Page 46 - Market Analysis Report of Optical Communications Field in China & Global market 2016

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More than 80% energy efficiency achieved
in optical fiber coating application
process using UV-LED lamps and novel chemistries
Pratik Shah1, Huimin Cao1, Kangtai Ren1, Xiaosong Wu1, Kate Roberts1, Todd Anderson1, Jackie Zhao2, Li Alex2, Jessica Wang2, Ad Abel3
1. DSM Functional Materials, 1122 St Charles St. Elgin, IL, USA
2. DSM Functional Materials, Zhangjiang High-Tech Park, Pudong, Shanghai,China
3. DSM Functional Materials, Slachthuisweg 30, Hoek van Holland, Netherlands
Introduction
CRU’s 2016 market report data indicates
~368 Million fiber km(Mfkm) were produced
last year, see Fig.1 and for 2016, an optimistic
view projects global demand of ~ 400 to 410
Mfkm, see[1]. To manufacture these fibers,
ample amounts of energy is required to
melt the glass preform, cool the glass strand
(~125μm) with helium and finally cure the
coating material for protection and high
speed winding of the final fiber product. In
this paper, which is a continuation of[2], we
will focus only on the energy required to cure
the coating material and the future demand
for enhanced fiber properties with high
operational efficiencies.
Figure 1: Historic fiber optic cable installation and coating material for every km of optical fiber
global projections (source: CRU 2016 market report)
Between 1990 and 2012, global energy use
increased by 54% while the associated CO2
emissions rose by 48%, see[3] and Figure 2.
In order to prevent future emissions, every
sector should try alternate and preventative
mechanisms. Our attempt here is to show an
alternate path for the optical fiber industry,
which can significantly impact optical fiber
manufacturers both environmentally and
financially.
Microwave powered medium pressured,
mercury (Hg)-based UV lamp systems have
Figure 2: World energy consumption 1990-2040 [3]
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historically been the primary resource for
facilitating the curing of optical fiber coatings.
However, this system suffers from some
fundamental limitations; such as, high electrical
power consumption, shorter life-time and use of
“Hg”which is now considered environmentally
hazardous, see[4].
These lamps emit characteristic wavelengths of
energy in the ratio of UV (25-30%), visible (5-
10%) and infrared (60-65%), see Fig.3 and[5].
Most of the curing energy is supplied by UVA
wavelengths. Also, these lamps require a pull
exhaust system to take out all the heat generated
by infrared radiation (IR), see Figs. 3, 4and[6].
Currently, 1 to 2 KWH is required to cure the
produced. This translates to a total of 400 to 800
Million-KWH required annually to cure fiber
coatings worldwide and also results in 532 to
1064 Million lbs of CO2 being generated, see[7].
Financially, some 53 to 106 Million dollars (10
cents = 1KWH) will be paid to global utilities
companies annually. Up to 80% of this amount
can be saved if UVLEDs are used in this sector.
Figure 3: Microwave lamp spectrum irradiance
and efficiencies
Figure 4: Microwave lamp’s air cooling requirements We have already p er for med substantial
UV-LED technology could offer substantial
benefits due to its fundamental semiconductor
characteristics and construction, such as instant
on-off, Hg-free, longer life, very low power
consumption and thus ultimate lower cost of
ownership. An additional benefit of UV-LED
technology is the absence of UVC rays which
typically produce ozone. However, present day
UV-LED curing systems encounter a primary
challenge with the lack of suitable chemistry
tailored for the monochromatic wavelengths
produced.
Over the past 40 years, most UV chemistry
has been formulated to react with broadband
mercury spectrums and relies on the shorter
wavelengths for surface cure and the longer
wavelengths for throug h cure. We have
developed specific chemistry for high power 395
nm +/- 10nm UV-LED lamps.
The combination of our low volatility formulations
and elimination of undesired infrared radiation
from the high speed curing process generates robust
and consistent fiber properties.
Large preforms (8-15,000 km) are already being
used in optical fiber production. Successful
production requires coating with low volatility to
maintain clean quartz tubes throughout the run
in order to obtain low fiber break and consistent
fiber properties such as high nd value, low
microbending and high cure conversion to take
advantage of the high operational efficiencies.
experiments and trials which will be discussed
in the next section.
Experimental
Multiple developmental coating systems were
applied on a 130μm O.D. stainless steel wire
using a custom designed Draw Tower Simulator
(DTS), see Fig.5, at speeds ranging from 750
m/min to 2100 m/min. Although the tower
stands less than 6 m, the distance between the
coating applicators is comparable to that of a
commercial fiber drawing tower.
The DTS was configured with five UV-LED
systems (395 nm +/-10nm), two after the
primary coating applicator and three after the
secondary coating applicator, all operating at
less than 2 KWH for the coating trials. The Wet-
on-Wet (WOW) processing condition were
performed with only 3 lamps.
We have performed several iterations of