to Ensure Safety and Efficiency?
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Magnetic Materials in Food Processing

In a food processing plant that pursues deliciousness and health, you may not think of "magnets" at the first time. However, these invisible magnetic field forces are indispensable key players in ensuring the safety of our dining tables and improving production efficiency. They are unknown, but they have a great responsibility - they are specifically designed to deal with those "uninvited guests" that may be mixed into food: metal impurities.

 

* Wide range of sources: Metal impurities may come from raw materials (such as harvester parts fragments and ore residues in grain), production equipment (such as screen wear, loose and falling mechanical parts), employee negligence (such as screws, washers), and even packaging materials.

* Huge harm:

Physical damage: Sharp metal fragments are a major threat to consumer safety and may cause damage to the mouth, esophagus, and even internal organs.

Equipment damage: Hard metal particles can seriously wear or even jam expensive crushers, grinders, pumps and valves and other key equipment, causing unexpected downtime and high repair costs.

Reputation and legal risks: Once products containing metal foreign matter enter the market, they will inevitably lead to consumer complaints, large-scale recalls, serious damage to brand reputation, and even face severe regulatory penalties and lawsuits.

 

The above factors are the stage where magnetic separators come into play. They use the magnetic field generated by powerful permanent magnets (such as neodymium iron boron) or electromagnets to accurately "capture" ferromagnetic metals (iron, steel) and some weakly magnetic metals (such as some stainless steel) at key points in the food processing process. The working principle is that when food materials flow through or approach a strong magnetic field area, the ferromagnetic metal impurities in them will be firmly adsorbed on the surface of the magnet by the magnetic force, while the pure food passes smoothly, achieving precise separation.

What types of magnetic separation equipment are used in the food industry?

There are several types of magnetic separation equipment commonly used in the food processing industry, including:

Plate magnets: These flat magnetic plates are most commonly found in conveyors or chutes. They are often used to remove metal contaminants from dry goods such as grains, seeds or pet food.

Grid magnets: Similar to plate magnets, grid magnets are also suitable for dry material applications. These magnetic separators are composed of multiple magnetic bars through which the material passes. The magnetic bars collect and remove iron impurities from the material. Grid magnets are available in a variety of designs to suit a variety of material types, such as flour, grain, sugar, and more.

Rotary magnets: These magnets are most effective for dry, sticky, difficult-to-flow products that have bridging issues, such as milk powder or sugar.

 In-line magnets: These types of magnetic separators include designs suitable for both dry and wet applications, as well as high-speed product lines, pump lines, and pneumatic conveying.

 

Magnetic Materials in Food ProcessingMagnetic Materials in Food Processing

 

Magnetic separation technology ensures safety: not only equipment, but also a system

* Comply with regulations and standards: HACCP (Hazard Analysis and Critical Control Points) system, ISO 22000, FSSC 22000 and other global food safety standards all list metal foreign matter control as a critical control point (CCP) or prerequisite program (PRP). High-performance magnetic separators are the basic hardware to meet these requirements.

* Equipment selection and verification: The magnetic strength, form and installation location must be scientifically selected based on material characteristics (dry/wet, particle size, flow rate), expected metal size and type. Equipment performance needs to be verified regularly (such as using standard test pieces).

* Strict maintenance procedures: This is the lifeline to ensure the continued effectiveness of magnetic separation equipment! Must establish and implement:

* Regular cleaning: Clean the metal impurities adsorbed on the surface of the magnet according to the plan (such as every shift, every day) to prevent accumulation from causing magnetic field shielding or re-mixing of impurities.

* Regular inspection: Check whether the magnet is damaged, whether the coating is intact (to prevent food contamination), and whether the magnetic force is attenuated (regularly use a gauss meter to test).

* Records and traceability: Detailed records of cleaning, inspection, and metal impurities found to ensure the process is traceable.

 

In the field of food processing, magnetic materials and their separation technology are by no means dispensable supporting roles. They are the cornerstone of building a food safety defense line and the guardian of efficient operation of the production line. Intercepting every potentially harmful metal impurity from the source is a manifestation of the modern food industry's responsibility for consumer health and a wise investment for companies to achieve sustainable development and win market trust.

Therefore, please pay attention to these "invisible guardians":

* Scientifically select applicable magnetic separation equipment.

* Strictly implement maintenance and cleaning procedures.

* Deeply integrate it into your food safety management system.

Why is rare earth magnet indispensable for new energy vehicles?
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In new energy vehicles, NdFeB permanent magnets are usually installed on the rotor of a permanent magnet synchronous motor (PMSM). When current passes through the stator winding to generate a rotating magnetic field, the permanent magnet's inherent magnetic field interacts with it, generating torque to drive the rotor to rotate - this is the precise physical process that occurs when you step on the "gate". Therefore, rare earth permanent magnets are called the "invisible heart" of new energy vehicles.

 

earth magnet

Rare earth permanent magnets: the "magnet king" of modern motors

The history of the development of rare earth permanent magnet materials can be described as an evolution of materials science. From the earliest natural magnets, to AlNiCo magnets in the early 20th century, to ferrite permanent magnet materials in 1947, humans have been constantly pursuing stronger magnetic properties. The real revolution occurred in 1983 when the third-generation rare earth permanent magnet material neodymium iron boron (NdFeB) came into being.

Why is neodymium iron boron called the "king of permanent magnets"? Its magnetic energy product is 10 to 15 times higher than that of ferrite, 5 to 8 times higher than that of traditional electric excitation materials, and second only to superconducting excitation. This material has extremely high remanence and coercivity, strong anti-demagnetization ability, and can allow the motor to generate a strong magnetic field in a smaller volume.

 

Why is it necessary for new energy vehicles?

Unlike traditional fuel vehicles, new energy vehicles have almost stringent requirements for drive motors: high power, small size, light weight, and high efficiency. Rare earth permanent magnet synchronous motors just meet these requirements perfectly:

Efficiency king: The efficiency can reach up to 97%, which is 6% higher than the efficiency of the induction motor used by Tesla in the early days, which directly translates into a longer driving range.

Power density king: Small size, light weight, and power density far exceeds other motor types, making vehicle layout more flexible.

Precise control: High speed regulation accuracy, fast response speed, and smooth and immediate power response.

In contrast, although AC induction motors are low in price and high temperature resistance, they have low power density; switched reluctance motors are low in price but have high noise and vibration. In terms of comprehensive performance, rare earth permanent magnet synchronous motors are undoubtedly the optimal solution for current new energy vehicle drive motors.

 

According to research, each new energy vehicle consumes an average of 2.5 kg of NdFeB permanent magnet materials. With the explosive growth of new energy vehicles:

In 2025, the global demand for rare earth magnets for new energy vehicles is expected to reach 30,000 tons.

The compound growth rate of rare earth magnet demand from 2021 to 2025 is 35%+, and new energy vehicles contribute about 60% of the growth.

Although rare earth permanent magnets are small, they have become an indispensable "industrial vitamin" for new energy vehicles. In the field of new energy vehicles, the essence of competition has shifted from the application level to the basic science level. With its advantages in rare earth resources and processing technology, China is transforming this strategic resource into a fulcrum for defining the future automotive technology paradigm.

What is a magnetic lifter? Why is it called the "invisible giant arm" in heavy industry?
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At the heavy steel plate lifting site, the crane moves slowly, but there are no steel cables or hooks below - only an inconspicuous metal plate adsorbing several tons of steel, hanging steadily in the air. Behind this is the power of the magnetic lifter, which uses the "invisible hand" of the magnetic field to completely revolutionize the way heavy materials are transported.

 

magnetic lifter

 

Core principle: precise control of magnetic field

Magnetic lifters are mainly divided into two types: permanent magnet and electromagnetic. The core of both types is to achieve adsorption and release through the control of magnetic field.

- Permanent magnet lifter: It uses high-performance permanent magnet materials such as neodymium iron boron (NdFeB) inside, and changes the distribution of magnetic lines of force by rotating the mechanical handle. When turned on, the bottom forms a longitudinal magnetic pole to adsorb the load; when closed, the magnetic lines of force are closed inside to achieve "zero magnetic leakage" release. The feature of not requiring power makes it extremely safe in power-off scenarios.

- Electromagnetic lifter: It relies on current to pass through the coil to generate a magnetic field, and the size of the magnetic force can be flexibly controlled by adjusting the voltage. The advantage is that it can be remotely controlled and is suitable for accurately separating single pieces of material from stacked plates. However, it requires continuous power supply and a backup battery to deal with the risk of power outages.

- Innovative combination: Electro-permanent magnet technology (such as Magswitch) combines the advantages of both. It only needs to be powered on for a moment to switch the magnetic state, and no power is required to maintain the magnetic force thereafter, with an energy saving rate of 95%, and supports remote control operation.

magnetic lifter

Why is it the darling of the industry?

1. Safe and reliable:

The maximum pull-off force of the permanent magnet type is 3.5 times the rated load, eliminating accidental falling off; the electromagnetic type avoids the arcing failure of the traditional contactor through contactless control technology (such as thyristor module) and improves stability.

2. High efficiency and energy saving:

Permanent magnets do not require electricity, and electromagnetics only consume electricity when working. Compared with hydraulic or mechanical clamps, energy consumption is reduced by more than 90%, and the cost of the cooling system is eliminated.

3. Lightweight design:

The high magnetic energy product of neodymium magnets reduces the size of the equipment by 50%, and it can be carried by manpower, greatly reducing the load of the crane.

Key usage tips: Avoid "magnetic traps"

The performance of magnetic lifters is affected by multiple factors, and ignoring these details may lead to accidents:

Influencing factors Performance changes Solution
Insufficient material thickness Lifting capacity decreased by 30%-50% Select equipment with higher rating
Surface roughness＞50μm Magnetic force attenuated by 40% Clean the surface or increase the number of magnets
High carbon steel load Magnetic force weakened by 5%-10% Calculate at 95% of the rating
High temperature environment (＞80℃) Neodymium magnets are irreversibly demagnetized Use samarium cobalt magnets (resistant to 350℃)

 

Good maintenance and monitoring can extend the life:

- Avoid impacting neodymium magnets (brittle materials are prone to breakage);

- Check magnetic force attenuation every two years and replace aged magnet modules;

- Electromagnetically check the battery capacity regularly to ensure that the power-off magnetic retention function is effective.

How Effective Is the Iron Filing Adsorption of Strong Magnetic Rods in New Energy Material Production?
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In the production of new energy materials, the strong magnetic iron-removal rods demonstrate excellent performance in adsorbing fine iron filings, which is mainly reflected in the following aspects:

 

1. High Magnetic Field Strength

Strong Magnetic Rods

Strong magnetic iron-removal rods are typically made from high-performance neodymium-iron-boron (NdFeB) permanent magnetic materials. These materials possess extremely high magnetic energy and coercivity, capable of generating a magnetic field strength as high as 12,000 - 16,000 Gauss. Under such a powerful magnetic field, even fine iron filings with diameters of just a few micrometers are attracted by the strong magnetic force and are adsorbed onto the surface of the magnetic rod. Experimental data shows that in a magnetic field environment of 13,000 Gauss, the adsorption force of a strong magnetic rod on 5μm iron particles can exceed 1,000 times their own weight.

 

 

2. Optimized Structural Design

The structural design of strong magnetic rods further enhances their ability to adsorb fine iron filings. Magnetic rods with a multi-layered magnet structure can effectively increase the magnetic field gradient, thereby improving the adsorption effect on fine iron filings. The outer layer of low-coercivity magnets first adsorbs larger iron filings, while the inner layer of high-coercivity magnets is responsible for capturing finer iron filings. This design can increase the adsorption efficiency of iron filings smaller than 1μm by about 20%. In addition, thinner magnetic rods can produce a more concentrated magnetic field, which is more advantageous for adsorbing fine iron filings.

 

3.Practical Application Effects

Strong Magnetic Rods

The application of strong magnetic rods in the production of new energy materials has shown significant results. For example, in the production process of silicon-carbon anode materials, by arranging strong magnetic rods in the material conveying pipeline to form an iron-removal device, fine iron filings in the raw materials can be effectively adsorbed, reducing the iron impurity content from an initial 20ppm to below 5ppm. In the grinding process of lithium iron phosphate cathode materials, using a strong magnetic rod with a diameter of 10mm, combined with an appropriate magnetic circuit design, can achieve a magnetic field strength on the surface of the magnetic rod of over 13,000 Gauss, effectively adsorbing fine iron filings generated during the grinding process.

 

 

4. Surface Treatment and Maintenance

The surface treatment process of strong magnetic rods is equally important. To prevent corrosion of the magnetic rod during use and to avoid difficulties in cleaning the adsorbed iron filings, the surface of the magnetic rod is usually treated specially, such as being covered with a stainless steel sleeve or food-grade plastic. This surface treatment does not affect the magnetic performance of the magnetic rod, but it can protect the service life of the rod and ensure that its ability to adsorb fine iron filings remains stable over the long term. Regular cleaning and maintenance of the strong magnetic rod are also crucial. Through reasonable maintenance measures, the magnetic rod can maintain good adsorption performance continuously.

 

How to Select the Appropriate Fluid Iron Remover for Chemical Raw Material Pipelines?
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To select an appropriate fluid iron remover for chemical raw material conveying pipelines, it is necessary to consider a variety of factors, including the physical properties, chemical properties, flow rate and pressure of the raw materials, as well as the material and structural design of the iron remover. Here are specific selection recommendations:

 

Fluid Iron Remover

 

1. Selection Based on the Physical Properties of Chemical Raw Materials

Low-viscosity, free-flowing liquid raw materials: Such as water-based solvents, petroleum products, etc., a conventional pipeline-type fluid iron remover can be chosen. The pipe diameter should match the conveying pipeline, and the best iron removal effect is achieved when the material flow rate is controlled at 0.5 - 1.5 m/s.

High-viscosity raw materials or those containing solid particles: Such as coatings, inks, adhesives, etc., a pipeline-type fluid iron remover with a scraper cleaning device should be selected. This device can automatically clean the iron impurities and viscous materials adhering to the surface of the magnetic rod during operation, preventing blockages.

 

2. Selection Based on the Chemical Properties of Chemical Raw Materials

Corrosive chemical raw materials: Such as sulfuric acid, hydrochloric acid, sodium hydroxide solution, etc., the material of the iron remover must have good corrosion resistance. Iron removers made of stainless steel, Hastelloy, titanium alloy, and other corrosion-resistant materials can be selected, and the magnetic rod's covering layer can be made of corrosion-resistant materials such as polytetrafluoroethylene (PTFE) or PPS.

 

3. Consideration of Flow Rate and Pressure

Flow rate: Choose a fluid iron remover with a suitable pipe diameter based on the flow rate to ensure smooth material passage.

Pressure: The rated pressure of the iron remover should be 1.2 - 1.5 times higher than the actual operating pressure of the pipeline to ensure the safe operation of the equipment.

 

4. Selection of Iron Remover Structure and Function

Automatic iron removal function: For continuous chemical production processes, selecting a fluid iron remover with an automatic iron removal function can reduce downtime and improve production efficiency.

Multi-layer filtration structure: Modern fluid iron removers often use a multi-layer filtration structure, which can enhance the iron removal effect.

High-temperature adaptability: If the chemical raw material is a high-temperature fluid, an iron remover made of high-temperature-resistant materials and equipped with a special cooling system should be selected.

 

5. Other Considerations

Magnetic strength of the iron remover: A fluid iron remover with a magnetic rod diameter of 25 mm can achieve a maximum magnetic strength of 12,000 Gauss, which is suitable for places with high requirements for iron impurity content.

Customized design: Based on specific process requirements, customized fluid iron removers can be selected to meet special requirements for flow rate, pressure, temperature, or chemical environment.

By following the above selection recommendations, it is possible to better choose a suitable fluid iron remover for chemical raw material conveying pipelines, ensuring the high purity of chemical raw materials and the smooth progress of the production process.

How Does ASRS (Automated Storage and Retrieval System) System Work? RACK
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Automated Storage and Retrieval Systems (ASRS) have revolutionized warehouse operations by enhancing efficiency, accuracy, and throughput. In this blog post, we'll explore the intricate workings of kingmoresmart ASRS, including the utilization of the four-way shuttle system, high-stability smart adaptive AGV forklifts, and miniload automated storage and retrieval system.

High Stability Smart Adaptive AGV Forklifts

Introduction to ASRS

ASRS is a sophisticated warehouse automation technology designed to automatically store and retrieve goods with minimal human intervention. It encompasses a variety of subsystems and components, each contributing to the seamless operation of the system.

 

The Four Way Shuttle System

At the heart of many ASRS implementations is four way shuttle automated storage system. This innovative technology comprises shuttle robots capable of moving horizontally and vertically within storage racks. Equipped with gripping mechanisms, these shuttles can grasp and transport storage containers or pallets to designated locations with precision and efficiency.

 

High Stability Smart Adaptive AGV Forklifts

In conjunction with the four-way shuttle system, ASRS often integrates high stability smart adaptive AGV forklifts. These AGVs are equipped with advanced sensors, cameras, and navigation systems that allow them to autonomously navigate warehouse environments. They can pick up and transport goods between storage racks and loading docks, optimizing material flow and minimizing downtime.

 

Miniload Automated Storage and Retrieval System

The miniload automated storage and retrieval system is another integral component of ASRS, particularly in facilities handling smaller items or parts. This system utilizes automated cranes or robotic arms to retrieve bins or totes from densely packed storage modules and deliver them to picking stations or packing areas. Miniload ASRS enhances storage density, accelerates order fulfillment, and reduces labor requirements.

 

How ASRS Works in Practice

In operation, ASRS begins with the receipt of goods into the warehouse. Incoming items are scanned, tagged, and assigned to storage locations based on predefined criteria such as SKU, size, or demand forecast. The four-way shuttle system and AGV forklifts work in tandem to transport goods to their designated storage locations efficiently.

 

When an order is received, the ASRS system orchestrates the retrieval of the required items from storage. The miniload ASRS retrieves smaller items, while the shuttle system and AGV forklifts handle larger pallets or containers. Once all items are gathered, they are conveyed to the packing area for consolidation and shipment.

 

ASRS represents a pinnacle of warehouse automation, leveraging cutting-edge technologies such as the four-way shuttle system, high-stability smart adaptive AGV forklifts, and miniload automated storage and retrieval systems. By streamlining storage and retrieval processes, ASRS enhances operational efficiency, accuracy, and scalability, enabling businesses to meet the demands of modern commerce with ease. Understanding the inner workings of ASRS provides valuable insights into the future of warehousing and logistics.



Comprehensive Guide What are the charms and applications of rod magnets?
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Rod magnets, the "long-distance runners" in the magnetic world, have become indispensable components in various industries and applications, from speakers, sensors, motors to magnetic therapy equipment, with their clear magnetic field direction, good axial action distance, excellent stability and economy. Although they may be surpassed by more modern powerful magnets in terms of absolute magnetic strength, rod magnets are still an irreplaceable and practical choice in areas that require directionality, long action distance, high temperature stability and low cost.

rod magnets

 

What is a bar magnet?

A bar magnet, as the name implies, is a long (cylindrical or cuboid) permanent magnet. It is one of the most basic and intuitive forms in the permanent magnet family. Its core physical properties are:

* Clear pole distribution: The two ends of the bar form a stable North Pole (N) and South Pole (S), which are the areas with the strongest magnetic force.

* Directivity of magnetic field: The magnetic field mainly extends along the long axis of the bar, forming a clear closed magnetic flux line between the two poles. The magnetic field in the middle area of ​​the bar is relatively weak.

* Material composition: The most common material is ferrite (ceramic magnet) because of its low cost, good corrosion resistance and stability. Neodymium iron boron (NdFeB) or aluminum nickel cobalt (AlNiCo) are used in high-performance applications, which can provide stronger magnetic force.

 

Core performance and unique charm

1. Directed magnetic field, clear and controllable: Its long strip structure naturally guides the direction of the magnetic field, and the two poles are clear, which makes it very advantageous in applications that require magnetic force in a specific direction (such as sensors, magnetic stirring).

2. Balance between strength and size: Although the magnetic force per unit volume may not be as good as some compact magnets (such as square magnets), by increasing the length, it can achieve a significant magnetic range in a specific direction.

3. Strong and durable: Especially sintered ferrite rods, which have excellent corrosion resistance, temperature stability (operating temperature can reach 250°C or even higher) and physical hardness, are not easy to demagnetize, and have a long service life.

4. Economical and practical: Ferrite rod magnets are one of the most cost-effective permanent magnets and are suitable for large-scale applications.

 

How to make it?

There are two main processes for making rod magnets:

1. Sintering process (mainstream):

* Raw material mixing: Mix ferrite (SrFe12O19 or BaFe12O19) or rare earth magnetic powder (such as NdFeB) with a binder, etc.

* Pressing: The mixture is pressed into a rod-shaped mold under a strong magnetic field. Magnetic field orientation is a key step, which makes the easy magnetization axis of the magnetic powder particles align along the length of the rod, giving the magnetic rod anisotropy (that is, the magnetic properties are optimal along the length).

* High-temperature sintering: The pressed green sheet is sintered and solidified in a high-temperature furnace (about 1200-1300°C for ferrite and about 1000-1100°C for NdFeB) to form a dense microcrystalline structure.

* Magnetization: The cooled "green sheet" is placed in an ultra-strong pulsed magnetic field for magnetization to activate its magnetism.

* Surface treatment and testing: Coating (such as epoxy, zinc, nickel) may be applied to enhance corrosion resistance, followed by strict dimensional, appearance and magnetic performance testing.

2. Bonding process:

* Mixing magnetic powder (such as ferrite, NdFeB or SmCo) with plastic (such as nylon, rubber) or resin.

* Made into a rod shape by injection molding or compression molding.

* The advantages are that complex shapes can be manufactured, high dimensional accuracy, and good toughness; the disadvantages are that the magnetic properties are usually lower than sintered magnets of the same material, and the temperature resistance is poor.

 

rod magnetsrod magnets

Ubiquitous:

Bar magnets are active in many fields due to their unique shape and stable performance:

* Education and demonstration: A classic teaching aid for physics classrooms to demonstrate magnetic poles, magnetic field lines, and magnetic interactions.

* Industrial sensing and detection:

* Magnetic sensors: Used to detect position, speed, and rotation speed (such as automotive ABS wheel speed sensors).

* Door magnetic switches: The core component for detecting the open and closed status of doors and windows in security systems.

* Magnetic separators: Adsorb and remove ferromagnetic impurities in recycling, mining, and food processing.

* Electronics and electrical:

* Speakers/receivers: Key components for providing a constant magnetic field inside traditional dynamic speakers.

* DC motors: Rod magnets are used in some small DC motors (such as toy motors) to provide a stator magnetic field.

* Magnetic stirrers: The core of the stirrer (often wrapped in Teflon) is the magnetic bar, which is driven by a rotating magnetic field at the bottom of the beaker.

* Daily necessities: magnetic door curtains, tool box fasteners, magnetic hooks, etc.

* Medical and scientific research: They are also used in some experimental equipment and simple magnetic therapy equipment (scientificity and standardization should be noted). They can even be found in some early or auxiliary components of magnetic resonance imaging (MRI) systems.

 

 

China's rare earth export control, the European automobile industry sounded the alarm,the opportunities and challenges of strong magnetic rods in the new energy industry
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The Impact of China’s Rare Earth Export Controls on the European Automotive Industry

1.Supply Chain Disruption Risks

Since April 2025, when China implemented export controls on certain medium and heavy rare earths (such as dysprosium, terbium, and samarium) and related magnets, the rare earth inventories of European automotive component suppliers have nearly been depleted. The European Association of Automotive Suppliers (CLEPA) has warned that many production lines and factories have already shut down due to rare earth shortages, and with inventories running out, more production lines are likely to halt in the coming weeks.

The German Association of the Automotive Industry (VDA) has also noted that the slow issuance of export licenses has prevented some suppliers from delivering products on time, thereby affecting the production schedules of automakers.

 2. Production and Economic Impacts

Rare earth magnets are core materials for key automotive components such as electric motors and sensors. Disruptions in the supply of rare earths can lead to production standstills in automotive assembly lines. For example, the Society of Indian Automobile Manufacturers has warned that the rare earth magnet inventories of India’s three major automakers can only sustain normal production for three days. If timely replenishment is not possible, the entire Indian automotive industry may face a complete shutdown.

In Europe, some companies have already been forced to suspend production due to their inability to obtain key rare earth magnets. This not only affects the production plans of automakers but also impacts the automotive industry, a pillar of the European economy.

 3. Industry Response Measures

Some automakers are considering relocating certain production processes to China to circumvent the export controls on rare earth magnets. In addition, some companies are accelerating the development of alternative technologies such as rare earth-free motors to reduce their dependence on rare earths.

The Impact of Rare Earth Policies on Strong Magnetic Rods in the New Energy Industry

Strong magnetic rods, often made from rare earth permanent magnets, are directly affected in terms of production costs by changes in rare earth policies and market conditions. When rare earth prices rise, the production costs of strong magnetic rods increase, putting cost pressure on manufacturers. However, on the other hand, the regulatory policies on the rare earth industry also prompt companies to focus more on product quality and technological innovation to enhance product value, thereby offsetting some of the cost increases.

In the new energy industry, the application of strong magnetic rods is extremely important. For example, in the production of batteries for new energy vehicles, the raw materials for batteries require a very high level of purity. The presence of ferromagnetic impurities can severely affect battery performance. Strong magnetic rods can efficiently adsorb these impurities to ensure the purity of battery raw materials. With the rapid development of the new energy vehicle market, the demand for high-quality batteries continues to grow, which in turn increases the market demand for strong magnetic rods. Despite cost pressures, the rapid development of the new energy industry provides a broad market space for strong magnetic rods.

To cope with the challenges brought about by changes in rare earth policies and market conditions, manufacturers of strong magnetic rods are actively taking measures. On one hand, they are increasing R&D investment to improve the utilization rate of rare earth materials through technological innovation, thereby reducing the amount of rare earths used per unit of product. On the other hand, they are strengthening cooperation with upstream and downstream companies to establish long-term and stable supply chain relationships to jointly address the risks of price fluctuations. For example, some companies have signed long-term agreements with rare earth suppliers to lock in rare earth purchase prices for a certain period, ensuring the stability of raw material supplies.

Amid the regulatory policies and market fluctuations in the rare earth industry, strong magnetic rods in the new energy industry face both challenges such as rising costs and opportunities for increased market demand. Through measures such as technological innovation and optimization of supply chain management, manufacturers of strong magnetic rods are expected to achieve sustainable development in the complex market environment and continue to provide strong support for the high-quality development of the new energy industry.

magnetic rod

How to Clean a Magnetic Rod?
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Magnetic rods are common cleaning tools, typically used to attract metal impurities such as iron filings and dust. They are widely used in industrial and home settings. Here are the methods for cleaning a magnetic rod:

 

bar magnet

 

Preparations Before Cleaning

1. **Power Off or Isolate**: If the magnetic rod is used in industrial equipment or an electrified environment, it is essential to cut off the power supply or remove it from the working environment before cleaning to ensure safety.

2. **Prepare Cleaning Tools**: Gather the necessary cleaning tools, such as brushes (both soft and hard bristle), cloths, and cleaning agents (such as alcohol or soapy water, depending on the material of the magnetic rod and the type of dirt).

Cleaning Steps

1. **Remove Adhered Materials**

   - **Manual Cleaning**: Gently scrape off iron filings, dust, and other impurities adhering to the surface of the magnetic rod with your fingers or tweezers. If there are a lot of adhered materials, you can place the magnetic rod in a container and shake it gently to let most of the impurities fall off.

   - **Using a Brush**: For stubborn adhered materials, use a soft-bristle brush to gently scrub. For harder stains, a hard-bristle brush can be used, but be careful with the force to avoid scratching the surface of the magnetic rod.

2. **Wipe the Surface**

   - **Wet Cloth Wiping**: Use a cloth dampened with water or cleaning agent to wipe the surface of the magnetic rod to remove residual dirt and dust. If the stains are heavy, you can increase the amount of cleaning agent used, but be careful not to let the cleaning agent seep into the interior of the magnetic rod.

   - **Alcohol Wiping**: For stains that are difficult to clean, you can use alcohol to wipe. Alcohol has good solubility and volatility, which can quickly remove oil and stains, and also disinfect and sterilize. After wiping, let the magnetic rod dry naturally.

3. **Inspection and Maintenance**

   - **Inspect the Surface of the Magnetic Rod**: After cleaning, carefully check the surface of the magnetic rod for scratches, dents, or other damage. If damage is found, it should be repaired or replaced in a timely manner to avoid affecting its normal use.

   - **Check the Magnetism**: Use some small iron filings or nails to test whether the magnetism of the magnetic rod is normal. If the magnetism is significantly weakened, it may be due to aging or damage of the magnets inside the magnetic rod, and it needs to be replaced in a timely manner.

Post-Cleaning Maintenance

1. **Drying**: Ensure that the magnetic rod is completely dry after cleaning to prevent residual moisture from causing rust or damage. You can let it dry naturally in a ventilated area or use a clean cloth to dry it.

2. **Storage Environment**: Store the magnetic rod in a dry, clean environment, away from corrosive substances, and avoid high-temperature and humid conditions to extend its service life.

3. **Regular Cleaning**: Depending on the frequency of use and the environment, regularly clean and maintain the magnetic rod. It is generally recommended to clean it once a week or month to keep it in good working condition.

 Precautions

- Do not use overly hard or rough tools to clean the magnetic rod to avoid scratching its surface.

- If the magnetic rod is made of magnetic material, be careful to avoid attracting other magnetic items during cleaning, which can cause damage or cleaning difficulties.

- For some special magnetic rods, such as those with electronic components or precision structures, be extra careful during cleaning to avoid damaging the internal structure.

- If there is rust on the surface of the magnetic rod, you can use a rust remover to treat it, but be sure to choose the appropriate rust remover to avoid corroding the magnetic rod.

In summary, when cleaning a magnetic rod, pay attention to the methods and force used, and also do a good job of maintenance after cleaning to ensure the performance and service life of the magnetic rod.

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