EP2873039A1

EP2873039A1 - A method, a system and a recordable and remotely readable medium for providing product quality information to a product

Info

Publication number: EP2873039A1
Application number: EP13745864.2A
Authority: EP
Inventors: Matti Alanen; Ari POUKKA; Ilkka KOIVUNIEMI
Original assignee: Metsa Fibre Oy
Current assignee: Andritz Oy
Priority date: 2012-07-13
Filing date: 2013-07-03
Publication date: 2015-05-20
Also published as: WO2014009605A1; FI126783B; FI20125794L; CN104428801A

Abstract

A method and a system for collecting, calculating and providing quality information of a product as well as a recordable and remotely readable medium attached to a bulk product. The method comprises measuring process parameters vital to the quality of said product in said process steps; and calculating an index indicative of the quality of the product. The parameters are normalized to form a contribution of the process step to an overall yield function of the production process, and the contribution of each process step to said yield function is combined incrementally to essentially contribute to said quality index of said product. The medium is for example a passive RFID tag.

Description

A METHOD, A SYSTEM AND A RECORDABLE AND REMOTELY READABLE MEDIUM FOR PROVIDING PRODUCT QUALITY INFORMATION TO A PRODUCT Background of the Invention

Field of the Invention

The present invention relates to a method for creating quality metrics for a product produced in a process, and to a system and a medium to provide for calculating, storing and marking the product with quality metrics data to support storage, processing and delivery of the product from factory to destination. The present invention also concerns a recordable and remotely readable medium attached to a bulk product. Description of Related Art

Pulp industry businesses are vitally dependent on smooth logistics. It is a matter of identifying and tracking cellulose products that leave a mill, to make sure that the right pulp is sent to the right customer, usually a paper factory, at the right time. Until now, this has required visual inspection of pulp unit labels or scanning of bar codes, providing merely a means for production lot identification. The traditional method of expressing the quality of pulp is based on measuring refining results of the pulp, which is done once or twice a week. This means that statistically reliable information about the pulp can be obtained only a few months after it has been produced. Present methods do not reliably indicate how even the quality of the products is.

In many applications where remote and fast identification is needed for identification, like in goods supply chains, RFID technology is being deployed. RFID is an acronym for Radio Frequency Identification.

A RFID system consists of a transceiver, or simply a reader, that sends out and receives a radio signal. Known RFID frequencies vary from kHz range up to the microwave GHz range. Usually on the product, there is a small RFID transponder - a "tag" - that contains a microchip with the product data, and an antenna. Depending on the application, a battery may be part of the tag (active tag) or there may be no internal energy source in the tag at all (passive tag). In the case of a passive tag, once the antenna receives the radio signal it is designed to be tuned into, the microchip becomes energized by the signal, and performs its single task of sending back the information about the product it contains. The range in which this response signal can be received varies from a few centimeters to 10 meters or more, depending on the power of the RFID transceiver and other parameters.

In the publications WO10072890A and WO 10072891 A is described an RFID tag that may be integrated in wood products or casings, thus being part of the product or casing and with no need to be removed once delivered. As especially passive tags are very tiny in size, and with the use of biodegradable materials as a substrate for holding the microchip and the antenna, the tags do not affect any recycling or waste burning policies in any way.

In the case of any product, it has to be determined what product information is contained in or on the product, and what kind of technology and tag is the best for the purpose.

Regarding the choice of technology, a barcode tag has its limitations in products that should carry a larger amount of information than just a product identification code. Also it has to be removed in products that are to be further processed, as a plastic tag with the size of a matchbox is not what a paper manufacturer wants to get into the machine. A pulp unit has both these requirements, as it would be desirable to contain also quality information about the product with the tag. An RFID tag with the size of a grain of sand, and provided on a biodegradable paper substrate, being further capable of carrying up to 32 kbytes of data, does not have neither of these drawbacks. Pulp units have unique requirements also in terms of quality information. Usually the pulp is pulped in water at the customer's paper factory, it is refined, its properties are analyzed and chemicals are added, as well as other process steps being taken.

Traditional methods of assessing pulp quality, which is reflected in the runnability of the paper machines, are inexact, they are sensitive to measuring conditions (e.g. to seasonal variations and humidity), they require time-consuming analysis and they are generally providing only isolated analysis points which means that they do not give representative data on the whole pulp unit. For the paper manufacturer it is essential that the pulp units received at the paper mill are of even and predictable quality. The more uniform in quality the pulp is, and the more accurate quality information about the pulp unit is known, the easier it is for the paper manufacturer to optimize paper manufacturing, to adapt the operation of the paper machine to the actual pulp quality and, if so desired, to tailor the paper product to final

specifications.

To create a quality system that is based on commensurate measurements across the production of the pulp, and that conveys this information to the customer, and also optionally takes into account any feedback from the customer, is a major object of the present invention.

Precise knowledge of the pulp quality in an identified pulp unit provides a unique opportunity for customers to optimise their own production. Accurate quality reporting advises the customer that a pulp lot is at the top end of the quality spectrum, meaning that it is possible to optimize or minimize the amount of the pulp or the chemical consumption. In fact, many times it is of key importance for the paper or board manufacturer to find the right amount of pulp for the corresponding paper or board or tissue product having the predetermined properties.

Likewise, electric power consumption in the refining process of the paper, board or tissue manufacturer could be reduced to lower the amounts of energy, when it is known that the latest pulp lot has good furnishing properties. Summary of the Invention

It is an aim of the present invention to provide a solution that takes both the product marking technology and the above mentioned quality issue into account. The present invention is based on the concept of normalizing the measured parameters in each process step to form a contribution of the process step to an overall yield function of said production process. Typically, the contribution of each process step to said yield function is combined incrementally essentially to contribute to the quality index of said product.

Utilizing the method, a system is provided for collecting, calculating and providing quality information of a product, such as a pulp product.

Further, a recordable and remotely readable medium attached to a bulk product, like a cellulose pulp unit, is according to the present invention represented by a passive RFID tag which carries information about a calculated quality index and information necessary for identifying said pulp unit. Tracking info about the pulp unit can be saved in the pulp mill's reporting system.

More specifically, the method according to the invention is characterized by what is stated in the characterizing part of claim 1.

The system according to the invention is characterized by what is presented in

characterizing part of claim 9 and the medium by what is stated in the characterizing part of claim 15. Considerable advantages are obtained. At present, quality information is typically obtained with intervals of ten minutes, amounting to about 1000 values a week. Therefore, with the present invention, reliable information about possible quality variations are obtainable online already during the running work shift. The utilization of RFID technology, in combination with the inventive concept of a quality index, enables the tracking of origin and quality all down to the unit size of 1 ton or 2 tons. Naturally, in the future information may be obtained more frequently or even continuously, but even in such cases, the novel invention provides considerable advantages in terms of effective monitoring of pulp quality. The quality index will replace tests on refined pulp, conventionally carried out for quality control purposes also at the client's premises.

Next, the invention will be examined more closely with the aid of a detailed description of preferred embodiments. Brief Description of the Drawings

Figure 1 shows a block diagram of the various inputs to the inventive quality index;

Figure 2 shows a diagram over the yield function and how process steps contributes to it; Figure 3 shows an on-line process display of the quality index;

Figure 4 shows an RFID tag to be used in the present invention;

Figure 5 shows a system according to the present invention; Description of Preferred Embodiments

The present technology relates to a method of providing product quality information to a product. Referring now to Fig. 1, the building blocks of this quality information, resulting in a quality index to be attached to the product, are:

- theory and research 1 ,

- mathematical model 2,

- customer feedback 3,

- quality index derived from mathematical model using process data measured at pulp mill 4A, and

- provided to customers 4B.

The results are compiled in a quality index algorithm and displayed on a process control system display. Because each paper machine is unique, the customer feedback 3 is an important factor for example because it gives information on the runnability of the pulp on the paper machine. When read at the paper machine, the quality index informs the control system of the machine about the raw material and of the running properties to be expected from it.

The method according to the invention includes the steps of measuring process parameters vital to the quality of the product. Such parameters and the measurement of them are known in the art, and are not part of the present invention. However, it has so forth not been known how to build a quality index that would be available on-line, i.e. an index that is being calculated while the pulp lot in question is being processed. The problem of measuring quality-relevant parameters in a multi-step process and calculating them almost in real-time has according to the present invention been solved by making the contributions of each process step commensurate and thus incrementally summable in a yield function.

A yield function of the above kind is depicted in Fig. 2, wherein the yield (%) is presented as a function of the Kappa number of the pulp. The Kappa number (having a value in the range of 1 to 100) is defined as an estimate of the amount of lignin.

In Fig.2, the effect on the yield function by the various processes is clearly visible. The more processing and bleaching, the lower the yield will be. But to achieve a certain bleach grade or Kappa number, processing has to continue until a reasonable value is achieved. It is also clear that the higher the yield, the more gentle the fiber treatment has been in the process, and the higher the tensile strength of the web in the paper machine will be.

In one embodiment of the present invention, three process steps as shown on the yield function f_ya, are monitored to create a quality index of the final product: cooking, oxygen bleaching or treatment, and final bleaching. As can be seen from the figure, the oxygen step can be omitted (yield function f_yb), but then the yield will typically be lower if Kappa number of the pulp fed to bleaching is maintained on the same level as when using an oxygen stage. On the other hand, if the oxygen delignification step is omitted without other changes made to the process conditions, yield will be high.

Different process parameters have an impact on yield. Thus, yield is affected by temperature, pH, the chemicals added, process delays and other process parameters, chemicals and results to be followed. In the present technology, the parameters are normalized and combined, in one embodiment incrementally summed as such, to provide a global yield function, which is a quality index of the process. The combination can also comprise incrementally summing the parameters after adjusting their values using modification coefficients.

The calculation algorithm is selected by mathematical methods such that it corresponds to overall client feedback as well as possible.

The yield functions are of utmost importance, as they serve as a normalization factor, making it possible to add the yield functions of all steps incrementally to the total yield function. When the whole process and it steps can be described with one yield graph, it is possible to build a quality index algorithm having as its input basic knowledge and analysis results on one hand, and on-line process information (the yield function) on the other hand, see Fig. 1. It should be pointed out that within the scope of the present novel technology it is possible to utilize the yield function concept also for other purposes, such as for cost calculations of the pulping process. Thus, the present concepts provides for minimization of production costs at pulp mill while attaining target product quality at paper or board mill. Another use of the present concept is for minimizing production costs at paper mill.

Fig. 3 depicts a specific example relating to a process information system at a pulping mill. Fig. 3 shows how the quality index develops over time in the process. In this case, the quality index 7 is calculated at specific time intervals, in the example in intervals of ten minutes during the process and for the readymade product. In ten minutes, a large mill is producing 12 -24 tonnes of pulp. The inventive quality index system reports the results 8 essential to quality, and also determines if there are any unreliable results 9.

Fig. 4 shows one of the smallest RFID tags on the market, to exemplify that the tags can be embedded in the cellulose pulp bales or units without affecting the product or is processing in any way. The tag 10 shown is a Hitachi® 0.05-mm "Square Super Micro RFID Tag" having a microchip 13 with a 128-bit memory 11, and antennas 12 as shown. The actual tag used in the present invention may be somewhat larger, the repulpable tag paper having a size of 27 x 92 mm and a grammage of 81.4 g/m². The RFID microchip is 0.6 x 0.6 x 0.1 mm, the antenna is made of silver paste and the tag is fastened with water-soluble adhesive to the pulp bale or unit.

The RFID tags used in the present invention are specially developed for identifying pulp. The RFID tags have been thoroughly tested by leading research authorities and

standardising organisations, e.g. VTT (Finland) and ISEGA (Germany). All results confirm that the RFID-tagged pulp is entirely safe as a raw material for manufacturing food packaging. The tags were tested to FDA and BfR standards. Packaging made from RFID-tagged pulp also complies with the HACCP system requirements that guide systematic and preventive self-supervision to ensure the safety of food and pharmaceutical products.

In addition to these third-party tests, the applicant has been working with several customers to study the impact of RFID tags on the paper manufacturing process and on the quality of the end product. The results of this work have been wholly favourable. It was found that the tags entirely disperse at the pulping stage. In relation to the huge scale of the paper manufacturing process, a single tiny tag in each tonne of pulp was considered a negligible foreign body in the resulting paper or end product. The relative proportions are evident when considering that an RFID tag microchip is the size of a single grain of sand. Also the direction of progress is clear: tags are becoming smaller, thinner and less complex while retaining excellent readability.

Also substantial progress has been achieved in the techniques used for fastening RFID tags to pulp units. They must be near enough to the outer surface of the pulp unit to enable efficient reading, but sufficiently deeply embedded to ensure that they remain undamaged. The studies done have also provided an opportunity to optimise the operation and positioning of the tag reader devices. Unlike other identification methods, there is no need for a direct line of sight between the reader and the tag, and several units can be identified with a single sweep. As the tag is inside the pulp unit, its exposure to soiling, physical stresses and other external disturbances is minimised.

RFID technology used in the inventive manner will essentially eliminate delivery errors and unplanned, excessive handling of pulp units. The system will help to optimise warehouse management, improving the efficiency of labour and automating functions that were previously performed manually.

To exemplify the above, the system generates required documentation, such as delivery notes and goods invoices, and all tracking information is available in real-time. This brings benefits for everyone involved in the supply chain, including logistical partners and customers. Using RFID technology speeds up material handling stages and improves the reliability of deliveries. It also helps to minimise human error through automation, and provides continuously updated real-time information on warehouse and raw material levels and on pulp quality. The inventive system enables efficient, reliable and highly automated tracking of products as they move around the world.

Example

In Fig 5 is shown the three main blocks of a typical cellulose pulp supply chain: the pulp mill 14, a port 15 and the receiving paper factory 16. These are all connected together by the system according to the present invention. The RFID- based system utilizes passive RFID tags (not shown) and remote readers, handheld readers 17, forklift-mounted readers 18, and a variety of gate readers 20 at several points along the journey from the mill to the customer. The readers are too small to be shown separately, but they are indicated in Fig. 5 by a radiation icon. The tags are coded and attached by an applicator 19 to a predetermined point between the bales inside each pulp unit. Each tag includes a microchip that retains information about the pulp in the unit. One RFID tag is used for each tonne of pulp, meaning that a tag will be placed on both sides of a two-tonne unit to improve readability.

Once each pulp unit has been provided with tags, it can be recognised at all points along the supply chain: at the pulp mill warehouse 14, on loading at the harbour 15, at the discharge port warehouse and at the customer's paper factory 16. An electronic tracking information system comprising a common server 22 that communicates tracking information both with the data system 21 of the pulp mill 14 and the corresponding system 23 of the paper factory, and a similar system 24 at the port 15, collects the information about read RFID tags and save it in the data system 21, where reports 26 can be issued. The electronic trail left by RFID is thus easily traced all the way back to processes in the pulp mill itself. The client will be provided with quality information but no process data relating to confidential operation data of the pulp mill.

It is clear to one skilled in the art that the invention is not restricted to the examples and embodiments presented above, but may vary within the scope of the appended claims.

Claims

Claims:

1. A method of providing product quality information to a product being produced by a pulping process in a number of process steps, the method including the steps of:

- measuring process parameters vital to the quality of said product in said process steps; and

- calculating an index indicative of the quality of the product,

c h a r a c t e r i z e d in that the measured parameters in each process step are normalized to form a contribution of the process step to an overall yield function of said production process, whereby the contribution of each process step to said yield function is combined incrementally to essentially contribute to said quality index of said product.

2. The method according to claim 1, wherein the product of the pulping process is cellulose pulp unit, and that said yield function is calculated by on-line measuring of product and process parameters in at least a cooking, an oxygen treatment and a bleaching process step, whereby the results are normalized as contributions to said yield function, said yield function being indicative of the amount of bleached cellulose calculated from the wood.

3. The method according to claim 1 or 2, wherein the said quality index is formed by calculating said yield function on-line, and by off-line laboratory analysis and customer feedback data of product samples and process conditions.

4. The method according to any of the preceding claims, wherein the quality index information is provided on a machine readable medium attached to said product in the form of a remotely readable RFID tag.

5. The method according to claim 4, wherein said RFID tag is formed on repulpable paper and fastened with a water-soluble adhesive to a pulp unit of said product.

6. The method according to claim 4 or 5, wherein said quality information is combined on said RFID tag with information necessary for identifying and tracking said pulp unit, whereby the information carried on said RFID tag is providing the necessary information for storage, delivery and processing of said pulp unit from the factory to customer.

7. The method according to any of the preceding claims, wherein the product quality information or principle of calculations is used for cost estimations for example at the customer or at the pulp mill.

8. The method according to any of the preceding claims, wherein said parametres are summed incrementally, optionally using individual correction coefficients of

corresponding parametres, to contribute to said quality index of said product.

9. A system for collecting, calculating and providing quality information of a product, whereby product and process data are measured and collected in a number of process steps in the production process of said product, c h a r a c t e r i z e d in that a yield function is formed, being indicative of the amount of the final product vs. the corresponding amount of raw material being fed to the production process, said yield function being incremental and essentially adding the normalized contributory yields of each of the measured and consecutive process steps together, and that said yield function essentially contributes to form a quality index of said product.

10. The system according to claim 9, wherein said product is a bulk product like a cellulose pulp unit, and that said yield function is calculated by on-line measuring of product and individual process parameters, selected for example from cooking, oxygen treatment and bleaching process step, whereby the results are calculated and normalized as contributions to said yield function.

11. The system according to claim 9 or 10, wherein said quality index is formed by said yield function calculated on-line, and by off-line data from laboratory analysis and customer feedback of product samples and process conditions.

12. The system according to any of claims 9 to 11, wherein the quality index information is provided on a passive RFID tag attached to said product.

13. The system according to claim 12 wherein said RFID tag is formed on repulpable paper and fastened with a water-soluble adhesive to a pulp unit of said product.

14. The system according to claim 12 or 13, wherein said quality information is combined on said RFID tag with information necessary for identifying and tracking said pulp unit, whereby said pulp unit is tracked and handled by reading said RFID tag throughout the storage, transport and processing steps of said pulp unit, from the factory to destination.

15. A recordable and remotely readable medium attached to a bulk product, like a cellulose pulp unit, said medium containing product information about said bulk product, c h a r a c t e r i z e d by that said medium is a passive RFID tag, carrying information about a calculated quality index for said pulp unit.

16. The recordable and remotely readable medium according to claim 15, wherein said RFID tag essentially consists of a microchip and an antenna formed on repulpable paper and fastened with a water-soluble adhesive to a pulp unit of said bulk product.