Firstly, the double-wall heat shrinkable pipe is a kind of cross-linked polyolefin material with high quality and soft outer layer, and the inner layer is processed with hot melt adhesive to form heat shrinkable pipe, which is also called double-wall pipe or heat shrinkable pipe in the industry. The outer material has the advantages of insulation, corrosion protection and wear resistance, while the inner material has the advantages of low melting point, waterproof, sealing and high adhesion. Dual-wall pipes are widely used in waterproof and leak-proof wiring of electronic equipment, anticorrosion protection of wire branches, repair of wires and cables, waterproof wiring of pumps and submersible pumps, etc. Secondly, the shrinkage ratio of double-walled tube is generally 3:1 and 4:1. Because the shrinkage ratio of double-walled heat shrinkable tube is relatively large, it can be applied to many irregular shape materials for insulation and sealing. The diameter of double-walled heat shrinkable tube varies from 2.4 mm to 25 mm, because the double-walled heat shrinkable tube is extruded and bonded by the outer base material and the inner hot melt adhesive, so it can not make a large diameter, so it is necessary to use the larger diameter. Separately glued mid-wall heat-shrinkable casing (this product will be described in detail later), from the packaging point of view, 12.7mm and later double-wall tubes are generally cut into one section to package (packaging length is 1.22m), because its flexibility has not allowed it to be wrapped in a plate, because there is hot melt adhesive inside, double-wall heat-shrinkable tube wall thickness heat-shrinkable tube is much thicker than ordinary electronic heat-shrinkable tube, flexible. The toughness is also lower. Thirdly, the outer material of double-walled heat shrinkable tube is soft, usually black, and can be processed into other colors, such as transparent double-walled heat shrinkable tube. The wall thickness is medium, and it has certain wear resistance and mechanical protection performance. The voltage resistance is generally greater than 10KV. It can be used for repairing the outer layer of cable with voltage below 10KV and for sealing and waterproofing insulation at the junction. Its adhesive layer can be bonded with plastics, rubber and gold. Genera and so on. Finally, the use of double-wall heat-shrinkable tube is similar to that of ordinary heat-shrinkable tube. Its initial shrinkage temperature is 70 C, its complete shrinkage temperature is 125 C, the melting temperature of inner glue layer is 70 C-100 C, and its working temperature range is - 40 C-125 C. Like ordinary heat-shrinkable tube, double-wall heat-shrinkable tube has two requirements of environmental protection and flame retardant. Usually, this requirement is directed at the outer base material of double-wall heat-shrinkable tube. Material and ordinary heat-shrinkable tube formula is similar, so UL, ROHS and other international certification is also practical, export sometimes need to issue relevant certification.
When purchasing double-wall heat-shrinkable pipes, the first step is to determine the caliber and shrinkage ratio and color you need. Generally, the shrinkage ratio of double-wall heat-shrinkable pipes sold in China is 3:1, and 4:1 for export is the product of double-wall heat-shrinkable pipes. We usually choose black color, because the application of double-walled tubes is bad, other colors are not necessary, and special color, manufacturers will charge special processing fees, and the addition of color masterbatches inside will also increase costs, so it is more expensive, but all because of customers, such as transparent double-walled heat shrinkable tubes for some customers. For the caliber of double-wall heat shrinkable pipe, it is usually fixed several kinds, 2.4, 3.0, 4.5, 6.0, 9.0, 12.0, 15.0, 19.0, 25.0 mm. For example, when used in cable insulation and waterproofing, if the diameter of cable is 7 mm, then we can choose 9.0, 12.0 two specifications. As for which one to choose, it depends on your own needs, similar to the caliber of heat shrinkable pipe, large size is easy to construct and shrink. The back wall thickness is thicker, the contraction is relatively delivered, and the price is expensive. Small caliber may bring trouble to the construction, but the economy is good. The flame retardant performance of double-wall heat-shrinkable tube depends on the performance and measurement of the flame retardant added in the formula of the outer base material, so the price of good flame retardant performance is also expensive. Ultimately, the sealing and waterproof performance of Sumitomo SUMITUBE heat-shrinkable sleeve depends on what hot-melt adhesive is used by the manufacturer. Good gum and bad gum effect heat-shrinkable tube pectin are also different, of course, the price is also different. Inequable.
Double-walled tube with rubber for automobile tubing protection: There are two kinds of middle-walled tube with SBRSM tape and RSFRM without tape. The middle-walled tube with SBRSM tape is composed of high-quality polyolefin material and environmentally friendly hot melt adhesive layer. The middle-walled tube without RSFRM tape is elaborately processed with high-quality polyolefin material, which is widely applicable to insulation protection of low-voltage electric power and mechanical strain buffer and room wear protection. It has the characteristics of insulation, sealing and waterproof (middle wall with adhesive), softness, extinguishing of outer layer, environmental protection and so on.
(1) Sealing and insulation protection of low-voltage power lines and cable joints and terminals;
(2) Extrusion resistance and abrasion resistance of wires, cables and various mechanical products;
(3) Sealing protection of marine cables;
(4) Pipeline anticorrosion and sealing;
Environmental friendly hot melt adhesive is used in the middle wall of tape adhesive. The insulation and sealing of the product are reliable, and it is suitable for the environment with RoHS instructions.
(5) Other places requiring close protection.
Product scope of use:
(1) Operating temperature: -45 ~125 C
(2) Shrinkage temperature 125 C
Standard colour: black (other colours can be customized)