A PET bottle and its cap that utilize the sealing principle of a sphere and the inner surface of a cone.

Abstract

Conventional PET bottles and caps often have a structure that uses flexible materials that are deformed to create a tight seal, which requires torque to open and close, and also presents challenges in recycling due to differences in materials. [Solution] This invention features a cap or bottle neck with a spherical or conical inner surface shape, achieving self-centering and sealing simultaneously through geometric contact between the two. This results in high airtightness even when using the same rigid material (e.g., PET), improving operability, recyclability, and appearance.

Description

Technical Field

[0006] , Both of these are needed for airtight sealing. , target , accuracy , This way of thinking is deeply ingrained in the industry. , Non , of , That is , , Caused by dimensional differences , Even against , sex , and , in , by , this , It has been taken for granted that it should be structured. , mainly

[0001] The present invention relates to the rationalization of the cap of a resin container, a PET bottle.

Background Art

[0002] Conventional PET bottles Due to manufacturing variations and geometric errors, a gap may form between the bottle neck and the cap, in order to ensure airtightness. soft packing or, cap bottle softer Composed of materials, adopt a structure that physically compresses the gap by the tightening force and material deformation.

[0003] Such a structure 、 In addition to geometric constraints that prevent axial misalignment and ensure parallelism of contact surfaces, manufacturing variations also play a role. 、 Insufficient material deformation and tightening force can lead to leakage. 。<� For users with less strength, such as the elderly or children, opening and closing the door was particularly difficult.

[0004] Because the cap is made from a different material than the bottle, material separation is required in the recycling process, which presents environmental challenges such as increased effort and cost.

[0005] In the sealing problem of PET bottles, it is Completely [[]END]]coaxial or both end faces completely parallel To bring it into contact with theory target [[]END]]impossible <000003![[]END]]。 this fundamental Conventional constraints were not adequately considered, and there was a tendency to simplistically understand that the cause of sealing failures was simply due to variations in manufacturing precision. hard The container take a hard This way of thinking is deeply ingrained in the industry. soft and lid and like hard quality bottle Even against make the cap with a flexible material It has been taken for granted that it should be structured. 。

[0006] Conventional PET bottle caps in have two types of gaps due to the axial misalignment between the cap and the bottle , and the bottom surface of the cap and the mouth surface of the bottle and of Non parallel sex caused by Geometric and the gaps due to the variation in manufacturing accuracy caused by Caused by dimensional differences the gaps of mainly two types The factors are present. 。 Both of these are needed for airtight sealing. These gaps of affect the tightening by deformation of the cap Therefore, they need to be absorbed at the same time. 、 If it is not tightened with sufficient force, Sealed Bad or Liquid leakage This is likely to occur. 。

[0007] Cap and plastic bottle but Different It is made up of materials In the case of recycling Sorting becomes necessary, and the collection process becomes more complicated. Recycling Processing Cost This was hindering the reduction of environmental impact and the improvement of resource recycling efficiency. 。

Summary of the Invention

Problems to be Solved by the Invention

[0008] Geometry target Contact structure of spherical surface and conical inner surface that is easy to seal Adopt The tightening force While reducing The cap and The bottle Same With the material By making it possible to manufacture 、 The challenge is to achieve both recyclability and convenience. 。

Means for Solving the Problems

[0009] In this invention 、The cap and the bottle In relation to the bottle opening Geometrically By adopting a spherical and conical inner surface structure that facilitates positioning and sealing, 、 This allows for natural positioning at the same time as tightening. 、 Geometric errors caused by axial misalignment and tilt can be reduced. 。 This 、Sealing of the bottle and the cap sex To Without relying on material deformation of the cap as in conventional methods 、 This can be achieved through geometric structures. 。

[0010] The contact between the sphere and the inner surface of the cone naturally provides a positioning function. 、 Cap and bottle neck On the spherical surface and the conical inner surface By contacting 、 The cap is automatically guided into a coaxial position during the tightening process, correcting any misalignment (axial misalignment or tilt). 。 This 、 This allows for a sealed structure that primarily targets only the minute gaps caused by manufacturing variations. 。 Also 、Spherical surface and The conical surface is a basic geometric shape Therefore 、 Processing Easy and 、 Because manufacturing tolerances can be kept relatively small, Only a slight Tightening force and Elastic deformation of PET resin enables sufficient sealing, and the burden of the tightening operation is also reduced.

Effects of the Invention

[0011] Structure of the inner surface of a sphere and a cone by , cap and bottle It can be positioned precisely. , This allows for minimizing the deformation of the material used to fill the gaps. child As a result, the tightening force of the cap seal is reduced. Convenience As it improves This is also advantageous for the manufacturing process.

[0012] cap Because there are few deformation requirements, The cap can also be manufactured from the same material as the bottle (PET). This eliminates the need to separate caps and bottles during recycling, saving time and effort, reducing costs, and improving the quality of recycled PET.

[0013] The cap requires less deformation. Nari , Transparent and resistant to deformation Made from PET material too Because we can make caps, we can simplify the screw-on structure of the cap and bottle. Furthermore, improvements such as shortening the cap engagement length become possible. Conventionally product plastic bottles and The design of that cap Sex manufacturing Sexual performance can be improved . [Brief explanation of the drawing]

[0014] [Figure 1] This diagram illustrates the contact between the spherical surface and the inner surface of the cone. Geometrically, the sphere inside the cone forms a circular contact area with the cone's surface, naturally creating a sealed structure that encloses the upper and lower spaces within the cone.

[0015] [Figure 2]This diagram illustrates the relationship between different cone angles and the corresponding spherical diameters, schematically showing the differences in cone angles (30 degrees, 45 degrees, and 60 degrees) in the contact structure between the spherical surface and the inner surface of the cone. The contact structure of the present invention is valid only at the point where the spherical surface and the inner surface of the cone geometrically coincide in the normal direction, and at this point the self-positioning function works naturally. When the cone angle is small (30 degrees), the sealing performance and axial misalignment correction effect are enhanced, but the contact stress on the material tends to concentrate, increasing the risk of plastic deformation and breakage. Conversely, when the angle is large (60 degrees), the contact becomes shallower, but the material load is distributed and breakage is less likely. Considering the Young's modulus and Poisson's ratio of PET resin, 45 degrees offers a good balance of sealing performance, self-positioning, and durability, making it suitable for practical design.

[0016] [Figure 3] This is an example of the design of an actual PET bottle neck and its cap, corresponding to Example 1. The cap has a spherical portion, and a portion of the inner surface of a cone, at a 45-degree angle to the axis, is formed on the inside of the bottle neck. As shown in the figure, the contact area for actually sealing the bottle is the spherical portion and the portion of the cone, but the rest of the bottle neck is omitted for the sake of the neck function. The spherical portion of the cap may also be omitted, except for the contact area and its periphery. [Modes for carrying out the invention]

[0017] By providing a spherical surface and a conical inner surface on the cap and bottle neck, respectively, a PET bottle and its cap can be constructed that utilize the sealing principle of the spherical surface on the conical inner surface. Geometrically, the positioning and sealing effect of the spherical surface and the conical inner surface are such that a tight seal between the cap and the bottle can be easily achieved. Furthermore, when closing the cap, the force applied during manufacturing... error Because the gaps caused by the PET material are absorbed by the elastic deformation of the PET material, the cap requires less deformation than conventional methods, resulting in improved convenience with less force required for sealing. Furthermore, since the cap and bottle are made from the same PET material, they are easier to recycle, contributing to cost reduction, resource recovery, and environmental protection. The moderate elastic modulus of PET allows for the absorption of manufacturing errors through minute deformation, resulting in a structure where the spherical portion is pressed against the inner surface of the cone. .

[0018] This invention can be used not only with PET bottles but also with similar containers. [Examples]

[0019] Figure 3 is a diagram illustrating one embodiment, showing an example of a PET bottle and its cap that are sealed by contact between a spherical and a conical surface. [Industrial applicability]

[0020] With 480 billion plastic bottles consumed annually, this product has significantly impacted people's production and lives. Even small improvements in the convenience of using plastic bottles, slight increases in their productivity, and slight improvements in their recycling would have a significant positive impact on improving people's lives, resource recovery, and environmental protection. [Explanation of symbols]

[0021] 1: The inner surface or part of a cone 2: A sphere or a part thereof 3: The neck of the bottle 4: Cap

Claims

1. A PET bottle and its cap that utilize the sealing principle of a sphere and the inner surface of a cone, wherein the parts of the cap or the mouth of the PET bottle that come into contact with each other have a spherical shape on one side and a shape corresponding to the inner surface of a cone on the other side. The characteristic of this invention is that the cap and bottle, having a spherical part and a conical inner surface part, use these parts as contact surfaces to achieve a seal between the cap and the bottle.

2. The PET bottle and its cap described in claim 1 have a structure that allows the cap to be positioned when closed by the contact between a spherical surface and the inner surface of a cone, and this positioning is a geometric positioning that is not affected by the coaxiality of the bottle opening and the cap and the parallelism of the plane, and the PET bottle has a spherical surface and a conical inner surface and can be sealed with little force, so the PET bottle cap is made of the same material as the bottle.

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