Design of pipe diameter of polyester‐ramie nonwoven lining material for pipeline rehabilitation

Abstract

In order to solve the problems of pipe diameter of polyester‐ramie nonwoven lining material used for sewage pipelines rehabilitation, the mathematical model of pipe diameter of lining material was established by using elastic mechanics method and composite piping design. The mixing ratio, the fiber web quantification and the needle‐punched density were selected to optimize the manufacturing process of polyester‐ramie nonwoven with thermal shrinkage rate and elongations at break, the results showed that the mixing ratio was 0.7, and the fiber web quantification was 600 g/m2, and the needle‐punched density was 180 thron/cm2. Under this process, the thermal shrinkage rate is 8.72%, and the elongation at break is 83%, which is close to the theoretical value, indicating that the response surface method has practical application value. Combined with the mathematical model and the optimal condition of manufacturing process, the design extremum of pipe diameter of lining material for sewage pipelines with different pipe diameters is predicted, which provides the theoretical basis for the preparation of polyester‐ramie nonwoven composites for pipeline rehabilitation.

Hot-pressing design of tubular polyester nonwoven lining material for pipeline rehabilitation

“…Polyester fibers were loosened on a fiber blending machine (XFH, Qingdao Jiaonan Knitting Co., Ltd. China), netted on a carding machine (CUARNICARD, Spain), and needle-punched on a needling machine (SCZ-1150, Changshu Instruments, China) with a fiber web areal weight of 500 g/m 2 , a needling density of 360 thorn/cm 2 , and a needling depth of 14mm to make polyester nonwovens. The lining material is made by hydraulic machine (BGD-8120, Qingdao Bogda Testing Instrument Co., Ltd. China) under the conditions of temperature 170∼190°C, time 2∼6s and pressure 2.4∼3.2MPa [1,17]. The hot-pressed material is sewn into a tube on a four-needle and six-thread feed-off arm model industrial interlock sewing machine (FW-740TA, Shing Ray Sewing Machine Co., Ltd. China), besides the sealing coating was applied to the seam by the above-mentioned process, so as to prepare the tubular material.…”

“…In practice, tubular polyester nonwoven composite material used for turnover lining of sewage pipeline has the characteristics of high tensile strength and good chemical stability, which can effectively extend the service life of the old pipe [1,2]. Among them, impervious membrane is an important part of tubular composite material, which is in direct contact with the conveying medium in the pipeline and mainly plays a role in anti-permeability and anti-corrosion [3,4].…”