Paper pulp for the manufacture of base paper for parchment

 

(57) Abstract:

Paper pulp refers to pulp and paper industry and can be used for the manufacture of base paper for parchment, widely used for packaging of various food products, dressings, medical industry and other products that require oil and water-proof packing. Paper pulp contains sulphate bleached hardwood pulp and bleached coniferous sulphate pulp. As bleached Kraft hardwood pulp it mainly contains the specified cellulose content of the pulp 86-91%. Specified deciduous pulp prepared mainly from aspen wood, or a mixture of aspen wood and birch wood, or a mixture of aspen wood, birch wood and alder wood. The use of the proposed paper pulp can improve structural integrity of parchment and his ironplanet when increasing the mechanical strength. 2 C.p. f-crystals, 2 tab.

The invention relates to the production of base paper for parchment, widely used for packaging of various food products, dressings, stalinvesta paper pulp for making paper-the basics consisting of a mixture of bleached Kraft hardwood pulp (60%), bleached softwood pulp with the addition of sulfite bleached hardwood (beech) cellulose (10-20%). (see Truhanov N. E. and other Technology packaging paper, ed. "The forest industry, M., 1974, pp. 108-111).

Obtained from such paper pulp base paper has insufficient mechanical strength and, in addition, requires a sophisticated technology due to the introduction of a special line for sulfite pulp.

The closest analogue of the present invention is paper pulp for the manufacture of base paper for parchment, including sulfate bleached softwood pulp and hardwood sulfate bleached pulp, with the specified paper pulp contains, wt%:

sulfate bleached softwood pulp - and 35-75

sulphate bleached hardwood pulp - 25-65. (See SU A1, 1245639, 23.07.86, CL NC D 21 H 11/04; D 21 H 27/06).

This paper weight as bleached Kraft hardwood pulp contains the specified pulp from aspen wood or mix it with birch and alder wood.

However, this paper weight attached from the paper-based parchment weeks the d ' structure parchment heterogeneous, while reducing its main operational property - ironplanet (increases zhiropronitsaemost).

There is also not high and the mechanical strength of the base paper and parchment, made from such pulp.

New technical result from the use of this invention is to improve the structural uniformity of parchment and his jeromepricemusic while increasing the mechanical strength as the base paper, and from the parchment.

This technical result is achieved in that paper pulp for the manufacture of base paper for parchment, including sulphate bleached hardwood pulp and bleached coniferous sulphate pulp, according to the invention contains the above components when following their ratio, wt.%: sulphate bleached hardwood pulp - 68-95 and sulfate bleached softwood pulp - 5-32.

At the same time as bleached hardwood pulp it contains the specified cellulose with a predominant content of the pulp 86-91%, which contributes to obtaining low values of seropositivity parchment, due to the high reaction ability is ocena from aspen wood, or of a mixture of aspen wood and birch wood, or of a mixture of aspen wood, birch wood and alder wood.

As sulfate bleached softwood in the present invention can be used cellulose derived both from the same species of coniferous wood, usually used for this task, and from a mixture of various species of wood - pine, spruce, larch, fir and other

The authors of the present invention, it was found that increasing the proportion of bleached Kraft hardwood pulp on 3-70% (in comparison with a paper weight of the prototype) contributes to the uniformity of the lumen of the paper base, which is especially important for parchment underweight 1 m2and obtaining of parchment that has both a reduced rate of seropositivity and high value of mechanical strength (for base paper and parchment). The use of bleached Kraft hardwood pulp with content-cellulose within 86-91% provides optimal values of seropositivity parchment and increases its shelf life.

So, by reducing the content of cellulose men whom I structure parchment - increases its fragility and reducing its strength, and with increasing content of the pulp over 91% parametersa the ability of the cellulose is degraded, and zhiropronitsaemost parchment increases.

Grinding softwood and hardwood bleached Kraft pulp exercise jointly.

Example 1. Take bleached sulfate pulp from hardwood is 100% aspen wood in the amount of 68% of the total number of pulp and mix it with bleached sulfate pulp from coniferous wood (mixture containing 82% pine, 15% spruce and 3% larch) in the amount of 32% of the total amount of the fibrous mass.

The resulting mixture is subjected to joint grinding on disk mill to 36oSHR.

Milled mass is subjected to low tide, pressing and drying on a paper machine.

The process of parlamentarian obtained base paper carried out on parchment machine sulfuric acid.

Specifications paper weight and parameters of the process of its preparation are presented in table 1.

The indicators obtained base paper and it made of parchment presented in table 2.

Examples 2-4. The paper is CLASS="ptx2">

Specifications paper weight and parameters of the implementation process of its production is presented in table 1.

The indicators obtained base paper and it made of parchment presented in table 2.

Examples 5-6 (the prototype).

According to the technology described in example 1, produced a paper weight on the prototype, containing, by weight. %: hardwood sulfate bleached pulp - 25-65, sulfate bleached softwood pulp - 35-75 at the limiting values of the components of paper pulp. The base paper and parchment is prepared as in example 1.

Specifications paper weight and parameters of the implementation process of its production is presented in table 1.

The indicators obtained base paper and it made of parchment presented in table 2.

From table 2 it is seen that the paper weight, obtained according to the invention, provides the base paper with the indicators of the breaking length than the base paper obtained from the mass of the prototype.

At the same time from table 2, shows the superior performance of parchment, made of base paper received from the paper pulp in comparison with parchment paper pulp, because more uniform structure, that improves its consumer properties.

1. Paper pulp for the manufacture of base paper for parchment, including sulphate bleached hardwood pulp and bleached coniferous sulphate pulp, characterized in that it contains these components when following their ratio, wt.%:

Sulphate bleached hardwood pulp - 68 - 95

Sulfate bleached softwood pulp - 5 - 32

2. The paper weight on p. 1, characterized in that as bleached Kraft hardwood pulp it contains the specified cellulose content of the pulp 86 - 91%.

3. The paper weight on p. 1, characterized in that as bleached Kraft hardwood pulp it contains the specified pulp from aspen wood, or a mixture of aspen wood and birch wood, or a mixture of aspen wood, birch wood and alder wood.

 

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