JPH1018194A - Paper of casing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain paper for casings, having an alkali-resistant property and a wet strength unnecessitating a preliminary impregnation treatment on the impregnation of viscose, excellent in the viscose-impregnating property, and giving the casings having high casing strengths. SOLUTION: This raw paper for casings comprises hemp pulp, is made from a pulp slurry containing the hemp pulp having a length-weighted average fiber length of 3.8-10mm and a number-average fiber length of 3.5-10mm as a main component, and has an air permeability of 155-200cm<3> /cm<2> /sec based on JIS-L1018.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a base paper for casing made of hemp pulp. More specifically,
The present invention has good wet strength and alkali resistance, and has excellent viscose impregnation when used as a casing for filling meat products such as ham and sausage, and furthermore, casing strength after casing processing, that is, bursting. The present invention relates to a high strength base paper for casing.

[0002]

2. Description of the Related Art Processed meat products such as ham and sausage are obtained by filling a kneaded product prepared by mixing raw materials into a tubular casing, and then performing a heat treatment, a sterilization treatment, a smoke treatment, and the like. There are two types of casing: natural casing and artificial casing (cellulose casing, collagen casing, plastic casing, fibrous casing, etc.). The advantage of artificial casing is that it is cheaper and more sanitary than natural casing, and the size of the product is constant. Widely used from.

[0003] However, cellulose casing has a drawback of low strength and weakness to humidity, and plastic casing has a drawback that smoke cannot be applied. For use, smoke-resistant and strong fibrous casing is used.

[0004] The fibrous casing is made by impregnating a paper base made of cellulose pulp with viscose, coagulating,
In this method, a reproduction process is performed.
No. 05,273. Viscose is an aqueous solution containing 7% by weight of cellulose and 6% of caustic soda (as NaOH). Therefore, the paper base is required to have wet strength and alkali resistance (strong resistance to alkaline liquid).

In order to provide such a paper base material with wet strength and alkali resistance that can withstand the above-mentioned viscose impregnation,
U.S. Pat. Nos. 3,135,613 and 3,2
As disclosed in the specification of Japanese Patent No. 75,456, dilute viscose liquid (cellulose content: about 1%) is pre-impregnated and regenerated.

However, in recent years, due to the high production cost of viscose and measures against environmental problems due to the generation of hydrogen sulfide, base paper manufacturers have been examining alternatives to pre-impregnation of viscose. For example, US Pat.
No. 8,546 discloses processing with polyvinyl alcohol.

However, since the base paper subjected to the pre-impregnation treatment has undergone more operation steps than the base paper not subjected to the pre-impregnation treatment, it not only leads to an increase in cost but also impairs the air permeability of the base paper. . The reduced air permeability makes it difficult to impregnate viscose with high viscosity, and it takes a considerable time to completely impregnate the viscose into the base paper.

[0008] Therefore, there has been a strong demand for a raw material pulp that can further improve the wet strength and alkali resistance of the paper base material without pre-impregnation.

The paper base material generally used for the base paper for casing is, for example, non-wood fibers from wood pulp such as softwood bleached kraft pulp, hemp (manila hemp, sisal hemp, flax, hemp, jute), cuso, mitsumata, etc. (Bast fiber) Paper made of pulp or nonwoven fabric is used.

[0010] Among them, a paper base material made of a manila hemp pulp, which has both air permeability and base paper strength and can be imparted in a well-balanced manner, by a wet paper machine is suitably used as a base paper for casing.

However, the base paper for casing obtained from conventional chemical pulp has insufficient wet strength and alkali resistance even when long fibers such as hemp pulp, which is a non-wood fiber, are used, and impregnated with viscose. Since it does not have the necessary wet strength and suitability for alkali resistance at the time, it is subjected to some kind of chemical treatment and processing as described above before use as a base paper for casing, and wet strength and alkali resistance that can withstand viscose impregnation as described above Is applied to the base paper and used as a base paper for casing.

As a method for improving the wet strength and alkali resistance of a casing base paper made of cellulose pulp as a raw material, a raw material of hemp pulp is prepared by neutral digestion of raw material with sodium sulfite and caustic soda. There is a method using neutral sodium sulfite pulp obtained, and a cooking method using caustic soda, which is also excellent in viscose impregnation.

As described above, base papers having high wet strength and alkali resistance and capable of exhibiting higher casing strength have been studied. That is, when the casing strength is low, the casing tends to burst when the ham maker fills the casing with meat or boil or smoke, which is a complaint to the casing maker. On the other hand, if the casing strength is high, it is of course possible to reduce the bag breakage rate of the casing in ham processing by a ham maker, but if the base paper can express high casing strength, the basis weight of the base paper may be reduced. And the amount of viscose to be impregnated can be reduced, and the cost of the casing can be significantly reduced. As described above, ham makers and casing makers are strongly demanding the appearance of base paper that exhibits high casing strength.

[0014]

DISCLOSURE OF THE INVENTION In view of the current situation, the present inventors have developed a base paper for casing made of cellulose pulp, which has wet strength and alkali resistance that can withstand casing processing, and is made of viscose. As a result of intensive research on casing base paper that has excellent impregnation properties and high casing strength, it contains hemp pulp having a specific average fiber length, thereby maintaining wet strength and alkali resistance that can withstand casing processing. Further, they have found that a base paper for casing having good viscose impregnation property and high casing strength can be obtained, thereby completing the present invention.

An object of the present invention is to have a wet strength and alkali resistance which makes pre-impregnation unnecessary at the time of viscose impregnation,
Another object of the present invention is to provide a base paper for casing which has excellent viscose impregnation property and high casing strength as a casing.

[0016]

The present invention relates to a base paper for casing made of hemp pulp, wherein the base paper has a length-weighted average fiber length of 3.8 to 10 mm and a number average fiber length of 3.10 mm.
Paper is made from a pulp slurry containing hemp pulp of 5 to 10 mm as a main component and has an air permeability of 1 according to JIS-L1018.
It is characterized in that it is 55 to 200 cm ³ / cm ² / sec.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The raw hemp for obtaining the hemp pulp of the present invention includes Manila hemp, hemp, flax, jute, sisal, ramie and the like. . Considering the availability of raw hemp, the suitability for quality as a base paper for casing, the uniformity of the quality, the price of raw hemp and the amount available, Manila hemp from the Philippines or from Ecuador in South America is preferred.

[0018] Since raw hemp usually has a length of 2 to 3 m, in order to facilitate its handling, the raw hemp is cut by a cutting machine such as a rotary cutter or a push cutter for digestion.
It is used after being cut into a length of 500 mm. For the actual digestion, a pressure vessel that can rotate during the digestion, such as an earth pot, is preferably used.

The conditions for digesting raw hemp to obtain unbleached hemp pulp usable in the present invention are 15 to 27% by weight, preferably 17 to 19% by weight of sodium sulfite per weight of absolutely dry raw hemp (all of which are Na ₂ SO 4). ₃ ) and caustic soda in an amount of 1 to 12% by weight, preferably 1 to 5% by weight, based on the dry weight of raw hemp
(Both as NaOH) and added at a temperature of 140-17
The temperature is 5 ° C., the liquid ratio is 5 to 15, and the holding time is 60 to 180 minutes.
In the method of digesting only with caustic soda, caustic soda is used in an amount of 9 to 15% by weight, preferably 10 to 1% by weight of absolutely dry raw hemp.
2% by weight (both as NaOH) at a temperature of 14
The temperature is 0 to 175 ° C, the liquid ratio is 5 to 15, and the holding time is 60 to 180 minutes.

The cooking of raw hemp can be carried out by a known method under the above-mentioned cooking conditions, and the unbleached hemp pulp after the completion of the cooking is washed by a known washing device to remove waste liquid from the pulp. Furthermore, after removing undigested matter (knots), binding fibers, and foreign substances (sand, dust, etc.) using a well-known roughing and selecting device,
Unselected bleached pulp is obtained.

Further, the unselected bleached pulp is bleached so as to have a Hunter whiteness of 65 to 75%. Base paper for casings made with bleached pulp having a whiteness of less than 65% has a yellow tint, and ham makers claim that sulfur content due to insufficient washing in the casing manufacturing process remains and is a subject of claims. Cheap. Also, as for the appearance of the ham, since the casing is more preferably colorless and transparent so that the meat can be seen clearly, it is desirable that the whiteness of the base paper is high.

The bleaching is performed in one step or two steps using a known bleaching agent such as chlorine dioxide and hypochlorite, and an oxygen-based bleaching agent such as oxygen and peroxide. Each of them is subjected to a bleaching treatment to have a desired whiteness. It is important to select bleaching conditions because pulp from caustic soda cooking has a lower whiteness before bleaching than pulp from sodium sulfite cooking.
Bleach to a range of 0-250 cps.

The bleached pulp thus obtained is preferably used in an unbeaten state (freeness: 720 to 740 mlcsf). However, the beatenness increases the bonding strength and the wet strength of the base paper for casing. And slightly beating it to further increase the alkali resistance (freeness: 650 to 700 m
lcsf) or, depending on the application, a freeness of 500 mlcs
Part of the pulp reduced to f may be used.

However, beaten pulp to further increase the strength of the base paper improves the bonding strength between the pulp and the wet strength and the alkali resistance of the base paper. However, when viewed with a single pulp fiber, the fibers are damaged by the beating. However, the single fiber strength is reduced. The pulp with higher single fiber strength has better casing strength, and beating causes a reduction in casing strength. Therefore, it is preferable to use hemp pulp in an unbeaten state.However, the present inventors have repeated studies on hemp pulp capable of expressing a casing strength equal to or higher than the unbeaten state, and as a result, the fiber length of the used hemp pulp is increased. As a result, it has been found that the casing strength can be greatly improved. Considering various conditions as a raw material for casing base paper,
Since Manila hemp is mainly used, the average fiber length in the unbeaten state is about 3.5 mm in length-weighted average fiber length and about 2.0 mm in number average fiber length in the case of ordinary Manila hemp. However, in order to develop a casing strength not less than unbeaten, hemp pulp is required to have a length-weighted average fiber length of 3.8 to 10 m.
It is effective to blend a fiber having a length of 3.5 m and a number average fiber length of 3.5 to 10 mm by weight of absolutely dry pulp in an amount of 40% by weight or more, preferably 50% by weight or more.

The average fiber length of the hemp pulp is less than 3.8 mm in length weighted average fiber length and 3.5 mm in number average fiber length.
If it is less than that, the casing strength of the unbeaten pulp is not changed, and the effect of improving the casing strength is small. Further, when the pulp is shorter than the unbeaten pulp, the air permeability is 150 cm ³ / cm ² /
Seconds or less, the viscose impregnation property is reduced, and the casing strength is further reduced. The length-weighted average fiber length is 3.8 to 10 mm, and the number average fiber length is 3.5 to 10
If the hemp pulp is less than 40% by weight based on the weight of the absolutely dried pulp, the air permeability becomes 150 cm ³ / cm ² / sec or less, the viscose impregnation property is reduced, and the casing strength is reduced. In the case of Manila hemp pulp, the upper limit of the fiber length is about 7 mm, but the upper limit is not particularly limited by using hemp pulp with longer fibers. However, the general upper limit fiber length that can be generally formed by a wet paper machine is 1
It is about 0 mm, and the air permeability of the obtained casing base paper is at most about 200 cm ³ / cm ² / sec.

As a method of obtaining hemp pulp having a desired fiber length, when a pulp having a fiber length of about Manila hemp is used,
It is preferable to collect only long fibers using a coarse mesh of 24 mesh or less using a fiber sieving machine. The sieving is preferably performed at a concentration as low as possible so that long fibers and short fibers can be easily separated. At a high concentration, the long fibers form a sheet on the mesh, and the short fibers hardly pass through the mesh. The base paper for casing made by using the long fiber pulp obtained by sieving, the long fiber with high single fiber strength, after being processed into the casing, forms a firm skeleton, and the high casing strength is high. can get. In addition, the long fiber pulp obtained by this sieving has a short porous fiber and fine fibers, so that it becomes a more porous sheet, has a high air permeability, and has improved viscose impregnation.

The base paper containing long fibers has a small amount of fine fibers, and there is no binding of fibers due to beating. Therefore, there is a concern that the wet strength and the alkali resistance of the base paper may be reduced. It is preferable to use a chemical such as a water-proofing agent or a wet paper strength enhancer in advance by adding it to the stock. In particular, when the polyamide epichlorohydrin resin and guar gum are used in combination as internal additives, the wet strength and anti-alkaline resistance of the paper base material are further improved. The base paper for casing obtained in this manner was reinforced by the strength of the base paper with the internal additive chemical, and was sufficiently usable.

The pulp having a fiber length as described above may have a freeness of 650 to 740 mlcsf for reinforcing the strength.
Of unbeaten pulp or beaten pulp.

The basis weight of the casing base paper varies depending on the desired use, but is appropriately selected and used within the range of 15 to 30 g / m ² . The drying conditions are not particularly limited, but a warm air dryer at 90 to 150 ° C. is usually preferably used.

[0030]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto. Incidentally,% in Examples and Comparative Examples is:
Unless otherwise specified, it indicates% by weight.

EXAMPLE 1 Ecuadorian raw hemp (grade N-4) was cut into 5 cm pieces.
In a laboratory autoclave in a liter container, then add caustic soda as NaOH at 12% based on the weight of the absolutely dry raw hemp, and digestion conditions: liquid ratio 10, maximum temperature 170 ° C, maximum temperature arrival time 90 minutes, maximum temperature holding time 90 minutes. Was digested.

After the digestion was completed, the contents of the autoclave were transferred to a 250 mesh stainless steel wire mesh to separate the crude pulp from the waste liquid, and the crude pulp was passed through a laboratory flat screen equipped with a 10-cut slit plate to obtain a selected pulp. Was. Further, to this selected pulp, sodium hypochlorite was added at 1.5% per pulp absolute dry weight, and supplementary alkali was added at 0.1%.
After adding 5%, bleaching at a pulp concentration of 3%, a bleaching temperature of 40 ° C. and a bleaching time of 120 minutes, the contents and used liquid are put on a 250-mesh stainless steel wire mesh to separate fibers and liquid, and the pulp is sufficiently separated. To obtain bleached pulp. The average fiber length of the obtained bleached pulp was 3.8 mm in length-weighted average fiber length and 2.0 mm in number average fiber length.

The pulp was passed through a Bauer sieving machine.
A 12 mesh screen was used to collect only the pulp that did not pass through the 12 mesh. The average fiber length of the obtained pulp was 4.2 mm in length weight and 3.8 mm in number average.

A polyamide epichlorohydrin resin (trade name: WS570, manufactured by Nippon PMC) was added as a wet paper strength enhancer to the pulp at a concentration of 1.2% based on the absolutely dry pulp weight.
Further, carboxymethylated guar gum (trademark: Mayploid 870, manufactured by Sansei Co., Ltd.) was added in an amount of 1.2% based on the absolutely dry pulp weight
It was added to paper stock, and the basis weight was 23 g /
An m ² casing base paper was prepared.

Measurement of fiber length of hemp pulp, wet strength of base paper for casing, alkali resistance, impregnation of viscose, casing strength and air permeability were measured by the following test methods.

Test Method (1) Fiber Length Measurement JAPAN TAPPI Paper Pulp Test Method No. 52
Kayani fiber length measuring device FS-20 based on "Fiber length test method for paper and pulp (optical automatic measurement method)"
It was measured using type 00. (2) Wet strength According to JIS-P8135. (3) Alkali resistance According to JIS-P8135, the tensile strength after immersing the base paper in a 6% aqueous sodium hydroxide solution for 10 minutes instead of water was measured, and the higher the numerical value, the higher the alkali resistance. I evaluated it. (4) Viscose impregnation A viscose solution having a cellulose content of 7% and a NaOH content of 6% was taken in a petri dish, and a 2.5 cm square casing base paper was floated on the viscose liquid. The time required for oozing all over was measured, and the shorter the time, the better the impregnation. (5) Rupture strength of casing 7% cellulose content, NaOH on one side of casing base paper
G of 6% viscose liquid by weight
/ M ² and then immersed in a 30% strength ammonium sulfate solution for 20 minutes, further immersed in a 5% strength sulfuric acid solution for 20 minutes, washed and dried to obtain a basis weight of 93 g.
/ M ² , and the obtained casing was immersed in water for 10 minutes, and then the burst strength was measured according to JIS-P8112. (6) Air permeability According to JIS-L1018.

Example 2 Papermaking was carried out in the same manner as in Example 1 except that 1.5% each of the internal chemicals of the polyamide epichlorohydrin resin and the carboxymethylated guar gum was added, and the obtained base paper for casing was tested. .

Example 3 Each of the sieved long fiber pulp obtained in Example 1 and the unbeaten pulp that had not been sieved was mixed with absolutely dry pulp by 50% each.
%, The paper was made in the same manner as in Example 1, and a test was made on the base paper for casing.

Comparative Example 1 Unbeaten pulp 10 obtained in Example 1 without sieving
0% was made in the same manner as in Example 1, and the obtained base paper for casing was tested.

COMPARATIVE EXAMPLE 2 The unsieved pulp obtained in Example 1 was blended with 70% by weight of absolute dry pulp, and the sieved long fibers were blended by 30% by weight of absolute dry pulp. The papermaking was performed in the same manner as described above, and the obtained casing base paper was tested.

Comparative Example 3 The unbeaten pulp obtained in Example 1 was dried with a beater to a freeness of 6%.
It was beaten to 50 mlcsf and paper-made in the same manner as in Example 1 without sieving, and the obtained base paper for casing was tested.
The fiber length of the beaten pulp was 3.6 mm in length-weighted average fiber length and 1.8 mm in number average fiber length.

Comparative Example 4 Paper was made in the same manner as in Example 1 using 100% pulp which had been sieved and passed through 12 mesh in Example 1, and the casing base paper obtained was tested. The fiber length of the pulp that passed through 12 mesh was 2.9 m in length-weighted average fiber length.
m, and the number average fiber length was 1.2 mm.

Table 1 shows the test results obtained in the examples and comparative examples.

[0044]

[Table 1]

As can be seen from Table 1, the base paper for casing which has hemp pulp having an average fiber length according to the present invention and has air permeability is excellent in viscose impregnation and has a burst strength of the casing after casing processing. high. The wet strength and alkali resistance of the base paper are the same as those of the unbeaten pulp, and the same level as the beaten pulp can be achieved without lowering the casing strength by adding a small amount of an internal additive (Examples 1 to 5).
3).

On the other hand, in the case where the content of the long fiber is small or the base paper for casing made of pulp having an average fiber length of not more than a predetermined value even if it is not beaten, the casing bursting strength is lower than that of the examples. (Comparative Examples 1 and 2) Further, the rupture strength of the casing is further reduced by advancing the beating (Comparative Example 3). Further, the casing base paper made of only short fibers has a remarkable decrease in the bursting strength of the casing (Comparative Example 4).

[0047]

EFFECT OF THE INVENTION The casing base paper according to the present invention has wet strength and alkali resistance that do not require pre-impregnation during viscose impregnation, and has excellent viscose impregnation.
In addition, it has the effect of having a high casing strength as a casing, and is extremely useful in practice.

Claims (1)

[Claims] 1. A base paper for casing made of hemp pulp, wherein the base paper has a length-weighted average fiber length of 3.8 to 10 m.
m, and paper is made from a pulp slurry containing hemp pulp having a number average fiber length of 3.5 to 10 mm as a main component, and is JIS-L1
018 to 155-200 cm ³ / cm ² /
Base paper for casing, characterized in seconds.