Effective hardware for connection and repair of polyethylene pipelines using ultrasonic modification and heat shrinkage. Part 2. Production bases for molding of epoxy repair couplings with shape memory

Abstract

Production bases developed for the molding of epoxy repair couplings with shape memory are described. It is established that maximum deformation of tubular blanks of the epoxy polymers under investigation, which had not been exposed to ultrasonic vibrations, did not lead to their failure and amounted to no less than 15-17%. Variation in the strength of heat-shrinking couplings based on epoxy compositions is studied as a function of the parameters of their ultrasonic treatment. Effective regime parameters for the ultrasonic treatment, which contribute to maximum strain hardening of the couplings with retention of an acceptable degree of their deformation, are presented.The production bases developed by Kolosov et al. [1,2] and examined below are a refinement of the familiar technology based on the method of producing heat-shrinking articles [3]. This method includes preparation of an initial blank by casting liquid, anhydride-hardened, epoxy polymers (EP) in appropriate molds, heating of the blank to the point of its transformation to a highly elastic state, and its deformation in a highly elastic state with subsequent cooling and retention of its stress state [4].The familiar technology based on the method outlined in [3] does not provide a sufficient safety factor for heatshrinking articles formed from EP in connection with incomplete realization of the strength and engineering properties of epoxy oligomers (EO). When the method described in [3] is used, therefore, additional operations involving banding (underwinding) of the glued-coupling connection obtained with a fiberglass tape is often required as a result of inadequate strength of the couplings so formed.Let us examine production bases for the formation of epoxy repair couplings with shape memory. Useable MaterialsAs in the method outlined in [3], a mixture of liquid and elastic components was used as the basic epoxy composition (EC) in the production bases that we have developed. As a rigid component, we used a complex aromatic diglycidyl ether in the form of a Grade UP-640 resin, which is produced in accordance with regulations established by the Ukrainian Research Institute of Plastics (UkrNIIPM in Donetsk). A block oligomer (BO) formed from aliphatic EO and an acid oligomer in the form of a modified Grade UP-599 EO (Technical Specification TU 6-05-1869-79) was employed as the elastic component. The ratio of the weight of the rigid to the elastic component was 3:2, respectively [5].

Functional Materials for Construction Application Based on Classical and Nano Composites: Production and Properties

“…Implementation of the developed approaches to the use of effective US devices allows obtaining a wide range of practically defect-free classical PCMs and NM PCMs for functional purposes. Effective hardware for connection and repair of polyethylene pipelines using US modification and heat shrinking are studied in [24][25][26][27][28]. The epoxyglue compositions and banding, fiberglass tape impregnated with epoxy compositions, thermistor couplings with shape memory and surface-treatment methods for polyethylene pipes are investigated.…”

Short Review of Studies on Modeling of Technology and Technical Means Used for Production of Classical and Nanomodified Functional Polymer Composite Materials

“…In addition, there is a decrease in the level of residual stresses in the repaired pipelines, which allows to extend the period of their operation. The paper [29] describes an improved methodology for forming epoxy repair couplings with shape memory effect based on the use of effective US treatment regimes. At the same time, the maximum deformation of the molded tubular blanks from EPs formed without US treatment was 15-17% at a diameter of 63 mm.…”

Simulation of intelligent sensors dipping into the melting polymer composite

“…Робота [7] присвячена застосуванню інтелектуальних полімерних матеріалів у хімічній промисловості та медицині, розглядаються особливості їх використання та застосування. За допомогою інтелектуальних датчиків можна здійснювати неруйнівний контроль і за якістю деяких процесів формування, наприклад, термоусадки з'єднувальних муфт з пам'яттю форми [8].…”