Grantee Research Project Results

Final Report: Reduced Cost Sewer Pipe Relining Using Ultrasonic Tape Lamination

EPA Contract Number: 68D00240
Title: Reduced Cost Sewer Pipe Relining Using Ultrasonic Tape Lamination
Investigators: Roylance, Margaret E.
Small Business: Foster-Miller Inc.
EPA Contact:
Phase: I
Project Period: September 1, 2000 through March 1, 2001
Project Amount: $69,959
RFA: Small Business Innovation Research (SBIR) - Phase I (2000) RFA Text |  Recipients Lists
Research Category: SBIR - Pollution Prevention , Nanotechnology , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)

Description:

During this Phase I program, Foster-Miller has developed techniques based on Ultrasonic Tape Lamination (UTL) to joining of plasticized PVC sewer liner material. This effort was undertaken in response to a need for environmentally sound and cost-effective methods for rehabilitation of aging water and sewerage pipe rehabilitation infrastructure. For this purpose, Foster-Miller worked with Ameron International, the Massachusetts Department of Environmental Protection (MassDEP) and the Massachusetts Water Resources Authority (MWRA) to evaluate the use of ultrasonic joining of liner materials. The use of ultrasonic joining has several significant advantages over the hot air field welding process currently used by Ameron. These advantages include the highly focussed nature of energy deposition during insonification, and the rapid generation of this localized heating through a combination of viscoelastic and frictional effects. Due to these advantages, ultrasonic welding methods allow rapid joining against the surface of a concrete sewer pipe which functions as a significant heat sink during conventional hot air welding, resulting in very long hot air welding times. The current hot air welding method also requires the use of a highly plasticized PVC "weld strip" in addition to the base material. This welding process advances at a rate of approximately 6 in./min, and requires two passes to complete the weld. Foster-Miller has demonstrated high strength ultrasonic welds in the plasticized PVC liner material using commercial off-the-shelf equipment, and has demonstrated weld times of 6 in. in 2.5 to 3 sec. In conjunction with our business partner Branson International, we have evaluated several alternate techniques and ultrasonic systems in order to identify a welding procedure and a field-deployable system based on modified commercial equipment that would provide the most energy, time and cost-effective solution to the current problem.

The Phase I program sought to adapt and demonstrate existing Foster-Miller UTL technology from the fabrication of fiber reinforced thermoplastic aerospace components to the application of plastics joining in lined pipe installation and existing pipe rehabilitation. The principal goal was to achieve an order of magnitude increase in welding speed. Specific objectives included the following:

• Define the material and performance requirements for a range of pipe rehabilitation systems.
• Identify the UTL operating parameters necessary to process the selected materials.
• Demonstrate, through laboratory fabrication and testing, that the necessary joint performance can be achieved.
• Develop the system operating envelope for field applications.
• Design a complete ultrasonic joining machine for fabrication and use in Phase II.
• Develop cost projections for welding unit and potential time and cost savings

Summary/Accomplishments (Outputs/Outcomes):

Technical Objectives Phase I Results Definition of the material and performance requirements for a range of pipe rehabilitation systems. ? Selected 0.10 in. thick plasticized PVC as liner material for joining trials.   ? Eliminated weld strip from joining process at Ameron's request.   ? Ameron specified a performance benchmark of 2000 psi measured on a Type IV D-638 specimens with a 0.5 in. overlap. Identification of UTL operating parameters necessary to process the selected material. ? Selected 20 kHz for energy deposition in thick adherends.   ? Determined that continuous welding caused excessive migration of molten material.   ? Designed energy directors to enhance plunge welding.   ? Selected welding times and pressures. Demonstration that the necessary joint performance can be achieved. ? Demonstrated 2000 psi against a concrete substrate on 1 in. square ultrasonic welds at Foster-Miller.   ? Demonstrated 2000 psi against a concrete substrate on 6 in. x 0.5 in. welds at Branson. Achievement of an order of magnitude increase in welding speed. Decreased joining time from 6 in./min to 6 in./3 sec. Development of the system operating envelope for field welding. ? Refined operating parameters including weld time, hold time amplitude and applied pressure.   ? Initiated discussions with Branson on field deployable welding system. Development of cost projections for welding unit and potential time and cost savings. ? Identified critical process variable and scale-up issues.   ? Prepared Phase II plans with Ameron.

Conclusions:

In summary, the Foster-Miller ultrasonic joining technique has exceeded the technical goals set for the Phase I program. The technology has been demonstrated against a realistic substrate, and has been shown to provide welds that meet the strength goals established by Ameron with joining times more than an order of magnitude shorter than the current method. Based on these results, Foster-Miller and Ameron propose to design and build a prototype field-deployable joining system and demonstrate its use in the field for installation of PVC liner materials.

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this project

Supplemental Keywords:

Infrastructure, sewer pipe repair, infiltration and inflow, I/I, ultrasonic welding., Scientific Discipline, Water, Engineering, Civil Engineering, Civil/Environmental Engineering, Engineering, Chemistry, & Physics, Environmental Engineering, relining, Massachusetts DEP, infrastructure , Ultrasonic Tape Lamination (UTL), sewer pipe

SBIR Phase II:

Reduced Cost Sewer Pipe Relining Using Ultrasonic Tape Lamination  | 2000 Progress Report  | Final Report