Grantee Research Project Results

Final Report: A Novel Approach To Manufacture Recycled Composite Timbers for Structural Applications

EPA Contract Number: 68D03022
Title: A Novel Approach To Manufacture Recycled Composite Timbers for Structural Applications
Investigators: Krishnaswamy, Prabhat
Small Business: Engineering Mechanics Corporation of Columbus (EMC2)
EPA Contact: Richards, April
Phase: I
Project Period: April 1, 2003 through September 1, 2003
RFA: Small Business Innovation Research (SBIR) - Phase I (2003) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , SBIR - Waste , Small Business Innovation Research (SBIR)

Description:

The research carried out during this project consisted of evaluating various joining technologies that would be suitable for structural-grade recycled plastic lumber (SGRPL) to manufacture recycled composite timbers (RCTs). The work involved welding or bonding laboratory-scale coupon specimens machined from SGRPLs and evaluating both the process parameters and performance of the bond for efficiency and strength. All SGRPL materials were provided by manufacturers as in-kind support due to their interest in commercializing this technology. Based on the laboratory trials, two methods of welding were selected as potential candidates for demonstrating feasibility using full-scale SGRPL specimens. One of these technologies, which showed much higher efficiencies, was used to prepare full-scale welded specimens. Several unique fixtures needed to be designed and fabricated to enable the processing of SGRPL using standard welding equipment both in the laboratory and at the manufacturing site. The full-scale specimens were prepared at the welding equipment manufacturer’s facilities, who provided the use of their facilities and equipment as in-kind support for this project. Upon successful completion of the evaluation of the full-scale specimens, the potential to use commercially available equipment for manufacturing RCTs was evaluated.

Summary/Accomplishments (Outputs/Outcomes):

Major findings from the Phase I feasibility study identified by Engineering Mechanics Corporation of Columbus were as follows:

· Smaller-dimension SGRPL specimens can be successfully welded to produce larger-dimension RCTs.

· Two methods of plastics welding showed considerable potential for commercialization.

· One of the welding methods was by far more efficient, with the lowest cycle times for fast production.

· Existing commercial equipment may be modified with appropriate fixtures especially designed to develop a prototype machine for large-scale commercial manufacture of RCTs.

· Welding techniques also may be used to produce RCTs with special cross sections, such as those for I-Beams, T-Beams, and Box-beams.

The success of this project will increase the markets for SGRPL significantly. The results anticipated from Phase II of this project are the development of novel designs, establishment of manufacturing and processing requirements, and fabrication of prototypes for RCTs. The enhanced properties of RCTs from this technology would allow the new product to replace chromated copper arsenate-treated wood in a number of applications such as joists, posts, beams, girders, and pilings.

Conclusions:

The major conclusion of this work is that use of a novel welding technology to manufacture RCTs using SGRPL is both technically feasible and commercially viable. The manufacturing process to be developed as a result of this work is anticipated to be cost-competitive and have much better performance parameters as compared with existing manufacturing technologies for RCTs. The superior performance of the new RCTs, coupled with lower lifecycle costs, is expected to provide a replacement for arsenic-treated wood in marine and waterfront structures, the market for which is estimated to be almost $800 million annually.

Supplemental Keywords:

structural-grade recycled plastic lumber, SGRPL, recycled composite timbers, RCTs, chromated copper arsenate, girders, pilings, marine applications, thermoplastic composites, structural joists, welding, platforms, small business, SBIR., Sustainable Industry/Business, RFA, Scientific Discipline, POLLUTION PREVENTION, Waste, Technology for Sustainable Environment, Chemical Engineering, recycling, Sustainable Environment, Municipal, Environmental Chemistry, cleaner production/pollution prevention, Environmental Engineering, municipal waste plastics, municipal waste, clean technology, scrap prepreg, green technology, environmentally conscious manufacturing, plastics, construction material, plastics recycling, commingled plastic, commingled plastics, plastic lumber, alternative materials, recycled plastics