PAINT AND POWDER CASE STUDY:
WAGNER MANUFACTURING

Background
Wagner is a remanufacturer of brake shoes that are used within a drum style brake for cars and trucks. The epoxy powder coating is used as a rust inhibitor. The smaller brake shoes have bonded pads, while the larger brake shoes have riveted pads. A new facility was built in mid 1993 for the processing of brake shoes. The old brake shoes are disassembled, cleaned, powder coated, cured, fitted with new brake pads, and repackaged for distribution to customers. The facility operates 90 hours per week.

The operation was initially designed with 7 separate remanufacturing cells. Each line contains one (1) 4' long short wave oven. The heating elements are T3 lamps with a reflective housing. Gas convection ovens were considered for the application, but too much floor space was required. The short wave ovens have the advantage of small footprint and reasonable energy consumption. The disadvantage has been the maintenance requirements for the systems. Within several months of the facility opening, the heaters began to fail. Every week there are two short wave ovens that undergo repairs averaging 7 hours per week of labor plus the parts cost. The cost of parts and labor equals 26,000 per year. More important than the parts and labor cost is the downtime and the associated overtime costs.

The Medium wave infrared oven achieved all of the goals for a new curing oven:

• Faster production capability
• Minimal floor space
• Reduced maintenance requirements
• Low energy consumption
• Reasonable capital expenditure

The facilities engineering team at Wagner Brakes decided it was time for a new approach. Due to past problems, the team decided that long term testing was required before jumping into heating technology. After two years of testing, that new approach has been approved. The decision was made to install seven replacement medium wave electric infrared ovens from Blasdel Enterprises.

ADVANTAGES OF USING IR FOR THIS APPLICATION:

Floor Space
The medium wave infrared ovens are either 6' or 10" long depending on the part size and weight. The short wave infrared ovens were 4' long. All ovens are 3' wide. The short wave ovens were operating at full power to cure the powder. The new medium wave Blasdel ovens were designed to operate at less than 50% power. This would allow future increases in line speed. It also meant that the ovens would be slightly longer in length, which would not adversely affect floor space. A convection oven would have required a minimum of 50' for the same project.

Maintenance
The short wave infrared ovens require an average of 7 hours per week of preventative maintenance. After two years of operation there have been zero heaters that prematurely failed in the Blasdel medium wave oven due to heater problems. There have been several heaters damaged due to conveyor problems, but this is not related to the heater design. With a typical life expectancy of 25,000 hours for Solar Products panel heaters, the customer will continue to operate for a long time with very few maintenance problems.


Energy Consumption
Often times the input power rating is viewed as the actual power usage for an electric infrared oven. In this case, the 10' oven running 9" brake shoes has 108kw of electric infrared installed. But, in actual operation, the energy usage is 41kw. The energy calculation is 41kw*hrx5.5cent per kw*hr= 2.25 per hour of operation. Based on the current production rate, that equates to 2/10 of 1 cent per part. In other words, it costs 1 cent to cure 5 brake shoes. The energy consumption for paint and powder applications typically accounts for less that 1% of the product selling price. Our guess is that this amount is well below that 1% margin. The best part is that Solar Products panel heaters maintain a consistently high radiant efficiency (80%) over time.

NOTE : Each 18" oven half can operate independently. This allows the heater output power to be adjusted to the part weight. Because the brake shoes range in weight from 1.5 - 15 lbs, they require different power output to match their curing times. The 10' oven is used for heavier parts.

The brake shoes range in size from 7" - 12" radius plus a heavy brake shoe for trucks (15lbs). The information relates to a 9" brake shoe in a 10' long oven.

Specifications	Details
Part description	Steel brake shoes
Coating	Black epoxy powder - 2.0 mils thick
Coating application	Automatic electrostatic spray gun in booth
Length of oven	6' Oven	10' Oven
Zones per oven	One Zone	Four Zones
Input power	64.8kw	108kw
Actual power usage	25 kw per hour	41 kw per hr
Oven type	Medium wave electric infrared
Heater type	Solar Products medium wave panel heaters
Conveyor type	Dual chain conveyor
Conveyor speed	2.75 fpm
Weight of part	1.5 - 15lbs
Gel and cure time (dwell time)	3.6 minutes

We are a distributor of infrared heaters. Always consult manufacturers installation instructions for proper installation of the products or systems shown on this website. © Copyright 1999-2019 Mor Electric Heating Assoc., Inc.

MOR ELECTRIC HEATING ASSOC., INC.
5880 Alpine Ave. NW - Comstock Park, MI 49321  USA
Tel 616-784-1121 - 800-442-2581 - Fax 616-784-7775
E-mail: sales@infraredheaters.com