Preheating and thermoforming polysulfone membrane into orthodontic appliance

Abstract

A method includes preheating a feedstock film of polysulfone (PSU), polyphenylsulfone (PPSF or PPSU) or polyethersulfone (PES) in an oven at a temperature of 350 DEG F to 450 DEG F for 30 to 200 seconds to produce a moisture-free film, the feedstock film being in the form of a web, sheet or disc, cutting the moisture-free film into pieces, and thermoforming each moisture-free piece to produce an orthodontic appliance.

Description

[0001] Inventors:

[0002] T. Grovik

[0003] applicant

[0004] Bixby International Inc.

[0005] Newburyport, Massachusetts

[0006] USA

[0007] Government Interest Statement

[0008] none.

[0009] CROSS-REFERENCE TO RELATED APPLICATIONS

[0010] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 373,434, filed on August 24, 2022, the disclosure of which is incorporated herein by reference in its entirety. Background Art

[0011] The present invention relates generally to dental braces and, more particularly, to preheating and thermoforming polysulfone films into dental braces.

[0012] Like traditional braces, dental braces are designed to move teeth a little at a time. Braces are plastic replicas of your teeth. Wearing the braces puts gentle pressure on your teeth, which slightly repositions them. Dental braces can be clear or opaque. Clear braces are one of many technological advances that have made orthodontic treatment less noticeable, and are one of many appliances orthodontists use to move teeth and straighten jaws.

[0013] Dental braces are made of sheets of membrane that easily absorb moisture from the air and change shape. This change in shape can affect the function of these dental braces. Therefore, a method is needed to help minimize moisture accumulation when these dental braces are molded. Summary of the invention

[0014] The following is a simplified summary of the innovation to provide a basic understanding of some aspects of the present invention. This summary is not a comprehensive description of the present invention. Its intention is neither to identify the main or key elements of the present invention nor to delimit the scope of the present invention. Its sole purpose is to introduce some concepts of the present invention in a simplified form as a prelude to a more detailed description later.

[0015] In one aspect, the present invention provides a method comprising preheating a raw film of polysulfone (PSU), polyphenylsulfone (PPSF or PPSU) or polyethersulfone (PES) in an oven at a temperature of 350°F to 450°F for 30 to 200 seconds to produce a moisture-free film, wherein the raw film is in the form of a roll, sheet or disc, cutting the moisture-free film into small pieces, and thermoforming each moisture-free film small piece to produce a dental brace.

[0016] These and other features and advantages will be apparent from a reading of the following detailed description and an overview of the associated drawings.It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of the aspects claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] These and other aspects will now be described in detail with reference to the accompanying drawings, in which:

[0018] Figure 1 Exemplary dental appliances made using non-preheated polysulfone (PSU), polyphenylsulfone (PPSF or PPSU), or polyethersulfone (PES) membranes are shown.

[0019] Figure 2 Exemplary dental appliances made using preheated polysulfone (PSU), polyphenylsulfone (PPSF or PPSU), or polyethersulfone (PES) membranes are shown. DETAILED DESCRIPTION

[0020] The subject matter of the present invention is now described with reference to the accompanying drawings, wherein like reference numerals are used to refer to like elements throughout the text. In the following description, for the purpose of explanation, many specific details are listed to provide a comprehensive understanding of the present invention. However, it is clear that the present invention can be implemented without these specific details. In other cases, well-known structures and devices are shown in block diagram form to facilitate the description of the present invention.

[0021] As used herein, the term "dental braces" refers to plastic orthodontic appliances that are shaped to fit over one's teeth and are used to correct or adjust one's dental alignment. Dental braces can be made from a variety of plastic materials, which can be opaque, transparent, translucent, opaque, or a combination thereof.

[0022] As used herein, polysulfone (PSU) refers to any of a class of resinous organic compounds belonging to the polymer family, the main structural chain of which most commonly includes a sulfonyl group (“-SO 2 -”), ether group (“-O-”), and isopropylidene group (“-C(CH 3 ) 2 -”) groups connected together to form a benzene ring.

[0023]

[0024] PSU is a high temperature resistant, amber, translucent plastic material with good mechanical properties. Polysulfone resists degradation from hot water and steam and is often used in medical and food preparation applications that require repeated sterilization.

[0025] As used herein, polyphenylenesulfone (PPSF or PPSU) is a polyphenylenesulfone having an aromatic ring connected by a sulfone (SO 2 ) groups connected. PPSF is a plastic plastic commonly used in rapid prototyping and rapid manufacturing (direct digital manufacturing) applications.

[0026] As used herein, polyethersulfone (PES) is a transparent, high-performance polymer known for its dimensional stability at elevated temperatures in air and water.

[0027] The present invention provides a method for extracting moisture from a PSU film, a PPSU film or a PES film to obtain a substantially moisture-free film, the method comprising preheating the film in an oven at a temperature of about 350°F to about 450°F for at least 30 seconds but not more than 200 seconds.

[0028] One preferred embodiment provides a method wherein the film is in the form of a roll, sheet or disc, each having a width of about 4 inches to about 6 inches and a length of about 10 feet to about 500 feet, and having a thickness of about 15 mils to about 40 mils.

[0029] Another preferred embodiment provides a method wherein the film is in the form of a roll having a width of about 5 inches and a length of about 25 feet to about 100 feet. Another preferred embodiment provides a method wherein the film is in the form of a roll having a width of about 5 inches and a length of about 25 feet to about 60 feet.

[0030] Another preferred embodiment provides a method comprising preheating the film in an oven at a temperature of about 400°F to about 420°F for at least 75 seconds but not more than 125 seconds. Another preferred aspect of this embodiment provides a method comprising preheating the film in an oven at a temperature of 410°F for 90 seconds.

[0031] Another embodiment provides a method, wherein the film is in the form of a coil, and further, wherein the preheating furnace includes an accumulator section to keep the film in a dry state. Another preferred embodiment provides a method, wherein the moisture-free film is cut into round pieces with a diameter of about 4 to about 6 inches. Another preferred embodiment provides a method, wherein the moisture-free film is cut into round pieces with a diameter of about 5 inches.

[0032] Another aspect of the present invention provides a method for thermoforming a moisture-free film sheet using an apparatus capable of punching a circular sheet into a dental appliance. Another preferred embodiment provides a method wherein the circular film sheet has a thickness of about 15 mils to about 40 mils. Another preferred embodiment provides a method wherein the circular film sheet has a thickness of about 20 mils.

[0033] The present invention utilizes an oven that includes a chamber with a belt mechanism that is capable of moving the film through the oven while heating the film to temperatures up to 500° F. These ovens can be custom manufactured to meet the specific requirements of the user.

[0034] The present invention also utilizes a thermoforming process for processing a disk into a dental appliance, e.g. This is a pressure forming machine that has many applications in tooth pressure forming and orthodontics.

[0035] Films in roll form can also be processed into dental braces using similar techniques.

[0036] like Figure 3 As shown, method 300 includes preheating (310) a raw film of PSU, PPSU or PES in an oven at a temperature of 350°F to 450°F for 30 to 200 seconds to produce a moisture-free film, the raw film may be in the form of a roll, sheet or disc.

[0037] The method 300 cuts ( 315 ) the moisture-free film into small pieces.

[0038] The method 300 performs a thermoforming process (320) on each moisture-free sheet to produce a dental appliance.

[0039] Although only a few embodiments have been described in detail above, other modifications may be made. All such modifications are intended to be covered by the following claims.

Claims

1. A method comprising: Preheating a raw film of polysulfone (PSU), polyphenylsulfone (PPSF or PPSU) or polyethersulfone (PES) in an oven at 350°F to 450°F for 30 to 200 seconds to produce a moisture-free film, the raw film being in the form of a roll, sheet or disc, Cut the moisture-free film into small pieces, and Each moisture-free sheet is thermoformed to produce a dental aligner.

2. The method of claim 1, wherein: The dental braces are orthodontic appliances that are shaped to be worn on teeth to correct or adjust tooth alignment.

3. The method of claim 1, wherein: The raw material film is one of a class of resin organic compounds belonging to the polymer family, and its main structural chain most commonly includes benzene rings connected by sulfonyl (-SO2-), ether (-O-) and isopropyl (-C(CH3)2-) groups.

4. The method of claim 1, wherein: The coils, sheets and discs each have a width of 4 inches to 6 inches, a length of 10 feet to 500 feet, and a thickness of 15 mils to 40 mils.

5. The method of claim 1, wherein: The raw film is in the form of a roll having a width of 5 inches and a length of 25 feet to 100 feet.

6. The method of claim 1, wherein: The raw film is in the form of a roll having a width of 5 inches and a length of 25 feet to 60 feet.

7. The method of claim 1, wherein: The preheating is performed in an oven at a temperature of 400°F to 420°F for 75 to 125 seconds.

8. The method of claim 1, wherein: The preheating was performed in an oven at 410°F for 90 seconds.

9. The method of claim 1, wherein the oven includes a reservoir portion to maintain the film in a dry state.

10. The method of claim 1, wherein: The oven includes a chamber with a belt mechanism designed to move the raw film through the oven while heating the film to temperatures up to 500°F.

11. A method comprising: Preheating a raw polyphenylsulfone (PPSU) film in an oven at a temperature of 350°F to 450°F for 30 to 200 seconds to produce a moisture-free PPSU film, the raw PPSU film being in the form of a roll, sheet or disc, Cut the moisture-free PPSU film into small pieces, and Each moisture-free sheet is thermoformed to produce a dental aligner.

12. The method of claim 11, wherein: The preheating is performed in an oven at a temperature of 400°F to 420°F for 75 to 125 seconds.

13. The method of claim 11, wherein: The preheating was performed in an oven at 410°F for 90 seconds.

14. The method of claim 11, wherein the oven includes a reservoir portion to maintain the film in a dry state.

15. The method of claim 11, wherein: The oven includes a chamber with a belt mechanism designed to move the raw film through the oven while heating the film to temperatures up to 500°F.

16. A method comprising: Preheating a raw polyethersulfone (PES) film in an oven at 350°F to 450°F for 30 to 200 seconds to produce a moisture-free PES film, the raw PES film being in the form of a roll, sheet or disc, Cut the moisture-free PES membrane into small pieces, and Each moisture-free sheet is thermoformed to produce a dental aligner.

17. The method of claim 16, wherein: The preheating is performed in an oven at a temperature of 400°F to 420°F for 75 to 125 seconds.

18. The method of claim 16, wherein: The preheating was performed in an oven at 410°F for 90 seconds.

19. The method of claim 16, wherein the oven includes a reservoir portion to maintain the film in a dry state.

20. The method of claim 16, wherein: The oven includes a chamber with a belt mechanism designed to move the raw film through the oven while heating the film to temperatures up to 500°F.

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