Patent Application
20220388739
Self-sealing closures for containers made of flexible materials are known in the art. The closures commonly have a flexible valve that is opened when a squeeze force is applied to the container creating a pressure that exceeds a threshold. This squeeze to open configuration is convenient as it allows consumers to dispense products with one hand and removes the step of opening and closing a cap. There are many examples of valves used in self-sealing closures. U.S. Pat. No. 4,988,016 to Hawkins describes a valve created from two sheets of flexible material heat welded together to form a channel. Squeezing the flexible package causes the channel to open into an ellipse shape allowing passage of the product from the container. Although this may be a low cost seal it is not a particularly effective seal as it may leak or allow the contents to be exposed to the outside environment. U.S. Pat. No. 6,050,435 to Randall G. Bush et al., describes a silicon seal with a slit that is opened by applying a squeeze force to the container. A slit in a flexible gasket is not ideal as it restricts the flow rate particularly for viscous fluids such as pastes and creams. Attempts to increase the flow rate, by increasing the size of the opening or varying the hardness of the elastomer reduce the effectiveness of the seal. U.S. Pat. No. 6,079,594 to Brown et al. describes a self-sealing closure having a marginal flange and a head portion with an orifice extending therethrough, which opens to permit fluid flow therethrough in response to pressure. This has the disadvantage of complexity and is not suitable for low cost applications.
A low cost, highly reliable self-closing airtight seal is needed.
To this end, embodiments of the present disclosure include a sealing closure for dispensing fluid. The sealing closure includes a closure body. The closure body has an attachment portion configured to attach to a container containing fluid, a dispensing portion, and a conduit connecting the attachment portion and dispensing portion and configured to direct fluid from the attachment portion to the dispensing portion. The sealing closure further includes a spring lid attached to the dispensing portion. The spring lid has a first portion coupled to the closure body, a second portion not attached to the closure body. The second portion is configured to contact the closure body when a pressure of the fluid is below a threshold, and flex to separate from the closure body when the pressure of the fluid meets or exceeds the threshold to create an opening for dispensing the fluid.
In some embodiments, the sealing enclosure includes a flexible seal on the dispensing portion of the closure body, the flexible seal being configured to contact the second portion of the spring lid when the pressure of the fluid is below the threshold. In some embodiments, the flexible seal is composed of thermoplastic elastomer (TPE). In some embodiments, the sealing enclosure includes a first part of the flexible seal that is attached to the second portion of the spring lid, and is configured to contact the second portion of the spring lid when it flexes to separate from the closure body when the pressure of the fluid meets or exceeds the threshold, and a second part of the flexible seal that is not attached to the second portion of the spring lid and creates the opening when the second portion of the spring lid flexes to separate from the closure body when the pressure of the fluid meets or exceeds the threshold. In some embodiments, the spring lid is composed of aluminum. In some embodiments, the sealing enclosure includes a chamber at the dispensing portion of the closure body, and a rim surrounding the chamber that contacts the spring lid. In some embodiments, the rim is composed of polypropylene. In some embodiments, the spring lid has a layer of polypropylene on a side configured to contact the rim, the layer of polypropylene coupling the spring lid to the rim in the first portion. In some embodiments, pressure that meets or exceeds the threshold can be generated by a human hand squeezing a container attached to the sealing closure.
Some embodiments include a fluid vessel comprising: the sealing closure coupled to the container containing the fluid. In some embodiments, the sealing closure is coupled to the container by threads in the conduit. In some embodiments, the sealing closure is welded to the container. In some embodiments, the sealing closure is riveted to the container.
The present disclosure describes various embodiments of closures having a flexible valve that is closed below a threshold squeeze force applied to the container. Reducing the volume of the container by squeezing, results in achieving a sufficient pressure buildup that enables dispensing of a product (i.e. a pressure threshold). The fluent product in the various embodiments may be contained in a plastic or aluminum tube, a flexible standup package or the like that is able to be squeezed (i.e. a container). The container may be configured to screw onto a thread or may be riveted, glued, co-molded etc. to the sealing closure.
The sealing closure includes a chamber, seal, and spring lid. Varying the dimensions of the chamber, seal and spring lid allow an infinite range of flow rates and required squeeze forces, without jeopardizing the integrity of the seal. In some embodiments, the squeeze forces to open the valve can be generated by a human hand squeezing the container of fluid. Embodiments of the seal provide a barrier able to withstand atmospheric moisture (75% relative humidity at 30° C.) for 3 months. This would prevent the container contents either drying out or becoming damp for this period, whilst also allowing easy dispensing.
In one embodiment the sealing closure is configured to screw onto a thread which is integrated into a container. The closure body may be manufactured from polypropylene and co-molded with thermoplastic elastomer (TPE) which is located in at least one part of the rim of a chamber of the closure body. A leaf spring composed of spring aluminum (or other metal) with a coating of polypropylene (or other polymer) on one side is heat welded in place over the chamber exit. A thin film is laid on the TPE to prevent the TPE welding to the lid in the exit area. The film can be a dissimilar polymer that does not weld to polypropylene. This protective film is removed after the heat welding step. During welding the lid is welded around the chamber opening which includes a portion of the TPE either side of the opening. This improves the seal and prevents escape of the product during dispensing. The resultant opening creates a single stream, which improves the dispensing and the ability of the seal to shut off the flow of product when it closes. In other embodiments, the opening is configured to provide multiple streams.
Thread 1b can be used to attach the closure to a container containing the fluid (see
When the fluid is not under pressure, the second portion of lid 2 that is not attached to the closure body rests in contact with the closure body or the seal 3. When resting in contact with seal 3, the spring lid 2 forms a sealing contact with seal 3. This sealing contact prevents ingress or egress of atmospheric gases and moisture, or the contained fluid.
In some embodiments, the opening is configured to open to a predetermined size for a variety of pressures. In other embodiments, the opening is configured to expand to a greater size in proportion to the applied pressure, to accommodate variable flow rates. Moreover, the size of the opening can be adjusted depending on the viscosity of the fluid product to be dispensed, and the generally desired amount needed per use. For example, a container of sunscreen may have a larger opening for large volume dispensation of the product, whereas an ointment container may have a smaller opening for dispensing a small portion. Similarly, an opening for toothpaste may be larger (even given the smaller amount needed) because the large opening facilitates a reasonable flow speed with the high viscosity of the fluid.
The closure can also be configured to open in response to different pressures depending on the target user. For example, in a container for operation by a toddler or child, the pressure threshold for dispensing fluid may be lower than a container for operation by an adult. Similarly, in a container for operation by an elderly or arthritic person, the pressure threshold may be lower than a container for operation by a healthy adult.
Although the invention has been described with reference to embodiments herein, those embodiments do not limit the scope of the invention. Modifications to those embodiments or different embodiments may fall within the scope of the invention.
