Maritime University of Szczecin
Akademia Morska w Szczecinie
2010, 24(96) pp. 100–104 2010, 24(96) s. 100–104
The problem of quality thermoisolation products
in selected company
Problem jakości wyrobów termoizolacyjnych w wybranym
przedsiębiorstwie
Jacek Sitko
Silesian University of Technology, Faculty of Organisation and Management Institute of Production Engineering
Politechnika Śląska w Gliwicach, Wydział Organizacji i Zarządzania, Instytut Inżynierii Produkcji 41-800 Zabrze, ul. Roosevelta 26, e-mail: jsitko@polsl.pl
Key words: product, quality, control, material, isolation Abstract
The article is showing selected aspects of the production, quality control and analysis of reasons for appearing material defects in termoisolation elements. On samples chosen for examinations an inspection appearing of defects was conducted. A production method and a quality semi finished products were analysed with respect to the influence on coming into existence defects.
Słowa kluczowe: produkt, jakość, kontrola, materiał, izolacja Abstrakt
Artykuł przedstawia wybrane aspekty produkcji, kontroli jakości i analizy przyczyn występowania wad mate-riałowych w elementach termoizolacyjnych. Na wybranych do badań próbkach przeprowadzono kontrolę wy-stępowania wad. Przeanalizowano metodę produkcji oraz jakość półproduktów pod kątem wpływu na po-wstawanie wybraków.
Introduction
Types of materials and products thermoisolation
Examinations and analyses were conducted on real products of functioning companies on Polish and foreign markets. Business name and of co-operating enterprises as well as some brand names of products to the conclusion mentioned above were left in the article omitted or changed. Thermo-isolation materials constitute the essential element of many elements machines, devices, industrial structures, modes of transport. Above all it is about a diverse scope and a frequency macro changes of temperature or microenvironments. Applying optiumum material constituting the protection and the height of feeling comfort amongst employees and users of installations all kinds are contributing simultaneously to the development of industry because the increasing demand.
Ranking of basic materials and thermoisolation products they presented below:
• wool, cotton – shapeless material in the form of short, loosely arranged natural fibres, of plastics, molten rocks, minerals, cinders, ceramics or glass;
• thermoisolation mat – elastic product, flat, consisting the layer of stringy material and unilateral or of double-sided facing;
• lamella mat – mat consisting of streams material with binder stuck to the elastic facing at keeping perpendicular arranging fibres to her surface; • thermoisolation felt – production elastic, flat,
constituting the layer of rock wool, containing binder;
• thermoisolation veil – develop in the form of the tape, consisting glass fibres arranged asymmetri-cally and glued together with binder;
• thermoisolation plate – flat product, stiff, in the shape of cuboid, cellular, stringy material with binder or grain with binder;
• thermoisolation jacket – stiff product in the shape of cylinder, stringy material with binder or grain with binder;
• block – stiff product about the regular shape, of cellular, stringy material with binder or grain with binder;
• rope – elastic product of stringy material in the plait or the facing.
Glass wool – production technology
The glass wool is received in the result of melting quartz sand and broken glass pulping of lava to glass fibres. At the unit a called modern technology was applied “with turning point in the field of pulping glass”. This technology it is an energy-efficient, completely waste-less manufac-turing process, focused on excellent pulping of glass to long, soft fibres immune to action of extrinsic factors. Reducing energy consumption of production is possible by applying a production process regained from the stove of warmth hereinafter. The advanced technology and the computer control of all stages manufacture allow to produce unusually resilient, long-lasting and quickassembly material in conditions possibly friendliest to the environment.
Insulating materials from glass wool provide individual users with comfort and the safety. In the global scale they are amending energy balance and they are contributing significantly for reducing greenhouse effect. The cleanness of production, a full range of products and the system of packing on palettes causes that the offer on isolation market in Poland has few competitors. Exceptionally light and resilient materials from the glass wool about very low rates heat conduction are used above all for a construction, where it is possible to apply them for internal and outside isolation of all types structure from basements until roofs.
In stock among others mats and plates are found in different sizes and about different thicknesses which are suitable for an isolation buildings newly being made, as well as for warming up already existing. Their assembly isn’t presenting problems, he is simple and fast. Packing products from the glass wool on palettes allows for the minimization transport costs and storing; after unpacking they are achieving guaranteed thickness. Thanks to compression individual customer can with ease transport the purchased insulating material to a home of one’s own.
Machines applied for the production of the glass wool
A so-called stove is abiding by production of glass wool a tank furnace, pulping machine and the polymer chamber. They are basic devices in the production lines. In the stove 120 Mg of glass are melting for twenty-four hours, in it the same blend is being smelted for the production different types of products. However we are getting the specific product thanks to the pulping machine and the chamber. They in them are causing changes in placing, by a computer, thanks to the program from the company “X”, from earlier already established parameters, to the specific product. On figure 1 a working disc pulping in the pulping machine was described.
Fig. 1. Pulping disc work
Rys. 1. Pracujący dysk rozwłókniający
Fig. 2. Polymer chamber Rys. 2. Komora polimeryzacyjna
Thanks to the chamber (Fig. 2) we are getting the right thickness of product.
The following technological operations are held in a zone of pulping and forming:
dispensing hot lava,
steering the speed of flow by pulping discs (Fig. 1),
inspection of pulping discs, controlling the fan,
being formed of fibres,
carrying fibres left a deposit on the net of transporter from the chamber,
cleaning the net of transporter with stream water,
returning water to station of cleaning.
In order to get the right consistency of mixt elements, all raw materials entered into the stove are being heated to temperature 1500°C, what are getting the consistency of molten glass thanks to. Arranging the heating system causes, that the temperature in every place of the stove is identical. This process is entire controlled by a computer, and by stealing the operator of the stove, responsible for parameters and processes in the stove. Figure 3 is showing the simplified scheme of the production line for the glass wool.
Fig. 3. Simplified scheme of the production line of the glass wool
Rys. 3. Uproszczony schemat linii produkcyjnej wełny szkla-nej
Issues of coming into existence products of insufficient quality
For expressing reasons for coming into existence of possible quality problems in company, they led full monitoring of whole process [1]. Machines were put together and it was divided in right zones. Machines, devices and testing apparatus are in this park which is responsible for a correct course of production. A number which reflected the order of course a production process was assigned to every zone.
1. Raw material; 2. To bake; 3. Pulping; 4. Polymerization; 5. Line; 6. Packing.
Searching for all problems associated with the production of imperfect products, and then assigning them to individual zones will be the best way. So that correctly find the cause and define them, one should to this purpose construct the diagram cause and effect which will be reflecting most often met reasons for coming into existence, qualitatively of sub-standard products. As the main failure or the effect of these causes an appearance the disagreement was established around specifi-cation of product and with quality standards had by the company.
Entire issues concerning reasons for coming into existence of the imperfect product they discussed thoroughly with the persons most competent in the given scope in company. For building diagram causally consecutive a method of brainstorming was used, where the chief technologist of plant was a moralizer of group [2]. Next during the process full of monthly monitoring, they effected distinguishing of reasons for appearing imperfect products.
Obtained information from the diagram causally consecutive served for assigning right problems to right zones to the production. It was needed, for determining the percentage share, most often of arising problems at the given episode of the production.
Zone 1
inappropriate qualities of materials delivered by supplier,
mistakes in providing regular doses of batch materials.
Zone 2
overheating batch material in the stove. Zone 3
resin is missing in the product, wrong values of product supplements. Zone 4
overheating product in the stove, nonpolymer of product in chamber. Zone 5
nondimension placing the longitudinal cut, nondimension placing the crosswise cut,
wrong placing the speed of the line, of what a wrong product weight is a reason.
Zone 6
wrong compression of product (inappropriate diameter).
Described above causes of the quality classifi-cation, concern very product, excluding features and quality parameters the way of packing, object the package and the way of storing [3]. On the basis these examinations, in the percentage presentation quartz sand drowning waste crosswise cut longitudinal cut white carpet receipt of fibres injection five
a degree of influence and a frequency were put together to the product deficiency six areas of influence. At this target a method was used Pareto-Lorenz, and for analysis his graph which the order of works will be reflecting (Fig. 4).
Fig. 4. Pareto–Lorenzo graph, participation introducing per-centage and of a scale of individual zones in generating the disagreement [3]
Rys. 4. Wykres Pareto–Lorenza przedstawiający procentowy i wagowy udział poszczególnych stref w generowaniu nie-zgodności specyfikacyjnych [3]
This balance sheet served for hierarchizing the order of research works above products, during the continuous operation. From regards for diversity of assortment in terms of mechanical as well as physicochemical parameters, they made a decision about narrowing examinations to the production of mats rolled up. The product which was chosen for analysis is wearing X 150.
On account the gigantic participation of zone 3 in generating material losses they made a decision about performing the in-depth analysis in order to limit this phenomenon.
Examination of the impact of deficiency in resin to physical-mechanical parameters of the product
With main element influencing properties physics mechanical of product there is resin. She is performing rolls of binder combining individual fibres, granting them after spolimeryzowaniu yellowish colouring. Thanks of the good quality of resin, the product has the nice colour as well as he is highly resilient. This springiness allows for compressing product into packages even to 700%. Thanks with it with property after unpacking, the product is returning at least to the nominal value.
The sub-standard product is rising from the account of the lack of resin (Fig. 5) which glass
fibres are covering, influencing mechanical as well as physical properties in the considerable way.
On every pulping disc nozzles which in the automatic way are administering the appropriate amount to resin with trial water to fibres are installed. Resin is being mixt up with water in relationship 50% on 50% is being led by filters with wires to nozzles being in a basket below the pulping disc. He is happening around nozzles, wires or filters are putting themselves causing total or partial obstruction. It is caused with pollutants being in the water trial. Deficiency in resin on one of discs causes de classifications under the quality account of the product. After spolimeryzowaniu, coated fibres resin have the yellow colour, rather than covered – white.
Fig. 5. Mat not having fibres covered with resin Rys. 5. Mata nieposiadająca włókien pokrytych żywicą
Influence not-pulp piece of broken glasses to physical properties of product
During the process of pulping glass many situations which in more distant phases of production influence the quality of final product are occurring. A problem is an essential problem operators are contending with which badly pulp piece of broken glasses. It isn't here about a wrong length or a thickness of fibres, but for micro blocking up ducts being in pulping discs. Those discs are steel plates which on their circumference have puny-new holes, by which, through the centrifugal force glass fibres are falling out. Lava from above molten which is rising from heating the broken glass up is sailing into these devices.
Every broken glass has certain ceramic ele-ments. Statistically 100 g of ceramic interjections is on 100 Mg of glass grinded down (Fig. 6). These interjections aren’t drowning in the same temperature as glass and therefore while pulping they are blocking ducts spinners causing their obstruction. Considerable collecting ceramic elements causes settling of hot glass on the circumference device. zone weight of appropriate material percentage share of the disagreement fibres covered with resin
fibres not covered with resin
Fig. 6. Considerable collecting ceramic material Rys. 6. Znaczne nagromadzenie materiału ceramicznego
After the certain time in the place of blocking ducts by ceramic interjections glass lava is gro-wing. As a result of long-term growing of hot glass he is coming into existence enough hulk which under the influence of the own weight is falling to the zone of forming on not yet polymer product. Next the great mouthful of lava is going through the polymerizational stove, in which wool is being cooked until well done. Temperature pulp after the departure from the chamber is taking piece of broken glasses out about 220, 260ºC but the tem-perature of lava about 1000ºC. After the transition through for zone of cooling the leading seaman is having a temperature about 30ºC too included in it not polymer glass about 750ºC. In the case if the mat of wool stayed with such a slice of hot lava so that rolled up into the roll (compressed 700%) it after the end of the certain time will be started to smoke.
Wool alone in itself isn’t combustible, but fusible material. He is happening this way, there-fore around glass lava packed doesn’t have an opportunity to cool off because around tightly wool is surrounding her. In the case if such a roll got the recipient a scolding to the company store, a lorry or the magazine, it could enough to serious in effects of the fire. From here an equipment allowing to detect the too high temperature of the product was also purchased. After localizing such a fragment of the product his meaning is taking place to the colour red. The operator in this case is obligated for removing such a mat from a more further produc-tion process.
In order to get know features having not pulp one should conduct glass examining basic declared parameters by the producer. One from main and all at the same time is most important thermal conductance [4]. In order to make it one should pick up material which the cold mouthful of the booze contains and cut the appropriate sample out.
150 X on account of standardizing conducted were used for the examination. For the safety they made the measurement pirometer inside tempera-tures of the mat in the place of dead lava. After obtaining the feedback the temperature is about 37ºC for analysis. The sample was put to device, in which measured thermal penetrability of material will be.
It results from the conducted examination that parameters declared by the producer for this product weren't fulfilled. Of course deficiency in air is a cause of such a state of affairs inside dead lava. Not a wool is heating it up, but the air contained in her structure.
Summary
Making analysis of functioning of a production process it is possible to state that the most losses are arising in 3 for zone. A factor is affecting which cause this smallest state affairs in the form of mistakes made by the operator of machines.
A quality batch materials provided the produc-tion glass wool to premises the company is a major problem. From it the plant should also conduct the reason advanced works relying on improvement in batch materials, so as broken glass or resin. He should also hold talks with suppliers of production materials to theme associated with the improvement of quality delivered. It is possible also to notice, what preventive steps were made in order to eliminate prospective damages. Installing the sensor high temperature on the line of glass wool was one of flagship ideas, what the problem with intercepting hot glass and letting in to the more further production disappeared.
References
1. URBANIAK M.: Zarządzanie jakością – teoria i praktyka. Wyd. Difin, Warszawa 2004.
2. WOLNIAK R.,SKOTNICKA B.: Metody i narzędzia
zarządza-nia jakością – teoria i praktyka. Wyd. Politechniki Śląskiej, Gliwice 2007.
3. SZKODA J.: Sterowanie jakością procesów produkcyjnych.
Wyd. Uniwersytetu Warmińsko-Mazurskiego, Olsztyn 2002.
4. SŁABOŃ Ł.: Analiza termodynamiczna procesu spalania
w komorze polimeryzacyjnej firmy Isover. Instytut Tech-niki Cieplnej, Politechnika Śląska, Gliwice.
Recenzent: dr hab. inż. Ruta Leśmian-Kordas, prof. AM Akademia Morska w Szczecinie
