US3516122A - Apparatus for making integral containers having parallel vertical walls - Google Patents
Apparatus for making integral containers having parallel vertical walls Download PDFInfo
- Publication number
- US3516122A US3516122A US640245A US3516122DA US3516122A US 3516122 A US3516122 A US 3516122A US 640245 A US640245 A US 640245A US 3516122D A US3516122D A US 3516122DA US 3516122 A US3516122 A US 3516122A
- Authority
- US
- United States
- Prior art keywords
- container
- female die
- male
- containers
- die
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/26—Component parts, details or accessories; Auxiliary operations
- B29C51/42—Heating or cooling
- B29C51/428—Heating or cooling of moulds or mould parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/04—Combined thermoforming and prestretching, e.g. biaxial stretching
- B29C51/06—Combined thermoforming and prestretching, e.g. biaxial stretching using pressure difference for prestretching
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/26—Component parts, details or accessories; Auxiliary operations
- B29C51/42—Heating or cooling
- B29C51/427—Cooling of the material with a fluid blast
Definitions
- the present invention relates to apparatus for making integral containers having essentially parallel vertical walls, from a formable material which is characterized by contraction as it cools.
- One type of integrally formed container which has been in wide usage for a number of years is provided with aligned pairs of vertical grooves on its interior walls, and is designed to slidably receive partitions inserted vertically into these pairs of grooves. It has been desired to provide stackability for this type of compartmentable container, but because of the presence of the grooves on the interior wall surfaces of the container it has heretofore been impossible to design a completely satisfactory stacking arrangement for this kind of container.
- a primary object of the invention is to provide apparatus for forming integral containers having essentially parallel vertical walls.
- Another object of the present invention is to provide apparatus for manufacturing stackable containers which do not incorporate stacking posts or convolutions in any of the walls thereof.
- a further object of the invention is to provide tooling for the manufacture of integral containers, which tooling is adjustable to accommodate the manufacture of otherwise identical containers of varying vertical heights.
- An additional object of the invention is to provide novel apparatus for manufacturing compartmentable containers of the type having aligned pairs of vertical grooves formed in the interior wall surfaces thereof, but which are also securely stackable in superimposed relationship.
- Yet another object of the invention is to provide a manufacturing apparatus which is peculiarly adapted to the economical manufacture of integrally formed containers having precisely parallel walls, from a polyolefin material.
- FIG. 1 is a perspective view of a set of tooling provided in accordance with the present invention, and a sheet of thermoplastic material from which a container is to be formed;
- FIG. 2 is an elevational view, partially in cross-section, of the apparatus of FIG. 1 as the forming operation is being commenced;
- FIG. 3 is a vertical cross-sectional view of the apparatus of FIG. 1 as the forming operation is advanced to a later stage;
- FIG. 4 is a vertical cross-sectional view taken on the line 4-4 of FIG. 3;
- FIG. 5 is a fragmentary horizontal sectional view taken on the line 5-5 of FIG. 3;
- FIG. 6 is an enlarged fragmentary vertical sectional view illustrating a detail of construction of the male die
- FIG. 7 is a perspective upside-down view of a portion of the forming ring of the male die.
- FIG. 8 is a fragmentary perspective view illustrating the corner portion of a completed container.
- a sheet 10 of formable material such as polyolefin
- a female die 30 is disposed beneath the sheet 10 while a male die 40 is disposed above the sheet 10.
- the initial step in the manufacturing operation is to heat the sheet of material to its sag point in a separate oven location, and thereafter immediately move it by means of the holder 20 to its position as shown in FIG. 1, interposed between the male and female dies.
- the preliminary forming of the material is done only by the female die 30, by an evacuation process, that is causing a pressure differential across the sheet 10 by evacuating the gas from the interior of the female die to cause a lower pressure in the interior as compared to normal atmospheric pressure.
- the sheet 10 and the female die 30 are moved relative to each other, so that the upper circumferential edge of the female die sealingly engages the undersurface of the sheet 10.
- Evacuation of the female die 30 causes the central portion of the sheet to assume the position shown in FIG. 2; and continued evacuation causes the sheet to assume very nearly the form of the interior wall and bottom surfaces of the female die.
- the female die and male die are moved vertically relative to each other, into engaging relationship as shown in FIG.
- a significant feature of the illustrated apparatus is that the side 41b and end walls 410 of a plug 41 of the male die 40 are exactly parallel to each other.
- a forming ring 42, FIG. 2 is vertically movable on plug 41 to any selected position (shown in dotted lines at alternate location to accommodate the male die to any desired container height.
- a bottom member 33 provides the bottom wall of the female die 30, and is vertically adjustable to any desired vertical position to accommodate the vertical height of a particular container to be formed, and may be fastened in any desired position of vertical adjustment, by means not shown.
- the temperature of the sheet of material 10 is carefully controlled prior to its application to the female die 30, and the female die is heated by some suitable means such as the external strip heaters 34, FIGS. 1 and 2, which encircle the side and end walls thereof.
- Female die 30 is provided with an air hose 36, FIG. 2, which communicates with the underside of movable bottom member 33, and a plurality of air openings 37 are formed in the bottom member 33 for allowing an increase or decrease of pressure, as the case may be, to the interior of the female die.
- the equipment is automatically controlled, by means not shown, so that the reduction of pressure within the interior of the female die occurs after the upper circumferential edge of the female die has engaged, and preliminarily sealed, the undersurface of the Work sheet 10.
- the upper circumferential edge of the female die 30 is provided with an upstanding portion 38, on the outside of which there is a circumferential shoulder 39. It is the upstanding portion 38 which accomplishes the preliminary sealing action, while as will be subsequently described there is later a final sealing action in which the shoulder 39 is also utilized.
- the male mold or die 40 includes as its primary element the plug 41 which is of substantially rectangular block configuration.
- the plug or block 41 is surrounded by a rectangular (as viewed in the horizontal plane) container rim forming ring 42, which ring is vertically adjustable up and down as viewed in FIG. 2 to a selected position of adjustment relative to the plug or block 41.
- the undersurface of the ring 42 is provided with a groove 43 which, in the position of the apparatus as shown in FIG. 3, effectively engages the edge 38 and shoulder 39 of the female die 30, not directly, but by grasping the corresponding portion of the sheet 10 therebetween.
- FIGS. 2 and 3 while the male die 40 is suspended underneath a ceiling support device 40a.
- Ring 42 is suspended from the ceiling support 40a by two ring support plates 44; plug 41 is supported by a plurality of threaded plug support rods 46; and the support rods 46 are adjustable so as to vary the relative vertical positions between the ring 42 and the plug 41.
- the fully formed container (formerly sheet 10') as shown in FIGS. 3 and 4 has a bottom wall 11, end walls 12, FIG. 2, and side walls 13, FIG. 3; while unused portions 14 of the sheet 10 which lie external to the dies are subsequently cut off and scrapped.
- the upper circumferential edge of the container has a cross-sectional configuration which is essentially an inverted short-handled dipper.
- a specific feature of the presently illustrated embodiment of the invention is the provision of the vertical ridges 49a on the exterior of the male plug 41, which permits forming vertical grooves on the interior walls of the completed container.
- forming ring 42 has an inner flange 39 in which interior grooves 39a are formed to receive the ridges 49a, and has exterior ridges 39! which form grooves 16a of the container.
- the top of flange 39 forms shoulder 15 of the container.
- the workpiece 10 is heated in a separate oven before being placed between the two dies of the present invention.
- the pre-heating temperature is approximately 400 degrees F.
- Female die 30 is heated to a somewhat lower temperature by means of the strip heaters 34.
- the male plug 41 is kept at a much lower temperature, in the approximate range from degrees to 200 degrees F., with its specific temperature depending upon the specific material being utilized and the size and height of the container being formed.
- the pipes or ducts 47 and 48, FIGS. 2 and 4 are coupled in series configuration, and a temperature-controlled fluid, such as water, is circulated therethrough for maintaining the temperature of the male plug 41 at a predetermined level.
- the shallower the container that is being formed the lower the temperature level that is maintained for the male plug; and for deeper containers, the male plug temperature is established at a higher level.
- the male plug is maintained at a constant temperature, as nearly as possible, which constant temperature is far below the setting temperature for the material, with the result that as soon as the material commences to be formed on the male plug a cooling action is initiated which causes the material to start to set.
- Female die is provided with a cooling pipe 35, FIG. 1, which extends around the external circumference of the die, being located near the top of outer walls thereof. Pipe is provided with spaced small openings on its upper surface.
- Cooling of the material is also initiated on the interior of the female die 30, at the time when the material is pressed against the male plug 41.
- Female die 30 in one end wall 31, FIG. 3, thereof is provided with a relief valve 36a, which is set at a fixed pressure level such as, for example, pounds per square inch.
- Air pressure is applied via the air hose 36 to the interior of the female die 30, for the purpose of pressing the material onto the male plug 41; the pressure of the source (not shown) that is connected to air hose 36 is substantially in excess of the pressure level for which the relief valve 36a is set; and the result therefore is that as soon as this control pressure level is reached inside the female die, air continues to flow at a rapid rate from the hose 36 to the openings 37 to the interior of the female die, and to be continuously exhausted from the interior of the female die through the exhaust valve 36a.
- the cooling and setting of the material are accomplished by means of the flow of air inside the female die 30, by the relatively cold temperature level of the male plug 41 prior to its being contacted by the much hotter material, and by the continued cooling of male plug 41 via the temperature controlled water fluid flowing inside the ducts 47 and 48. At the same time the air supply to pipe 35 ensures the very rapid cooling of the excess of waste material 14.
- An essential characteristic of the polyolefin or other material used in accordance with the invention is that it contracts during the cooling and setting process.
- the slower cooling of the rim of the container therefore results in the upper portions of the side and end walls of the container remaining in a slightly expanded condition, at least a few thousandths of an inch, relative to the lower portions of the side and end walls, prior to the material having completed its setting process.
- the container is then stripped from the mold, before the setting action is completed, and while the upper wall portions are still in this slightly expanded condition.
- the novel method of the present invention of stripping the container from the male plug just before the setting process is completed, is successful in forming the containers in accordance with a good standard of quality, and at the high rate of speed required in modern manufacturing facilities.
- the relief valve 36a of the female die is shown located above the particular position in which the movable bottom member 33 has been fastened. However, it is in fact preferred to locate the relief valve near the bottom of the female die, in such position that it will always lie beneath the bottom member 33.
- the advantage of this arrangement is that it prevents any contact between the container material and the intake port of the relief valve, and therefore precludes the possibility of malforming of the container by virtue of a stoppage of the exhaust flow of air out of the relief valve.
- Pressure forming on the male plug 41 has at least one advantage which is quite inobvious. This has to do with the adjustability of the tool for different container heights.
- the exhaust holes 41a, FIG. 6, which lie above the forming ring 42; however, it is not necessary to close oif these unused exhaust ports.
- the male plug 41 were being exhausted by evacuation of air in its interior, any unused opening communicating between the interior and exterior of the male plug would have to be closed oif, and this requirement would present a very difficult problem relative to the adjustable use of the tool.
- the manufacturing method described ob viates this problem.
- the apparatus of the present invention can be used on straight-walled containers, as well as the ridged wall structure as presently illustrated.
- An advantage of the ridged wall construction is, however, that a lesser amount of material is required to achieve the same degree of struc tural support for stacked or superimposed containers.
- hose section 48 is carried in the forming ring 42 and movable therewith, and that the hose sections 47 and 48 are coupled together by a flexible intervening section 47a, FIGS. 2 and 4.
- An apparatus for forming containers of thermoplastic or the like material said apparatus being adjustable to form containers of differing vertical heights, comprising in combination:
- said outer surface of said male die being essentially parallel to the direction of relative movement between said male and female dies;
- An apparatus as claimed in claim 1 including means for adjustably moving said male die relative said depth determining means.
- said depth determining means comprises an element having a groove disposed therein for forming the rim of a container formed by said apparatus.
- An apparatus as claimed in claim 1 including means for cooling said container to be formed by said dies; and wherein said groove of said depth determining means and said projection of said female die cooperate to retard the cooling by said cooling means of the portion of the container positioned between said groove and said projection.
- cooling means includes a perforated pipe positioned about said apparatus to spray cooling fluid on said material used to form the container, said perforated pipe being disposed exterior of said dies during the forming of the container.
- said female die includes a wall portion and a bottom portion, said bottom portion being movable relative said wall portion as a function of the relative positions of the depth determining means and the male die.
- said bottom portion being movable relative said wall portion as a function of the relative positions of the depth determining means and the male die.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
Description
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US317355A US3400111A (en) | 1963-10-18 | 1963-10-18 | Method for making integral containers having precisely parallel vertical walls |
US64024567A | 1967-05-22 | 1967-05-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3516122A true US3516122A (en) | 1970-06-23 |
Family
ID=26980907
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US640245A Expired - Lifetime US3516122A (en) | 1963-10-18 | 1967-05-22 | Apparatus for making integral containers having parallel vertical walls |
Country Status (1)
Country | Link |
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US (1) | US3516122A (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3659991A (en) * | 1970-04-03 | 1972-05-02 | Plasti Vac Inc | Clamping frame for plastic vacuum forming machine |
US3771155A (en) * | 1970-09-09 | 1973-11-06 | Hitachi Ltd | Color display system |
US3867085A (en) * | 1974-01-03 | 1975-02-18 | Nrm Corp | Thermoforming apparatus with web support means |
US3926708A (en) * | 1972-10-25 | 1975-12-16 | Teledyne Ryan Aeronautical | Method of manufacturing high strength fiber reinforced thermo plastic parts |
US3986809A (en) * | 1971-02-25 | 1976-10-19 | Ball Corporation | Apparatus and method for removing molds from articles with undercut pieces |
US4009981A (en) * | 1975-11-10 | 1977-03-01 | Rosen Stanley R | Universal mold tooling system for thermoforming molds |
US4080416A (en) * | 1975-03-20 | 1978-03-21 | International Fabric Molders, Inc. | Method for making multi-layer molded padded products |
US4162884A (en) * | 1976-12-10 | 1979-07-31 | Multivac Sepp Haggenmuller Kg | Apparatus for shaping plastics foils |
US4278414A (en) * | 1979-02-16 | 1981-07-14 | Kennedy Sky-Lites, Inc. | Apparatus for making plastic skylights |
US4381910A (en) * | 1981-02-23 | 1983-05-03 | Aisin Seiki Kabushiki Kaisha | Apparatus for molding pulley for toothed belts |
CH673603A5 (en) * | 1987-09-22 | 1990-03-30 | Alusuisse | Press blowing super-plastically deformable metal sheet - using cooling nozzle to decrease metal expansion in areas to be most highly deformed |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2129268A (en) * | 1936-05-15 | 1938-09-06 | Nat Battery Co | Mold for plastic materials and method of making the same |
US2230189A (en) * | 1933-01-31 | 1941-01-28 | Plax Corp | Apparatus for forming articles from organic sheet material |
US2254376A (en) * | 1938-06-04 | 1941-09-02 | Lyon George Albert | Method for making wheel disks |
US3218379A (en) * | 1963-01-02 | 1965-11-16 | Illinois Tool Works | Process and apparatus for forming plastic cups or the like |
US3224239A (en) * | 1962-08-17 | 1965-12-21 | Continental Can Co | Pneumatic reshaping of cans |
US3235639A (en) * | 1963-05-07 | 1966-02-15 | American Can Co | Solid flanged thermoplastic articles and apparatus and method for making the same |
US3258813A (en) * | 1963-01-28 | 1966-07-05 | Dynamics Corp America | Pressure forming of plastic film |
US3338997A (en) * | 1963-03-14 | 1967-08-29 | Dow Chemical Co | Method and apparatus for forming plastic containers |
US3342914A (en) * | 1964-07-13 | 1967-09-19 | Illinois Tool Works | Method and apparatus for deep draw molding |
-
1967
- 1967-05-22 US US640245A patent/US3516122A/en not_active Expired - Lifetime
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2230189A (en) * | 1933-01-31 | 1941-01-28 | Plax Corp | Apparatus for forming articles from organic sheet material |
US2129268A (en) * | 1936-05-15 | 1938-09-06 | Nat Battery Co | Mold for plastic materials and method of making the same |
US2254376A (en) * | 1938-06-04 | 1941-09-02 | Lyon George Albert | Method for making wheel disks |
US3224239A (en) * | 1962-08-17 | 1965-12-21 | Continental Can Co | Pneumatic reshaping of cans |
US3218379A (en) * | 1963-01-02 | 1965-11-16 | Illinois Tool Works | Process and apparatus for forming plastic cups or the like |
US3258813A (en) * | 1963-01-28 | 1966-07-05 | Dynamics Corp America | Pressure forming of plastic film |
US3338997A (en) * | 1963-03-14 | 1967-08-29 | Dow Chemical Co | Method and apparatus for forming plastic containers |
US3235639A (en) * | 1963-05-07 | 1966-02-15 | American Can Co | Solid flanged thermoplastic articles and apparatus and method for making the same |
US3342914A (en) * | 1964-07-13 | 1967-09-19 | Illinois Tool Works | Method and apparatus for deep draw molding |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3659991A (en) * | 1970-04-03 | 1972-05-02 | Plasti Vac Inc | Clamping frame for plastic vacuum forming machine |
US3771155A (en) * | 1970-09-09 | 1973-11-06 | Hitachi Ltd | Color display system |
US3986809A (en) * | 1971-02-25 | 1976-10-19 | Ball Corporation | Apparatus and method for removing molds from articles with undercut pieces |
US3926708A (en) * | 1972-10-25 | 1975-12-16 | Teledyne Ryan Aeronautical | Method of manufacturing high strength fiber reinforced thermo plastic parts |
US3867085A (en) * | 1974-01-03 | 1975-02-18 | Nrm Corp | Thermoforming apparatus with web support means |
US4080416A (en) * | 1975-03-20 | 1978-03-21 | International Fabric Molders, Inc. | Method for making multi-layer molded padded products |
US4009981A (en) * | 1975-11-10 | 1977-03-01 | Rosen Stanley R | Universal mold tooling system for thermoforming molds |
US4162884A (en) * | 1976-12-10 | 1979-07-31 | Multivac Sepp Haggenmuller Kg | Apparatus for shaping plastics foils |
US4278414A (en) * | 1979-02-16 | 1981-07-14 | Kennedy Sky-Lites, Inc. | Apparatus for making plastic skylights |
US4381910A (en) * | 1981-02-23 | 1983-05-03 | Aisin Seiki Kabushiki Kaisha | Apparatus for molding pulley for toothed belts |
CH673603A5 (en) * | 1987-09-22 | 1990-03-30 | Alusuisse | Press blowing super-plastically deformable metal sheet - using cooling nozzle to decrease metal expansion in areas to be most highly deformed |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NESTIER CORPORATION Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:MIDLAND-ROSS CORPORATION;REEL/FRAME:003921/0855 Effective date: 19811029 Owner name: MIDLAND-ROSS CORPORATION, 20600 CHAGRIN BLVD. CLEV Free format text: SECURITY INTEREST;ASSIGNOR:NESTIER CORPORATION;REEL/FRAME:003921/0847 Effective date: 19811030 |
|
AS | Assignment |
Owner name: VANGUARD INDUSTRIES, INC., VIRGINIA Free format text: ASSIGNOR WISH TO CORRECT SPELLING OF FIRST WORD OF ASSIGNEES NAME IN ASSIGNMENT DATED DEC. 4, 1972 FROM VANGUARD, INDUSTRIES, INC., TO VANGUARD INDUSTRIES, INC;ASSIGNOR:SHELL OIL COMPANY;REEL/FRAME:004048/0013 Effective date: 19800410 Owner name: VANGUARD INDUSTRIES, INC. Free format text: ASSIGNOR WISH TO CORRECT SPELLING OF FIRST WORD OF ASSIGNEES NAME IN ASSIGNMENT DATED DEC. 4, 1972 FROM VANGUARD, INDUSTRIES, INC., TO VANGUARD INDUSTRIES, INC.;ASSIGNOR:SHELL OIL COMPANY;REEL/FRAME:004048/0013 Effective date: 19800410 |