Four major chaos in exposed cable materials: Cables with the same appearance and sheathed materials can vary greatly in quality

It is well known that the low-price winning bid system in the cable industry has forced the industry to lower the technical indicators and procurement prices of raw materials. In order to secure orders, raw material manufacturers have been fiercely competing in the red ocean market, giving up their social responsibilities and sowing many hidden dangers. This article will expose the four major chaos in cable materials. Everyone should be vigilant and take precautions.

one

In flame-retardant polyvinyl chloride and flame-retardant polyethylene, antimony trioxide is a highly efficient flame retardant. This is because it has a good flame-retardant synergistic effect with halogens, which can increase the oxygen index of the material and its self-extinguishing performance when away 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 stibnite (Sb2O3) and oxidizing it to produce Sb2O3. The product is then purified to remove arsenic and iron, reduced to metallic antimony with carbon, further smelted and purified, and oxidized to obtain pure Sb2O3. Antimony and arsenic are sister minerals, so repeated purification is required to remove arsenic.

At present, the arsenic content of high-purity antimony trioxide in China is controlled at ≤300ppm. However, antimony trioxide that has not undergone repeated purification also has a large market because it is cheap.

At present, antimony trioxide with a purity of over 99.5% on the market is all priced at over 55,000 yuan per ton, while the so-called antimony trioxide without purification is only sold at 15,000 yuan per ton, with a price difference of nearly four times. If 5% of the formula is added, the price of just this one material will differ by 2,000 yuan per ton, but this is by no means the terrifying point of cutting corners. What is arsenic trioxide? Arsenic trioxide, commonly known as arsenic trioxide, with the molecular formula As2O3, is the most commercially valuable arsenic compound and a major starting material for arsenic chemistry. It is also one of the oldest poisons, odorless and tasteless, and appears as a white, frosty powder, hence the name arsenic trioxide. This is a highly toxic by-product produced during the processing of several designated minerals, such as gold mining, high-temperature distillation of arsenopyrite (toxic sand) and condensation of its white smoke, etc." It is well known that arsenic trioxide has long been banned by REACH, but such a toxic raw material is still widely used by most domestic material manufacturers. Many cable manufacturers use cables in a confusing way and do not set environmental protection requirements in their procurement standards, which results in harm and hidden dangers to front-line personnel and society.

two

So-called low smoke zero halogen flame retardant materials refer to a type of flame retardant material that does not contain halogens and has a low smoke emission. Conventional flame retardants include aluminum hydroxide, magnesium hydroxide and phosphorus-nitrogen type flame retardants, etc., rather than flame retardants containing halogens and other heavy metal salts. However, the quality of the materials currently used in China varies greatly. Not only do they fail to meet the physical property requirements, but most of the sheaths are filled with non-flame-retardant calcium carbonate or directly use recycled low-smoke and halogen-free waste materials.

Optical cables produced with low smoke zero halogen flame retardant materials feature superior flame retardant performance, very little smoke when burning, and no release of corrosive gases. Therefore, they are widely used in nuclear power plants, subway stations, telephone exchanges and computer control centers, high-rise buildings, shopping malls, hotels, radio and television stations, important military facilities, oil platforms, etc., as well as in places where people are concentrated. Places with low air density. The halogen-free and low-smoke characteristics of optical cables, when a fire occurs, slow spread speed, low smoke concentration, high visibility, and small release of harmful gases, facilitating personnel evacuation. However, the materials currently used in China vary greatly in quality. Not only do they fail to meet the physical property requirements, but most of the sheaths are filled with non-flame-retardant calcium carbonate or directly use recycled low smoke zero halogen materials. At present, it is understood that the types of optical cables involving the use of recycled materials and calcium carbonate filling instead of flame retardant sheaths mainly include: butterfly-shaped optical cables, low-voltage cables, video cables, railway signal cables, etc. It is mainly used in places such as tracks or indoor buildings. The sheath material filled with calcium carbonate is not only non-flame-retardant but also flammable, and it cannot meet the requirements of flame spread speed and smoke emission during combustion. The practice of cutting costs purely for the sake of profit, disregarding the quality of the project.

The service life of optical cables with recycled plastic sheaths is yet to be evaluated. The greatest hazard is that they are prone to aging and cracking, which cannot effectively protect the core of the optical cables and significantly reduce their service life.

three

Let's talk about polyethylene recycled materials again. Recycled materials themselves are made under the guise of environmental protection, using discarded products. Regardless of the impact such usage has on market order, there is a huge risk in the product itself. Even if additives are added again, they cannot make up for the defects generated inside the material. Therefore, its service life will be much shorter than that of brand-new materials, and it may even age and crack in a short period of time.

When it comes to recycled materials, people always ask what the difference is between brand-new materials and recycled materials? Recycled materials are made by recycling and crushing plastic products and scraps, adding additives, and then re-granulating them. Due to the uncertainty of the sources of plastic products and scraps, there are many impurities contained in them, the quality is very unstable, and the physical properties vary greatly between batches. In terms of mechanical and electrical properties such as tensile strength and toughness, it is far inferior to brand-new materials. The product color will also be darker and dull, with poor gloss. Most recycled materials have an unpleasant smell, some similar to the strong odor of dishwashing liquid, and some have a pungent smell. Apart from the performance differences of the above-mentioned materials, the most significant distinction lies in their application. Recycled materials, due to their high content of impurities and non-biodegradable inorganic substances, will result in a rough, matte, and even granular surface of the products after extrusion. Compared with the smooth and fine surface of brand-new materials, this has a significant impact on the appearance of the products. The oxidation induction period is an indicator for evaluating the thermal degradation resistance of materials during molding processing, storage and use. It is a method that uses differential thermal analysis based on the exothermic reaction when plastic molecular chains break to test the degree of accelerated aging of plastics in high-temperature oxygen. However, due to the inconsistent sources and the characteristics of multiple processing, the molecular chains of recycled materials have partially broken. Even if additives are added again, the internal defects of the material cannot be remedied. Therefore, its service life will be much shorter than that of brand-new materials, and it may even age and crack in a short period of time.

four

Soft PVC material has excellent electrical, mechanical, physical and electrical properties, is widely available in resources and low in price, and is widely used in various types of wires, cables and optical cables. However, in recent years, some cable material enterprises have used inferior and low-priced so-called substitute plasticizers to produce low-priced PVC cable materials that seriously fail to meet the standard requirements.

The most commonly used PVC cable material is the 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 oil. What is the result when it is added to the cable material? What harm does it cause to the performance of the material and the long-term use of the cable? Epoxy fatty acid methyl ester, with a flash point of 170 to 190 degrees Celsius, has certain compatibility with PVC resin. After adding PVC, there is a significant risk of precipitation, which is manifested as oil seepage in summer and frosting in winter. Depending on different formulas and processing techniques, the time for precipitation also varies. Some show signs within one or two months, while others may take one or two years, or even several years, to become apparent.

Cables made of such materials will constantly show the phenomena of oil leakage and white leakage as the laying time increases. In addition, as the amount added increases, it is very easy to cause the quality loss of thermal aging to be substandard, and a large addition amount can lead to serious nonconformity.