Nalco micro-programs
replace RDF
By Larry Bonday
Traditional retention drainage and formation (RDF) chemistries
create difficulty in
controlling the yankee
coating. This, combined with the perceived impact to softness
and absorbency, can result in the underuse of these RDF chemistries
in tissue and towel grades. Today's new microparticle and micro-polymer
programs are tailored directly to the machine's operating condition
and product quality specifications. This eliminates tissue
makers' concerns with traditional RDF chemistries.
New micro-particle and micro-polymer programs developed by Nalco
Company deliver the cost savings of traditional RDF programs, while
at the same time improving the process stability of both the wet
end of the machine and the yankee coating. The cost savings are
due to improvement in fibre yield and the reduction in use of process
and functional chemistries. The improved wet end stability obtained
from these new RDF programs typically results in less frequent
and less severe upset conditions on the machine. The improved yankee
coating performance translates into improved creping efficiency,
improved sheet properties, and lower yankee coating addition rates.
The proven ability of Nalco Company to tailor new RDF programs
directly to the machine operating conditions and product quality
specifications means that the tissue maker can produce any range
of high softness toilet paper or high absorbency towel while still
enjoying the benefits of improved machine stability and lower operating
cost. Larry Bonday is Program Manager, Tissue Towel Grades, Paper
Service Division, Nalco Company.
Plasticizing release: a new approach
By Chris Rozett
Amazon Papyrus is launching
a line of oil-free, plasticizing release agents for tissue creping.
Some reasons to make the switch to a plasticizing release include
high oil prices, uneven yankee temperature profiles, increased
use of acacia furnish and difficult-to-coat Yankees.
There are two major ways
in which plasticizers excel as release agents:
| • |
Oil-based releases migrate away from the hot
dryer surface, giving a concentration gradient in the Z direction
of the coating matrix. Plasticizing release agents, on the other
hand, dehydrate along with the adhesive in the coating matrix.
There is a minimal gradient across the thickness of the coating.
This gives a more uniformly softened coating with minimal hard
coating buildup. The graphic shows the potential relative release
concentrations in the coating matrix for oil-based and plasticizing
release agents. |
| • |
Plasticizers work to soften the coating matrix without stripping
the coating
off the dryer.
They help to build up the coating thickness, which allows mills
to reduce the amount of creping adhesive used. The result is
a soft, bulky coating that gives good yankee and blade protection
while maximizing sheet softness. |
Chris Rozett is Technical Marketing Manager with Amazon Papyrus
Chemicals.
Trio of Buckman innovations
Buckman has created
the MAGNOS™ product line of yankee coating chemicals specifically
for the ATMOS premium
tissue technology developed by our partner Voith. The key benefits
are improved sheet transfer and uniform adhesion of the structured
sheet to the yankee cylinder surface and finely-tuned creping control
resulting in better machine runnability and premium tissue properties.
In support of the MAGNOS chemistries, complementary products are
available, including wet end chemistry control, fibre-modification
enzymes, Optimyze® enzymatic stickies
control and fabric
care, and process
water treatment.
A second innovation from the company is the new SELECT yankee dryer
adhesive system, which provides coating optimization never before
achievable with yankee dryer packages.
SELECT uses a relatively hard and robust hybrid first adhesive to
provide uniform coating and superior yankee dryer protection plus
high bond strength between the coating and the sheet at the doctor
blade. A second soft rewettable coating is used to increase sheet
attachment at the pressure roll. Buckman currently has a selection
of adhesives to meet varying process demands.
The third innovation consists of recently-developed enzyme products
Buzyme 2535 and 2523S, which were created specifically to condition
the fibre - particularly virgin softwood fibre and recycled fibre
- before it is refined. This treatment can improve bonding strength,
enhance the refining process, and reduce expensive fibre usage,
as well as increase tensile, reduce porosity, and improve coating
holdout.
EDT enzymes for cost savings
As energy costs continue to climb, recycled tissue producers are
seeking ways to reduce energy use. Enzymatic Deinking Technologies
(EDT) offers innovative, mill-tailored solutions to this growing
problem. With the use of EDT's products, natural enzyme mechanisms
can be leveraged to improve the papermaking process which can result
in substantial reductions in energy use. EDT's Enzynk® and Refinase® products
have enabled mills to improve tissue/towel production, increasing
quality while offering multiple strategies to reduce energy through
increased pulper defiberization, greater tonnage output, reduced
refining, and reduced drying energy.
One of our applications enhances pulper action in breaking down
the fibre matrix. This approach shortens pulping time, which decreases
energy use, as pulping is one of the most energy-intensive stages
in a deink plant. For mills that are bottlenecked at the pulper,
this method is also instrumental in increasing output. Enhanced
fibre yield through reduced fine screen rejects has also been observed.
Enzymatic deinking has further helped mills increase production
rates while maintaining deinked pulp quality, notably reducing specific
energy cost per ton produced. Energy use is not a fully variable
cost. Many EDT customer applications focus on this type of fibre
modifications that enhance drainage and increase total output.
In the same vein, EDT uses enzymatic treatments to 'clean' fibres
to be more conducive to hydrogen bonding, thus strengthening the
sheets. Because final tissue sheet strength is an important driver
for the level of refining energy imparted to the stock, mills can
decrease refining energy without compromising sheet strength and
can also consider options to degrade furnish use and cost to varieties
that would provide less strength. Also significant in driving energy
use per ton are dewatering and drying dynamics. EDT uses enzymatic
treatments to enhance stock drainability and allow steam to escape
more readily, thereby reducing energy use on the machine.
Altogether, the advantages of these tailored enzymatic approaches
have proven to be considerable, saving mills over $15/ton in energy,
and are likely to remain important options as energy costs continue
to rise.
Innovation across the range
Hercules' well known range of Kymene® wet strength resins has
been enhanced by several
new offerings in 2008. Kymene® 920,
available in Europe and North
America, meets Generation 2 regulatory standards for epi-residuals
whilst offering Generation 1 wet strength resin performance. Additionally,
in Europe only, Kymene® 227LXP
and Kymene® 33VSP offer Hercules' highest ever functionality
in the ultra low AOX and
Generation 3 wet strength categories respectively, due to a unique
proprietary manufacturing process.
In yankee coating, Hercules
has introduced a range of
'plasticized' Crepetrol® base coats globally to address the
requirements of low moisture
or aggressive recycled fibre
tissue manufacture without hard coating buildup. This is augmented
by a new patented polymer high temperature base coat in North America
and later this year in Europe as well as the availability of laboratory
crepe performance modeling for customers via our three regional
applications laboratories in North America, Europe and Asia. Additionally
in 2008, Hercules introduced a range of Dimension™ converting
technology. Boosting the value of tissue products is a primary concern
in today's competitive market. The Dimension™ converting range
comprises three remarkable technologies that offer papermakers new
opportunities in the areas of tissue lotions, biodegradable tissue
for use with septic tank systems, and converting adhesives.
Finally, Hercules' process chemistries in the field of contaminant
control and microbiological control continue to evolve with new
generation DeTac® pitch and stickies control and expansion of
the market leading Spectrum® ammonium bromide control into new
geographies.
Cargill fibre additives for better strength
Cargill is coming out with a line of enhanced fibre additives designed
to increase the strength
of tissue and towel products while lowering manufacturing costs.
Sourced from renewable agricultural seed fibres and made using a
totally chlorine-free (TCF) process, the soon-to-be-branded product
line presents an alternative to the typical chemical approaches
for achieving the tissue strength properties desired by consumers.
The high hemicellulose composition of Cargill's enhanced fibre additives
improves fibre-to-fibre bonding. This enhances the strength of the
paper sheet (wet and dry tensile) and provides a tool for tissue
makers to optimize fibre furnish increase paper machine productivity,
minimize refining requirements, reduce wet end chemical usage and
lower overall manufacturing costs. A reduction in refining adds
additional benefits for increased bulk and improved softness in
tissue grades.
Cargill conducted a number of customer trials over a wide range
of grades before deciding to build a manufacturing facility in Cedar
Rapids, Iowa. Production is expected to start in November.
For more information, contact Cargill at +1 952 742-4332.
AROSURF®PA 873 tissue softener
The new AROSURF®PA 873 from Evonik Goldschmidt GmbH is suitable
for virgin, low strength, and recycled fibres. AROSURF®PA-873
is a universally compatible, highly concentrated liquid, recommended
as an overspray softener for tissue at the felt, on the yankee,
or after sheet formation. The new softener can be dispersed with
an in-line mixer immediately before spray application. Aqueous dispersions
at 5-10% of AROSURF® PA-873 have low viscosity and are easily
applied by spray boom. The pick-up varies, according to the desired
softness, from 0.5-5% product on tissue weight.
AROSURF® PA-873 imparts a soft handfeel (surface softness) and
does not have significant influence on tensile strength or water
absorbency. It is based on vegetable and synthetic raw materials
and does not contain solvents or VOCs. It is food contact compliant
in line with FDA 21 CFR § 176.210. Due to its mild ingredients,
it does not require a hazard warning label in line with EC directives
on dangerous materials. It is listed on the following inventories:
EINECS, TSCA, Canada (DSL), Japan (ENCS), Australia (AICS), Philippines
(PICCS), China. The product has a shelf life of 12 months and is
on current production.
Clariant's Cartaspers® PSM for stickies control
Cartaspers PSM® Liquid is a new polymer designed for stickies
control in the tissue manufacturing process. This water-based, non-ionic
polyester dispersion reduces the build-up of stickies in the wet
end and on felt/wire fabrics.
In a wet-end application Cartaspers PSM Liquid has a strong affinity
for the hydrophobic stickies and works by encapsulating the stickies
preventing them from agglomerating. In a wire or felt treatment
application, it forms a mono-molecular hydrophilic 'coating' over
the synthetic fibres and prevents stickies from adsorbing onto the
wire or felt.
Cartaspers PSM Liquid readily biodegrades and is compatible with
most cationic and anionic chemical additives. This FDA-compliant
product can be part of your green initiative since Cartaspers PSM
Liquid received the prestigious P2 Recognition Project Award from
the US Environmental Protection Agency as an innovative new pollution-preventing
product.
F
or more information, call +1-800-727-3710 or email: paperexpert@clariant.com.
