THERMOFORMING
CASE STUDY:
MACHINE RETROFIT WITH BROWN IN-LINE EQUIPMENT
The
Company:
A manufacturer of paper and
plastic cups and plates
A multitude of Brown roll-fed thermoforming machines
In business since the early 1900's
The
Problem:
The cost of operating the thermoforming
equipment was dragging down profits.
Several machines were retrofitted with gas catalytic heaters in an
effort to reduce energy costs.
Why The Gas Catalytic Retrofit
Didn't Work
While gas catalytic heaters realized
substantial energy savings over the existing Calrod heaters, the
increased cycle times and loss of quality control quickly gobbled up the
savings. Product consistency was poor leading to a decrease in quality
control and a 10-15% increase in the reject rate. The company was left
with machines that had a slow output and were limited in use for the
product line.
The
Solution:
- Retrofit with Solar Products electric panel
heaters.
- Energy consumption was reduced by 35%. (The
increase in line speed was not included in this savings).
- Line speed has been increased by 17%. (In fact, the
line speed could be increased even more based on the heater output,
but is limited by an in-line proprietary process that completes the
product.)
- On a second machine retrofit, the energy savings
was 50% while maintaining the same line speed.
- Product quality improved over the old Calrod
heaters.
- The reject rate has been lowered as compared to the
original Calrod heaters
- Due to an increase in zoning, there is better
control over the sheet temperature. The operators find the machine
easier to control. The temperature uniformity is so good that the
company is experimenting with a thinner gauge material (styrene)
which will offer increased material savings.
- The outer heaters can be shut off when running a
smaller mold. This increases energy savings.
- Due to Solar Products' ability to offer custom size
heaters (without the custom price), zoning was designed to precisely
match the specific requirements of the company's machinery. Zoning
was increased from 6 to 13 zones, increasing product quality while
maximizing energy efficiency.
- A lunch button was added to reduce the electrical
consumption during the break time by reducing the heater
temperature.
- The oven control system was designed in a
co-operative effort between Steve Benjamin, Inc. and the customer to
produce an oven that can hold a tolerance of 1oF in an
open air environment.
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