Speed up solution for cable extrusion: high activation magnesium hydroxide improves plasticizing effect

The extrusion process is one of the key steps in the manufacturing of wires and cables. Its efficiency and quality directly affect the performance and production cycle of the product. With the intensification of market competition and the increasing demand for delivery cycles from customers, how to improve extrusion speed and shorten production time has become a key issue of concern for many cable companies.

Although adding a large amount of inorganic fillers (such as ordinary magnesium hydroxide) to traditional cable materials can improve flame retardancy, it often leads to difficulties in plasticization, increased melt viscosity, decreased flowability, and other problems, which in turn affect extrusion speed and surface quality of finished products. In recent years, the introduction of highly activated magnesium hydroxide has significantly improved the plasticizing effect while maintaining excellent flame retardancy, providing a practical and feasible technical path for accelerating cable extrusion.

1、 Common difficulties in extrusion molding process

Extrusion molding refers to the process of heating and melting thermoplastic or rubber materials, and then coating them onto conductors or cable cores through molds to form an insulation layer or sheath. In this process, if the material contains a large amount of inorganic fillers, the following problems often occur:

Uneven plasticization

Poor dispersion of fillers leads to stress concentration points inside the melt, affecting the mechanical properties and appearance quality of the product.

The viscosity of the melt is too high

A high filling amount will increase the melt resistance, resulting in an increase in extrusion torque and equipment load, which limits the increase in extrusion speed.

Processing temperature sensitivity

Ordinary magnesium hydroxide is prone to premature dehydration at high temperatures, causing defects such as bubbles and voids, which reduces the yield of finished products.

Equipment wear and tear intensifies

The hardness of the filler particles is high, and long-term use can easily cause wear on components such as screws and barrels, increasing maintenance costs.

These problems not only reduce production efficiency, but also increase the operating costs of enterprises, which urgently need to be solved through material innovation.

2、 Technical advantages of highly activated magnesium hydroxide

The so-called "highly activated magnesium hydroxide" refers to magnesium hydroxide products that have undergone special physical or chemical treatments to enhance their surface activity, reduce particle size, improve dispersion, and possess stronger interfacial compatibility. Compared to traditional magnesium hydroxide, it exhibits significant advantages in the cable extrusion process in the following aspects:

Improve the rheological properties of materials

Highly activated magnesium hydroxide has lower surface tension and higher wettability, making it easier to uniformly disperse in polymer matrices, effectively reducing melt viscosity, improving fluidity and extrusion speed.

Optimize the plasticization process

Its surface modification technology enhances the bonding force with the resin, making it easier for the entire system to achieve a good plasticization state during heating, reducing melt fracture and surface defects.

Control the rhythm of water release

After activation treatment, the dehydration temperature curve of magnesium hydroxide is more controllable, avoiding the problem of bubbles caused by rapid evaporation of water during extrusion and improving the stability of finished product quality.

Reduce equipment wear and tear

The characteristics of finer particle size and smoother surface reduce the frictional effect of fillers on equipment, extending the service life of key components of extruders.

3、 Analysis of Practical Application Cases

A well-known domestic cable production enterprise is facing problems such as slow extrusion speed, rough surface, and high scrap rate when producing low smoke halogen-free flame-retardant cables. The original formula used ordinary magnesium hydroxide as the main flame retardant, with a filling ratio of over 60%. Although it can meet the requirements of flame retardancy, it seriously affects the extrusion efficiency.

Under the guidance of technical personnel, the company replaced ordinary magnesium hydroxide with highly activated magnesium hydroxide and made minor adjustments to the formulation system. The effect of the renovation is as follows:

The extrusion speed has increased by more than 25%, and the production capacity per unit time has significantly increased;

The melt pressure drops by about 15%, the motor load is reduced, and energy consumption decreases accordingly;

The surface smoothness has significantly improved, and the product qualification rate has increased from 85% to over 96%;

The flame retardant performance was not affected, and both the vertical combustion test and smoke density test met the standard requirements.

This successful case demonstrates that using highly activated magnesium hydroxide instead of traditional materials can not only solve the problem of increasing extrusion speed, but also balance environmental protection and safety requirements, bringing considerable economic benefits to enterprises.

4、 Scope of application of highly activated magnesium hydroxide

Highly activated magnesium hydroxide is suitable for various cable material systems, especially for the manufacturing of the following types of high-performance cables:

Low smoke halogen-free flame-retardant cable (LSZH)

Widely used in places with high requirements for environmental protection and safety, such as subways, hospitals, and data centers.

FIRE RESISTANT

Cables that need to maintain power supply function for a certain period of time under fire conditions, such as fire protection systems, emergency lighting lines, etc.

High voltage cables for new energy vehicles

There are high requirements for the electrical performance, thermal stability, and environmental protection indicators of materials.

Rail Transit Cable

The material is required to have good weather resistance, flexibility, and fire resistance.

By applying highly activated magnesium hydroxide in these high-end cable products, not only can efficient extrusion be achieved, but also the increasingly strict environmental regulations and high standard demands for product quality from end users can be met.

For enterprises seeking to improve extrusion efficiency, reduce production costs, and meet environmental requirements, adopting highly activated magnesium hydroxide is undoubtedly an important choice worth trying.

Under the current trend of pursuing efficient, green, and intelligent development in the cable industry, material innovation has become the core driving force for promoting industrial upgrading. Highly activated magnesium hydroxide, with its excellent plasticizing improvement ability and environmental protection characteristics, is gradually becoming a key technical support for cable extrusion speed improvement solutions.