The reason of polypropylene surface pitting corrosion tape

Now solve the problem of corrosion in the pipeline industry to a tape that is always used when polypropylene anti-corrosion adhesive tape, but when to use always appear all sorts of problems, such as tape will appear the phenomenon of foaming, in addition to this phenomenon, of course, will also be common with the tape surface appeared a lot of pitting, is affecting the effects of the use of adhesive tape and not beautiful, is the cause of the tape surface pitting what kind of? Let's look at. < br />
1, anticorrosive tape pp material containing trace under the environment of high temperature can volume expansion of low molecular substances, such as air, water, solvent, or low molecular volatiles. < br />
2, raw material in the process of plasticizing extruder, the heated volume expansion of low molecular substances, but limited to extrusion machine and forming membrane space steric effect, repressed in material volume difficult to release. < br />
3, once the squeeze film mouth, immediately volume expansion, but only to trace its expansion stress would not be enough to destroy the PP layer surrounding it, otherwise it would be the formation of a surface pockmark. < br />
4, due to the uneven nozzle injection of cold water membrane, splashing water droplets along a jet Angle. < br />
5, because of low molecular substances in polypropylene anti-corrosion tape distribution uneven with stochastic characteristics of materials, thus forming the bulge is characterized by random uneven distribution. < br />
6, anticorrosive coating forming often use spray or water-cooled styling spray under way. < br />
7, when ejected cold water splash to not and speed of corrosion level, according to the rules can result in local area on the coating surface quenching, because the water is in a jet Angle of sputtering, and with the movement of the surface contact, so the local rapid cooling zone is half spherical or oval. < br />
8, carrying the hardened plastic film of membrane is greater than the force needed for molten plastic noumenon intensity, molten plastic in the plastic overall contracting, molten plastic and the hardened plastic under the effect of shrinkage stress disconnect, form a vacuum bubble. < br />
9, due to its polypropylene anti-corrosion tape expansion rate is greater than the extrusion speed, the expansion stress in not completely leave the film is released in full, so the bulge to half spherical or oval shape. < br />
10, when anticorrosion pipeline into the refrigeration environment, anticorrosive coating start overall cooling contraction to finalize the design at this point the water quenching effect of the surface has hardened. < br />
above all is the reason why polypropylene surface pitting corrosion tape, for the reasons for pitting had certain understanding after, it needs us to pay more attention in the construction process in the future, of course, in the construction of time in addition to pay attention to the problems above, pay more attention to external factors such as weather and environment, thus ensuring tape will not because of some external factors effect use effect, at the same time, it is important to note when it's in use in the correct operating practices in construction, so as to guarantee the effect of adhesive tape and the service life.
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