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1. (WO2019032564) METHOD AND APPARATUS FOR THERMOFORMING AN ARTICLE
Nota: Texto obtenido mediante procedimiento automático de reconocimiento óptico de caracteres.
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WHAT IS CLAIMED IS:

1. A method of providing a shallow draw thermoformed article, the method comprising

extruding a sheet comprising non-aromatic polymeric materials, conditioning the sheet with an outer surface of a rotating roller and at least a portion of the outer surface that contacts the sheet has a first surface roughness between about 100 Ra (microinches) and about 400 Ra (microinches),

rotary thermoforming the sheet onto a mold to provide an article -blank web after conditioning the sheet, and

cutting the article-blank web to provide the shallow draw thermoformed article.

2. The method of claim 1, wherein the first surface roughness is about 200 Ra (microinches).

3. The method of claim 1, wherein the cutting stage is performed using a rotary cutter.

4. The method of claim 1, wherein the rotary thermoforming stage includes applying the sheet to a rotary thermoformer, the rotary thermoformer including a rotor mounted to rotate about a rotation axis of the rotary thermoformer, the mold which is coupled to the rotor for rotation therewith, and a curl-blocking strip coupled to the rotor and including a plurality of protrusions that extend radially outward away from the rotor toward the sheet to engage and block the sheet from curling away from the rotor during the rotary thermoforming stage and the method further comprises directing forced fluid toward the rotor at a location aligned axially with the curl-blocking strip.

5. The method of claim 1, wherein the outer surface of the roller includes a first portion that extends circumferentially around the roller and a second portion that extends circumferentially around the roller, the first portion has the first surface roughness, and the second portion has a second surface roughness that is greater than the first surface roughness.

6. The method of claim 5, wherein the roller has a first end and a second end spaced apart axially from the first end relative to a rotation axis of the roller, the second portion is located axially at both the first end and the second end of the roller, and the first portion extends axially entirely between the second portion located at the first end of the roller and the second portion located at the second end of the roller.

7. The method of claim 6, wherein the first surface roughness is about 200 Ra (microinches) and the second surface roughness is about 400 Ra (microinches).

8. The method of claim 7, wherein the shallow draw thermoformed article has a clarity of about or greater than about 50% as measured using ASTM D 1746 and a haze less than about 60% as measured using ASTM D 1003 procedure B.

9. The method of claim 8, wherein the shallow draw thermoformed article is a lid for a drink cup and the non-aromatic polymeric materials include at least polypropylene.

10. A method of providing a shallow draw thermoformed article, the method comprising

extruding a sheet comprising polymeric materials,

conditioning the sheet with an outer surface of a rotating roller and the outer surface of the rotating roller has a surface roughness of less than about 400 Ra (microinches), rotary thermoforming the sheet onto a mold to provide an article -blank web, and cutting the article-blank web to provide the shallow draw thermoformed article having a clarity of about or greater than about 50% as measured using ASTM D 1746 and a haze of about or less than about 60% as measured using ASTM D 1003 procedure B.

11. The method of claim 10, wherein the clarity of the shallow draw thermoformed article is between about 50% and about 95% as measured using ASTM D 1746.

12. The method of claim 11, wherein the clarity of the shallow draw thermoformed article is greater than about 60% as measured using ASTM D 1746 and the haze of the shallow draw thermoformed article is between about 20% and about 40% as measured using ASTM D 1003 procedure B.

13. The method of claim 10, wherein the sheet has an average thickness of less than about 0.012 inches.

14. The method of claim 13, wherein at least a portion of the surface roughness of the outer surface of the rotating roller is between about 100 Ra (microinches) and about 240 Ra (microinches).

15. The method of claim 10, wherein the rotary thermoforming stage includes applying the sheet to a rotary thermoformer, the rotary thermoformer including a rotor mounted to rotate about a rotation axis of the rotary thermoformer, the mold which is coupled to the rotor for rotation therewith, and a curl-blocking strip coupled to the rotor and including a plurality of protrusions that extend radially outward away from the rotor toward the sheet to engage and block the sheet from curling away from the rotor during the rotary thermoforming stage.

16. A method of providing a shallow draw thermoformed article, the method comprising

extruding a sheet comprising polymeric materials, the polymeric materials comprising a polypropylene homopolymer first resin and a polypropylene impact copolymer second resin,

conditioning the sheet with an outer surface of a rotating roller and at least a portion of the outer surface of the rotating roller that contacts the sheet has a surface roughness of less than about 400 Ra (microinches),

rotary thermoforming the sheet onto a mold to provide an article -blank web, and cutting the article-blank web to provide the shallow draw thermoformed article.

17. The method of claim 16, wherein the polymeric materials further comprise a polypropylene random co-polymer third resin.

18. The method of claim 17, wherein the polymeric materials comprise about 25% to about 55% by weight the polypropylene homopolymer first resin, about 45% to about 60% by weight the polypropylene impact copolymer second resin, and about 1% to about 15% by weight the polypropylene random co-polymer third resin.

19. The method of claim 16, wherein the surface roughness of at least the portion of the outer surface of the rotating roller that contacts the sheet is between about 100 Ra (microinches) and about 240 Ra (microinches).

20. The method of claim 16, wherein the shallow draw thermoformed article has a clarity of about or greater than about 50% as measured using ASTM D 1746 and a haze of about or less than about 60% as measured using ASTM D 1003 procedure B.