Insulating ladders are mostly used for special climbing tools such as power engineering, telecommunication engineering, electrical engineering and hydropower engineering. The good insulation characteristics of the insulation ladder ensure the life safety of workers to the greatest extent.
Classification of insulated ladders
brief introduction
Insulating ladders are divided into insulated single ladders, insulated soft ladders, insulated bamboo ladders (fishing rod ladders), insulated joint ladders, insulated single straight ladders, insulated composite ladders, insulated ladders (insulated herringbone single ladders, insulated telescopic composite ladders, insulated telescopic herringbone ladders), insulated benches, insulated high benches, insulated lifting platforms and fully insulated scaffolding.
Characteristics of insulation ladder
(1) is non-conductive, with novel appearance and elegant appearance.
(2) Corrosion resistance (acid resistance, alkali resistance, corrosion resistance of various gas and liquid media such as organic solvents and salts). According to the requirements of practical use, o-benzene, m-benzene and vinyl resin can be economically selected as matrix materials), which are resistant to decay and fading.
(3) light weight and convenient handling
(4) Low water absorption and good flame retardancy (the flame propagation rate (ASTME-84) of common flame retardant grille is less than 25; The flame spread rate of advanced flame retardant ethylene grille shall not exceed 10. Oxygen index is not less than 28(GB8924)).
(5) High strength and light weight (the density of glass fiber reinforced plastic grille is less than 2, which is only 1/4 of steel and 2/3 of aluminum. Its strength is 10 times that of rigid PVC, and its absolute strength exceeds the level of aluminum and ordinary steel). It has excellent impact resistance, insulation and magnetic permeability.
Manufacturing technology of insulating ladder
The insulation is made of gradient mining unsaturated resin and glass fiber polymerization pultrusion. The material is epoxy resin combined with pin and rod technology, and the surface of shaft steel parts is provided with protective coating. The processed surface of insulating layer pressing material is treated with insulating paint. Anti-skid design of ladder support and ladder foot is not easy to fatigue, and all parts of the ladder have no sharp edges and corners, which has high safety and strong insulation performance; Low water absorption and corrosion resistance.
Product material
Glass fiber reinforced plastic, also known as epoxy resin, is an insulating material with high hardness and high insulation performance.
Invention principle of insulating ladder
The theory of electron energy band points out that electrons in solids are only allowed to exist in certain energy states, and these energy states can form separate energy bands.
Electrons tend to occupy the lowest energy band first. Insulated step valence band is the highest energy band that can be filled at absolute zero. The energy band above valence band is called conduction band, and the gap between valence band and conduction band is called energy gap. Above absolute zero, valence band electrons are partially excited, jump to conduction band and become conduction band electrons, leaving holes in valence band. According to the energy band theory, the energy band filled with electrons or empty energy band has no contribution to the conductance, and the conductance only comes from the semi-full energy band. Conduction band electrons and valence band holes are collectively called carriers. The conduction band of metal is partially filled, so it has good conductivity. For semiconductors and insulation ladders, the valence band of the insulation ladder is zero-filled, while the conduction band has no electrons. At room temperature, due to the small energy gap, semiconductors can form electron-hole pairs through thermal excitation, so they have certain conductivity. On the contrary, most insulated ladders usually have a very large band gap, and it is difficult for valence band electrons to be excited to the conduction band, so the carrier concentration of insulated ladders is extremely low, and accordingly the conductance is extremely low, or this material is insulated.
Matters needing attention of insulating ladder
Before use
1. Before using the ladder every time, be sure to carefully check the surface of the ladder for cracks, serious wear, parts, ropes, etc. And damage that affects safety.
2, when using a ladder should choose hard, flat ground, in order to prevent the danger of sideways.
3. Check whether all ladder feet are in good contact with the ground to prevent slipping.
4. If the height of the ladder is more than 5 meters, please be sure to set F8 or above stay wires in the middle and upper part of the ladder.
5, dizziness, dizziness, drunkenness or physical discomfort are strictly prohibited to use the ladder.
6. When working around the doors and windows, the doors and windows must be fixed first to prevent the doors and windows from hitting the ladder.
7. Be extra careful when using ladders in windy conditions, or try not to use ladders.
8. Use the most suitable ladder height correctly, and don't attach or place anything up and down the ladder to increase the height.
9. Without the permission of the manufacturer, the ladder shall not be connected with other structures, and the damaged ladder shall not be used and maintained.
10, it is forbidden to hold the cross brace when the ladder rises and falls, in case your fingers are cut.
When in use
1, it is absolutely forbidden to exceed the working load of the ladder.
2, the ladder foot has anti-slip effect. However, people still need to hold the ladder directly with their hands to remind them to protect it (at the same time, to prevent the ladder from tilting) and step on the foot of the ladder to prevent the foot from moving.
Be sure to wear flat shoes when climbing the ladder to avoid slipping and accidents.
4. When climbing a ladder or working, always keep your body in the middle of the rung of the ladder, keep your body upright, and don't stretch out, or you may have an accident because you lose your balance.
5, someone on the ladder, it is forbidden to shift.
6. Only one person is allowed to climb or be on the ladder.
After use
Please clean the ladder after work and put it in a dry place.
Requirements for manufacturing and using insulated ladders:
The material, size and strength of the insulated ladder (hereinafter referred to as ladder) shall meet the relevant requirements of GB/T17889.1999 and GB/T 17889.2- 1999.
Ladders can be made of fiberglass, metal, wood, etc.
The length of the straight ladder shall not exceed 6m, and the overall extension length of the extension ladder shall not exceed 1 1m, and a stop device shall be provided to ensure that the extension and non-extension overlap at least 1m..
All personnel should be trained or instructed before using ladders.
It is forbidden to use temporary ladders made on site.
It is forbidden to use ladders for people suffering from dizziness or who may affect their balance due to taking drugs.
Inspection requirements for insulated ladders:
Newly purchased insulation ladders shall be inspected before use, and shall be inspected regularly during use, with inspection marks affixed. At the same time, the ladder should be inspected before each use to ensure that it is always in good condition.
Before using the ladder, ensure that the working safety load does not exceed its maximum allowable load.
The faulty ladder should be stopped, labeled as "unusable" and repaired in time.
When the insulation ladder is seriously bent, deformed or damaged, it should be scrapped in time. Scrapped ladders should be destroyed to ensure that they can no longer be used.
Inspection contents of insulation ladder:
Whether the function of the ladder is suitable for work;
Safety of ladder, whether there is pedal shortage or ladder body damage, fracture, corrosion, deformation and cracking;
Whether the safety non-slip feet are in good condition;
Whether the ladder is marked as qualified;
Whether the plug is intact;
The state of the pedal or pedal, whether there is dirt, oil or grease attached;
Whether the hardware is in good condition (tie rods, rivets, stay rods, nuts, bolts and legs);
Whether the tension rope and pulley are in good condition;
Whether the ropes fixed by all straight ladders, telescopic ladders and herringbone ladders over 2.4m (including 2.4m) are in good condition.
After passing the inspection, it shall be marked. You can color the ring or label it.
High quality, good quality
On the premise of ensuring safety, the better the quality, the lighter the insulation ladder. Because we must use higher-performance raw and auxiliary materials, more advanced production technology and more scientific structural design, we can reduce the weight of products under the premise of ensuring safety. Lighter insulated ladders are more convenient to use.
Electrical insulation ladder is a ladder made of glass fiber and epoxy resin. It has the advantages of high strength, corrosion resistance, beautiful appearance and good electrical insulation. Usually it can withstand the power frequency test voltage of "220kV/m". Therefore, the FRP ladder can be used as a safe climbing tool for power system. Used to replace metal ladders and bamboo ladders. Prevent electric shock accidents caused by induced electricity and misoperation. After strict testing, the FRP ladder can also be used as a ladder for high voltage live working.
Main technical parameters of electrical insulation ladder
1, insulation material density ≥ 1.95g/cm3.
2. Water absorption of insulating materials
3. The tensile strength of the material >; 350 MPa
4, material surface hardness 50 (Babbitt)
5. Surface pressure resistance of insulating materials >; 12kv (valid value)
6. Design load >; 880 (cattle)
(1) Appearance and assembly
1. appearance: the appearance of each part of the ladder should not have sharp edges and corners, but should be inverted arc.
2. Assembly: It shall comply with the provisions of YB3205.
(2) General requirements
1, raw materials should be pre-selected for inspection.
2. The surface of aluminum alloy parts should be anodized, and the surface of shaft steel parts should have a protective coating; The processed surface of insulating layer pressing material should be coated with insulating paint.
3, metal parts surface roughness should be 6.3 or less.
The machined surfaces of all parts shall be regular and smooth. The surface of insulating parts shall be smooth, free from bubbles, wrinkles or cracks, obvious scratches and overheating marks, and the color shall be natural (from light yellow to green to brown).
(3) Power frequency withstand voltage test
1, 450kV/1 .8m,1min.
Faults and other anomalies should not occur during the test.
materials performance
The insulation material density of the insulation ladder is ≥1.95g/cm3; Water absorption of insulating material: 350Mpa, surface hardness 50 (Babbitt alloy); Surface withstand voltage of insulating material >:12kv (r.m.s); Design load >; The surface of 1500N insulator shall be smooth, free from bubbles, wrinkles or cracks, obvious scratches and overheating marks, and the color shall be natural.