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Minimering av inställningsbit vid rotationstryckning : genom analys av Almedahls tryckeri / Almedahls, textile printing, rotary screen printing, adjustment piece, pattern adjustment, laser adjustment prototypeFRISK, ANNA, HELIN, JENNIE January 2010 (has links)
Textiltryckning är en komplicerad process där många faktorer påverkar resultatet. Orsaken till denna komplexitet beror på att varje steg påverkas av föregående steg i processen.När tryckningen äger rum ska arbetet från flera olika avdelningar kopplas samman. Inställningsbiten avgörs bland annat av svårighetsgraden vid mönsterpassningen, som beror på mönstrets design. Om det tryckta mönstrets färgnyanser stämmer överens med färglikare beror på tillblandningsprocessen i färgköket.Då mönstrets detaljrikedom ökar betyder det även att svårighetsgraden att utföra mönsterpassningen tilltar. Det är därför av intresse, ur flera synvinklar, att förenkla mönsterpassningen även om mönstret inte är komplicerat. Ju svårare mönster, desto mer väv går åt för att göra mönsterpassningen. Väven som används till mönsterpassning kan inte säljas vidare utan blir spill som skickas iväg till förbränning. Ur både miljö- och kostnadssynpunkt är det önskvärt att förenkla mönsterpassningen så att mängden spillväv minskar.Arbetets uppgift är att undersöka om det är möjligt att korta ner inställningsbiten som går åt till mönsterpassningen genom att hitta en ny arbetsmetod för maskinoperatörerna. För arbetets genomförande är en granskning av processtegen fram till och med tryckning nödvändig. Eftersom området är outforskat är tillgången på litteratur med anknytning till inställningsbiten vid rotationstryckning liten. Därför är observationer av tryckningar det viktigaste redskapet för att förstå problematiken med arbetet då mönsterpassningen genomförs.Tester för att undersöka ett antal hypoteser utförs. Men då området kring minimerad inställningsbit på rotationstryckmaskiner är outforskat, betyder det även att tillgången på standardiserade tester är obefintlig. Under arbetet har därför tre olika tester tagits fram specifikt för rotationstryckmaskinen TRY1 hos Almedahls, varav två genomfördes. Till Test 2 togs en laserpassprototyp fram och resultaten indikerade att detta kan vara en bra metod för att minimera inställningsbiten vid rotationstryckning. / <p>Textile Printing is a complex process and many factors affect the result and the cause of this complexity is due to the pre-treatment of the fabric. The work from several departments is linked together when the printing takes place. When it comes to the adjustment piece it is related to the level of pattern complexity which, in turn, is due to the design of the pattern and to what degree the printed colour matches the colour sample. This depends on the mixing process in the colour kitchen.Increasing the amount of details in the pattern leads to increasing the level of difficulty to perform the pattern adjustment. It is therefore of great interest from several points of view to simplify the pattern adjustment, although the pattern contains a large amount of details. It is a fact that the quantity needed for the adjustment piece increases when the pattern design is complex. The fabric which is used to carry out the pattern adjustment becomes waste and is sent to incineration. Therefore, from an environmental as well as an economical perspective, it is desirable to simplify the pattern adjustment which, in turn, reduces the amount of fabric waste.The purpose of the report is to examine whether it is possible to shorten the adjustment piece which is related to the pattern adjustment. To understand the complexity of this subject, an examination of the entire process, from the pre-treatment until the printing takes place, is necessary.Since the area is unexplored, the availability of relevant literature related to the adjustment piece is not particularly large. Therefore, observations of the printing process are the most important tool for understanding the problem associated with the adjustment of the pattern. Tests to examine a number of hypotheses are performed. But since the subject of minimizing the adjustment piece for rotary screen printing machines is unexplored, it also means that the availability of standardized tests is non-existent. During the work with the adjustment piece, three different tests have therefore been developed specifically for the rotary screen printing machine TRY1 at Almedahls, of which two were carried out.A laser adjustment prototype was created for Test 2. The test results indicated that it might be a good method to minimize the adjustment piece in rotary screen printing.</p><p>Program: Textilingenjörsutbildningen</p>
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Waves over Fabric : Why they appear and how to reduce them.FRISK, ANNA January 2013 (has links)
Almedahls have for some time started to receive more customer complaints about uneven roller blind fabrics or so-called waves over fabric. The waves are a major problem for Almedahls customers since they make it hard to cut the fabric into roller blinds. The company believes that the waves appear due to different process parameters within their finishing line but the company do not yet know how or where. The thesis project strives to find an explanation to what waves over fabric are, why they appear and how they can be reduced. The documentation that Almedahls have made of the problem so far, including photographs and customer complaints reports, was examined. Orders produced from four selected grey-weaves during the last three years was examined and compared to received customer complaints and standard operations lists. No clear relationship was found and weaves with longer process lines did not seem to cause more waves to appear. However, addition of an extra colouring to the standard operations appeared to be more frequently occurring when a standard operations list had been changed.Waves over fabric were at an early stage related to the mechanical properties of the weaves as the weaves are exposed to stresses and strains during the entire production line. In Almedahls’ finishing line the web and the beam tensions and the levelling mechanisms in the stenter frames appeared to be the parameters which especially apply stresses and strains. Tensile tests were performed to examine the mechanical properties of a few of Almedahls grey-weaves and half processed weave. The test results showed that a strain between 11-27 % can be applied before the test samples start to deform while calculations of the amount of strain applied by the stenter frames showed to be much less, between 2.5-3.5 %. The difference in size between the test samples and the weaves must be considered when comparing these results. The small, repeated strains applied by the finishing line may eventually lead to permanent deformation of the weaves and appear as waves. The combination of the web and the beam tensions can also result in a stretch in the bias-direction of the weave which cause deformation in the middle of the weave where waves most often appear.The thermal properties of the same weaves were also tested through DSC, Differential Scanning Calorimetry, tests. The test results showed that the polyester material in the weaves does not melt or deform at the temperatures Almedahls use in their processes. The shrinkage of the grey-weaves during the de-sizing processes was also considered through width measurements. The conclusion was that the structure of the grey-weave influences how much the weave will shrink and the dimension change of the weave may influence the appearance of waves and needs more investigation. / Program: Magisterutbildning i textilteknologi
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Waves over Fabric : Why they appear and how to reduce them.Frisk, Anna January 2011 (has links)
Almedahls have for some time started to receive more customer complaints about uneven roller blind fabrics or so-called waves over fabric. The waves are a major problem for Almedahls customers since they make it hard to cut the fabric into roller blinds. The company believes that the waves appear due to different process parameters within their finishing line but the company do not yet know how or where. The thesis project strives to find an explanation to what waves over fabric are, why they appear and how they can be reduced. The documentation that Almedahls have made of the problem so far, including photographs and customer complaints reports, was examined. Orders produced from four selected grey-weaves during the last three years was examined and compared to received customer complaints and standard operations lists. No clear relationship was found and weaves with longer process lines did not seem to cause more waves to appear. However, addition of an extra colouring to the standard operations appeared to be more frequently occurring when a standard operations list had been changed.Waves over fabric were at an early stage related to the mechanical properties of the weaves as the weaves are exposed to stresses and strains during the entire production line. In Almedahls’ finishing line the web and the beam tensions and the levelling mechanisms in the stenter frames appeared to be the parameters which especially apply stresses and strains. Tensile tests were performed to examine the mechanical properties of a few of Almedahls grey-weaves and half processed weave. The test results showed that a strain between 11-27 % can be applied before the test samples start to deform while calculations of the amount of strain applied by the stenter frames showed to be much less, between 2.5-3.5 %. The difference in size between the test samples and the weaves must be considered when comparing these results. The small, repeated strains applied by the finishing line may eventually lead to permanent deformation of the weaves and appear as waves. The combination of the web and the beam tensions can also result in a stretch in the bias-direction of the weave which cause deformation in the middle of the weave where waves most often appear.The thermal properties of the same weaves were also tested through DSC, Differential Scanning Calorimetry, tests. The test results showed that the polyester material in the weaves does not melt or deform at the temperatures Almedahls use in their processes. The shrinkage of the grey-weaves during the de-sizing processes was also considered through width measurements. The conclusion was that the structure of the grey-weave influences how much the weave will shrink and the dimension change of the weave may influence the appearance of waves and needs more investigation. / Program: Magisterutbildning i textilteknologi
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