Common Quality Defects and Preventive Measures for High-Pressure Steel-Wire-Braided Rubber Hose Assemblies

　　Common Quality Defects and Preventive Measures for High-Pressure Steel-Wire-Braided Rubber Hose Assemblies

　　 High-pressure steel-wire-reinforced rubber hose Common quality defects in assemblies and their prevention: No matter how precise the instrument, errors are inevitable. The following outlines preventive measures to address quality‑related issues.

　　① The causes of core twisting include a bent iron core, non‑parallel forming rollers, uneven tension in the forming tape (film), and inadequate adhesion between the inner rubber and the iron core. To address these issues, straighten or replace the iron core, align and adjust the forming rollers, regulate the tension of the forming tape (film) during production, and inspect the diameter of the inner tube blank while controlling the extrusion process of the inner rubber.

　　② The causes of delamination in the tube blank include oil contamination between the film and adhesive tape, the presence of solvents or other isolating substances that impair adhesion, insufficient pressure in the water‑wrapped fabric, and excessively high roller‑pressing speed during forming. To address these issues, clean the tube blank, appropriately increase the water‑wrapped fabric pressure, and reduce the roller‑pressing speed.

　　③ The causes of cracks at the outer rubber joint are insufficient tension in the water‑wrapped fabric and poor plasticity of the rubber compound. To address these issues, appropriately increase the tension of the water‑wrapped fabric and resolve any quality problems related to hot mixing and calendering in the preceding process steps.

　　④ The “bamboo‑leaf” pattern on the tube blank surface is caused by uneven tube diameter, inconsistent tension in the water‑wrap fabric, and uneven overlap width. To address these issues, ensure strict control of uniform and consistent diameter during forming, and maintain uniform and consistent tension in the water‑wrap fabric and overlap width.

　　⑤ The cause of ovality on the outer surface of the tube blank is excessive overlap width of the film and adhesive tape; to address this issue, it is necessary to control the cutting widths of the adhesive tape and film in the preceding process.

　　 High-pressure steel-wire-reinforced rubber hose The production process

　　1. Use a mixer to compound the inner, middle, and outer rubber layers according to the formulation; then extrude the inner hose using an extruder, wrapping it around a soft or rigid core coated with a release agent (the liquid nitrogen freezing method can also be employed without a core).

　　2. The calender rolls the material into a thin intermediate adhesive sheet, applies a release agent, winds it up, and then cuts it to the specified width according to process requirements.

　　3. On a winding or braiding machine, the inner oil‑filled tubing is wound or braided with copper‑plated steel wire or copper‑plated steel strand. Simultaneously, on the same machine, thin rubber interlayers are wound between each pair of layers of copper‑plated wire or strand. The ends of the wound wire are secured with ties (in some earlier models, the copper‑plated wire must first undergo pre‑stress shaping).

　　4. Once again, apply an outer rubber coating on the extruder, followed by wrapping a lead or fabric vulcanized protective layer.

　　5. Vulcanization is carried out using a vulcanizing tank or a salt bath.

　　6. Remove the vulcanization protective layer, extract the tube core, crimp the upper pipe fitting, and perform a pressure test on a sample.

　　In summary, the production of high-pressure hydraulic hoses involves a wide range of equipment and raw materials, and its manufacturing process is quite complex. However, in recent years, the production processes for hydraulic hoses based primarily on plastics or thermoplastic elastomers have been somewhat simplified; yet, due to the high cost of these alternative materials, rubber remains the dominant feedstock.

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