Cup-forming process and machine
09713906 ยท 2017-07-25
Assignee
Inventors
Cpc classification
B29C2037/90
PERFORMING OPERATIONS; TRANSPORTING
B31B50/322
PERFORMING OPERATIONS; TRANSPORTING
B29C35/02
PERFORMING OPERATIONS; TRANSPORTING
B29D22/003
PERFORMING OPERATIONS; TRANSPORTING
B31B2105/001
PERFORMING OPERATIONS; TRANSPORTING
B31B2105/00
PERFORMING OPERATIONS; TRANSPORTING
B31B2110/10
PERFORMING OPERATIONS; TRANSPORTING
Y10T156/1002
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B31B50/741
PERFORMING OPERATIONS; TRANSPORTING
B31B2105/0022
PERFORMING OPERATIONS; TRANSPORTING
B29D24/002
PERFORMING OPERATIONS; TRANSPORTING
International classification
B29D24/00
PERFORMING OPERATIONS; TRANSPORTING
B29C35/02
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A cup-forming machine includes having a male mandrel and a female receiver. The male mandrel uses a cup body blank and a floor blank to form a body of a cup. The female receive receives the body and forms a rolled brim on the body to establish a cup.
Claims
1. A method of making a plastic cup, the method comprising the steps of providing a plastic cup body blank and a the cup consist of a plastic floor blank, each of the cup body blank and the floor blank being made from insulative cellular non-aromatic polymeric material, heating the cup body blank, heating a male mandrel to provide a heated male mandrel, folding the cup body blank around the heated male mandrel after heating the cup body blank, transferring heat from the heated male mandrel to the cup body blank to minimize stress in the insulative cellular non-aromatic polymeric material so that formation of visible imperfections in the cup are minimized during the folding step, joining an outer tab of the cup body blank and an inner tab of the cup body blank together to form a cup side wall, coupling the floor blank to the cup side wall to form a cup body on the heated male mandrel, warming a female receiver to provide a heated female receiver, transferring the cup body from the heated male mandrel to the heated female receiver, and curling a top edge of the cup body to form a rolled brim on the cup body to establish a plastic cup.
2. The method of claim 1, further comprising the step of orienting the cup body blank to cause a circumference of the rolled brim to be aligned transverse to a machine direction established during formation of the insulative cellular non-aromatic polymeric material.
3. The method of claim 1, wherein the heated male mandrel has a temperature between about 150 degrees Fahrenheit and about 250 degrees Fahrenheit.
4. The method of claim 3, wherein the heating step includes the steps of providing a cartridge heater coupled to the male mandrel and using the cartridge heater to apply heat to the male mandrel to establish the heated male mandrel.
5. The method of claim 4, further comprising the step of controlling application of heat to the male mandrel from the cartridge heater using a mandrel heat controller coupled to the cartridge heater.
6. The method of claim 5, further comprising the step of sensing the temperature of the heated male mandrel with a sensor associated with the male mandrel and coupled to the mandrel heat controller to communicate the temperature of the heated male mandrel to the mandrel heat controller.
7. The method of claim 1, wherein the heated female receiver has a temperature between about 100 degrees Fahrenheit and about 250 degrees Fahrenheit.
8. The method of claim 7, wherein the warming step includes the steps of providing a band heater coupled to the female receiver and using the band heater to apply heat to the female receiver to establish the heated female receiver.
9. The method of claim 8, further comprising the step of controlling application of heat to the female receiver from the band heater using a receiver heat controller coupled to the female receiver.
10. The method of claim 9, further comprising the step of sensing the temperature of the heated female receiver with a sensor associated with the female receiver and coupled to receiver heat controller to communicate the temperature of the heated female receiver to the receiver heat controller.
11. The method of claim 3, wherein the heated male mandrel has a temperature of about 200 degrees Fahrenheit and the heated female receiver has a temperature of about 175 degrees Fahrenheit.
12. The method of claim 1, wherein the heated male mandrel has a temperature of about 140 degrees Fahrenheit.
13. The method of claim 1, further comprising the step of applying a lubricant to the top edge of the cup body prior to the curling step.
14. The method of claim 1, further comprising the step of pre-curling the top edge of the cup body prior to the curling step.
15. The method of claim 1, further comprising the steps of loading the cup body blank on a loading turret prior to the folding step.
16. The method of claim 1, further comprising the step of inserting the cup floor blank into a floor-receiving space formed in the heated male mandrel prior to the coupling step.
17. The method of claim 16, further comprising the step of bonding the cup floor blank to the cup side wall.
18. The method of claim 1, wherein the male mandrel is rotatable about a first axis and the female receiver is rotatable about a second axis located in spaced-apart relation to the first axis.
19. The method of claim 1, further comprising the step of forming the cup side wall after the heating step to cause any creases in the cup side wall to have a depth of less than about 100 microns.
20. The method of claim 19, wherein any creases in the cup side wall have a depth of less than about 5 microns.
21. The method of claim 1, wherein cells included in the insulative cellular non-aromatic polymeric material have a cell aspect ratio of between about 1.0 and about 3.0.
22. The method of claim 21, wherein the cell aspect ratio is between about 1.0 and about 2.0.
23. The method of claim 21, wherein the insulative cellular non-aromatic polymeric material has an average cell dimension of about 0.01954 inches in width and about 0.00853 inches in length.
24. The method of claim 21, wherein the insulative cellular non-aromatic polymeric material has an average cell dimension of about 0.01854 inches in width and about 0.00828 inches in length.
25. The method of claim 1, further comprising the step of deforming plastically a selected region of the cup body to provide a plastically deformed first material segment having a first density in a first portion of the selected region of the cup body and a second material segment having a relatively lower second density in an adjacent second portion of the cup body.
26. The method of claim 1, wherein the heated male mandrel has a temperature between about 100 degrees Fahrenheit and about 250 degrees Fahrenheit.
27. The method of claim 26, wherein the heated male mandrel has a temperature of about 200 degrees Fahrenheit.
28. The method of claim 1, wherein the heating step uses a heat-control system that includes a power source and a mandrel heater coupled to the male mandrel to provide heat to the male mandrel in response to receiving power from the power source.
29. The method of claim 28, wherein the heat-control system further includes a mandrel heater controller coupled to the power source and to the mandrel heater to cause power to be supplied to the mandrel heater so that the heated male mandrel is maintained.
30. The method of claim 29, wherein the mandrel heater is a cartridge heater.
31. The method of claim 30, wherein the male mandrel is formed to include a bore and the cartridge heater is arranged to lie in the bore.
32. The method of claim 31, wherein the male mandrel is formed to include first, second, and third bores arranged to lie in spaced-apart relation to one another to define an equilateral triangle shape.
33. The method of claim 32, wherein the male mandrel includes an outer surface, each bore is defined by an associated inner surface, and the inner surface of each bore is spaced apart from the outer surface of the male mandrel by about 0.08 inches.
34. The method of claim 29, wherein the heat-control system is coupled to the female receiver and configured to provide means for heating the female receiver to establish a heated female receiver to cause heat from the heated female receiver to be transferred to the cup body.
35. The method of claim 34, wherein the heat-control system further includes a receiver heater coupled to the female receiver to heat the female receiver.
36. The method of claim 35, wherein the heat-control system further includes a receiver heater controller coupled to the power source and the receiver heater to cause power to be supplied to the receiver heater so that the heated female receiver is maintained.
37. The method of claim 36, wherein the mandrel heater controller includes a mandrel sensor arranged to sense a temperature of the heated male mandrel.
38. The method of claim 37, wherein the receiver heater controller includes a receiver sensor arranged to sense a temperature of the heated female receiver.
39. The method of claim 35, wherein the receiver heater is a band heater.
40. The method of claim 39, wherein the female receiver includes an inner surface and an outer surface and the band heater is coupled to the outer surface.
41. The method of claim 35, wherein the heat-control system further includes a male-turret slip ring arranged to interconnect the power source and the mandrel heater and a female-turret slip ring arranged to interconnect the power source and the receiver heater.
42. The method of claim 1, wherein the male mandrel is formed to include a floor-receiving space therein and a floor of a cup body is arranged to lie in the floor-receiving space.
Description
BRIEF DESCRIPTIONS OF THE DRAWINGS
(1) The detailed description particularly refers to the accompanying figures in which:
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DETAILED DESCRIPTION
(21) A cup-forming process 100 in accordance with the present disclosure includes a staging materials operation 102, a heating male mandrels operation 104, a forming a body operation 106, a heating female receivers operation 108, and a forming a brim operation 110 as shown in
(22) Staging materials operation 102 includes a loading body blanks operation 1021, a placing body blanks operation 1022, a heating body blanks operation 1023, a loading laminated roll operation 1024, and a cutting floor blank operation 1025 as shown in
(23) During staging materials operation 102, each male mandrel 302 is heated by a male turret-heater unit 406 in heating male mandrels operation 104 as suggested in
(24) When male mandrels are heated in heating male mandrels operation 104, forming a body operation 106 then proceeds. Forming a body operation 106 includes a forming a platform-support member operation 1061, an inserting the floor operation 1062, a folding body blank operation 1063, a joining operation 1064, a wrapping operation 1065, and a bonding operation 1066 as shown in
(25) During forming a body operation 106, each female receiver 304 is heated or warmed by an associated female turret-heater unit 402 to produce heated female receivers 304 in heating female receivers operation 108, also called warming female receivers operation 108, as shown in
(26) When female receivers are warmed in warming female receivers operation 108, forming a brim operation 110 then proceeds. Forming a brim operation 110 includes a transferring operation 1101, a lubrication operation 1102, a pre-curling operation 1103, a curling operation 1104, and an ejecting operation 1105 as shown in
(27) A portion of cup-forming machine 300 is shown, for example in
(28) Male turret 310 includes, for example, a series of equally spaced apart male mandrels 302 as shown in
(29) Female turret 314 includes, for example, a series of equally spaced apart female receivers 304 as suggested in
(30) Each male mandrel 302 is substantially the same as every other male mandrel. Male mandrel 302 is formed to include three bores 302A, 302B, and 302C as suggested in
(31) A thickness 301 is established between an outer surface 303 of male mandrel 302 and an inner surface 305 of each bore 302A, 302B, 302C as suggested in
(32) An insulative gasket may be positioned between each male mandrel 302 and a support structure included in male turret 310. An example, the insulative gasket may be made of mica, ceramic, or the like and configured to minimize transfer of heat from male mandrel 302 to the support structure and other components included in cup-forming machine 300.
(33) Cup-forming machine 300 further includes a heat-control system 410 as shown, for example, in
(34) Male turret-heater unit 406 includes a male heater controller 412 and a mandrel heater associated with each male mandrel 302. As shown in
(35) As an example, the cartridge heater is configured to use 115 V electricity and provide 400 W of heat in the range of about 200 degrees Fahrenheit plus or minus about 50 degrees Fahrenheit. The sensor may be a Type J thermocouple. Male heater controller 412 is, for example, an ATHENA controller, model number 18-JF-U-B-B-B-0-00-0-AE. Male heater controller 412 operates in a 0-1400 degree Fahrenheit range and is supplied by 115/230 Volt AC power.
(36) Female turret-heater unit 402 includes a female heater controller 418 and a receiver heater associated with each female receiver 304. As shown in
(37) Insulative cup 10 is made from a multi-layer sheet 80 formed during a cup-manufacturing process. As an example, multi-layer sheet 80 includes a skin 81 and a strip 82 of insulative cellular non-aromatic polymeric material as shown in
(38) Insulative cup 10 includes, for example, a body 11 having a sleeve-shaped side wall 18 and a floor 20 as shown in
(39) Insulative cellular non-aromatic polymeric material is configured in accordance with the present disclosure to provide means for enabling localized plastic deformation in at least one selected region of body 11 (e.g., side wall 18, rolled brim 16, floor mount 17, and a floor-retaining flange 26 included in floor mount 17) to provide (1) a plastically deformed first material segment having a first density in a first portion of the selected region of body 11 and (2) a second material segment having a relatively lower second density in an adjacent second portion of the selected region of body 11 as suggested, for example, in
(40) Insulative cup 10 is made of a multi-layer sheet 80 as suggested in
(41) Film layer 54 is then printed with an ink layer 66. As an example, ink layer 66 includes graphics and the graphics are shown on insulative cup 10 as a pair of triangles in
(42) An insulative cellular non-aromatic polymeric material produced in accordance with the present disclosure can be formed to produce an insulative cup 10. As an example, the insulative cellular non-aromatic polymeric material comprises a polypropylene base resin having a high melt strength, a polypropylene copolymer or homopolymer (or both), and cell-forming agents including at least one nucleating agent and a blowing agent such as carbon dioxide. As a further example, the insulative cellular non-aromatic polymeric material further comprises a slip agent. The polypropylene base resin has a broadly distributed unimodal (not bimodal) molecular weight distribution.
(43) Insulative cellular non-aromatic polymeric material is used during cup-forming process 100 to make insulative cup 10 as suggested in
(44) An unexpected property of multi-layer sheet 80 including strip 82 of insulative cellular non-aromatic polymeric material is its ability when bent to form a round article, such as insulative cup 10. Surface 105 is wrinkle free as is surface 107 as shown in
(45) In addition to surface topography and morphology, another factor that was found to be beneficial to obtain a high quality insulative cup free of creases was the anisotropy of the insulative cellular non-aromatic polymeric strip. Aspect ratio is the ratio of the major axis to the minor axis of the cell. As confirmed by microscopy, in one exemplary embodiment the average cell dimensions in a machine direction (machine or along the web direction) of an extruded strip 82 of insulative cellular non-aromatic polymeric material was about 0.01954 inches (0.50 mm) in width by about 0.00853 inches (0.22 mm) in height. As a result, a machine direction cell size aspect ratio is about 2.29. The average cell dimensions in a cross direction (cross-web or transverse direction) was about 0.01845 inches (0.47 mm) in width and about 0.00828 inches (0.21 mm) in height. As a result, a cross-direction aspect ratio is about 2.23. In one exemplary embodiment, it was found that for the strip to withstand compressive force during cup forming; one desirable average aspect ratio of the cells was between about 1.0 and about 3.0. In one exemplary embodiment one desirable average aspect ratio of the cells was between about 1.0 and about 2.0.
(46) The ratio of machine direction to cross direction cell length is used as a measure of anisotropy of the extruded strip. In exemplary embodiments, a strip of insulative cellular non-aromatic polymeric material may be bi-axially oriented, with a coefficient of anisotropy ranging between about 0.1 and about 3. In one exemplary embodiment, the coefficient of anisotropy was about 1.1.
(47) If the circumference of the cup is aligned with machine direction of strip 82 with a cell aspect ratio exceeding about 3.0, deep creases with depth exceeding about 200 microns are typically formed on an inside surface of the cup making it unusable. Unexpectedly, it was found, in one exemplary embodiment, that if the circumference of the cup was aligned in the cross direction of extruded strip 82, which can be characterized by cell aspect ratio below about 2.0, no deep creases were formed inside of the cup, indicating that the cross direction of strip 82 was more resistant to compression forces during cup formation.
(48) One possible reason for greater compressibility of an extruded strip with cells having aspect ratio below about 2.0 in the direction of cup circumference, such as in the cross direction, could be due to lower stress concentration for cells with a larger radius. Another possible reason may be that the higher aspect ratio of cells might mean a higher slenderness ratio of the cell wall, which is inversely proportional to buckling strength. Folding of the strip into wrinkles in the compression mode could be approximated as buckling of cell walls. For cell walls with longer length, the slenderness ratio (length to diameter) may be higher. Yet another possible factor in relieving compression stress might be a more favorable polymer chain packing in cell walls in the cross direction allowing polymer chain re-arrangements under compression force. Polymer chains are expected to be preferably oriented and more tightly packed in machine direction.
(49) In exemplary embodiments, cell aspect ratio is about 2.0 when the formed cup circumference is aligned in the direction of extruded strip. As a result, the surface of extruded strip with crystal domain size below about 100 angstroms facing inside the cup may provide favorable results of achieving a desirable surface topography with imperfections less than about 5 microns deep. In addition, it has been found that the use of heated male mandrels 302 and heated female receivers 304 minimizes the formation of deep creases on the inside of the cup.
(50) In one aspect of the present disclosure, the polypropylene resin (either the base or the combined base and secondary resin) may have a density in a range of about 0.01 g/cm.sup.3 to about 0.19 g/cm.sup.3. In one exemplary embodiment, the density may be in a range of about 0.05 g/cm.sup.3 to about 0.19 g/cm.sup.3. In one exemplary embodiment, the density may be in a range of about 0.1 g/cm.sup.3 to about 0.185 g/cm.sup.3.
(51) It has been found during development of the present disclosure that if the circumference of insulative cup 10 is aligned with the machine direction of strip 82 of insulative cellular non-aromatic polymeric material, deep creases with a depth in excess of about 200 microns are typically formed on surface 107. Unexpectedly, it has been determined that if the circumference of insulative cup 10 is aligned generally perpendicular to machine direction, the formation of deep creases on surface 107 may be lessened to some extent, indicating that the cross-direction to the machine direction of extruded insulative cellular non-aromatic polymeric material is resistant to compression forces during formation of insulative cup 10. It is believed that this is a result of the orientation of the polymer chains of extruded insulative cellular non-aromatic polymeric material which are oriented and more tightly packed in machine direction.
(52) Body 11 is formed from a strip 82 of insulative cellular non-aromatic polymeric material as disclosed herein. In accordance with the present disclosure, strip 82 of insulative cellular non-aromatic polymeric material is configured through application of pressure and heat (though in exemplary embodiments configuration may be without application of heat) to provide means for enabling localized plastic deformation in at least one selected region of body 11 to provide a plastically deformed first sheet segment having a first density located in a first portion of the selected region of body 11 and a second sheet segment having a second density lower than the first density located in an adjacent second portion of the selected region of body 11 without fracturing the sheet of insulative cellular non-aromatic polymeric material so that a predetermined insulative characteristic is maintained in body 11.
(53) Sleeve-shaped side wall 18 includes an upright inner tab 514, an upright outer tab 512, and an upright fence 513 as suggested in
(54) Rolled brim 16 is coupled to an upper end of sleeve-shaped side wall 18 to lie in spaced-apart relation to floor 20 and to frame an opening into interior region 14. Rolled brim 16 includes an inner rolled tab 164, an outer rolled tab 162, and a rolled lip 163 as suggested in
(55) Floor mount 17 is coupled to a lower end of sleeve-shaped side wall 18 to lie in spaced-apart relation to rolled brim 16 and to floor 20 to support floor 20 in a stationary position relative to sleeve-shaped side wall 18 to form interior region 14. Floor mount 17 includes a web-support ring 126, a floor-retaining flange 26, and a web 25. Web-support ring 126 is coupled to the lower end of sleeve-shaped side wall 18 and configured to provide the second sheet segment having the second density in the third 103 of the selected regions of body 11. Floor-retaining flange 26 is coupled to floor 20 and arranged to be surrounded by web-support ring 126. Web 25 is arranged to interconnect floor-retaining flange 26 and web-support ring 126. Web 25 is configured to provide the first sheet segment having the first density in the third 103 of the selected regions of body 11.
(56) Floor-retaining flange 26 includes an alternating series of upright thick and thin staves arranged in side-to-side relation to extend upwardly from web 25 toward interior region 14 bounded by sleeve-shaped side wall 18 and floor 20. A first 261 of the upright thick staves is configured to include a right side edge extending upwardly from web 25 toward interior region 14. A second 262 of the upright thick staves is configured to include a left side edge arranged to extend upwardly from web 25 toward interior region 14 and lie in spaced-apart confronting relation to right side edge of the first 261 of the upright thick staves. A first 260 of the upright thin staves is arranged to interconnect left side edge of the first 261 of the upright thick staves and right side edge of the second 262 of the upright thick staves and to cooperate with left and right side edges to define therebetween a vertical channel 263 opening inwardly into a lower interior region bounded by floor-retaining flange 26 and a horizontal platform 21 included in floor 20 and located above floor-retaining flange 26. The first 260 of the upright thin staves is configured to provide the first sheet segment in the fourth 104 of the selected regions of body 11. The first 261 of the upright thick staves is configured to provide the second sheet segment in the fourth 104 of the selected regions of the body 11.
(57) An insulative cup formed from a non-expanded polystyrene material having a layer of printed film adhered thereto may be considered non-recyclable because it would require the segregation of the film layer, which would not be desirable to introduce as part of the regrind into the extrusion process. Recyclability of articles formed using the insulative cellular non-aromatic polymeric material of the present disclosure minimize the amount of disposable waste created. In comparison, beaded expanded polystyrene cups that break up into beads and thus ordinarily cannot be reused easily in a manufacturing process with the same material from which the article was formed. In addition, paper cups that typically have an extrusion coated plastic layer or a plastic lamination for liquid resistance ordinarily cannot be recycled because the different materials (paper, adhesive, film, plastic) normally cannot be practicably separated in commercial recycling operations.