Dispersants and Flocculants for Tissue Paper Manufacturing-Dow
Product Description
UCARFLOC
TM Polymers are water-soluble, specialty poly (ethylene oxide) dispersants that serve as outstanding formation aids in Asian tissue-making processes. As pulp slurry additives, UCARFLOC TM Polymers improve sheet formation in thin papers such as tissue paper, and in the ? rst layer of paper boards. They help produce very even paper without pinholes while improving opacity, brightness, lubricity, and printability.
A Range of Molecular Weight Grades
To meet different production demands, Dow offers a
complete line of UCARFLOC TM Polymers, with molecular weights ranging from 4 million to 10 million. The molecular weight distributions of all UCARFLOC TM Polymers are controlled within a very narrow range, so they provide very consistent performance.
Advantages in Asian Tissue-Making Processes UCARFLOC TM Polymers are ideal formation aids in processes used in Asia to produce tissues and other thin papers:
? Allows increased paper machine speed ? Good sheet formation without pin-holes (? sh eyes)
? Good quality paper can be obtained even with low pulp beating levels
? Reduces staining of felts, forming wires, and vats ? Improved release of paper on dryers
Fast Formation of High-Viscosity Solutions
UCARFLOC TM Polymers dissolve quickly using familiar, conventional equipment. They reach full viscosity within two hours and can then be used immediately. They form very high viscosity solutions with excellent dispersion and retention capabilities.
The following table provides information about typical dissolution speed.
Cleaner Process and Discharge Water
In addition to their dispersion capabilities, UCARFLOC TM Polymers act as in-process ? occulants that keep process water (white water) cleaner. They bind up pulp ? ber, ? llers, and other additives and more completely deposit them on the forming sheet. Because UCARFLOC TM Polymers are nonionic, they perform this task effectively even in furnishes that contain high concentrations of dissolved anionic species. This capability conserves process water and ef? ciently controls pollution in the ? nal discharged waste water. No extra waste treatment is needed when using UCARFLOC TM Polymers.
Consistent Polymer Properties
UCARFLOC TM Polymers are produced under very carefully controlled conditions that yield consistent
molecular weight distributions and other properties. The Dow Chemical Company’s world-class quality control system helps UCARFLOC TM Polymers deliver consistent performance, batch after batch.
Chemical Structure
Chemically, UCARFLOC TM Polymers are poly (ethylene oxide) polymers with the fundamental structure:
-(CH 2-CH-O-)n -Typical Tissue Paper Application of UCARFLOC TM
Polymers
UCARFLOC TM Polymers are typically dissolved and fed
to papermaking processes using equipment similar to that
shown in the diagram below. The polymer is dispersed and
dissolved in the dissolving tanks, followed by water level
adjustment to create a uniformly concentrated feed
solution. Before use in the papermaking process, the
solution is diluted to its ? nal working concentration in the
dilution box.
The general process is as below:
1) Dissolving
In this process, it is very important for the
UCARFLOC TM Polymer to be dispersed very well. Two key special techniques are used to improve dispersion:a) Use a special feeding machine A good feeding machine can make
UCARFLOC TM Polymers disperse very well. Special feeding devices, like those in the ? gure at right, could be used in this application. The baf? es inside
control the dropping speed of the UCARFLOC TM Polymer. When the water is introduced, it forms a
? at water curtain that carries the UCARFLOC TM
Polymer powder into the dissolving tank very
uniformly.
b) Use proper stirring blades
Stirring blades are very important in dispersing the
UCARFLOC TM Polymer powder. At least two layers
of blades should be introduced. The upper layer
should drive the water into the inside while the
lower layer should drive the water to the upside. In
such a situation, the water ? ow will be turbulent and
bring the UCARFLOC TM
Polymer powder into
solution. Otherwise, the powder will ? oat and accumulate on the surface of the water, resulting Water
3) Dilution tank
A dilution tank is used to dilute the UCARFLOC TM Polymer solution to 1/30~1/50 of the original concentration. One pipe from service tank feeds
UCARFLOC TM Polymer solution and one pipe feeds water into the tank. There are several baf? es in this tank to make the water ? ow turbulent, thus making the ? nal diluted solution more uniform. There are also some screens in this tank to prevent small gel masses from ? owing into the paper forming process.4) Paper forming
Diluted UCARFLOC TM Polymer solution ? ows into the trough in which the vacuum cylinder mold is partly immersed. The diluted pulp also ? ows into the trough and mixes with diluted UCARFLOC TM Polymer solution. Mixing completes within a very short time, then the vacuum helps to remove the water. After that, the formed paper is transferred from one belt to another belt, which will carry the paper into the dryer.Alternatively, diluted UCARFLOC TM Polymer solution and pulp are pre-mixed, then the mixture is sent into the trough and the process that follows is the same as above.
5) Dryer
Dries the wet paper.
Application Levels and Factors that Affect the Application
The typical addition level for UCARFLOC TM Polymers is 0.3 to 2 kg per ton of paper. For very high speed paper machines (1,300 – 1,500 m/min), a higher dose (1.5 – 2.0 kg/ton of paper) of UCARFLOC TM Polymer is required to achieve the necessary level of pulp dispersion. The table below provides recommended use levels for various types of paper.
Dissolving Concentration
A rough upper limit of UCARFLOC TM Polymer concentration in this application is as below:
UCARFLOC TM 310 Polymer: Max. 400ppm UCARFLOC TM 309 Polymer: Max. 500ppm UCARFLOC TM 304 Polymer: Max. 600ppm
Of course, these data will change according to different dissolving and dilution situations.
Agitating speed and time
Agitating is very important in dissolving. Generally the upper limit speed of the tip point of the blade should be less than 1m/sec. Otherwise, there will be a drop of the viscosity.
The top viscosity that will be reached is as below, according to our experiments:
UCARFLOC TM Polymer: 1.5-2.0 hrs
Water quality
Water quality is another key point that requires attention. Chlorine and some other organic or inorganic impurities will harm the UCARFLOC TM Polymer solution sharply. Since almost all tissue paper manufacturers in China are located beside rivers and directly use roughly puri? ed river water to produce tissue paper, the water quality will differ from one location to another one. Generally, sodium thiosulfate is used to neutralize the effect of chlorine. The selection of a speci? c grade of UCARFLOC TM Polymer often depends on the dissolution equipment available. For example, equipment designed to dissolve polymer with a molecular weight of 7 million may not perform well at all with a polymer molecular weight of 4 million. Some experimentation with various grades of UCARFLOC TM Polymers may be necessary to identify the correct material.
Technical Support
Dow provides global customer service and very rapid response for technical support issues concerning
UCARFLOC TM Polymers. We can help you with polymer recommendations and the right methods to incorporate them into your process.
Product Safety
When considering the use of any Dow products in a
particular application, you should review our latest Safety Data Sheets and ensure that the use you intend can be accomplished safely. For Safety Data Sheets and other product safety information, contact Dow at the numbers on the back cover. Before handling any other products mentioned in the text, you should obtain available product safety information and take necessary steps to ensure safety of use.
Dispersants and Flocculants for Tissue Paper Manufacturing For more information, complete literature, and product samples, you can reach
a Dow representative at the following numbers:
From the United States
and Canada
Phone: 1-800-447-4369
Fax: 1-989-832-1465
In Europe
Toll-Free: +800-3-694-6367
Phone: +32-3-450-2240
Fax: +32-3-450-2815
In Latin America
Phone: +55-11-5188-9222
Fax: +55-11-5188-9749
In Asia Paci? c
Phone: +60-3-7958-3392
Fax: +60-3-7958-5598
All Asia Paci? c countries except Indonesia & Vietnam
Toll-Free call: 800-7776-7776
Toll-Free fax: 800-7779-7779
NOTICE: No freedom from any patent owned by Seller or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer’s use and for ensuring that Customer’s workplace and disposal practices are in compliance with applicable laws and other governmental enactments. Seller assumes no obligation or liability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.
Published April 2006