CN1088277A - Process for making highly finished kraft paper - Google Patents

Abstract

A kind of process for making highly finished kraft paper belongs to the paper pulp fiber bleaching and handles.Its technology is successively through stripping off the skin, chip, boiling, washing material and the paper pulp fiber that is processed into of deslagging process with larch according to the invention, by weight with slurry: the mixed of calcium hypochlorite=100: 4 stirs, bleaching liquor half an hour, wash after concentrating that to expect into whiteness be 19 °～21 ° paper pulp; Make highly finished kraft paper through making beating, online, squeezing, optical pressure, oven dry, press polish successively again.Manufacturing technique is simple, raw material are inexpensive, the surface smoothness of manufactured goods is good, color is pale yellow, dust is low, intensity and tightness height, can be used as the package paper of various class commodity.

Description

Process for making highly finished kraft paper

The invention provides a kind of process for making highly finished kraft paper, belong to the paper pulp fiber bleaching and handle.

China's the fifties, because timber resources is abundanter, make brown paper and adopt red kahikatea, the brown paper quality that this raw material is made is good, but minimizing along with timber resources, begin to adopt larch to produce that paper color dark, dust that brown paper, particularly northern China paper plant adopts the larch brush wood to join to mix a part of broad-leaved to produce more are many, one-tenth paper surface smoothness is low from the sixties, intensity is low, tightness is low.China adopts in south bamboo pulp to join to mix a small amount of needle long fiber wood pulp to produce brown paper more, and this brown paper appearance color is dark, and intensity is low, is not suitable for packing high-grade goods.External country as paper-making industry prosperities such as Canada, the U.S., Finland, generally all adopt red kahikatea raw material better, that class is higher to make brown paper, its boiling method is sulfate process mostly, the brown paper papery of producing with above-mentioned raw materials and method is good, extremely welcome on Chinese market, but this pulp import costs an arm and a leg, and import is obstructed so that interrupt.

The objective of the invention is to avoid above-mentioned deficiency of the prior art and provide that a kind of to adopt inexpensive larch be the manufacturing technique that the red kahikatea raw material of raw material substitution produces fine quality brown paper.

Purpose of the present invention realizes with following technical scheme: with water content less than 35%, the cold water extract is less than 2.21%, the hot water extract is less than 1.9%, the 1%NaOH extract is less than 13.03%, lignin content less than 27.44% larch through stripping off the skin, chip, boiling, wash the paper pulp fiber of the preorder PROCESS FOR TREATMENT one-tenth of material and slagging-off composition, by weight with fiber: the mixed stirring that calcium hypochlorite equals 100: 4, bleaching liquor 20～30 minutes washes after concentrating that to expect into whiteness be that 19 °～21 ° paper pulp is again via making beating, online, squeezing, optical pressure, oven dry, press polish, after handling, post-order process curling and that rewinding is formed makes highly finished kraft paper.

The present invention compared with prior art institute's tool advantage is: be raw material with more low-grade larch 1,, through processing technology provided by the invention manufacture paper with pulp paper that the red kahikatea raw material that becomes to be equivalent to expensive higher class manufactures paper with pulp, to have solved homemade brown paper gloss dark, paper surface dust is many, the problem that intensity is low, have through the brown paper of this processes that lustrous surface is good, color is pale yellow, intensity is high, tightness is big, have that performance is good, price is low, brown paper that can the substituting import one pulp production.2, just can produce high-quality brown paper without pulp inlet, for country has saved foreign exchange.3, papermaking is raw materials used abundant, helps the paper mill and continues to produce.4, paper technology is simple, only needs to add in former brown paper processing process to bleach the technology of changing colour, and processing technology is easy to realize.

Describe the present invention in detail below in conjunction with embodiment.

Process for making highly finished kraft paper:

Larch → strip off the skin → chip → boiling → wash material → slagging-off → bleaching to change colour → concentrate → wash material → making beating → flow box → online → squeezing → optical pressure → oven dry → press polish → curl → rewinding → finished product.Most preferred embodiment be select for use moisture less than 35%, the cold water extract less than 2.21%, the hot water extract less than 1.9%, the 1%NaOH extract less than 13.03% and lignin content less than the new carbon material of 27.44% larch, take 15～20mm, wide 15mm, the thick 3～5mm of growing up that chip behind crust and the tender skin off, the wood chip that cuts is placed on 170m ³In the digester and to send into alkali concn be that 15%～17% NaOH and sulphidity are 25%～30% alkali lye boiling 4.5 hours～5.5 hours, its boiling card uncle valency requires within 43～53, can guarantee into the paper page like this and have the higher intensity and the even surface of gloss, residual alkali of flush away and fiber fines on the pressure wash engine again after the boiling, then, the paper pulp fiber bleaching of removing residue is changed colour.Generally all adopt calcium hypochlorite and chlorine segmentation to association with pulp bleaching both at home and abroad, the present invention is not equipped with chlorine, only change colour with calcium hypochlorite, when changing colour, according to weight with slurry: calcium hypochlorite is admixed calcium hypochlorite in the slurry in 100: 4 ratio, bleaching under the normal temperature 20～30 minutes in floating tower, is again through 10m after 19 °～21 ° paper pulp concentrates with whiteness ²Vacuum pulp washing machine washing, wash chlorine off, and then through four φ 450 disks mill series connection making beating, the present invention adopts traditional fourdrinier machine to manufacture paper with pulp, with beating degree is header box before the paper pulp of 20～22SR pumps into the paper machine, adjusts the flow box before the paper machine after the concentration, and its water level is 22cm～24cm, online then, online concentration is 0.35%～0.4%, and the paper motor speed is 80m～140m/ branch, and this speed can increase and decrease according to the concrete ability of paper machine, then successively through squeezing, optical pressure, its optical pressure linear pressure is 20kg/cm～25kg/cm, and is dry on drying cylinder again behind the optical pressure, oven dry air pressure is 1.8kg/cm～2.0kg/cm, set up sprayer unit after the oven dry, with water yield spraying in 20kg/ hour, to stablize the uniformity of moisture content, it is different and different that injection flow rate is looked paper machine speed, improve the presentation quality and the smoothness of page, page is sent into the calender press polish after spraying, and linear pressure is 30kg/cm～40kg/cm, be highly finished kraft paper from what calender came out, at last with the formation warehouse-in of reel and sheet paper.General reel specification is 1092mm, 787mm etc., also can produce according to user's requirement, and the sheet paper specification is 787mm * 1092mm.

Table one has provided the fiber size of larch and other raw material.

Table two has provided the chemical analysis (%) of larch and other raw material.

Table three has provided the various performances of highly finished kraft paper that adopt paper technology of the present invention to manufacture paper with pulp.

Table four has provided the various performances of the brown paper that produces with larch raw material employing old technology.

Table five has provided the various performances of making brown paper with the American Red kahikatea.

Table three

Index name		Unit	Regulation
				Quantitatively		g/m 2	70±3.5
80±4.0
	90±4.5
100±5.0
	120±5.0
Bursting strength is not less than		70g/m 2	KPa (kgf/cm)				265(2.7)
	80g/m 2			310(3.16)
		90g/m 2			355(3.62)
	100g/m 2			401(4.08)
		120g/m 2			465(4.74)
	Tearability vertically is not less than			70g/m 2		KN (gf)	800(81.57)
80g/m 2		990(100.94)
			90g/m 2	1200(122.36)
100g/m 2		1350(137.65)
			120g/m 2	1490(151.93)
Degree of sizing is not more than		g/m 2			30
			Delivery moisture content			％	6.0～10.0

Table four

Index name		Unit	Regulation
				Quantitatively		g/m 2	70±3.5
80±4.0
	90±4.5
100±5.0
	120±5.0
Bursting strength is not less than		70g/m 2	KPa (kgf/cm 2)				245(2.49)
	80g/m 2			296(3.01)
		90g/m 2			320(3.26)
	100g/m 2			380(3.87)
		120g/m 2			420(4.28)
	Tearability vertically is not less than			70g/m 2		KN (gf)	750(76.47)
80g/m 2		940(95.85)
			90g/m 2	1120(114.21)
100g/m 2		1280(130.51)
			120g/m 2	1410(143.77)
Degree of sizing is not more than		g/m 2			30
			Delivery moisture content			％	6.0～10.0

Table five

Index name		Unit	Regulation
				Quantitatively		g/m 2	70±3.5
80±4.0
	90±4.5
100±5.0
	120±5.0
Bursting strength is not less than		70g/m 2	KPa (kgf/cm 2)				256（2.61）
	80g/m 2			308(3.14)
		90g/m 2			349(3.55)
	100g/m 2			392(3.99)
		120g/m 2			465(4.74)
	Tearability vertically is not less than			70g/m 2		KN (gf)	784(79.94)
80g/m 2		985(100.43)
			90g/m 2	1170(119.3)
100g/m 2		1310(133.57)
			120g/m 2	1450(147.85)
Degree of sizing is not more than		g/m 2			30.0
			Delivery moisture content			％	6.0～10.0

About larch test-tube baby wall thickness average out to 9mm, more than one times, its fibre morphology and average length and chemical composition can see Table one and table two than the test-tube baby wall thickness of red kahikatea.From the given data of table three～table five, shown and adopted low-grade larch raw material and adopt brown paper processing technology provided by the present invention, its performance of highly finished kraft paper of making is equivalent to external brown paper with high-grade red kahikatea raw material processing and manufacturing, same is raw material with larch, the brown paper that adopts old technology and adopt processes provided by the present invention to go out, its performance difference is bigger, pale yellow with larch raw material and the brown paper color that adopts processing technology provided by the invention to produce, dust is low, the intensity height, the tightness height can satisfy the package paper of various from low to high class commodity on the domestic market, and cheap.

Claims (1)

1. A kind of process for making highly finished kraft paper, comprise successively by stripping off the skin, chip, boiling, wash the preorder technology that material and slagging-off are formed, successively by making beating, online, squeezing, optical pressure, oven dry, press polish, curl and reach the post-order process that rewinding is formed, the invention is characterized in water content less than 35%, the cold water extract is less than 2.21%, the hot water extract is less than 1.9%, the 1%NaOH extract is less than 13.03%, the paper pulp fiber that lignin content becomes via the preorder PROCESS FOR TREATMENT less than 27.44% larch, by weight with fiber: calcium hypochlorite stirs by 100: 4 mixed, bleaching liquor 20～30 minutes, wash after concentrating that to expect into whiteness be 19 °～21 ° paper pulp, handle through post-order process again and make highly finished kraft paper.