FEATURE: PAPER CHEMICALS
A saving grace for a resource-strapped industry
2009's range of innovative new chemical technologies for the pulp and paper industry
In the midst of a global economic
recession, pulp and paper mills around the world are either shutting down or (in the case of most local mills) reducing their production levels in preparation for the tough year ahead. This will have a direct affect
on the paper chemicals suppliers, who are in the same boat as the paper producers.
With this in mind, this year will perhaps be met with fewer new chemical products on the market and instead more revamped
existing products, with paper chemical suppliers under greater pressure to quickly respond to the economic crisis.
Nevertheless, paper chemical technologies that will find success in the following year will
be those that better equip the papermaker to face the economic onslaught. We take a look at the best chemical technologies from Clariant, Buckman Laboratories and SA Paper Chemicals hitting South African markets
that save the papermaker time, money and natural resources.
THE USE OF ENZYMES
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Although enzymes are not a novel concept in the paper industry, their innovative use certainly promises to take the industry by leaps and bounds, through paper chemical suppliers such as Buckman Laboratories - the market leader in enzymes for the pulp and paper industry.
Having initiated research and development work some 17 years ago with the first applications achieved 15 years ago, Buckman now has a commercial product range for a wide variety of applications including:
• Bleaching enhancement
• Biological deposit control
• Starch modification
• Both wet-end and size press starch boil-outs
• Stickies management
• Pitch management
• De-inking
• Drainage management
• Vessel picking
• Fibre modification for strength and energy management
Part of Buckman's success with enzymes stems from the ability to formulate very specific enzymes to meet industry needs. This combined with the proprietary stabilisation package gives the Buckman enzymes a shelf life of six months or more un-refrigerated, making them viable options in the harsh pulp and paper working environment.
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Buckman is possibly the only company to have commercialised enzymes in all 5 continents, and is experiencing great interest in enzymes for fibre modification.
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Fibre modification enzymes
Fibre modification enzymes are mono-component protein catalysts designed to reduce the activation energy of specific reactions. Effects include strength increase/decrease, increased drainage, vessel segment modification, opacity/porosity modification, etc. Benefits from properly applied enzymes include improved softness, partial or complete starch elimination, fibre substitution, energy reduction (refining and or drying) and/or paper machine speed increases. The diagram below illustrates how an enzyme can allow the same strength to be achieved with less refining, or how an enzyme will allow greater strength development with unchanged refining levels.
SA Paper Chemicals' microbiological program
SA Paper Chemicals has introduced a unique microbiological program, Spectrum® XD3899, which is based on Ammonium Bromide technology. This exclusive and patented technology uses a stoichiometric blend of Ammonium Bromide and Sodium Hypochlorite to form a Bromide Activated Chloramines (BAC). This BAC has the unique characteristic of a low oxidizing potential, but kills unwanted microorganisms quickly with a fast degradation rate (30–180min) to harmless chemicals, not producing any AOX.
Benefits seen in over 600 paper/board machines in the world include:
• Efficacy on a wide range of microorganisms
• Reduce machine downtime for wash-ups
• Reduce sheet defects and breaks, improve runnability
• Not consumed by organic or nitrogen compounds
• Highly effective against biofilm
• Very effective in catalase and odour control
• Excellent for starch preservation
• No interference with wet-end chemicals
• FDA 176.300 and 176.170 approved
ALTERNATIVE ASA EMULSIFICATION CHEMISTRY
Buckman Laboratories introduces Bubond 650: an efficient, stable liquid product used for emulsification of ASA for internal sizing. This product brings two significant benefits: Firstly it allows for ASA use where no starch cooker is available.
Secondly, it allows for substitution of current wet end starch which can deliver a number of benefits to the mill concerned including overall cost reduction, sizing efficiency improvement and wet end emulsion starch elimination. Not only is cooked wet end starch a source of sizing variability when poorly controlled, but the use of a cool liquid for emulsification dramatically reduces the risk of hydrolysis of the ASA before reaction with the fibre.
Between 7 and 17% improvements in sizing efficiency have been seen with conversion to Bubond 650, and performance can be further enhanced in combination with Buckmans' latest ASA product Buckman 157. Buckman 157 is formulated for enhanced emulsification and has shown up to 20% reductions in sizing consumption when converting from previous ASA chemistry.
DEFOAMERS
SA Paper Chemicals' latest pulp mill defoamer is the Advantage® VE (3901 and 3702), a patented biodefoamer technology for the pulp industry. The products are based on natural agric-based oils. All raw materials are readily available and naturally occurring. This biodegradable and environmentally friendly product range is an excellent replacement for silicone based emulsions/concentrated product and conventionally oil-based products.
The products are APE/NPE free, contain no animal derivatives, paraffinic oils and base silicone fluid, are dioxin precursor compliant, FDA and BfR approved and is classified per OSHA as non-hazardous. The biodefoamer therefore uncouples pulp producers from traditional petroleum and synthetic chemical feedstock while mitigating the impact of increasing energy and raw material cost.
Advantages recorded include:
• Improved Defoaming, Drainage, and Washer Efficiency compared to industry standards
• Reduced Chemical Consumption
• Biodegradable and Environmentally Friendly
• Energy Savings Potential
SCALE CONTROL IN DIGESTERS
In pulp and paper mill systems, scale can affect end product quality, accelerate corrosion, and decrease production. Buckman's newly developed Busperse 2012 has shown great performance addressing these problems by eliminating scale in continuous digesters, stock lines, vacuum pumps, screens, evaporators, heat exchangers and headboxes.
The product is an anionic dispersant and scale inhibitor designed for pulp and paper mills. It uses dispersion, crystal modification, and threshold inhibition to inhibit the formation of scale deposits involving calcium carbonate, calcium sulfate, and barium sulfate. Buckman Laboratories claim that the cost efficiency of the product is unsurpassed at present, with each conversion proving to return significant value to the operation concerned.
PITCH AND STICKIES MANAGEMENT
In an attempt to reduce their reliance on virgin fibre and to reduce environmental costs, there is a growing use of waste materials in the papermaking process. With this comes the need for chemical technologies to do away with the subsequent increase in stickies. In response to this, Buckman Laboratories, Clariant and SA Paper Chemicals have brought out new products for the management of stickies.
SA Paper Chemicals: DeTac® 7225
This patented technology for pitch control, is based on a cellulose polymer with a hydrophobic modification. The cellulose provides a protective layer for deposition control in the stock, on the machine and throughout the drying section. The products perform without or in conjunction with a micro fixative and have the ability to partially or fully replace talc, when added to the pulp mill. The products are not affected by temperature, pH and conductivity.
The DeTac® 7225 is a nonionic hydrophobically modified cellulose blended with a nonionic surfactant. The modified cellulose controls the deposition by hydrophobic adsorption to pitch surfaces which then through hydrogen bonding with the fiber retain the pitch out of the system. The surfactant provides product stability and some deposition control. The three mechanisms that are affected are the reduction in tackiness, an improvement in colloidal stability and a reduction the concentration of the pitch.
The products are FDA and BfR approved and is APE/NPE free. Benefits were seen:
• Talc replacement
• Reduced chemical usages – Bleach, OBA and cleaning chemicals
• Improved product quality, productivity and efficiencies
• No interference with wet-end chemicals
• Decrease downtime for cleaning
• Cost effective program
Clariant: Cartaspers® PSM
Clariant's award-winning Cartaspers® PSM is a nonionic, readily biodegradable, hydrophilic polymer which has a high affinity for hydrophobic surfaces. Cartaspers® PSM won an award from the US EPA in 2007, one of only three such honors made by the EPA among the thousands of new chemicals submitted to the agency for registration during any one year. The agency acknowledged that Cartaspers® PSM "provides reduced worker exposure to VOC emissions and improved paper machine operational efficiency during the use of post-consumer waste in the production of paper products."
Cartaspers® PSM is applied to the wet-end of a paper machine to treat the stickies in the pulp. Additionally, the product may be used to condition the machine clothing. Added continuously to the shower water, the fabric monofilaments are encapsulated by a "protective hydrophilic polymer layer". On each revolution of the paper-making wire or felt, the contamination is washed away and a fresh layer of product applied. This leads to a significantly reduced requirement for cleaning solvent.
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Buckman Laboratories is introducing Optimyze® Plus – their next generation of enzymatic stickies control products. Optimyze® Plus is a proprietary multi-component blend of enzymes and a dispersant designed to target both pitch and stickies.
While pitch and stickies are problematic for quality and runnability on their own, their impact is often worsened when they occur together. This makes Optimyze® Plus the ideal product for stickies management. Mills looking to increase recycled content or substitute current recycled material with cheaper recycled material without adverse impact on quality or runnability may benefit from the use of this product.
Buckman and AMCOL
Buckman's pitch control products will also be heightened by the announcement late last year that a global cooperative agreement had been signed between AMCOL and Buckman Laboratories. This collaboration combines the strengths of both companies by using AMCOL'S expertise in bentonite technologies and superior product specifications and Buckman's full product line of specialty chemicals and technical support.
This gives Buckman access to AMCOL's full range of bentonite products around the world. These include products for retention, drainage, pitch control, water clarification and any other applications where bentonite may be used. AMCOL is the largest bentonite supplier in the world, and is known for the high quality bentonite it has provided to the industry over the years.
SIZING AGENTS
imPress® ST9 Technology
A new technology from Hercules Incorporated, imPress® ST Surface Size Technology, delivers superior sizing cost performance and excellent runnability compared to traditional surface sizes. The ease of use and high sizing development of this new technology offers the paper manufacturer the opportunity to reduce internal size addition and shift a majority of size development to the size press.
imPress® ST is a cellulose reactive surface sizing agent designed to impart high levels of sizing for a variety of applications. This product is low foaming, compatible with most size press additives and enables the paper manufacturer to change the balance between wet end and surface size addition. Several potential benefits result from the increased flexibility in sizing and wet end chemistry management available with this technology.
The product is added directly to the size press run tank(s). Compatible with most common size press starches, it can be used in conjunction with optical brightening agents (OBAs), salts and defoamers typically used in size press applications with no adverse effects.
CLEANING DRYER DEPOSITION
Dryer Can Passivation. (DSP)
SA Paper Chemicals' DSP is a unique, novel and effective method for control of dryer can contaminants. The DSP technology includes special application equipment, chemicals and application knowledge to improve the functionality of dryer can operation.
The technology not only reduces deposition, dusting and linting in the dryer section, but also provides opportunities to improve the papermaking process. Applying chemistry in the dryer section is fundamentally different to the wet -end. For this reason, specially designed equipment has been developed for the application of product in the dryer section.
The concept is similar to a non-stick cooking spray one might use on a hot frying pan to prevent food from sticking to the hot metal surface. Three products are currently available – Zenix® DS7145, 7148 and 7151. Selection of the product depends on whether the paper/board is being sized or not. The products are FDA approved and APE free.
Application can be to the drying cylinder itself or to the felt. Over 200 machines worldwide are currently using this technology. References are find in newsprint, coated paper & LWC, linerboard, corrugated medium, wood free mechanical paper, white and colored board and low grade printing paper. Some other opportunities noted are:
• Reduction in picking and scaling at the printer
• Less holes and breaks.
• Increase machine speed.
• Increase in sheet smoothness.
• Improvement in moisture profiles
• Reduction in doctor blade wear.
FASTER DRYING
Hi-Phase® 40D
SA Paper Chemicals has also developed the cationic rosin emulsion, Hi-Phase® 40D, which offers the board manufacturer the ability to size cost effectively at pH 6.5 to 7.0. This patented technology ensures faster development in the drying section with board drying temperature generally much lower than that fine paper. The adduct is specially tuned for these drying conditions.
The cationised product retains itself on the fiber through the coacervate dispersion technology, by combining an anionic surfactant with a cationic polymer. The small particle ensures good spreading on the fiber surface, further enhancing the effective development of the size in the drying section. Product has shown excellent resistance against hydrogen peroxide, water and acid ink.
Advantages reported:
• Production of hard size grades at pH=7.0
• Decrease in Edge wick penetration
• Cost effective solution
• FDA and BfR approved
DRY AND WET STRENGTH
Increased recycling has led to a growing problem of deteriorating fibre strength. A number of paper chemical technologies have recently been developed to address this issue.
Buckman's strength resins
Buckman Laboratories offers a full range of strength resins which will improve cost-efficiency, and resolve production and quality issues by giving the papermaker ability to meet strength requirements cost effectively. Product development in this arena has given rise to higher solids wet and dry strength resins, bringing cost reductions through reduced transport requirements. The dry strength resins have also delivered significant drainage improvements, further increasing the return on investment for the programs.
Buckman has been further developing a range of chemistries that allow partial replacement of starches used in papermaking. The improved dry strength resins allow optimizing of wet end starch, as does Bubond 650 which can be used to replace the starch normally used for ASA emulsion. Current evaluations are investigating the efficacy of a new product that can be used to substitute significant amounts of spray starch where it is used for plybond. Similarly, another product is being evaluated for its use in the substitution of size press starch.
Clariant: Cartabond® 0701E liquid
Clariant's paper business has also recently tackled the lack of dry strength through recycling, and has come up with Cartabond® 0701E liquid, a dry strength additive for stock application under neutral-to-alkaline papermaking conditions. The product is suitable for all paper and board grades, but especially beneficial where recycled fiber is the main raw material.
Typical examples here are brown packaging papers manufactured from old corrugated containers, tissue produced by fully bleached virgin or recycled fibers. All strength parameters can be improved, says Clariant, adding that the key to the innovation is a combination of ionic and hydrogen bonding for the superior strength. Starch relies almost entirely on hydrogen bonding for strength development but ionic bonding, which is up to five times stronger, allows enhanced performance.
RHEOLOGY MODIFIERS
Clariant's Cartacoat® RM rheology modifiers have recently been redesigned with production cost savings for the customer in mind. Ultimately, paper and print quality is improved through positive effects on paper gloss and improved smoothness. (For more information, see our New Technology feature on Clariant's rheology range; page FILL THIS IN)
DYES
Clariant has also introduced Cartasol® Yellow M-NGL liquid, an economical new cationic yellow dye, exclusive to Clariant. It is particularly suitable for dyeing unbleached, recycled and mechanical pulps typically used for packaging papers. It can be applied at the size-press when cationic surface size is used. The new product comes with a better cost profile than its former version, whilst allowing excellent dyeing properties, clear backwaters, excellent bleed fastness and improved light fastness. It also features a good health & safety profile and meets REACH requirements.
FUTURE PRODUCTS
There are certainly a wide range of paper chemical products to equip pulp and paper mills in the rough year ahead. There are also a number of future products yet to be released, such as SA Paper Chemicals' Rezosol® and Crepetrol® range. The already well known products in this range will be further expanded during 2009. New coating, release and creping products for specific applications will be presented by SA Paper Chemicals to the tissue manufacturers to ensure that they stay locally and internationally competitive.
For more information on these products, contact your local representative from Buckman Laboratories, Clariant and SA Paper Chemicals.
