冷收縮套管

電纜頭防護用冷縮管與熱縮管的區別

電纜頭防護用冷縮管與熱縮管的區別

對於戶外電纜、接頭處等防護由熱縮管逐漸改為冷縮管,是為了適應行業的發展也是降低了電纜的故障率。冷縮產品運行可靠,施工時間短,大大縮短了事故的處理時間。
讓我們來瞭解瞭解在施工過程中冷縮產品和熱縮產品的主要差異在哪?
    首先,交聯電纜是有由電纜的外護套、金屬鎧裝、內護套、填充物、銅遮罩層、外半導層、絕緣層、內半導層、導線等組成。因此,有什麼樣的電纜結構就需要有什麼樣的材料及其工藝的電纜附件和他一一對應與配套,使電纜能在任何自然環境下安全運行。其中需要重視的四大因素:密封、絕緣、電場、工藝。             
讓我們來瞭解瞭解在施工過程中冷縮產品和熱縮產品的主要差異在哪。

1】密封
    分電纜頭都是安裝在戶外架空、直埋等環境裡,因此,防水。防潮氣就成為確保電纜頭安全運行的關鍵之一,也就需要考慮其密封性能和方法。目前國內、國外首選的方法就是使用有高彈性的密封膠、其工藝簡單性能可靠也使他成為使用的主流,但是使用這種膠要特別考慮膠的性能,因為密封膠的性能直接影響到接頭處的密封性能,要想選擇一種既能和電纜體表面還能和附件材料表面粘結的很牢固的膠,同時還要滿足不同的溫度變化環境裡都能完美使用的膠是什麼困難且重要的。
    而冷縮產品實際上就是彈性電纜附件,也就是說利用矽橡膠本身的彈性在工廠預先擴張放入支撐條。到現場套入指定位置,抽掉支撐條使其自然收縮。這種結束就是冷收縮技術。這種附件就是冷縮的電纜附件,因此這種冷縮附件具有良好的“彈性”,可以避免由於大氣環境、電纜運行中負載高低產生的電纜熱脹冷縮之間產生的空隙,造成擊穿事故,而熱縮產品最大的缺點就是本身的彈性不能完全滿足與電纜同呼吸,所以冷縮產品用於溫差大,受氣候環境影響大的地域使用是最佳選擇。
2】絕緣
    電纜頭的絕緣要求是滿足相與相之間的絕緣盒相對地之間的兩大絕緣。
相對相的絕緣的矽橡膠式、熱縮材料的兩種絕緣材料,通常絕緣性能還要根據材料的單位絕緣指標結合材料的厚度來滿足要求。全冷縮附件其性能指數是24kv/mm設計運行厚度應滿足12mm,可經得起雷電衝擊和過電壓的考驗。熱縮附件是多種複合材料混合而成,經過輻照加工具有熱收縮功能,其單位絕緣指數喂1.8~2.0kv/mm,因此設計厚度要比矽橡膠材料相對厚3~4mm,即:15~16mm,才可達到運行要求。
    相對地的絕緣是防止電荷由於高電位往低電位爬的安全距離。冷縮管矽橡膠材料具有良好的彈性,只要設計合理,其強大的回彈性即有足夠的抱緊力,無論環境發生熱脹冷縮,都保證緊緊包著電纜被包的部位。這樣就防止水與潮氣的吸入,安全的內爬距離就得到很好的保證。熱縮附件只有在安裝時,溫度才夠滿足他的收縮條件,當溫度低時,由於電纜的熱膨脹係數與熱縮材料的膨脹係數不同,就有可能產生脫層,因此出現裂縫,這樣水和潮氣就會子啊呼吸作用下進入,從而破壞系統的絕緣。由於沒有矽橡膠那樣的彈性,所以也會給安全帶來影響,這個就是熱縮產品相對冷縮產品的弱點。
3】電場
    冷縮附件在電場處理是應用幾何法,通過應力錐改變電場分佈的,是用一定幾何形狀和精確的R角度來解決的,這種方法比較容易控制和檢驗。在工廠就可以確保和實現。而熱縮附件的電廠處理方法是用線性參數改變電場的分佈,必須依靠兩個重要參數:a體積電阻、b介電常數,由於其生產工藝複雜,受環境因素變化大,所以難以控制參數的穩定,因此對品質的穩定性就會產生影響。
    更具以上的分析,冷縮管和熱縮管具有本質上的區別。但只要在正常的條件運行都可符合安全的要求,但隨著環境的變化,冷縮管與熱縮管相比都有不可比擬的差異和優勢;此外冷縮管是用特殊模具製成,安裝完成後的形狀十分美觀,安裝施工速度迅速;節省時間;抗污染等優點。
    DWH高倍率矽橡膠冷縮管採用特製矽橡膠原料製成,具有收縮倍率大,物理機械性能優異,耐刺紮等優點。適用於通訊、有線電視連接接頭的防水防潮密封,電線電纜連線的絕緣密封以及其它類型連接件的絕緣保護等。其連續使用溫度:-60200、擴張倍率達4倍左右,適合不同直徑的連接密封
    今天我們處於高速發展的社會中,企業的不斷發展其電力系統經常需要面臨高負荷、高溫、低溫、沿海多雷雨等環境考驗,只有穩定的運行才能保證企業的穩定發展。因此在電力系統中選用高性能的電纜附件是相當重要的,冷縮管的出現滿足這一要求,從而使得冷縮管得到了更加廣泛的應用。

The difference between the cold shrink tube and the heat shrinkable tube for cable head protection

For outdoor cables, joints and other protection from heat shrinkable tubes to cold shrink tubes, in order to adapt to the development of the industry and reduce the failure rate of the cable. The cold-shrinkable product runs reliably and has a short construction time, which greatly shortens the processing time of the accident.
Let us understand the main differences between cold shrinkage and heat shrinkage during construction.
First, the cross-linked cable is composed of an outer sheath of the cable, a metal armor, an inner sheath, a filler, a copper mask layer, an outer semi-conductive layer, an insulating layer, an inner semi-conductive layer, a wire, and the like. Therefore, what kind of cable structure requires the kind of materials and the cable accessories of the process and his one-to-one correspondence and matching, so that the cable can operate safely in any natural environment. Among the four factors that need attention: sealing, insulation, electric field, and process.
Let's take a look at the main differences between cold-shrink and heat-shrink products during construction.


[1] Seal
The sub-cables are installed in an outdoor overhead, direct burial environment, etc., and therefore waterproof. Moisture resistance is one of the keys to ensuring the safe operation of the cable head, and its sealing performance and methods need to be considered. At present, the preferred method at home and abroad is to use a highly elastic sealant, and its simple process and reliable performance also make him the mainstream of use, but the use of this glue should especially consider the performance of the glue, because the performance of the sealant directly affects The sealing performance at the joint, it is difficult to choose a glue that can adhere to the surface of the cable body and the surface of the accessory material, and also to meet the requirements of different temperature change environments. important.

The cold-shrinking product is actually an elastic cable accessory, that is to say, the elasticity of the rubber itself is pre-expanded into the support bar at the factory. Nest to the site at the specified location and remove the support bar to naturally contract. This end is the cold shrink technique. This kind of accessory is a cold-shrinkable cable accessory, so the cold-shrinkable accessory has good "elasticity", which can avoid the gap generated by the thermal expansion and contraction of the cable due to the atmospheric environment and the load in the cable operation, resulting in breakdown. Accidents, and the biggest disadvantage of heat-shrinking products is that their elasticity cannot fully satisfy the same breathing with cables. Therefore, cold-shrinking products are used for areas with large temperature difference and are affected by climate and environment.

[2] Insulation
The insulation requirement of the cable head is to satisfy the two major insulations between the phase-to-phase insulation box and the ground.
Two kinds of insulating materials of insulating rubber and heat-shrinkable materials of opposite phase generally have insulation properties according to the unit insulation index of the material and the thickness of the material. The performance index of the fully cold-shrinkable accessory is 24kv/mm. The design running thickness should meet 12mm, which can withstand the test of lightning impulse and overvoltage. The heat shrinkable accessory is a mixture of a variety of composite materials. It has a heat shrinkage function after irradiation, and its unit insulation index is fed 1.8~2.0kv/mm. Therefore, the design thickness is 3~4mm thicker than the rubber material, namely: 15~ 16mm, can meet the operational requirements.

Relative insulation is a safe distance to prevent the charge from climbing to a low potential due to high potential. The cold-shrinkable tube rubber material has good elasticity. As long as the design is reasonable, its strong resilience has sufficient holding force, and no matter the thermal expansion and contraction of the environment, it is ensured that the cable is wrapped tightly. This prevents the inhalation of water and moisture, and the safe internal creep distance is well guaranteed. The heat shrinkable attachment is only suitable for the shrinkage condition when it is installed. When the temperature is low, since the thermal expansion coefficient of the cable is different from the expansion coefficient of the heat shrinkable material, delamination may occur, so cracks occur, so that water and The moisture will enter under the breath, thus destroying the insulation of the system. Because there is no elasticity like enamel rubber, it will also have an impact on safety. This is the weakness of the heat shrinkable product relative to the shrinking product.

[3] Electric field
The cold shrink attachment is applied in the electric field processing. The electric field distribution is changed by the stress cone. It is solved by a certain geometry and an accurate R angle. This method is easier to control and test. It can be ensured and realized at the factory. The power treatment method of the heat shrinkable attachment is to change the distribution of the electric field with linear parameters, and must rely on two important parameters: a volume resistance, b dielectric constant, due to the complicated production process, large changes due to environmental factors, so it is difficult to control the parameters. Stable, so it will have an impact on the stability of quality.
More than the above analysis, the cold shrink tube and the heat shrink tube are essentially different. However, as long as it is operated under normal conditions, it can meet the safety requirements, but as the environment changes, the cold-shrink tubing has incomparable differences and advantages compared with the heat-shrink tubing; in addition, the cold-shrink tubing is made of a special mold. The shape after installation is very beautiful, the installation speed is fast; save time; anti-pollution and other advantages.

DWH high-rate 矽 rubber cold-shrink tubing is made of special enamel rubber material, which has the advantages of large shrinkage ratio, excellent physical and mechanical properties, and resistance to puncturing. It is suitable for waterproof and moisture-proof sealing of communication and cable connection connectors, insulation and sealing of wire and cable connection, and insulation protection of other types of connectors. Its continuous use temperature: -60 ° C ~ 200 ° C, expansion ratio of about 4 times, suitable for connection seals of different diameters
Today, we are in a fast-developing society. The continuous development of the company's power system often needs to face environmental tests such as high load, high temperature, low temperature, and thunderstorms along the coast. Only stable operation can ensure the stable development of the enterprise. Therefore, it is very important to select high-performance cable accessories in the power system. The appearance of cold-shrink tubing meets this requirement, which makes the cold-shrink tubing more widely used.