Deciphering The Chaos In Cable Material Quality

Deciphering The Chaos In Cable Material Quality

As is well known, the lowest-price bidding system in the cable industry has led to the industry having to reduce the technical specifications and purchase prices of raw materials.

In order to secure orders, raw material manufacturers are engaged in fierce competition in the red ocean market, fighting to the point of being battered and bruised. They continuously lower their ethical standards, abandoning social responsibility and professional integrity. Instead of using their professional knowledge to contribute to the development of society, they have sown numerous hidden dangers!

We will provide examples of common hazardous materials currently on the market, hoping to resonate with our peers and call on the industry to pay attention to environmental protection requirements, to produce high-quality green products, and to refrain from manufacturing non-standard products!

I. In flame-retardant polyvinyl chloride (PVC) and flame-retardant polyethylene, antimony trioxide is an extremely effective flame retardant. This is because it has a good synergistic flame-retardant effect with halogens, which can improve the oxygen index of the material and its self-extinguishing performance when removed from the flame.

However, many material manufacturers use low-quality antimony trioxide containing "arsenic trioxide, commonly known as arsenic trioxide," to deceive many optical and electrical cable factories. Antimony trioxide is produced by calcining and oxidizing stibnite (Sb2O3) to generate Sb2O3, purifying it to remove arsenic and iron, then reducing it to metallic antimony with carbon, further refining it, and finally oxidizing it to obtain pure Sb2O3. Antimony and arsenic are associated minerals, hence the need for repeated purification to remove arsenic.

Currently, in China, the arsenic content in high-purity antimony trioxide is controlled at ≤300ppm. However, antimony trioxide that has not undergone repeated purification also has a large market, simply because it is cheap! At present, antimony trioxide with a purity of over 99.5% on the market is priced above 55,000 yuan per ton, while the so-called antimony trioxide that has not been purified is sold for only 15,000 yuan per ton, with a price difference of nearly four times.

If added at a proportion of 5% in the formula, just this one material alone would result in a price difference of 2,000 yuan per ton. But this is by no means the most terrifying aspect of cutting corners. The truly dreadful part is much more serious!

What is arsenic trioxide? The following is quoted from Baidu Baike: "Arsenic trioxide, commonly known as arsenic, has the molecular formula As2O3 and is the most commercially valuable arsenic compound and the main starting material for arsenic chemistry. It is also one of the oldest poisons, odorless and tasteless, appearing as a white powdery frost, hence the name arsenic. It is a highly toxic byproduct generated in the processing of certain specified minerals, such as gold mining, high-temperature distillation of arsenopyrite (arsenic pyrite), and condensing its white smoke."

As is well known, arsenic trioxide (As2O3) has long been banned by REACH, yet this highly toxic raw material is still widely used by the majority of material manufacturers in China. Many cable manufacturers use it without understanding the risks, and their procurement standards do not include environmental protection requirements. This results in harm and potential hazards to frontline workers and society.

II. So-called low-smoke halogen-free flame-retardant materials refer to flame-retardant materials that do not contain halogens and produce a small amount of smoke. Conventional flame retardants include aluminum hydroxide, magnesium hydroxide, and phosphorus-nitrogen flame retardants, rather than those containing halogens and other heavy metal salts.

However, the quality of materials currently used in China is highly variable. It is not only failing to meet the physical property requirements but also, in most cases, the jackets are filled with non-flame-retardant calcium carbonate or directly use recycled low-smoke halogen-free waste materials.

Cables and optical cables produced using these materials have excellent flame-retardant properties, produce very little smoke when burned, and do not emit corrosive gases. Therefore, they are widely used in nuclear power plants, subway stations, telephone exchanges, computer control centers, high-rise buildings, shopping malls, hotels, television stations, important military facilities, oil platforms, and other places where there are many people and the air density is low.

The halogen-free low-smoke and low-halogen low-smoke characteristics of optical cables mean that in the event of a fire, the spread is slow, the smoke concentration is low, visibility is high, and the release of harmful gases is minimal, facilitating the evacuation of personnel. However, the quality of materials currently used in China is highly variable. It is not only failing to meet the physical property requirements but also, in most cases, the jackets are filled with non-flame-retardant calcium carbonate or directly use recycled low-smoke halogen-free materials.

As is currently understood, the types of optical cables and electrical cables that mainly involve the use of recycled materials and calcium carbonate as a substitute for flame-retardant jacket materials include: butterfly optical cables, low-voltage cables, video cables, and railway signal cables, etc. These are primarily used in tracks or indoor buildings and similar locations. The use of calcium carbonate as a filler in jacket materials is not only non-flame-retardant but also flammable, and it fails to meet the requirements for flame spread rate and smoke emission during combustion. This practice is entirely driven by profit and cost reduction, disregarding the quality of the project.

Optical cables and electrical cables using recycled plastics as jackets have their service life yet to be assessed. The greatest danger is that they are prone to aging and cracking, which fails to provide effective protection for the cable cores, significantly reducing the service life of the optical and electrical cables.

III. Let's also discuss polyethylene recycled materials. Recycled materials are themselves marketed under the guise of environmental protection, using discarded products. Regardless of the impact such use has on market order, the products themselves pose significant risks. Even with the addition of additives, it is impossible to compensate for the internal defects of the materials, resulting in a much shorter service life compared to new materials, and even cases of aging and cracking within a short period.

When it comes to recycled materials, people often ask what the differences are between virgin materials and recycled materials. Recycled materials are made by recycling and shredding plastic products and waste edges, adding additives, and then re-pelletizing them.

Because the sources of plastic products and waste edges are uncertain, this leads to a high content of impurities, very unstable quality, and large differences in physical properties between batches. In terms of mechanical and electrical properties such as tensile strength and toughness, recycled materials are far inferior to virgin materials. The color of the products also tends to be darker and duller, with poor gloss. Most recycled materials have an unpleasant odor, some similar to the strong smell of detergent, while others are pungent.

In addition to the above differences in material properties, the biggest difference lies in their usage. Due to the high content of impurities and non-degradable inorganic substances, the surface of the extruded products made from recycled materials can be rough, matte, and even granular. Compared to the smooth and delicate surface of products made from virgin materials, this has a significant impact on the appearance of the products.

The oxidation induction period is an indicator for evaluating the material's resistance to thermal degradation during processing, storage, and use. It is a method of testing the degree of accelerated aging of plastics in high-temperature oxygen conditions based on the exothermic reaction when the plastic molecular chain breaks, using differential thermal analysis.

However, due to the inconsistency in the sources of recycled materials and their characteristic of being processed multiple times, their molecular chains have already partially broken. Even with the addition of additives, it is impossible to compensate for the internal defects of the materials. Therefore, their service life is much shorter than that of virgin materials, and they may even age and crack within a short period.

IV. Soft PVC materials have good electrical, mechanical, and physical properties. They are widely available and inexpensive, making them widely used in various types of electrical cables and optical cables. However, in the past decade, some cable material enterprises have used inferior and low-priced so-called substitute plasticizers to produce low-price PVC cable materials that seriously fail to meet standard requirements.

The most commonly used PVC cable material is so-called epoxy fatty acid methyl ester, which is actually epoxy "gutter oil." It is a chemical product obtained by oxidizing various types of gutter oils. What are the results of adding it to cable materials, and what are the hazards to the material's properties and the long-term use of the cables?

Epoxy fatty acid methyl ester has a flash point of 170 to 190 degrees Celsius and has a certain degree of compatibility with PVC resin. However, there is a significant risk of exudation when added to PVC, manifested as oiling in summer and blooming in winter. The time of exudation varies depending on different formulas and processing technologies. Some may show signs within one or two months, while others may take one or two years, or even several years to manifest.

Cables made from this material will continuously exhibit oiling and whitening phenomena as the laying time increases. Moreover, as the amount added increases, it is easy to cause the heat aging mass loss to be unqualified. A large amount of addition can lead to serious unqualification.

The mixture of epoxy soybean oil and epoxy fatty acid methyl ester is a common method for this type of PVC material. For this kind of PVC material, a large amount of epoxy soybean oil is likely to cause the low-temperature performance of the material to be unqualified, while a large amount of epoxy fatty acid methyl ester can cause problems with heat aging mass loss.

The air pollution caused by epoxy fatty acid methyl ester should not be underestimated. The epoxy fatty acid methyl ester available on the market is basically made from gutter oil, which has a rancid lard smell. Due to the high volatility of epoxy "gutter oil", the workshop space is filled with an unpleasant odor during the production and processing process, and the impact on human health needs to be assessed.

In recent years, chlorinated epoxy fatty acid methyl ester has also gradually entered the field of PVC materials, and its hazards are similar to those of epoxy fatty acid methyl ester.

In flame-retardant PVC materials, the addition of antimony trioxide can quickly improve their flame-retardant properties. Normal antimony trioxide is expensive, but some unscrupulous enterprises use a large amount of arsenic-containing antimony trioxide flame retardants, or even all arsenic compounds, with the main components being arsenic trioxide and arsenic pentoxide, which are the main components of arsenic. The harm of arsenic to the human body has been described earlier in this article.

The addition of high-arsenic flame retardants can cause the heat aging mass loss of PVC materials to be unqualified. The addition of arsenic can reduce the heat stabilization time, and more stabilizers need to be added to balance it. Due to the impact of arsenic on heat stability, the addition of arsenic is more likely to cause PVC materials to produce scorched materials during the processing process, manifested as a large number of burnt particles in the PVC materials in the barrel when the time is slightly longer, with many surface rough spots, requiring a large amount of material discharge to eliminate, resulting in low processing efficiency and large material waste.

Cables are closely related to our daily lives. They can be found everywhere, from the small devices like computer mice and laptops at our fingertips to large vehicles such as airplanes in the sky, trains on the ground, and ships in the water. Safety is a concern for everyone. Everyone wants to live in peace and prosperity! "Make good cables, live a good life, and eliminate hidden dangers at the source!" This is the basic social responsibility that cable professionals should possess!

Conclusion

In the face of the serious situation of cable material quality chaos, we should pay more attention to those outstanding enterprises that are committed to improving product quality and environmental standards. YINSU Flame Retardant Company is one of the leaders, we specialize in providing efficient and reliable flame retardant solutions for cable and composite materials. With advanced technology and rich experience in the industry, YINSU Flame Retardant has developed a series of flame retardant products that meet international environmental standards, which can not only significantly improve the flame retardancy of cable materials, but also effectively reduce the emission of hazardous substances and guarantee the environmental friendliness of the production process.

Our products are widely used in all kinds of cables and composite products, such as power cables, communication cables, composite materials for construction, etc. Our products are subjected to strict quality testing and certification to ensure the stability and reliability of our products. YINSU Flame Retardant always takes customers' needs as the guide and provides customized flame retardant solutions to help customers solve practical problems and enhance the competitiveness of their products. Under the current background of increasingly fierce market competition, choosing YINSU Flame Retardant Company as a partner can undoubtedly provide strong support for the sustainable development of the enterprise, and jointly promote the green transformation and high-quality development of the cable and composite material industry.