CND photosensitive cured fiberglass prepreg tape

1、 Product Overview

CND photosensitive cured fiberglass prepreg tape is a domestically developed brand product that summarizes the advantages and disadvantages of similar foreign products. The development direction of this product is to use it as a protective material for directional pipeline crossing. Therefore, the product structure design that improves strength, hardness, rigidity, toughness, and reduces stress concentration caused by hollowing is the highlight of this technology development. After a year of development and more than two years of application improvement, the CND photosensitive cured fiberglass prepreg has been tested through dozens of pipeline crossing and joint filling applications, as well as the overall coating protection of crossing two Xinjiang Hetian Caiyu rivers. It has become a mature technology product with far ahead technical indicators compared to other similar products at home and abroad. The technologies we use on this product include: fabric felt composite weaving reinforced fiber technology, epoxy polyurethane photosensitive resin, surface dispersion strengthening technology, extrusion impregnation technology, embedded overlap without hollow drum coating technology, and flexible epoxy coating bottom bonding technology. Through the application of these technologies, the CND photosensitive cured fiberglass protective cover prepreg has the following technical performance characteristics.

 image1 Application of CND photosensitive curing FRP prepreg tape as pipeline anti-corrosion coating in the directional crossing of Yulong Kashi River in Hotan, Xinjiang

2、 Product Features

2.1High strength, high rigidity, and high resistance to deformation. As a protective material for pipeline crossing, high strength and high deformation resistance are necessary to prevent tearing by gravel inside the tunnel.Due to the use of advanced cloth felt composite woven reinforced fiber technology and extrusion impregnation technology, the pre impregnated tape of CND photosensitive cured fiberglass protective cover has a tensile strength of 280MPa and a deformation load resistance of 350N/5mm after curing, which is 2-5 times that of other similar products at home and abroad (other products have a tensile strength ≤ 80MPa and a deformation load resistance of 40-140N/mm).

2.2High toughness and crack resistance. By using epoxy-Polyurethane photosensitive resin can achieve 5 ° bending without cracking in the three-point bending test after curing the pre impregnated tape of CND photosensitive cured fiberglass protective cover. This indicator is twice as high as other similar products at home and abroad (other products do not crack at 2 ° C) and meets the corresponding technical requirements for 3-layer PE and fusion bonded epoxy powder coatings (see relevant technical standards). This ensures that under extreme conditions, the protective sleeve will not be crushed when subjected to significant local deformations.

2.3 High adhesion to 3-layer PE and fusion bonded epoxy powder coatings. All photosensitive fiberglass protective cover products themselves have no adhesion and must be bonded to the bottom surface through a low coating material in the middle. Many people only consider the bonding strength in this regard, but do not consider whether the bonding material itself can withstand the stress under extreme crossing conditions. Therefore, many bonding failures do not come from insufficient bonding force, but from the fragmentation of the bonding material itself! For this purpose, our company has developed solvent-free flexible epoxy based coatings. This coating is compatible with the pre impregnated tape of CND photosensitive cured fiberglass protective cover, and can be used in combination. Its adhesion to steel reaches 13MPa (reaching the level of double-layer epoxy joint coating), to fusion bonded epoxy powder coating reaches 12.7MPa, and to 3-layer PE coating reaches 4-10MPa (higher than epoxy fiberglass protective coating). The most valuable thing is that the coating has good flexibility, bending 5 degrees without cracking, ensuring that the adhesion will not fail under extreme penetration conditions.

2.4 High surface hardness. Like steel materials, in order to achieve high scratch resistance, wear resistance, and puncture resistance, surface hardening treatment must be carried out while improving the overall strength of the material, such as the gears, cutting tools, shafts, and shaft sleeves that we commonly use. The surface hardening technology of the steel industry was also used in the production of the pre impregnated tape for the CND photosensitive cured fiberglass protective cover, using dispersion strengthening technology to achieve a Barkol hardness of 70 for the CND photosensitive cured fiberglass protective cover used for overall wrapping, while other similar products only have 40-50. Imagine, what would happen if one day the hardness of the CND photosensitive cured fiberglass protective cover exceeded that of the rock passing through the tunnel? We will usher in lossless time travel!

2.5 Non hollow drum overlapping overall wrapping technology. Hollowing, especially continuous hollowing, is one of the main causes of damage to the external protective coating when pipelines pass through. To this end, our company adopts a double-layer staggered production technology, which enables the pre impregnated tape of CND photosensitive cured fiberglass protective cover to have a staggered structure of two fabrics, two felts, and five oils. Covering the pipeline with such a product can completely eliminate the hollow area at the continuous circumferential overlap, and achieve four sided bonding of the head to head overlap, forming the strongest protective layer. This safest crossing protection structure is currently only available with the use of CND photosensitive cured fiberglass protective cover pre impregnated tape.

2.6 High shrinkage rate. The pre impregnated tape of CND photosensitive cured fiberglass protective cover has a high shrinkage rate of 1.5-3%. It is 10 times higher than other products at home and abroad (1.5 ‰ for other products). What are the benefits of high shrinkage rate? The meaning of shrinkage is the same as that of heat shrink tubing, which is necessary for pipeline patching.

3、 Product Offering Form

According to different usage requirements, such as ordinary buried pipeline patching, crossing pipeline patching, and overall covering of crossing pipelines, corresponding products of different types and structures have been designed. among which,The CND-500 type is a one cloth, one felt, three oil fiberglass structure, suitable for repairing ordinary buried pipelines; The CND-870 type is a two cloth, two felt, and five oil structure, suitable for making joint repairs when crossing clay soil; The CND-870H type is a structural product of two cloth, two felt, and five oil belt surface hardening technology, suitable for making joint repairs for gravel soil crossing pipelines;; The CND-870HW type is a product with two fabrics, two felts, and five oils, equipped with surface hardening technology and staggered structure, suitable for overall wrapping of gravel soil crossing pipelines. Each product is customized in size according to the diameter of the pipeline, packaged in a blackout bag inside and packed in cardboard boxes outside. The supporting materials include: specialized gloves, specialized rubber hammers, wrapping film, and transparent tape.

4、 Product performance

table1                   CNDPre impregnated tape for photosensitive cured fiberglass protective coverMain technical performance indicators

5、 Product Usage

Joint filling for ordinary pipeline sections, joint filling for horizontal pipeline crossing sections, and overall wrapping for horizontal pipeline crossing sections. Please refer to 'Technical Applications' for specific applicationsIntegrated wrapping technology in pipeline crossing.

6、 Use reference

6.1 The construction of CND photopolymerization protective cover must consider the weather, with humidity ≤ 70RH during construction. Within 48 hours after construction, there must be a cumulative direct sunlight exposure time of more than 12 hours (only required for crossing pipelines).

6.2 The inner side of the CND photopolymerization protective cover is cloth, and the outer side is felt, with the cloth facing the pipeline and the felt facing outward. If twisted backwards, the CND photopolymerization protective cover will not provide protection.

6.3 For specific construction methods, please refer to the technical specifications of the relevant structure.

6.4 Key and Requirements for Construction Technology of CND UV Curing Protective Cover:

6.4.1 Blocking ultraviolet rays is very important and can greatly extend the effective operation time;

6.4.2 The end of the main operator must pass over the top of the pipe, otherwise the auxiliary operator will loosen if tightened;

6.4.3 Tightening must start from the middle to ensure that the concave part in the middle is compressed and contracted;

6.4.4 The edges should be closely adhered without wrinkles, and the transparent tape should be oriented correctly and tightly wrapped to ensure quality;

6.4.5 Construction quality requirements: fit, no wrinkles, and edges not raised.