In the precast concrete manufacturing process, the method of fixing the formwork is one of the key factors affecting production efficiency, cost, and product quality. With the development of technology, magnetic systems have gradually become an emerging method of formwork fixing, bringing about many significant changes compared to traditional formwork clamps.

01 Fundamental Differences in Technical Principles

The application of magnetic systems and traditional formwork clamps in precast plants is primarily reflected in their fundamentally different working principles.

Traditional formwork clamps typically rely on mechanical fastening, such as screws, bolts, and clamps, applying physical pressure to the mold to achieve fixation. This method requires pre-drilling or welding into the formwork and platform, with each connection point requiring individual fasteners and manual operation.

Magnetic systems, on the other hand, rely on the strong attractive force of permanent magnets. The magnetic field generated by high-performance neodymium magnets firmly bonds the formwork to the steel platform.

The working principle of magnetic systems is not complex. These devices contain high-performance permanent magnets. A magnetic control box enhances and shields the magnetic force of the internal magnetic blocks, keeping them in an active or inactive state. When the magnetic box is active, the holding surface at the bottom of the magnetic block adheres tightly to the precast concrete production platform, providing a secure hold.

When the magnetic block is pried up with a lever, most of the magnetic force is shielded by the magnetic control box, significantly reducing the bottom magnetic force, allowing the magnetic box to be easily removed from the platform manually. This technology avoids dependence on external energy sources and works entirely based on the physical properties of the magnets themselves.

02 Comparative Analysis of Efficiency and Cost

In precast component production, time is money. The difference in efficiency and cost between magnetic systems and traditional clamps directly determines the project's profitability.

Traditional clamps require drilling, installing screws, and tightening bolts one by one. This process is not only time-consuming but also prone to errors. Taking stair precast component molds as an example, traditional side mold connections require top screw fixing and bottom pin positioning, making the operation complex.

Magnetic systems significantly improve installation speed. Industry data shows that using magnetic systems can reduce template installation time by more than 70%. A simple magnetic box switch can instantly and firmly fix the entire side mold, eliminating the need to adjust each fastener individually.

From a cost perspective, while traditional template clamps have a lower initial investment, their long-term operating costs are higher. Mechanical fasteners are easily damaged and require regular replacement; drilling and welding can cause permanent damage to the mold platform, shortening its lifespan; and labor costs remain consistently high.

In contrast, while magnetic systems have a higher initial investment, they offer significant cost advantages. Once installed, the magnetic device can be reused thousands of times, far exceeding the lifespan of traditional clamps. Since no drilling or welding is required, the formwork and mold table remain intact, significantly reducing maintenance costs.

The precast concrete magnet can withstand a weight of 2100 kg, making it extremely lightweight and suitable for use in precast concrete plants. It can be easily accessed by crane. This strong load-bearing capacity enables it to meet the production needs of the vast majority of precast components.

03 Key Performance Data Comparison

The table below illustrates the performance differences between the magnetic system and traditional template clamps from multiple perspectives:

The data shows that magnetic systems have significant advantages in terms of efficiency, durability, and adaptability, especially in assembly line production environments where frequent disassembly and assembly of templates are required.

04 Enhanced Quality and Precision

The quality of precast components directly impacts the safety and durability of buildings. In this regard, the magnetic system demonstrates its unique advantages.

Traditional clamps, relying on manual tightening, are prone to inconsistent tightening force, leading to formwork deformation or displacement, which in turn affects the dimensional accuracy of concrete components. This is especially true during vibration table operations, where traditional clamps are prone to loosening and formwork displacement.

The magnetic system, however, provides continuous and uniform clamping force through evenly distributed magnetic points. For example, the LSC-2100 magnetic box has a vertical pull-out force exceeding 2100 kg, and its uniform attraction ensures that the formwork does not shift during production.

The magnetic system also significantly improves the formwork's reset accuracy. Since re-alignment is unnecessary, the formwork can be accurately reset after each assembly and disassembly, greatly improving the dimensional consistency of components during mass production. This is crucial for prefabricated buildings, as the dimensional accuracy of components directly determines the efficiency of on-site installation and the overall quality of the building.

05 Application Scenarios and System Types

Magnetic systems are widely used in precast plants, covering various component production scenarios from simple to complex.

The most basic application is side mold fixing. The side mold is firmly attached to the mold table using magnetic boxes; this is the most common application. Depending on whether the mold table is fixed or vibrating, and the height of the mold (component thickness), different magnetic boxes with varying suction power and sizes can be selected.

For example, when producing composite slabs on a fixed mold table, a magnetic box with a suction power of 600-1000 kg is selected, while a magnetic box with a suction power of 1000 kg is required when producing composite slabs on a vibrating mold table. When producing wall panels, magnetic boxes with a suction power of 1350 kg or 1800 kg are needed.

Magnetic side molds offer a more integrated solution. This type of mold embeds the magnetic suction cup system directly into the steel mold, forming an integrated design. Because the suction cup system is located inside the steel mold groove, concrete residue or other contaminants will not damage the entire mold system.

Embedded component fixing magnetic bases are another important application. When producing precast concrete components, various switch holes and pipe holes need to be left, and various connection or lifting sleeves also need to be pre-embedded. Magnetic bases are used for fixing, which does not damage the platform, ensures the embedded parts do not slip, and guarantees a secure fixation.

In addition, there are specialized tools such as magnetic chamfering strips used to create neat chamfers on the edges of precast concrete components. These rubber magnetic chamfering strips are lighter than iron chamfering strips and also have a certain degree of flexibility, greatly facilitating their use in actual production.

06. Dual Considerations for Safety and Environment

Safety is always paramount in the construction industry. Magnetic systems offer significant improvements in this regard.

Traditional formwork clamps require the use of power tools and welding, posing a high risk of worker injury. Magnetic systems drastically reduce these risks—eliminating the need for drilling and welding, reducing the use of heavy tools, and eliminating sparks and flying metal debris during operation.

Especially in assembly line operations requiring frequent formwork adjustments, traditional methods may require overhead cranes for installation and dismantling, while magnetic systems allow for most tasks to be completed manually, reducing the safety hazards associated with large equipment.

From an environmental perspective, magnetic systems are also more advantageous. Traditional clamps generate significant amounts of metal debris and exhaust fumes during use, while magnetic systems produce virtually no pollutants.

Furthermore, the ability to be reused thousands of times greatly reduces material consumption and waste generation. The reusable nature of magnetic systems makes them a more sustainable construction technology option.

Frequently Asked Questions

Q: How strong is the attraction force of a precast magnetic system?

A: Precast magnetic systems provide reliable attraction force, typically ranging from 500 kg to over 1800 kg per unit, depending on size and design. They are carefully designed to withstand the pressure of new concrete and ensure precise alignment of the formwork.

Q: Is it safe to use a magnetic formwork system near steel molds?

A: Yes! These systems are specifically designed for steel molds. The magnets provide a strong holding force without damaging the mold, and their design ensures a uniform distribution of attraction force, preventing deformation.

Q: Can I add magnets to my existing formwork system?

A: Absolutely. Many magnetic systems are compatible with existing molds. Retrofitting usually requires only minor adjustments and can significantly improve efficiency without replacing major equipment.

Q: What are the maintenance requirements for precast magnets?

A: Magnetic systems have low maintenance costs. Regular cleaning to remove concrete residue and occasional checks for surface wear or corrosion ensure long-term performance and safety.

Q: Are magnetic formwork systems suitable for all types of concrete?

A: Magnetic formwork is suitable for most concrete mixtures, including high-strength concrete, lightweight concrete, and precast concrete. However, for concrete mixtures with very coarse particles or high fiber content, careful placement may be necessary to ensure uniform contact and secure fixation.