THERMOFORMING
CASE STUDY:
MAIER MANUFACTURING
Background
Maier
Manufacturing is a medium sized thermoforming operation that specializes
in replacement parts for motorcycles and all terrain vehicles. In
business since 1972, they have 55 employees in 45,000 total square
footage of office, manufacturing, and warehouse space. The products are
marketed from a catalog to dealers throughout the USA.
Maier has two double station thermoforming units and two single
station units. The platen sizes vary from 32" X 48" up to
48" X 75"
The
Problem
Sales
were increasing and Maier could not keep up with normal production (This
is a problem every manufacturer would like to have.) Due to demand,
overtime was turning into a second shift. Maier was forced into
reviewing 3 options:
The new
machine would not only cost $100,000 to purchase but would additionally
require labor to operate, power to run, floorspace and additional
maintenance time. The 2nd shift option would have required additional
labor personnel, supervision, increased overhead costs and more
headaches.
The
Solution
After
weighing the options the decision was made to retrofit the equipment.
The retrofit would primarily consist of changing the heaters, controls,
and power switching devices. Maier knew from past experience with a
Heartland thermoforming machine that the productivity could be
significantly increased with Solar Products panel heaters over the
existing metal sheathed tubular heaters. The heaters were sized at 15
watts/sq in (wsi) for a total of 108 kw. The old heaters were 50 kw
total for both the top and bottom heaters. The old heaters were cycling
on between 80-100%. The new heaters are cycling on between 30-60%.
The
decision was made to increase the power available in the event that more
power was required with future products or materials. The control system
selected was a Cutler-Hammer programmable logic controller (PLC) model D
100A with 32 outputs for individual zones. The timer/counter access
module assists in quick and easy programming of the heater cycle times.
The power switching devices were upgraded from mechanical contractors to
mercury relays, which are very common for sheet fed equipment.
The complete
upgrade cost $15,000. This included top and bottom heaters with mounting
frame, PLC with touch screen, electrical enclosure, 32 mercury relays,
control cabinet wiring, new high voltage power feed to equipment, 120
hours labor, a larger vacuum tank, and all the running around required
for a project such as this.
The Results
The ABS
and Polyethylene sheet heating time was reduced by an average 84%. What
used to take 5 days can now be done in 2.84 days. Even though the
available power more that doubled, the actual power usage was reduced by
10%. Another benefit was a much more even heat over the sheet. As a
result, the forming and stretch is more uniform. It also ensures less
material stretch marks. The old heaters had a rejection rate due to
uneven heating, which has been eliminated with the new heaters. click
here to see the details
The Bottom
Line
Maier
Manufacturing realized a total return on their retrofitting investment
in only 9.2 months, and on heater investment in less than 4 months.
Machine output capacity increased by 43% and there was no overtime, 2nd
shift or new equipment purchase. Result: an amazing 76% increase in
productivity.
The increase
in productivity is based on the fact that sheets of ABS went from 45 to
80 sheets per day-a 77.7% increase-and polyethylene went from 40 to 70
sheets a day- a 75% increase. On average a 76.26% increase in
productivity. A 43% increase in machine output derives from what used to
take 5 days can now be done in 2.84 days, resulting in 43% more
available machine time. Total ROI is based on a retrofitting cost of
$15,000, a $62.21/day reduction in labor cost, and a $13.33/day
reduction in electrical cost. Electrical rate is 0.07834 KW/hr. The
calculations is as follows: $15,000/($62.21 + $13.33/day)=198.5 days to
recoup the initial investment or 9.16 months, assuming a 40 hour work
week. Your actual savings may vary depending on the local utility rates,
labor costs and retrofit
costs.
Even More
Benefits!
The ROI
was calculated using the reduction in electrical usage and labor. There
were many items not used in the ROI calculation that do pertain, such
as:
