Oriented Strand Boards or OSBs are engineered wood panels where rectangular wood stands are arranged in cross oriented layers and binded together with resin.
Luli Group Co., Ltd, has the capability and capacity to produce High Quality OSB yet with competitive pricing. It is the result from the huge investment into latest cutting edge technology from Germany – the world leader in technology, engineering and innovation. Capitalizing on such advancement, Luli Group OSB R&D team continues to develop and design OSB with wider application, higher usability and marketability without neglecting the importance to be environmental friendly.
Advantages of OSB:
These greener options to Plywood are moisture resistant, have high load capacities and are customizable to different sizes, thickness and shapes.Uses of OSB:
OSB is a material with favorable mechanical properties that make it particularly suitable for load-bearing applications in construction. The most common uses are as sheathing in walls, Flooring, and roof decking. OSB also sees some use in furniture production.
The details of OSB:
1. Sizes: 1220mm x 2440mm(Standard Size), 1250mm x 2500mm or according to customer`s request.
2. Thickness: From 6mm to 20mm.
3. Materials: Poplar, Pine or combination according to customer`s request.
4. Glue: MR, Melamine glue, WBP, MDI
5. Density: About 600kg to 650kg
6. Grade: Packing , construction and furniture,etc.
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The low-voltage and low-current operation characteristics of the security (weak current) system cannot avoid the weaknesses of immunity and over-voltage and over-current capability. A research report pointed out that when the magnetic induction intensity reaches 0.07 GS when the lightning activity occurs, the computer malfunctions; when the magnetic induction intensity exceeds 2.4 GS, the equipment is permanently damaged.
Security industry has its special characteristics of lightning protection
The modern lightning protection project is a systematic project, including the two major parts of a building direct lightning strike lightning protection and electrical equipment surge protection. The engineering design emphasizes all-round protection, comprehensive management, and fortification. When a lightning strike occurs, the lightning discharge induces a lightning strike over-voltage and over-current of the electromagnetic pulse. The weak system can be damaged by the power system, signal transmission, grounding system, and the building direct lightning protection system through conduction and induction.
Security and lightning protection is to protect the various subsystems from normal and stable operation, and to prevent direct lightning strikes and lightning electromagnetic pulse interference as the main purpose. Provide corresponding lightning protection products and solutions for each security system application environment. Since the security system includes intrusion alarm systems, video security monitoring systems, building intercom systems, and access control systems, each system involves a large number of devices, so lightning protection in the security industry is more complex and special. Wu Yang, deputy general manager of Shenzhen Tiandun Lightning Technology Co., Ltd., summed up the particularity of lightning protection in the security industry: Security and lightning protection needs to consider various subsystems such as video surveillance and alarms. Each system is faced with many types of equipment and scattered distribution points. Equipment is installed outdoors and other characteristics; system signal transmission with coaxial cable, optical cable, wireless and other transmission methods; equipment power is complex, usually near the power, centralized power supply, voltage AC and DC, 12V, 24V , 220V and other voltage levels. These objective environmental factors place high demands on lightning protection.
In a word, compared with the traditional industry's lightning protection, the lightning protection system in the security industry has many types of protection signals, requires high lightning protection precision, has a large number of independent lightning protection zones, and has a complex system of lightning protection.
Missing standards on security and lightning protection
Wu Yang of Shenzhen Tiandun Thunderbolt stated that at present, different industries in China have different requirements for lightning protection, and communications, railways, and electric power industries have high requirements for lightning protection, and even the requirements for conformity determination for products entering the industry. However, there is no clear industry standard for the application of lightning protection products in the security industry. Tian Zhenhua, product manager of Hangzhou Hikvision Digital Technology Co., Ltd. also stated: “At present, the entire security industry will add lightning protection design when developing products and design solutions, but there is no uniform industry standard. In the security engineering, lightning protection system It is not a rigid requirement, only inspection requirements, companies install lightning protection wafers or lightning protection board is mainly to meet the needs of customers. Although there is no unified standard for lightning protection and security products, but companies are basically the same approach in this regard." In practical applications, all mine protection engineering companies and lightning protection product manufacturing companies choose the relevant industry standards as guidance documents for the lightning protection standard of security projects for the characteristics of the actual application process of security monitoring and control projects, and usually refer to GB50348-2004 "Safety Prevention "Engineering Design Specification", GB50343-2012 "Building Electronic Information System Lightning Protection Technical Specifications" and so on.
In addition, Ling Jie, deputy general manager of Shanghai UMC Industrial Co., Ltd. believes that in addition to the above reference standards, the lightning protection standard for the security industry is GA/T670-2006 "Technical Requirements for Lightning Protection of Lightning Protection Systems for Safety Precautions." The lightning surge protection of equipment, power lines, signal lines, etc. have all put forward specific requirements.
Combination of lightning protection and lightning protection of buildings
Security weak lightning protection is mainly for protection against surges occurring during the operation of indoor security equipment. Its characteristic is that it is a low voltage and small current relative to strong lightning protection. Its requirements must be sufficient to meet the needs of lightning protection. The transmission performance and requirements of the signal/power supply of the security system are to ensure that the normal path of the security system signal/power supply cable can be instantaneously cut off when an induced lightning surge occurs and the grounding device is simultaneously turned on. The earth releases a large amount of induced current, so that powerful inductive surge currents are prevented from being invaded and damaged by security cables to the security equipment. However, when the surge-free system is operating normally, the lightning protector must not affect the normal transmission of the signal, so that the signal is not deformed or attenuated, just as there is no access to the lightning protection device.
The strong electricity is also the anti-inductive lightning, which is to reduce the instantaneous high-voltage induced current (also the surge current) to a safer voltage during the lightning strike, that is, to discharge the high-voltage induced large current generated instantaneously to the grounding device. Lightning protection in general buildings is divided into multiple levels of protection, which can be described as layers of defense, weakening the large induced currents/voltages generated by strong power transmission systems. The first level is generally at the building substation and the second level at each building. At the third floor of each floor, and for the security system in the engine room also need to set a level, the voltage to the room level is already very low, the inrush current is also smaller, but for security (weak) equipment or high voltage High current, so still need to set a level of protection.
Lingjie of Shanghai United Power Co., Ltd. introduced: “At present, security products are mainly designed for weak lightning protection. When the product is doing test reports, it is only a test of resistance to voltage interference. It is basically impossible to resist direct lightning strikes, so The entire security system needs to take into account the strong lightning protection.†Tian Zhenhua, Hangzhou Hikvision, affirmed this statement: “Lightning protection in the security industry requires a combination of multiple protections. As the weak lightning protection is only an auxiliary lightning protection solution, It is not a matter of direct lightning protection, so security and lightning protection need to be combined with lightning protection of the building, because the high voltage generated by a lightning strike can burn out the security cables and security front-end equipment."
Front end, transmission end, back end classification protection
The security system includes front-end information collection equipment, transmission lines and back-end storage and monitoring centers, and lightning surge protection for each part must be treated differently.
1, front-end equipment protection
The front-end equipment is mainly divided into indoor and outdoor. If the outdoor equipment is far away from the building and is not within the effective protection scope of the building's direct lightning protection device, it is necessary to consider installing a lightning protection device; if it is already in the lightning receptor (lightning rod or other Front-end equipment within the scope of protection of existing lightning protection systems of high-rise buildings or lightning conductors is generally no longer considered for direct lightning protection. Such as outdoor cameras, within the effective protection range of the building air-termination device, in order to prevent lightning induction, the camera power line and signal line led along the telephone pole should be worn in the grounded steel pipe to achieve the shielding function, in order to prevent lightning induction. Currents intrude into the front-end equipment along the line, and a corresponding arrester should be installed on each line in front of the device. The arrester must be connected to earth and ensure the grounding quality. Otherwise, the lightning arrester is equal to or not installed.
It is worth noting that an isolated isolated pole camera should be equipped with an independent lightning rod to prevent direct lightning, but the pole camera should be placed within the effective protection scope of the independent lightning rod, and the distance between the independent lightning rod and the pole camera should be as far as possible (guaranteed Under the premise of effective protection, the influence of the strong magnetic field of the magnetic discharge current to the camera cable on the lightning conductor shall be avoided. In addition, the camera pole and the mounting bracket are preferably made of steel (there is wind-resistant steel, It also has good electrical conductivity and shielding performance, and also has to do very good grounding (ground resistance to achieve lightning protection requirements); indoor front-end equipment needs to be lightning-induced surge protection, video surveillance system through the conventional three-in-one (video + control + power supply), 2 in 1 (video + power supply) lightning protection products, protection of front-end equipment such as camera power, video, PTZ control.
2, transmission protection
Mainly include transmission signal lines and power line protection. Transmission lines should be strongly recommended for direct burial. Overhead is not recommended because overhead lines are the most vulnerable to lightning strikes. If non-airborne is not available, in order to avoid damage to the end-to-end equipment, the overhead cable itself should be strengthened. For example, use high-quality shielded cables, increase the density of shielded copper mesh, and shield the copper mesh from grounding; try to get the overhead line Walking along the building, but away from the flat conductors of the lightning conductor, grounding should be done on each pole during transmission. The overhead cable overhead cable and the overhead metal cable should be grounded. Both the signal source and the power supply at the input should be connected to the appropriate arresters.
3, back-end storage and monitoring center equipment protection
From the standpoint of direct lightning protection, the building where the monitoring center is located should have lightning rods, lightning conductors, or lightning protection nets that prevent direct lightning strikes. From the perspective of inductive lightning protection, various metal pipelines entering the monitoring center should be connected to anti-radar grounding devices. When the overhead cable is directly introduced, an arrester shall be installed at the entrance to the house, and the cable outer sheath and the self-supporting steel cable shall be connected to the grounding device. The monitoring center shall be equipped with an equipotential connection box and shall be led out with a copper bar. It is best to walk around the wall of the monitoring center (under the anti-static floor) and ground the lightning protector, PE wire, equipment protection ground, and anti-static ground. Metal pipe slots, etc. are all connected to the equipotential copper bar to prevent dangerous potential differences. Copper wires are used for grounding wires of various types of surge protectors (arresters), etc., and they are electrically connected to the equipotential copper bar with the shortest possible and thickest wire diameters.
External lightning arrester is better than built-in lightning arrester
The external SPD refers to the SPD installed on the power supply line and the signal line. The built-in SPD refers to the lightning protection device or lightning protection module integrated in the device. Currently, the built-in SPD has fewer mature products. In general, lightning protection components such as discharge tubes and TVS are installed on circuit boards. According to Wu Yang of Shenzhen Tiandun Lightning, at present, more than 90% of lightning protection devices are externally used in security systems. Although the cost of external surge arresters is higher than that of built-in surge arresters, external surge arresters are generally favored by engineering companies.
External lightning arresters are usually designed, manufactured and sold by professional lightning protection manufacturers. They have the advantages of good lightning protection and easy replacement. Built-in lightning arresters are usually designed, manufactured and sold by security equipment manufacturers, with low cost advantages. However, once the built-in lightning protection module is damaged, it is necessary to perform maintenance or replacement of the security equipment, which is difficult for the user to accept. Wu Yang of Shenzhen Tiandun Thunderbolt predicted that external lightning arresters will continue to be the mainstream in the future.
Built-in lightning arrester or built-in surge protection module. According to Lingjie analysis of Shanghai UMC, the built-in surge protection module corresponds to the product test standard of IEC61000. The surge protection range is wider, but the energy is generally not high, and the larger surge in the standard is only achieved. Similar to 4kV/2kA (1.2/50us, 8/20us combined wave). Relative to the standard of lightning protection, energy is far from enough. The test standards referenced by the external lightning protection module are IEC61643-11 (GB18802.1) and IEC61643-21 (GB18802.21). The application of the standard lightning protection requirements is generally more than 5kA (8/20us), which is much larger than the built-in lightning protection module. Surge protection module test requirements. When the surge module starts protection, it needs to discharge a certain current, so it will produce a certain secondary induction. The external lightning protection module can better avoid the secondary induction than the built-in surge protection module. Therefore, in the actual engineering design, even if the security equipment has built-in lightning protection device, it still needs external protection module for re-protection.
Conclusion
The lightning protection of the security system is a large and complex system engineering. In the design process, it is necessary to consider complete solutions from direct lightning protection, equipotential bonding, reasonable cabling, and installation of SPD, and ignore any one of them. It may bring serious security risks to the entire project. Based on the current state of the art of lightning protection technology, it is impossible to fundamentally prevent lightning or surge from damaging the security system. With the development of electronic technology, fine design of electronic products, response time and current discharge capability of lightning protection products. , Compressive strength and other aspects have put forward higher requirements. It is impossible to "make a statement" to make lightning protection of the security system. How to provide more effective and complete lightning protection solutions for security systems may be the direction of many lightning protection manufacturers. 
Standard missing security equipment how to make lightning protection measures
Lightning is an acoustic, optical and electrical phenomenon that occurs in the atmosphere. There are many explanations for the formation of lightning. It is generally believed that the formation of small water droplets with positive and negative charges results from the rise of hot air and the heat exchange during the cooling process of cold air. Cumulonimbus, in the formation of cumulonimbus clouds, under the action of the atmospheric electric field and the temperature difference electrification effect and the crushing electrification effect, positive and negative charges respectively accumulate in different parts of the cloud. When the charge accumulates to a certain degree, the discharge occurs between the cloud and the cloud or between the cloud and the ground, which is called "lightning." When lightning strikes, the instantaneous pulse current released will generate huge thermal energy and mechanical energy, and induce pulse over-voltage and over-current, causing serious consequences such as building collapse, fire, casualties, communication interruption, and system paralysis. In view of the powerful destructiveness of lightning and its great impact on people's production and life, for centuries, people have never ceased to study the destructiveness of lightning and how to prevent it, and invented lightning rods, lightning protection strips, etc. Although the facilities prevent and reduce the damage caused by lightning to a certain extent, it often happens that electrical equipment is damaged due to lightning. In the security industry, front-end cameras, perimeter fence equipment, and other indoor and outdoor equipment are the first to be destroyed.