JP3348545B2 - Base paper for fibrous casing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fibrous casing base paper made of hemp pulp. More specifically, the present invention has excellent wet strength and alkali resistance without pre-coating the base paper with wet strength or alkali resistance by pre-coating, and further, fills meat products such as ham and sausage. The present invention relates to a fibrous casing base paper capable of improving the strength of the casing when the casing is used.

[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 subjecting the product to 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.). Artificial casings are cheaper and more sanitary than natural casings, and the size of the product is constant. Widely used for its advantages. However, cellulose casing has the disadvantage of low strength and weakness to humidity, and plastic casing has the disadvantage of not being able to apply smoke. Smokeable and strong fibrous casings are used.

A fibrous casing is made by impregnating a paper base made of cellulose pulp with an aqueous viscose solution,
This method has been subjected to coagulation and regeneration, and this method is disclosed in U.S. Pat. No. 2,105,273. The viscose aqueous solution is an aqueous solution containing a solid content concentration of 7% of cellulose and 6% of sodium hydroxide in a weight ratio. Therefore, a paper base material is required to have wet strength and alkali resistance (strong resistance to alkaline liquid). Is done. In order to provide such a paper base material with wet strength and alkali resistance that can withstand the impregnation of the viscose, US Pat. No. 3,135,61
No. 3, and 3,275,456, a dilute aqueous viscose solution (1% cellulose content)
Pre-impregnation and regeneration treatment. Further, in order to achieve the above object, US Pat. No. 5,108,546 discloses that a paper base material is treated with polyvinyl alcohol, and Japanese Patent Publication No. 4-16129 discloses that a chitosan treatment is performed. Is disclosed.

In general, paper base materials used for base paper for fibrous casing include wood pulp such as conifer bleached kraft pulp, hemp (manila hemp, sisal hemp, flax, hemp, jute), cuso, mitsumata and the like. Paper made of non-wood fiber (peel fiber) pulp or non-woven fabric is used. These pulp are usually chemically pulp completely digested by kraft cooking or caustic soda cooking, and furthermore, chlorine bleaching chemicals such as known chlorine dioxide and hypochlorite, oxygen, peroxide bleaching chemicals and alkalis. Are used to obtain desired whiteness.

However, the base paper for fibrous casing obtained from such chemical pulp has low wet strength and alkali resistance even when a long fiber length is used, such as hemp pulp, which is a non-wood fiber. Because it does not have the necessary wet strength and suitability for alkali resistance required when impregnating it, before using it as a fibrous casing base paper, as described above, in order to impart wet strength and alkali resistance to the paper substrate in advance Is actually used as the base paper after being subjected to some kind of chemical treatment and processing in advance. Therefore, in order to smoothly perform the processing for impregnating the viscose aqueous solution, a raw material that can further improve the wet strength and alkali resistance of the paper base material itself as well as improving the strength by the post-treatment. The appearance of pulp was desired.

[0006]

In view of the above situation, the present inventors have conducted intensive studies on a method for improving the wet strength and alkali resistance of a casing base paper made of cellulose pulp, and as a result, By using neutral sodium sulfite pulp obtained by digesting pulp raw material with sodium sulfite and caustic soda instead of caustic soda digestion, Fibrous with high whiteness without bleaching and excellent wet strength and alkali resistance It was found that a base paper for casing was obtained, and the present invention was completed. It is an object of the present invention to eliminate the need for bleaching with a bleaching chemical, have high whiteness, and wet strength and alkali resistance enough to be directly immersed in an aqueous viscose aqueous solution, even if wet strength and alkali resistance have not been previously imparted by a precoat. An object of the present invention is to provide a fibrous casing base paper having excellent casing strength and high casing strength after being impregnated with an aqueous viscose solution.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a fibrous casing base paper made of hemp pulp, wherein the hemp pulp is digested with a cooking liquor consisting of sodium sulfite and caustic soda, and bleached with a bleaching chemical. Not done,
And the hunter whiteness according to JIS P 8123 is 7
It is a base paper for fibrous casing characterized by being at least 0%.

The raw hemp for obtaining the hemp pulp for the present invention includes Manila hemp, hemp, flax, jute, sisal, etc., which are appropriately selected and used. Considering the availability of raw hemp, uniformity of quality, price of raw hemp, available quantity, etc., Manila raw hemp from Philippines and South America Ecuador is preferred.

[0009] Since raw hemp usually has a length of 2 to 3 m, in order to make it easy to handle, the raw hemp is cut with a cutting machine such as a rotary cutter, a push cutter and the like for 20 to 50 hours.
Cut to a length of 0 mm before use. The digestion is performed by using a pressure vessel that can rotate during the digestion, such as an earth pot, by using sodium sulfite in an amount of 15 to 27% by weight, preferably 17 to 19% by weight (all in the form of Na ₂ SO ₃ ), and Caustic soda is added in an amount of 1 to 12% by weight, preferably 1 to 5% by weight (all in the form of NaOH) based on the dry weight of raw hemp, and the temperature is 140 to
This is performed at 175 ° C. for a holding time of 60 to 180 minutes. Conditions outside these ranges are not suitable because pulp having the desired properties cannot be obtained or is uneconomical.

The reason why the above-mentioned small amount of alkali (eg, caustic soda) is added from the beginning of the cooking is that the pH of the cooking liquor becomes acidic due to the acid generated as the cooking proceeds, For neutralization of sodium sulfite. Thus, p of the cooked liquor at the end of cooking
The addition ratio of alkali is adjusted so that H becomes 6.5 to 7.8, preferably 6.7 to 7.3. Because the raw hemp is bulky, it is preferable to repeat the stuffing while blowing steam when the raw hemp adjusted in length is introduced into the earthen pot prior to the digestion, and hunt down. The digested hemp pulp is washed by a known washing device to remove waste liquid from the pulp, and is further processed by a known roughing and selecting device to obtain undigested material (knots), bound fibers, foreign matter (sand, dust, etc.). Etc.), the selected pulp is used for papermaking as such without bleaching. Hunter whiteness of selected pulp is
It has more than 70% without bleaching with bleaching chemicals. However, there is a limit to this upper limit of whiteness,
78 to take advantage of not using any bleaching chemicals
% Is the limit.

The fibrous casing base paper of the present invention is obtained by pulping the above-mentioned selected pulp obtained by digesting with a neutral sodium sulfite method using a known paper machine, and forming the sheet into a sheet. Is appropriately selected from the range of ²⁰ to 30 g / m ² depending on the desired use of the fibrous casing. The paper machine used may be any of a long net, a circular net, or an inclined wire type, and when wet papermaking is performed, a papermaking auxiliary chemical such as a wet strength reinforcing agent or a paper strength enhancer is appropriately used as necessary. Is added.

The fibrous casing base paper thus obtained has a whiteness of 70 without using a bleaching chemical.
Up to 78% and excellent wet strength and alkali resistance, so that it can be directly impregnated into an aqueous viscose solution of high viscosity and alkali without pre-coating a diluted viscose liquid. Even if you do
A fibrous casing can be obtained without tearing or paper breakage.

[0013] The reason why the base paper for fibrous casing of the present invention is excellent in wet strength and alkali resistance has not been sufficiently elucidated and the details are unknown, but the raw paper is obtained by digesting raw hemp with neutral sodium sulfite. When compared at the same degree of cooking, the pulp yield is higher than that of pulp obtained from alkaline cooking such as soda cooking and kraft cooking, and the resulting pulp whiteness is high, so bleaching treatment, especially hypochlorite By not bleaching the pulp with chlorine-based bleaching chemicals such as acid salts, there is no accompanying fiber damage, and in the pulp in the stage of making fibrous casing base paper, hemicellulose such as pentosan,
It is presumed that more polysaccharides such as pectin remain, which may contribute synergistically.

[0014]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto. In addition,% in an Example and a comparative example shows a weight% unless there is particular notice.

Example 1 Ecuadorian hemp pulp (grade N-4) was cut into 5 cm pieces and placed in a 5 liter laboratory autoclave, then sodium sulfite was converted to Na ₂ SO _{3 at} 19% by weight of absolutely dry hemp. Caustic soda was added as NaOH in an amount of 1% based on the weight of the absolutely dried raw hemp, and the digestion was carried out under the digestion conditions of a liquid ratio of 7.5, a maximum temperature of 160 ° C., a maximum temperature arrival time of 90 minutes, and a maximum temperature holding time of 90 minutes. After the digestion was completed, the contents of the autoclave were transferred onto a 250 mesh stainless steel wire mesh, and the crude pulp and the waste liquid were separated. The crude pulp was passed through a laboratory flat screen equipped with a 10-cut slit plate,
Selected pulp was obtained. At this time, the yield of the selected pulp was 74.1.
%, Screen residue rate was 0.02%, kappa number of the selected pulp was 6.9, Hunter whiteness was 73.3%, and freeness of unbeaten pulp was 737 ml CSF (Canadian standard freeness).

The selected pulp is filtered with a beater to a freeness of 65.
The mixture was beaten to 0 ml CSF, and a polyamide epichlorohydrin resin (trade name: WS570, manufactured by Nippon PMC) was added as a wet strength reinforcing agent in an amount of 1.5% based on the weight of the absolutely dry pulp.
A base paper for a fibrous casing having a basis weight of 23 g / m ² was obtained in an experimental hand-making machine. The whiteness, kappa number, freeness, wet tensile strength of the base paper, alkali resistance, viscose impregnation rate, and casing strength of the obtained pulp were measured by the following test methods.

Test method (1) Hunter whiteness According to JIS P 8123. (2) Copper value According to JIS P 8211. (3) Freeness According to JIS P8121. Canadian standard freeness. (4) Wet tensile strength According to JIS P 8135. (5) Alkali resistance According to JIS P 8135, 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 better the alkali resistance. Was evaluated. (6) Viscose impregnation rate A viscose aqueous solution having a solid content of 7% of cellulose is taken in a petri dish, and a 5 cm × 3 cm base paper for casing is floated on the viscose solution, and the viscose solution oozes on the surface of the base paper. The time required for immersion was measured and defined as the impregnation rate. (7) Casing strength Cellulose content 7 on one side of base paper for fibrous casing
% Viscose aqueous solution with a solid content of 1%
000 g / m ² , and then immersed in an aqueous solution of ammonium sulfate having a solid content of 30% for 20 minutes, and then immersed in an aqueous solution of sulfuric acid having a solid content of 5% for 20 minutes, washed and dried to obtain a basis weight of 93 g. / M ² , and the resulting casing was measured for wet tensile strength according to JIS P8135.

Example 2 The cooking chemical was sodium sulfite 20% (as Na ₂ SO ₃ ),
The digestion was carried out in the same manner as in Example 1 except that caustic soda was changed to 5% (as NaOH) to obtain a selected pulp of Manila hemp. Selected pulp yield is 73.3%, screen residue rate is 0.09%, kappa number of selected pulp is 5.3, Hunter whiteness is 74.2%, and freeness of unbeaten pulp is 719.
ml CSF (Canadian Standard Freeness). Further, using the selected pulp, a fibrous casing base paper was obtained in the same manner as in Example 1, and tested in the same manner as in Example 1.

EXAMPLE 3 The cooking chemicals were 17% sodium sulfite (as Na ₂ SO ₃ ),
The digestion was carried out in the same manner as in Example 1 except that the amount of caustic soda was changed to 1% (as NaOH) to obtain a selected pulp of Manila hemp. Selected pulp yield is 80.9%, screen residue rate is 0.18%, kappa number of selected pulp is 8.4, Hunter whiteness is 72.4%, and freeness of unbeaten pulp is 719.
ml CSF (Canadian Standard Freeness). Further, using the selected pulp, a fibrous casing base paper was obtained in the same manner as in Example 1, and tested in the same manner as in Example 1.

Example 4 The cooking chemical was sodium sulfite 25% (as Na ₂ SO ₃ ),
The digestion was carried out in the same manner as in Example 1 except that caustic soda was changed to 5% (as NaOH) to obtain a selected pulp of Manila hemp. The selected pulp yield is 71.9%, the screen residue ratio is 0.02%, the kappa number of the selected pulp is 5.1, the hunter whiteness is 75.8%, and the freeness of the unbeaten pulp is 723.
ml CSF (Canadian Standard Freeness). Further, using the selected pulp, a fibrous casing base paper was obtained in the same manner as in Example 1, and tested in the same manner as in Example 1.

Example 5 The cooking chemical was sodium sulfite 15% (as Na ₂ SO ₃ ),
A refined pulp of Manila hemp was obtained in the same manner as in Example 1 except that the caustic soda was changed to 10% (as NaOH). Selected pulp yield: 72.3%, screen residue rate: 0.01
%, Kappa number of selected pulp is 4.9, Hunter whiteness is 70.2%, Freeness of unbeaten pulp is 740 ml CS
F (Canadian standard freeness). Further, using the selected pulp, a fibrous casing base paper was obtained in the same manner as in Example 1, and tested in the same manner as in Example 1.

COMPARATIVE EXAMPLE 1 Except that the cooking chemical was changed to caustic soda 18% (as NaOH), cooking was performed in the same manner as in Example 1 to obtain a selected pulp of Manila hemp. The selected pulp yield is 72.6%, the screen residue ratio is 0%, the kappa number of the selected pulp is 7.8, the hunter brightness is 46.3%, and the freeness of the unbeaten pulp is 73.
It was 2 ml CSF (Canadian standard freeness). further,
To this selected pulp was added 1% of hypochlorite soda based on the absolute dry weight of the pulp, and the mixture was bleached under no load in a beater while the pulp concentration was 3%, the temperature was 40 ° C., and the bleaching was performed for 45 minutes. The liquid was separated from the used liquid by transferring the contents to above, and washed with water to obtain bleached pulp. The hunter whiteness of the pulp was 58.8%.
Using this bleached pulp, a fibrous casing base paper was obtained in the same manner as in Example 1, and tested in the same manner as in Example 1.

COMPARATIVE EXAMPLE 2 Except that the cooking chemical was changed to 12% of caustic soda (as NaOH), cooking was performed in the same manner as in Example 1 to obtain a selected pulp of Manila hemp. The selected pulp yield is 73.9%, the screen residue rate is 0.24%, and the kappa number of the selected pulp is 8.8.
8. Hunter whiteness was 46.8%, and freeness of unbeaten pulp was 725 ml CSF (Canadian standard freeness).
Further, the selected pulp was bleached with sodium hypochlorite in the same manner as in Comparative Example 1, and washed with water to obtain bleached pulp. The hunter whiteness of the pulp was 59.7%. Using this bleached pulp, a fibrous casing base paper was obtained in the same manner as in Example 1, and tested in the same manner as in Example 1.

Comparative Example 3 Cooking was carried out in the same manner as in Example 1 except that the cooking chemicals were changed to caustic soda 19% (as NaOH) and sodium sulfide (as Na2S) 5% to obtain a selected pulp of Manila hemp. The selected pulp yield is 72.8%, the screen residue ratio is 0.10%, the kappa number of the selected pulp is 8.2, the hunter whiteness is 48.9%, and the freeness of the unbeaten pulp is 727.
ml CSF (Canadian Standard Freeness). Further, the selected pulp was bleached with sodium hypochlorite in the same manner as in Comparative Example 1, and washed with water to obtain bleached pulp. The hunter whiteness of the pulp was 58.6%. Using this bleached pulp, a fibrous casing base paper was obtained in the same manner as in Example 1, and tested in the same manner as in Example 1.

Table 1 shows the results obtained in Examples 1 to 5 and Comparative Examples 1 to 3.

[0026]

[Table 1]

As can be seen from Table 1, the fibrous casing base paper of the present invention has high wet strength, excellent alkali resistance, and excellent strength when formed into a casing (Examples 1 to 5). . These base paper strengths indicate that the base paper has the necessary strength when impregnating with a viscose aqueous solution without pre-coating a processing agent such as a viscose dilute solution in advance. On the other hand, the soda digested pulp (Comparative Examples 1 and 2) and the kraft digested pulp (Comparative Example 3) have low whiteness of base paper, low wet strength, and poor alkali resistance. Cannot be directly impregnated with a viscose aqueous solution to produce a casing. These base papers are pre-coated with a dilute viscose liquid to impart wet strength or alkali resistance, and then impregnated with the viscose aqueous solution. Otherwise, tears and paper breaks will occur in the impregnation process, causing operational problems. Further, these base papers do not change the impregnation rate of the viscose aqueous solution, but have poor strength when formed into a casing.

[0028]

As described in detail above, the present invention provides:
It has high whiteness and excellent wet strength that can withstand the occurrence of breakage or paper breakage even if it is directly impregnated with a viscose aqueous solution with high viscosity even if wet strength and alkali resistance are not previously imparted to the base paper by precoating. This has the effect of providing fibrous casing base paper having alkali resistance and high strength when formed into a casing.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-141760 (JP, A) JP-A-52-76196 (JP, A) JP-A-4-126885 (JP, A) JP-A 57-76 112485 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) D21H 11/00-27/42 D21C 3/22, 3/06

Claims (1)

(57) [Claims] 1. A base paper for fibrous casing comprising hemp pulp, wherein the hemp pulp is digested with a cooking liquor comprising sodium sulfite and caustic soda, not subjected to bleaching treatment with a bleaching chemical, and JIS. P 812
3. A base paper for fibrous casing, wherein the hunter whiteness according to No. 3 is 70% or more.