Method for manufacturing glass container
Provided is a method for manufacturing a glass container with which a glass container having a distinctively shaped inner space and excellent aesthetic appearance can be manufactured in good yield. The method for manufacturing a glass container includes steps (A) to (E). (A) A step of introducing a gob into a mold through a funnel. (B) A step of blowing air into the mold through the funnel, bringing a plunger disposed on a side opposite the side to which the funnel is fitted in contact with the gob, separating the plunger from the gob, and forming a recess on the surface of the gob. (C) A step of removing the funnel from the mold and fitting a baffle to the mold. (D) A step of blowing air from the plunger, and forming an inner space inside the gob with the recess as a starting point while simultaneously forming an outer shape by pressing the outer side of the gob to a molding surface of the mold to obtain a glass container of the final shape. (E) A step of transferring the glass container of the final shape to a cooling mold and cooling the same.
1. A method for manufacturing a glass container comprising steps (A) to (E);
(A) A step of introducing a gob into a mold through a funnel after fitting the funnel to the mold,
(B) A step of blowing air into the mold through the funnel, bringing a plunger disposed on a side opposite the side to which the funnel is fitted in contact with the gob, separating the plunger from the gob, and forming a recess on the surface of the gob, the recess formed on the surface of the gob having a maximum diameter of a value within the range of 4 to 24 mm and a depth of a value within the range of 3 to 10 mm,
(C) A step of removing the funnel from the mold and fitting a baffle to the mold,
(D) A step of blowing air from the plunger, and forming an inner space inside the gob with the recess as a starting point while simultaneously forming an outer shape by pressing the outer side of the gob to a molding surface of the mold to obtain a glass container of the final shape, wherein
the inner space formed inside the gob includes a passage portion formed in communication with the outside and an accommodating portion formed continuously from the innermost end portion of the passage portion,
the passage portion has a cylindrical shape and the accommodating portion has a spherical shape,
the following relational expression (1) is satisfied in a case where the passage portion has a cylinder diameter C (mm) and the accommodating portion has a sphere diameter B (mm)
7≤ B−C≤ 15 (1),
(E) A step of transferring the glass container of the final shape to a cooling mold and cooling the same.
2. The method for manufacturing a glass container according to claim 1 , wherein the cylinder diameter C is a value within the range of 4 to 24 mm and the sphere diameter B is a value within the range of 11 to 39 mm.
3. The method for manufacturing a glass container according to claim 1 , wherein the ratio of the volume of the inner space is a value within the range of 15 to 30 vol % in a case where the volume of the glass part of the glass container of the final shape is 100 vol % in step (D).
4. The method for manufacturing a glass container according to claim 1 , wherein a glass container of the final shape is formed further having a second inner space at a position facing a first inner space in a case where the inner space is defined as the first inner space in step (D) by a baffle having a projecting molding surface part being used as the baffle in step (C).
5. The method for manufacturing a glass container according to claim 1 , wherein the air blown from the plunger in step (D) has a pressure of a value within the range of 1.5 to 3 kPa and the duration of the air blowing is a value within the range of 1.04 to 1.25 seconds.