The Chinese hose industry has a history of more than half a century. With the development of the hydraulic industry, the hose industry has gradually prospered. Today, there are more than 200 single-wire braided rubber hose manufacturers in my country.
Rubber hoses have many varieties, specifications, different functions, different performances, wide application areas, and different manufacturing methods. But as a steel wire braided hose, it is mainly used in hydraulic systems in engineering machinery, coal and other industries. However, due to the high pulse frequency and harsh installation environment of construction machinery, the requirements for hoses are relatively strict.
The production of steel wire braided hose is a relatively complex and huge project, which requires the cooperation of many conditions. In our actual work, we feel that the following issues have a greater impact on the quality of the hose.
1. Defects of The Inner Rubber Layer
The inner rubber layer is a key component of the hose structure. It is in direct contact with the conveyed medium. The inner rubber layer is required to have good compactness and mechanical properties to ensure the sealing performance of the hose under pressure.
We believe that the following factors will cause the quality of the inner rubber layer:
(1) Inner rubber formulation. If it does not have good media resistance and "two high and one low" performance, that is, high tensile strength, high hardness and low compression set performance, it is easy to cause leakage or even appear after assembling metal joint The phenomenon of pipe joint pull-out;
(2) Inner Rubber Purity. The purity of the inner rubber is the highest level we pursue. Whether from raw materials or impurities in subsequent processing, when the hose is pressurized, the inner rubber will be perforated by the repeated action of hydraulic pressure;
(3) Injury to the inner rubber layer. Such as poor drape, unsatisfactory spindle tension, steel wire stabbing the inner rubber, and blasting will occur here;
(4) The inner rubber layer is perforated. If the core rod release agent is not uniformly distributed, vaporization points will be formed during vulcanization, resulting in pinholes, and the hose will pierce under pressure.
We believe that the above-mentioned internal rubber defects are the Achilles’ heel, and for users, they are even more critical. The vaporization point is the most difficult to avoid, which involves the selection of the release agent, the application process, and the cleanliness of the tube. The inspection of the finished product is difficult, and if the inspection is missed, it will bring serious consequences to the user. Therefore, the manufacturing of high-quality hoses and inner rubber layers has set the first barrier.
2.Reinforcement Layer Compactness
The reinforcement layer is the main pressure-bearing component of the hose and an important part of the pipe structure. It is a bridge connecting the upper and lower parts, focusing on the pressure resistance of the structure. Such as: poor drape of steel wire strands, insufficient braiding tension and unevenness, poor cooling effect, resulting in The braided layer is loose, and the hose blasting occurs exclusively in the weak link; the braided structure is not flat, which affects key parameters such as the adhesion of the adhesive layer, the blasting pressure and even the impulse performance, Blistering, uneven size, etc., all threaten the structural integrity of the reinforcement layer, and make the hose have hidden dangers of early blasting.
The reinforcement layer is required to have excellent impact resistance and flex resistance, but all factors need to be considered. From a technical point of view, we strive to make the reinforcement layer have a copper wall and iron wall defense effect through precise design, difference requirements, process systems and other measures, and lay a solid foundation for the integrity of the hose. This is our goal and the biggest challenge we have to meet in the manufacture of hoses.
3.Aging Resistance of The Outer Rubber Layer
In addition to protecting the reinforcement layer, the outer rubber layer must also meet the needs of the use environment and working conditions. Nowadays the operating conditions of construction machinery are more stringent than the product standards, and the aging of the outer rubber has become the most likely problem. This adds more difficulty to our work and adds more conditions. The first is the formulation design. More factors must be considered, not only long-term exposure to the atmosphere or under severe weather conditions, but also bending, dynamic, and ultraviolet requirements; secondly, the cost structure, the high operating price of raw materials, the expansion of the range of quality elements, and the price of hoses Long-term weakness and continued development of the company's funds; the third is the installation essentials, such as installation distortion, too small bending radius, and special location, which will cause early aging and cracking of the rubber hose and shorten the life of the hose.
4.Pulse Performance Fluctuations
There are two main indicators to measure the quality of the hose: pressure resistance and pulse performance.
As the pressure resistance, it is the most comprehensive inspection of the hose. To do the pressure test according to the standard, there are detailed rules such as length, temperature, pressure, curvature, and time. In fact, it is only the most basic and most basic threshold. All customers think and operate according to their traditional traditions and habits. Only meet their expectations of assembly, installation, use, and shelf life. The entire process of product sales is basically completed only when the market is recognized. Because practice is the only criterion for testing truth.
During the pulse test, there are occasional early failures and unstable performance. We believe that the key is to pass the tightness of the overall structure of the hose; secondly, all process standards and related systems strive to ensure the integrity of the hose throughout the entire construction process and stabilize it in an ideal state; in fact, the hose is like a group. It is also measuring whether they are united and whether they have enough cohesion to twist them together to resist the invasion of outsiders.
The pros and cons of hoses show the company's mechanism, management mode, core competitiveness, quality control philosophy, hardware, software, and other all-round configuration and optimization levels. To a certain extent, products are the epitome of corporate culture and the extension of connotation.