CN sản xuất giấy carton sóng

Công nghệ sản xuất giấy carton sóng Chương 11 Corrugated board Construction : linerboard and medium Material :heavy paper -containerboard Facings -kraft linerboard Medium -one-ply sheet, hardwood or recycled fiber Linerboard (flat facing) Medium (fluted wavy) Four types combined board a Single Face one medium one liner board (for protective wrapping) b Single Wall (Double Face) one mediu two liner boards 二 c Double Wall two mediums three liner boards d Triple Wall three mediums four liner boards Direction: Machine Direction Cross Direction flute direction Flute Profile: arches with proper curve the strongest way to span space Flutes as arches - resist bending and pressure, support weight, as cushion Proper curve: between U and V (Also has its advantages) Flutes also as a insulator to protect sudden temperature changes Vertical linerboard provides strength; protects from damage Several standard shapes (A,B,C,E,F…) , Contrast: A-flute the largest profile B-flute smaller than A C-flute between A and B E-flute smaller than B F-flute micro-flute New flute -Macro-flute Combined board -Different flute profiles combined in one board one layer of medium might be A-flute while the other C-flute Manipulate the compression and cushioning strength, total thickness of the board Standard flute configurations Flute Flutes/ m Flutes/ ft Thickness * Factor A 100~120 30~36 4.67 mm 1.54 B 145~165 44~50 2.46 mm 1.32 C 120~140 36~42 3.63 mm 1.42 E 280~310 86~94 1.19 mm 1.27 *Not including facings; 1foot = 0.3047999m “Take-up factor” is the length of medium per length of finished corrugated board Described: the component of grammage or basis weight, from outside to inside eg corrugated board “205/127C/161” Outside liner = 205grams; Medium = 127 grams, formed to C-flute; Inside liner = 161grams Fiberboard Grades : Weight ; Thickness ; Material Grammage: the mass in grams per square meter Basis weight: the weight in pounds per 1,000 square feet ( abbreviated lb/MSF) The most commonly used corrugating medium weights Grammage/g Basis Weight/b 127 26 147 30 161 33 195 40 Material : Linerboard - natural kraft ;Solid bleached white kraft ; Mottled white ; oyserboard Linerboard with a whiter surface provide better graphics  Recycled or secondary fiber -producing both two components Recycled board -smoother surface finish; low Coefficient of Friction; excellent printing surface  The most commonly used linerboard grades, based on Mullen burst test grading kg = 2.2046 b meter = 3.28084 foot g/m2 = 0.205 b/MSF North American Grades Grammage Basis Weight 127g 26b 161g 33b 186g 38b 205g 42b 337g 69b Other grades - European Grades Grammage 125g 150g -200g 225g 250g 300g 400g 440g A generation of newer linerboards has high-performance boards, meeting ECT (Edgewise Compressive strength) rather than Mullen burst test and basis weight requirements Lighter grades of the high-performance boards to get satisfactory performance Corrugating Adhesive The corrugating machine forms the medium into a fluted pattern and bonds it to the linerboard facings , usually with a starch-based adhesive 1) A starch-based adhesive applied at about 10 to 14 grams per square meter 2) Requirements : not tolerant high moisture and loses strength quickly 3) When higher resistance is needed, starches can be modified or supplemented by the addition of various polymeric materials 4) Weather-resistant adhesive would maintain box properties at a somewhat higher level for a longer period 5) Water-resistant adhesive would be required for those applications where the finished container will be in actual contact with water for periods of time, and the coating or waxed should be treated Broad Manufacture Corrugating machine is made up of a set of stations that take the appropriate linerboards and mediums, shape the flutes, join fluted medium to linerboards Precondition medium with heat and steam  Pretreated linerboards to the same temperature and moisture Brass fingers Flute tips adhesive The single-facer of a corrugating machine is where the flutes are formed and bonded to the inside liner [...]... performance Unbalanced constructions - more problems with board wrappage Heavier liner is placed on the outside for better printing and on the inside for better compression strength CN tái sinh giấy Chương 11 11.4 CN sản xuất giấy tái sinh  ... outside for better printing and on the inside for better compression strength CN tái sinh giấy Chương 11 11.4 CN sản xuất giấy tái sinh