A daily glass bottle and can ultra-lightweight forming process

Abstract

This invention provides an ultra-lightweight molding process for daily-use glass bottles and jars. A rotary press is used to cool molten glass through a mold to obtain glass bottles and jars. The molten glass is then pressed through a preliminary mold and transferred to a final mold for final shaping using a pressure blow molding process. A small-mouth punch is used during the preliminary mold pressing. The punch is divided into a working section and a fixed section. The working section has a top diameter of 13.798 mm, a bottom diameter of 18.74 mm, and a thickness of 2.2 mm. A cooling core is installed inside the punch, also divided into a working section and a fixed section. The working section has a bottom diameter of 10 mm and a top diameter of 4.8 mm. A 2.2 mm diameter vent is located at the top of the working section, and multiple vents are located on the sidewalls. Compared to existing technologies, this invention reduces the amount of raw materials used in glass bottle and jar production, lowers the weight of the bottles and jars, improves the yield rate, and allows for a larger internal capacity within the same volume.

Description

Technical Field

[0001] This invention belongs to the field of glass bottle and jar production technology, specifically relating to an ultra-lightweight molding and processing technology for daily-use glass bottles and jars. Background Technology

[0002] Glass bottles and jars are widely used in the packaging industry, especially for beverages such as beer, fruit tea, and jujube juice, due to their non-toxic, odorless, transparent, aesthetically pleasing, barrier properties, airtightness, abundant and readily available raw materials, low price, and reusability. They also possess advantages such as heat resistance, pressure resistance, and washability. They can be sterilized at high temperatures or stored at low temperatures. Because glass bottles and jars are made from more than a dozen raw materials, including crushed glass, soda ash, sodium nitrate, barium carbonate, and quartz sand, through processes such as melting and shaping at 1600 degrees Celsius, they are inherently heavy, significantly impacting transportation and usage costs. Therefore, weight reduction is crucial, necessitating research into ultra-lightweight glass bottles and jars. Existing glass bottles and jars are generally manufactured using either blow-blown or press-blown methods. Blow-blown involves feeding molten glass into a glass forming mold, where it is blown twice—once in the initial mold and once in the final mold—to achieve the desired shape. Because of this two-stage blowing process, the wall thickness of the glass bottles and jars is somewhat random. Blow-blown is suitable for manufacturing thicker bottles and jars, but when the bottle body is thinner, the thickness variation is significant, potentially leading to uneven bottle strength. Press-blown, on the other hand, involves first pressing molten glass into a preliminary mold to create a basic shape, and then transferring it to the final mold for further blowing. Bottles and jars manufactured using press-blown have a uniform thickness, ensuring consistent strength even when the bottle body is thin. Therefore, press-blown is generally used to produce thinner glass bottles and jars. In other words, press-blown is the optimal choice for achieving ultra-lightweight everyday glass bottles and jars. However, in the initial molding process of the pressure blow molding method, the punch used is generally close to a cone shape with a large flare, which is suitable for making glass bottles and jars with large mouths. It is difficult to use the pressure blow molding method to manufacture small-mouthed bottles such as beer bottles and beverage bottles. Although there are some small-mouth pressure blow molding technologies now, how to ensure the strength of the bottle body when making small-mouthed glass bottles and jars is a problem that needs to be solved for the ultra-lightweighting of daily-use glass bottles and jars. Summary of the Invention

[0003] To address the above problems, this invention provides an ultra-lightweight molding process for everyday glass bottles and jars. The process employs a pressure blow molding technique to form the glass bottles and jars. By improving and upgrading the initial mold punch and cooling core, and by specially designing the inner cavity of the initial mold, the glass bottles and jars can achieve a lighter weight.

[0004] The process provided by this invention involves using a rotary press to heat molten glass through a mold to form and cool glass bottles and jars. According to the glass bottle and jar production process, the raw materials for glass production are prepared according to a predetermined ratio and then fed into a furnace for heating and melting to form molten glass. The molten glass is then fed into the rotary press for forming. The mold forming process uses pressure blow molding. First, the molten glass is injected into a preliminary mold for initial pressing to form a bottle preform. Then, it is transferred to a final mold for blowing expansion and final shaping. During the preliminary mold pressing, the bottle preform is formed mainly through the cooperation of the preliminary mold and the punch. The inner cavity of the preliminary mold is divided into two parts: a pouring cavity and a bottle cavity. The pouring cavity is located above the bottle cavity, through which the molten glass enters the bottle cavity. Then, the end cap seals the pouring cavity from above, and the punch extends into the bottle cavity. Under the interaction of the bottle cavity and the punch, the molten glass forms a hollow bottle preform that fits the inside of the bottle cavity. To reduce the weight of the glass bottles, a small-mouth punch is used during the initial molding process. The punch is hollow inside with an opening at the bottom and consists of a working section and a fixed section, with the working section located above the fixed section. The working section has a top diameter of 13.798 mm, a bottom diameter of 18.74 mm, and a thickness of 2.2 mm. Inside the punch is a hollow cooling core, also divided into a working section and a fixed section, with the working section above the fixed section. The working section has a bottom diameter of 10 mm and a top diameter of 4.8 mm, with a 2.2 mm diameter vent at the top. Multiple vents are located along the axial direction on the sidewall of the working section. After the preform is formed, cooling gas is introduced into the cooling core. The cooling gas flows through the vents into the punch, reducing the punch temperature and consequently lowering the preform temperature. To improve the cooling efficiency of the cooling core, there are four vents per row on the sidewall of the working section, with a 45° angle difference between adjacent rows and a 2 mm spacing between each row.

[0005] To ensure uniform thickness of the glass bottles, the preforms need to have a more suitable shape after pressing, allowing for more even expansion during blow molding. Therefore, the dimensions of the initial mold cavity need to be improved. The cavity length is 109mm, with a mouth diameter of 25.4mm, a waist diameter of 37mm, a shoulder diameter of 44mm, a bottom diameter of 50mm, and a base diameter of 44.5mm. The distance from the shoulder to the mouth is 29mm. After these improvements, the internal capacity of the initial mold is significantly reduced, allowing for a maximum injection weight of 175-180g of molten glass per cycle.

[0006] The present invention has the following advantages over the prior art: (1) By improving the initial mold, the inner cavity capacity is reduced, and the weight of the glass liquid injected each time is greatly reduced, so that the weight of the finished glass bottles and jars is reduced by 18.5-20% compared with the existing process. This reduces the amount of raw materials used in the production of glass bottles and jars, reduces the demand for natural resources, and at the same time, the reduction in bottle weight reduces transportation costs, making the use of glass bottles and jars more convenient.

[0007] (2) A complete glass bottle and jar small-mouth press blow process has been formed, which can be applied to the production and manufacturing of other types of glass bottles and jars by adjustment.

[0008] (3) The quality of the finished glass bottles and jars produced has been greatly improved. The probability of the bottle shoulder cracking phenomenon has been greatly reduced, which has improved the qualification rate of the glass bottles and jars. The thickness of the bottle body has been reduced while maintaining good strength, preventing the glass bottles and jars from cracking during transportation and use, and also allowing the glass bottles and jars to have a larger internal capacity under the same volume. Attached Figure Description

[0009] The present invention will now be described in further detail with reference to the accompanying drawings.

[0010] Figure 1 This is a schematic diagram of the punch structure for the initial mold; Figure 2 This is a schematic diagram of the cross-sectional structure of the punch in the initial mold; Figure 3 This is a schematic diagram of the cross-sectional structure of the cooling core of the initial mold; Figure 4 for Figure 3 Enlarged schematic diagram of the structure of section A in the middle; Figure 5 This is a schematic diagram of the internal cavity structure of the initial mold. Detailed Implementation

[0011] To further illustrate the concept of the present invention, the specific embodiments of the present invention will be further described below with reference to the accompanying drawings: Example 1

[0012] A lightweight molding process for everyday glass bottles and jars involves forming molten glass using pressure blow molding, which includes initial mold pressing and final blow molding. The weight of molten glass injected into the initial mold each time is 180g. The initial mold has an inner cavity divided into a pouring cavity and a bottle cavity. The pouring cavity is located above the bottle cavity, which is 109mm long. The bottle cavity has a mouth diameter of 25.4mm, a waist diameter of 37mm, a shoulder diameter of 44mm, a bottom diameter of 50mm, and a bottom surface diameter of 44.5mm. The distance from the shoulder to the mouth of the bottle cavity is 29mm. Figure 5 As shown.

[0013] The punch is divided into a working section and a fixed section. The working section is located above the fixed section. The top diameter of the working section is 13.798 mm, the bottom diameter is 18.74 mm, and the thickness of the working section is 2.2 mm. Figure 1 , 2 As shown. The cooling core is divided into a working section and a fixed section. The working section is located above the fixed section. The bottom diameter of the working section is 10mm and the top diameter is 4.8mm. A 2.2mm diameter vent is opened at the top of the working section. Multiple vents are arranged along the axial direction on the sidewall of the working section. There are four vents per row on the sidewall of the working section, with a 45° angle difference between adjacent rows and a 2mm spacing between each row. Figure 3 , 4 As shown. Example 2

[0014] A lightweight molding process for everyday glass bottles and jars involves forming molten glass using pressure blow molding, which includes initial mold pressing and final blow molding. The weight of molten glass injected into the initial mold each time is 175g. The initial mold has an inner cavity divided into a pouring cavity and a bottle cavity. The pouring cavity is located above the bottle cavity, which has a length of 109mm. The bottle cavity has a mouth diameter of 25.4mm, a waist diameter of 37mm, a shoulder diameter of 44mm, a bottom diameter of 50mm, and a bottom surface diameter of 44.5mm. The distance from the shoulder to the mouth of the bottle cavity is 29mm.

[0015] The punch is divided into a working section and a fixed section. The working section is located above the fixed section. The top diameter of the working section is 13.798 mm, the bottom diameter is 18.74 mm, and the thickness of the working section is 2.2 mm. The cooling core is also divided into a working section and a fixed section. The working section is located above the fixed section. The bottom diameter of the working section is 10 mm, the top diameter is 4.8 mm, and a 2.2 mm diameter vent is opened at the top of the working section. Multiple vents are arranged along the axial direction on the sidewall of the working section. There are four vents per row on the sidewall of the working section of the cooling core. The angle between adjacent rows of vents differs by 45°, and the spacing between each row of vents is 2 mm.

[0016] Control Group 1 The glass bottles and jars are made using the blow-blown method. The weight of the molten glass injected into the initial mold each time is 220g. The inner cavity of the initial mold is divided into a pouring cavity and a bottle cavity. The pouring cavity is located above the bottle cavity. The length of the bottle cavity is 112mm. The diameter of the bottle cavity is 25.7mm at the mouth, 37.3mm at the waist, 44.1mm at the shoulder, 49.7mm at the bottom, and 44.2mm at the bottom surface. The distance from the shoulder to the mouth of the bottle cavity is 22mm.

[0017] In the above embodiments, Examples 1 and 2 were manufactured using the methods provided in this invention, while Control Group 1 used existing molds and processes to manufacture glass bottles and jars via a blow-blowing method. The glass bottles and jars manufactured in the three groups were tested and their strength compared. The results are shown in the table below:

[0018] As shown in Table 1, the glass bottles and jars manufactured using the process provided by this invention achieve a weight reduction of 18.18% to 20.45%, while effectively improving the shoulder breakage rate and increasing the product qualification rate. Simultaneously, the internal volume is further increased while maintaining a lighter weight. Compared to existing technologies, the ultra-lightweight molding process for daily-use glass bottles and jars provided by this invention effectively reduces bottle weight while ensuring bottle strength, while maintaining the same bottle body strength. The use of small-mouth press-blown technology overcomes the problem that small-diameter glass bottles and jars cannot be processed using press-blown technology, allowing for the widespread application of press-blown technology.

[0019] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Various modifications and variations can be made by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made using the present invention should be included within the protection scope of the present invention.

Claims

1. A lightweight molding process for daily-use glass bottles and jars, comprising using a rotary press to form and cool molten glass through a mold to obtain glass bottles and jars, wherein the mold forming is performed by pressure blow molding, and the molten glass is pressed through a preliminary mold and then transferred into a final mold for final shaping, characterized in that: When the molten glass is pressed into the initial mold, a small-diameter punch is used. The punch is hollow inside and has an opening at the bottom. The punch is divided into a working section and a fixed section. The working section is located above the fixed section. The top diameter of the working section is 13.798 mm, the bottom diameter is 18.74 mm, and the thickness of the working section is 2.2 mm. A hollow cooling core is also provided inside the punch. The cooling core is divided into a working section and a fixed section. The working section is located above the fixed section. The bottom diameter of the working section is 10 mm, the top diameter is 4.8 mm, and the top of the working section has a 2.2 mm diameter air hole. The side wall of the working section has multiple air holes along the axial direction. There are 4 air holes per row on the side wall of the working section of the cooling core. The angle between two adjacent rows of air holes differs by 45°, and the spacing between each row of holes is 2mm. The inner cavity of the initial mold is divided into a pouring cavity and a bottle cavity. The pouring cavity is located above the bottle cavity. The length of the bottle cavity is 109mm, and the diameter of the mouth of the bottle cavity is 25.4mm, the diameter of the waist is 37mm, the diameter of the shoulder is 44mm, the diameter of the bottom is 50mm, and the diameter of the bottom surface is 44.5mm. The distance from the shoulder to the mouth of the bottle cavity is 29mm; During the pressure blow molding process, the weight of the molten glass injected each time is 175-180g.

2. The ultra-lightweight molding and processing technology for daily-use glass bottles and jars according to claim 1, characterized in that: During the pressure blow molding process, the weight of the molten glass injected each time is 175g.

Images