ANPING COWAN WIRE MESH & MACHINES CO., LTD , https://www.cowanfences.com
There are mainly three types of safety nets widely used in China: safety nets, safety nets, and dense-security nets. Their protective principle is: The role of the flat net is to stop falling people and objects, to avoid or reduce the fall and physical damage; vertical net role is to prevent people or things from falling. The strength of the net must withstand the longitudinal pulling force and impact strength of the human body and the objects such as the carrying tools when they fall.
Pingnet and Lientech mainly evaluate 13 items such as tether spacing and length, rib spacing, side rope breaking strength, net rope breaking strength, tendon breaking strength, flame retardant performance, impact resistance performance, etc.; Product Breaking Strength × Tensile Elongation, Trapezoidal Tear Strength, Eye Opening and Closing Strength, Flame Retardant Performance, Penetration Resistance, and Impact Resistance 12 items.
These test items are required to pass the safety net test equipment to detect whether the product performance of the safety net is qualified. The latest national test standard implemented by the safety net is GB5725-2009. The standard requirements are as follows:
1. The net ropes, side ropes, and ribs ropes of flat nets have a strong breaking force (This item can be inspected by the ZW-738 safety net tensile tester of the safety net testing equipment), and the flat net's edge rope breaking strength is ≥ 7000N. Strong fixed net; net rope breaking strength ≥ 3000N, can effectively prevent people from falling, not torn; traction rope breaking strength ≤ 3000N, to prevent the human body from being hurt by the traction rope, play a necessary buffer. (At present, safety net companies first reduce the cost, reduce the diameter of the ropes and net ropes, and second, the structural design is unreasonable, resulting in unqualified).
2. The impact resistance performance of the flat net is safe (this item can be detected by the ZW-732 safety net impact tester of the safety net test equipment). The test method is to use a steel ball with a diameter of 500mm and a mass of 100kg to simulate the human body falling from a height of 7m. The test result requires that the net rope, rib rope, and tether do not break, and the test weight does not touch the ground. (If the safety net enterprise fails the impact safety performance, it will not be able to prevent the human body or objects from crashing into the sky and protect the safety of construction workers.)
3. The breaking strength of the dense-mesh safety grid * the elongation-elongation project (this item can be detected by the ZW-738 safety net tensile tester of the safety net inspection equipment). GB5725-2009 standard requires A-class network breaking strength × elongation at break ≥ 60kN · mm, B-level network breaking strength × elongation at break ≥ 50kN · mm. This indicator is to assess the anti-scratch ability of the net, and it can also detect the quality of raw materials. (At present, safety net companies have many unqualified targets, and inferior raw materials are used in raw materials.)
4. The impact resistance performance of the compact mesh safety net (This item can be detected by the ZW-732 safety net impact tester of the safety net test equipment). This safety feature is used to block people, sight, natural wind, splashes, and uncontrolled small objects. The test method is to use a steel ball with a diameter of 500mm and a mass of 100kg to simulate the impact of the body falling down. The drop height A is 1.8m and the B grade is 1.2m. The test results require that cross-section items should not be penetrable or have obvious damage.
5. The flame-retardant performance of the compact mesh safety net (This item can be tested by the safety net test equipment ZF-621 safety net flame tester). The test of this project adopts the vertical combustion test, requiring that the longitudinal and lateral renewal and smoldering test pieces are not more than 4s. If the flame-retardant performance is unqualified, once a partial fire occurs, it will ignite a piece of the safety net, causing fire and injuring people and objects, thereby causing a safety accident in construction. There have been many accidents of this kind, causing great adverse social effects. Most of the reasons are that the company adds insufficient flame retardant during production or the mixing is not uniform when the flame retardant is added. The detection found that the flame retardant performance of the safety net was affected greatly by the heterogeneity of the sample, and the flame retardant performance of different parts of the same net body was different, which greatly affected the determination of the test results and brought about fire safety hazards.
Through many years of national product quality supervision, spot checks and entrusted inspections, many safety network manufacturers have generally paid insufficient attention to the inspection of the factory, lacked full-time inspection personnel, and the factory records were confusing. The implementation rules for production licenses for special labor protection articles clearly require safety net manufacturers to have safety net impact testing machines, safety net tensile testing machines (accuracy: ±1%), safety net testing steel balls (100 kg), and safety net penetration testing machines. , Through bars (5kg), safety net vertical burner (accuracy: 0.1 seconds) and other equipment for factory product quality inspection. With the State General Administration of Quality Supervision, Inspection and Quarantine of the safety net production license issuance and quality supervision, the State Safety Supervision Bureau attaches importance to the safety production license and Lao An certification, safety net production companies must strictly in accordance with GB5725-2009 "safety net" standard It is also one of the necessary conditions for the application of a safety net for ultraviolet light to apply for a production license and labor safety certification.
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The importance of safety net testing equipment
The importance of safety net detection equipment The safety net is a type of protective equipment for the prevention of fall injuries. It has a wide range of applications and is mostly used in construction sites for various high-level operations. The hidden dangers of falling from high places often occur on shelves, roofs, windows, suspensions, deep pits, deep troughs, etc. The degree of fall injury varies with the size of the fall, ranging from disability to death. The safety net can be fully enclosed and can effectively prevent people and objects from falling down, prevent fire caused by welding sparks, reduce noise and dust pollution, and achieve the effect of civilized construction, environmental protection, and beautification of the city.