Method for manufacturing soft capsule and apparatus for manufacturing the same

1. A method for manufacturing a soft capsule containing a filling within a shell portion formed of a shell-sheet, comprising

ejecting a molten shell material in the form of a sheet having an almost uniform thickness from a spreader box, and cooling the shell-sheet ejected from the spreader box by a casting drum, and

supplying shell-sheets thus obtained between a pair of die rolls so as to face each other, joining the shell-sheets by butt joint function of the die rolls, and supplying the filling from a segment in a filling supply section between the shell-sheets in time for joining,

wherein the shell portion is formed by blending starch, λ carrageenan, a metal salt, dextrin, a plasticizer, and water as components for a raw material composition,

wherein the shell-sheets are dried by irradiation of a medium wavelength infrared ray before they are joined by the pair of die rolls,

the shell-sheets used herein are each dried by a single-sided drying, in which the shell-sheet positioned on the casting drum is irradiated with a medium wavelength infrared ray to thereby dry mainly the one surface of the shell-sheet corresponding to outside of a capsule,

to form into a sheet-form having an almost uniform thickness, an appropriate viscosity, and moisture content and enhanced adhesiveness between mutual sheets; and

the filling is supplied to the shell-sheets in time for joining the shell-sheets at a segment section temperature of 35 to 50° C. without applying excessive heat load to a capsule filling to perform encapsulation,

wherein the drying of the shell-sheets occurs prior to the encapsulation.

2. The method for manufacturing a soft capsule according to claim 1 , wherein the wavelength of the medium wavelength infrared ray to be applied for drying the shell-sheet is 0.8 to 4.0 μm.

3. The method for manufacturing a soft capsule according to claim 1 , wherein the shell-sheet is dried by medium wavelength infrared irradiation up to a moisture content of 19 to 29% at a stage of feeding between the pair of die rolls.

4. The method for manufacturing a soft capsule according to claim 1 , wherein the shell portion in a liquid state before drying contains 5 to 25 parts by weight of λ carrageenan, 0.5 to 10 parts by weight of a metal salt, 3 to 100 parts by weight of dextrin, 20 to 80 parts by weight of a plasticizer, and 90 to 160 parts by weight of water relative to 100 parts by weight of starch.

5. The method for manufacturing a soft capsule according to claim 1 , further containing κ carrageenan and τ carrageenan so as to satisfy a ratio of λ carrageenan: κ carrageenan: τ carrageenan=1:0.1:0.1 to 1:0.8:0.2.

6. An apparatus for manufacturing a soft capsule containing a filling coated with a shell portion formed of a shell-sheet, comprising:

a sheet molding section forming the shell-sheet having an almost uniform thickness from a molten shell material,

a capsule molding section joining shell-sheets supplied between a pair of die rolls so as to face each other by butt joint function of the pair of die rolls having a molding projection, and

a filling supply section supplying a filling to the shell-sheets in time for joining the shell-sheets,

wherein the sheet molding section comprises a spreader box ejecting a molten shell material in the form of sheet having an almost uniform thickness and a casting drum cooling the shell-sheet ejected from the spreader box,

the sheet molding section is further provided with a dryer equipped with a medium wavelength infrared heater; the shell-sheets are irradiated with a medium wavelength infrared ray from the heater to thereby obtain an almost uniform thickness, an appropriate viscosity, and moisture content; and the sheets of this state are fed to the capsule molding section,

wherein the dryer is configured to dry the shell-sheet by employing a single-sided drying, in which the shell-sheet placed on the casting drum is irradiated with a medium wavelength infrared ray to thereby dry mainly the one surface of the shell-sheet,

wherein the wavelength of the medium wavelength infrared ray applied from the medium wavelength infrared heater of the dryer to the shell-sheet is 0.8 to 4.0 μm, and

wherein the dryer dries the shell-sheet prior to encapsulation of the capsule.

7. A method for manufacturing a soft capsule containing a filling within a shell portion formed of a shell-sheet, comprising

ejecting a molten shell material in the form of a sheet having an almost uniform thickness from a spreader box, and cooling the shell-sheet ejected from the spreader box by a casting drum, and

supplying shell-sheets thus obtained between a pair of die rolls so as to face each other, joining the shell-sheets by butt joint function of the die rolls, and supplying the filling from a segment in a filling supply section between the shell-sheets in time for joining,

wherein the shell portion is formed by blending starch, λ carrageenan, a metal salt, dextrin, a plasticizer, and water as components for a raw material composition,

wherein the shell-sheets are dried by irradiation of a medium wavelength infrared ray before they are joined by the pair of die rolls,

the shell-sheets used herein are each dried by double-sided drying, in which the shell-sheet is removed from the casting drum and taken out in a transport path, in which the medium wavelength infrared ray is separately applied to each of the surfaces to thereby dry both surfaces of the shell-sheet,

to form into a sheet-form having an almost uniform thickness, an appropriate viscosity, and moisture content and enhanced adhesiveness between mutual sheets; and

the filling is supplied to the shell-sheets in time for joining the shell-sheets at a segment section temperature of 35 to 50° C. without applying excessive heat load to a capsule filling to perform encapsulation,

wherein the drying of the shell-sheets occurs prior to the encapsulation.

8. The method for manufacturing a soft capsule according to claim 7 , wherein the shell-sheet is dried by medium wavelength infrared irradiation in at least two stages and both surfaces of the shell-sheet are dried by irradiating one of the surfaces of the shell-sheet separately in each stage.

9. The method for manufacturing a soft capsule according to claim 7 , wherein the wavelength of the medium wavelength infrared ray to be applied for drying the shell-sheet is 0.8 to 4.0 μm.

10. The method for manufacturing a soft capsule according to claim 7 , wherein the shell-sheet is dried by medium wavelength infrared irradiation up to a moisture content of 19 to 29% at a stage of feeding between the pair of die rolls.

11. The method for manufacturing a soft capsule according to claim 7 , wherein the shell portion in a liquid state before drying contains 5 to 25 parts by weight of λ carrageenan, 0.5 to 10 parts by weight of a metal salt, 3 to 100 parts by weight of dextrin, 20 to 80 parts by weight of a plasticizer, and 90 to 160 parts by weight of water relative to 100 parts by weight of starch.

12. The method for manufacturing a soft capsule according to claim 7 , further containing κ carrageenan and τ carrageenan so as to satisfy a ratio of λ carrageenan: κ carrageenan: τ carrageenan=1:0.1:0.1 to 1:0.8:0.2.

13. An apparatus for manufacturing a soft capsule containing a filling coated with a shell portion formed of a shell-sheet, comprising:

a sheet molding section forming the shell-sheet having an almost uniform thickness from a molten shell material,

a capsule molding section joining shell-sheets supplied between a pair of die rolls so as to face each other by butt joint function of the pair of die rolls having a molding projection, and

a filling supply section supplying a filling to the shell-sheets in time for joining the shell-sheets,

wherein the sheet molding section comprises a spreader box ejecting a molten shell material in the form of sheet having an almost uniform thickness and a casting drum cooling the shell-sheet ejected from the spreader box,

the sheet molding section is further provided with a dryer equipped with a medium wavelength infrared heater; the shell-sheets are irradiated with a medium wavelength infrared ray from the heater to thereby obtain an almost uniform thickness, an appropriate viscosity, and moisture content; and the sheets of this state are fed to the capsule molding section,

wherein the dryer is configured to dry the shell-sheet by employing a double-sided drying, in which the shell-sheet is removed from the casting drum and taken out in a transport path, in which the medium wavelength infrared ray is separately applied to each of the surfaces to thereby dry both surfaces of the shell-sheet,

wherein the wavelength of the medium wavelength infrared ray applied from the medium wavelength infrared heater of the dryer to the shell-sheet is 0.8 to 4.0 μm, and

wherein the dryer dries the shell-sheet prior to encapsulation of the capsule.

14. The apparatus for manufacturing a soft capsule according to claim 13 , wherein

when the double-sided drying is performed by taking out the shell-sheet separately from the casting drum to the transport path and supplying air toward the irradiation surface of the shell-sheet from an upstream side to a downstream side in the sheet transport direction, and a support is provided so as to support the shell-sheet from below.