P2 Through Teamwork at Freudenberg-NOK
Summary
Freudenberg-NOK, an automotive parts manufacturer, successfully uses waste reduction teams to identify and implement pollution prevention opportunities throughout their Cleveland, Georgia facility.
Background
Freudenberg-NOK produces a variety of automotive parts such as oil seals, O-rings, valve stems, and dust covers. Total Quality Management (TQM) plays an important role in the operation. Freudenberg-NOK’s “Growtth” program, which stands for “Get Rid Of Waste Through Team Harmony”, uses Kaizen teams for problem solving and process improvement. Kaizen is the Japanese word for improvement.
Kaizen teams are formed monthly at Freudenberg facilities to focus on opportunities for improvement. The teams consist of seven to eight employees representing different areas from within the organization, and usually meet for four days. Team members begin with training on problem solving dynamics and methodologies. A facilitator and team leader are responsible for directing the team’s activities. On the last day, the team makes a presentation of its findings and recommendations to plant management.
P2 Modifications
Process Optimization
The molding process for making rubber parts results in excess material, or flash, around the edges of the molded part. The flash is removed from the part and becomes waste. A significant amount of scrap rubber waste was being generated each year.
The weights of the rubber prep, the molded product, and the flash were measured for each oil seal product in order to determine which products were creating the most flash. Prep weight specifications were examined for those products that appeared to be generating an excessive amount of flash. Each molded product has a target prep weight to insure that unfill defects do not occur. An unfill condition occurs when a portion of the mold is not completely filled with rubber. Tests determined the prep weight could be lowered for seven products by about one gram each.
Raw Material Substitution
Reducing VOCs is a concern for Freudenberg-NOK since most of its technologies are based on the use of solvents. A methanol-based adhesive used to bond rubber and metal part components was generating about 40 tons of VOCs annually. To reduce VOCs, a project was initiated to develop a water-based adhesive to replace the methanol-based adhesive. The new adhesive was formulated by the materials development group. Implementation of the new adhesive reduced annual methanol consumption at the plant from 240 drums to 24.
Equipment Modification
Another process that generates VOCs at the Cleveland facility is a dip coating operation. Baskets of metal parts are dipped into a coating bath containing methyl ethyl ketone. VOCs come from the evaporation of methyl ethyl ketone from the bath and from drying the coated parts after they have been removed from the bath.
While investigations into lower solvent coatings and solvent recovery have not yet proven feasible, a modification to the dip coating bath was successful. Chilled water was circulated through coils around the coating bath. This helped lower the bath temperature, reducing the evaporation rate of the methyl ethyl ketone. As a result, additions of methyl ethyl ketone to the bath were reduced by six drums per month.
Results
By lowering the prep weight for seven molded products, flash generation was reduced by about 3.4 tons per year, saving about $76,000 in raw material costs. The substitution of a water-based adhesive for the methanol-based adhesive reduced methanol usage by 216 drums per year. In addition, annual VOCs emissions were reduced by 38 tons, resulting in an annual operating savings of $21,000 per year.
Modifications to the dip coating bath operation reduced VOC emissions by 13.2 tons per year. The implementation of this source reduction activity also saved $13,500 per year in methyl ethyl ketone purchases. Since the plant already had a chilled water system, all that was required was piping installation at a cost of about $500. The operating cost of the chillers is minimal because they utilize the existing plant cooling water.