CA1164370A - Synthetic resin made thin-walled bottle and method of producing same - Google Patents
Synthetic resin made thin-walled bottle and method of producing sameInfo
- Publication number
- CA1164370A CA1164370A CA000429480A CA429480A CA1164370A CA 1164370 A CA1164370 A CA 1164370A CA 000429480 A CA000429480 A CA 000429480A CA 429480 A CA429480 A CA 429480A CA 1164370 A CA1164370 A CA 1164370A
- Authority
- CA
- Canada
- Prior art keywords
- bottle
- ribs
- walled
- thin
- synthetic resin
- 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
Links
- 239000000057 synthetic resin Substances 0.000 title claims abstract description 12
- 229920003002 synthetic resin Polymers 0.000 title claims abstract description 11
- 238000000034 method Methods 0.000 title description 3
- 238000000465 moulding Methods 0.000 claims description 5
- 238000000071 blow moulding Methods 0.000 abstract description 11
- 239000000543 intermediate Substances 0.000 description 23
- 230000001965 increasing effect Effects 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000000875 corresponding effect Effects 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
- 235000014171 carbonated beverage Nutrition 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000004645 polyester resin Substances 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- OWNRRUFOJXFKCU-UHFFFAOYSA-N Bromadiolone Chemical compound C=1C=C(C=2C=CC(Br)=CC=2)C=CC=1C(O)CC(C=1C(OC2=CC=CC=C2C=1O)=O)C1=CC=CC=C1 OWNRRUFOJXFKCU-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000003028 elevating effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Containers Having Bodies Formed In One Piece (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
This invention provides a tubular intermediate for a thin-walled synthetic resin bottle. The thin-walled bottle has ribs at least at its bottom portion, and the bottle bottom is raised up frusto-conically or shaped undulatory. The tubular intermediate is previously formed with ribs which become thin-walled protuberant ribs after blow molding. The thin-walled bottle is produced by blow-molding the ribbed tubular intermediate.
This invention provides a tubular intermediate for a thin-walled synthetic resin bottle. The thin-walled bottle has ribs at least at its bottom portion, and the bottle bottom is raised up frusto-conically or shaped undulatory. The tubular intermediate is previously formed with ribs which become thin-walled protuberant ribs after blow molding. The thin-walled bottle is produced by blow-molding the ribbed tubular intermediate.
Description
1 l~A3'7{~
This application is a division of application Serial No. 339,303 filed on November 6, 1979.
This i-nvention relates to an intermediate preform used to prepare a thin-walled synthetic resin bottle, particularly one formed with ribs at its bottom and/or other parts, and a method of producing such bottle.
Heretofore, glass bottles have been commonly used as containers for carbonated or refreshing drinks. However, because of their heavy weight, such glass bottles entail high transportation cost and also are inconvenient to handle.
Generally, the container cost and transportation cost account for a substantial portion of the price of such drinks, so that reduction of these costs can great-ly influence the total price of the product.
In order to overcome such problems, attempts have been made to use a bottle made from a synthetic resin which was reduced in wall thickness by means of biaxial orientation and which was formed cylindrical at its barrel portion and also bulged out spherically downwards at its bottom wall. Such a bottle although thin-walled, is provided with sufficient strength because of the biaxial orientation. However, since the bottom wall of the bottle is bulged out spherically downwards, the bottle can not be placed upright stably unless a skirt-like support member is additionally provided to the bottle bottom portion.
This results in an increased cost and marred external appearance, and also if such support member is improperly fitted, the bottle may tilt and, during auto-mated filling of the bottle with a liquid, the bottle mouth might be dislodged from the filling nozzle, thus causing improper charging of the liquid.
Provision of a bulged leg portion at the periphery of the bottle bottom wall may be used for effecting proper standing of the bottle, but in such case, insufficient strength is provided to the bottle bottom portion because the ~ ~6~370 under side of the leg portion is excess;vely lessened in wall thickness, thus making the bottle easily breakable.
In application 339,303 is described a synthetic resin thin-walled bottle in which at least one other part than the neck portion is biaxially oriented to thin the wall thickness and which has a barrel portion circular in cross-section shape, characterized in that the bottom portion comprises a frusto-conical portion extruding inwardly into the bottle, and has a plurality of radial ridged ribs in the ground-engaging section of the bottom between the lower end portion of the frusto-conical portion and the lower end of the barrel portion.
In application 339,303 is ~urther described a method of producing a synthetic resin thin-walled bottle having a frusto-conical portion at the bottle bottom comprising: forming, by injection molding, an intermediate provided with a plurality of radial ridges at least at its bottom portion; heating the inter-mediate to a temperature at which biaxial orientation can occur; setting the heated intermediate in a blow molding die; and subjecting the intermediate to blow molding in the die, thereby to form a thin walled bottle having radial ribs at a ground~engaging section formed between the lower end of a substantially circular cross-section barrel portion, and an inwardly projecting frusto-conical bottom portion.
This invention provides an intermediate used for molding a synthetic resin thin-walled bottle, said intermediate being of a bottomed and tOp-Open tubular configuration and biaxially oriented to form a thin-walled bottle, characterized in that said intermediate is provided at least at its bottom portion with a plurality of ridges extending radially from the center of said bottom portion.
Brief Descr~ion of the D awings Figure 1 is a partially cut-away sectional view of a synthetic resin 3 7 ~) made thin-walled bottle according to onc embodiment of the invention in applica-tion 339,303;
Pigure 2 is a sectional view taken along the linc II - II of Figure l;
Figure 3 is a cross-sectional view of a bottle which is a modified version of the invention in application 339,303;
Figure 4 is a sectional view of an intermediate used in maki.ng the bottle of Figure l;
Figure 5 is a partially cut-away sectional view of a thin-walled bottle also according to application 339,303;
; 10 Figure 6 is a partially cut-away perspective view of a further thin-walled bottle in accordance with application 339,303;
Figure 7 is a sectional view of an intermediate used in making the bot-tle of Figure 6;
Figure 8 is a sectional view of another ~hin-walled bottle according to application 339,303;
Figures 9 and 10 are bottom views showing the different bottom con-figurations of the bottle of Figure 8;
Figures 11, 12~ 13 and 14 are sectional views of the principal parts of the bottles which are modified versi.ons of the bottle of Figure 8;
Figure 15 is a partially cut-away view of a different thin-walled bottle according to application 339,303;
Figure lG is a sectional view of an intermediate used in making the bottle of Figure 15;
Figure 17 is a bottom view of the bottle of Figure 15;
Figure 18 is a partially cut-away view of an alternative thin-walled bottle according to application 339,303;
~ ~ B 4 3 7 0 Figure 19 is a partially cut-away view o~ a further different thin-walled bottle according to application 339,303;
Figure 20 is a view taken along the line XX - XX of Figure 19 in the direction of arrows;
Figure 21 is a sectional view of the principal parts of a bottle which is a modification of the bottle of Figure 19; and ~ igure 22 is a sectional view taken along the line XXI1 - XXII of Figure 20. Whilst this invention is concerned with the intermediates used primarily, its understanding is facilitated by considering all of these figures.
Consider first Figures 1 to 4. It will be seen that the biaxially oriented synthetic resin thin-walled bottle 1, from bottom upwards, a bottom wall 2, a cylindrical barrel portion 3, a shoulder portion 4 and a neck portion 6. The neck portion is provided with an ex~ernal thread S to be engaged with a cap. ~s for the material for the bottle of this invention, saturated poly-ester resin is preferred, but it is also possible to use other synthetic resins, such as polypropylene, vinyl chloride, etc., which are capable of increasing the mechanical strength of the bottle by biaxial orientation.
The bottom wall 2 of the bottle 1 is centrally shaped inwardly of the bottle to form a frusto-conical portion or mountain-shaped rising 7. Thus, the underside of the bottom portion between the lower edge of said po~tion 7 and the lower end of the barrel portion 3 forms the ground-engaging section 8.
On the inside of this ground-engaging section are provided a plurality of ridged ribs 9 which are arranged radially as viewed from above as shown in Figure 2.
In case the wall thickness of the bottle is made extremely thin, the outer end of each of said ribs 9 is extended along the axial line to an upper part oE the bottle barrel portion.
Such a bottle may be formed in the following way. First, a bottomed and top-open tubular intermediate 11 is formed by injection molding from a syn-thetic resin which can be biaxially oriented. The neck portion 1~ of this tubular intermediate 11 is provided with an external thread 13 so that it can immediately serve as the neck of the bottle. ~n the inside o~ the bottom portion 1~ of said tubular intermediate 11 are provided the ridges 15 such as shown in ~igure 4. Such ridges 15 are provided in plurality in radial arrangement from the center of the bottom, but no such ridge may be provided in the central part because of formation of the frusto-conical raised-up portion 7. The thus formed intermediate 11 is heated to a temperature at which b]ow molding can be accom-plished, and then it is set in a blow molding die and while blowing compressed air thereinto, the interior side of the bottom portion 14 of said intermediate is pushed down by a push-down bar or other means to effectuate biaxial orienta-tion. The molding die used here is one which has an internal configuration which allows formation of the desired external shape of the thin-walled bottle 1.
In case the additional ridges 16 are provided around the lower part of the intermediate 11, there will be formed the protuberant ribs 9, 17 on both inside and outside of the bottle as shown in Figure 3 to ~urther increase the bottle strength.
Thus, the bottle is of cylindrical shape with small wall thickness, but being biaxially oriented, it has high mechanical strength and is light in weight. Also, since an inwardly projecting frusto-conical portion 7 is provided at the bottom, the bottle can well withstand the internal pressure which de-velops with a carbonated drink is charged into the bottle under high pressure, and even if the raised-up portion 7 should be deformed under such internal pres-3 ~ 0 sure, the bot-tle bottom does not swell out spherically downwards as in the case of a flat-bottom bottle~ and hence hori~ontality of the ground-engaging portion 8 of the bottle will not be impaired. Therefore, the bottle will not tilt when it is placed uprightly, and further, since a plurality of ribs 9 are provided radially (as viewed from above~ on the inside of the ground-engaging section 8 of the bottom wall, the strength of the lower portion of the bottle is increased to provide an extremely high impact strength at accidental drop of the bottle.
Referring to Figure 5, there is shown a second bottle where the ridged ribs 9a formed at the bottle bottom portion ex*end to the slant of the frusto-conical portion 7 and also to the lower part of the barrel portion 3 of the bottle thereby to increase resistance against buckling load at the lower section of the bottle barrel portion.
A third bottle is shown in Figures 6 and 7. In this bottle, the ribs 9b are formed extending along the full axial length of the barrel portion as shown in Figure 6, whereby the buckling strength is greatly increased.
There are also provided ring-shaped annular constrictions 18 around the lower part of the barrel portion 3. This can increase stretch ratio of the barrel portion 3 while elevating its strength owing to the rib function.
The intermediate used in this bottle is provided with long strips of ridges 19 which extend along the axial line of the tubular intermediate 11.
Such ridges 19 may be provided on the outer periphery of the intermediate 11.
In Figures 8 to 14 is shown a fourth bottle. In this case, *he bottle bottom portion 20 has its central part bulged out inwardly of the bottle to form a frusto-conical raised-up portion 21~ with the base part of said raised-up po-rtion 21 being stepped to form a gentle rising portion 22. This portion 21 may be either formed into a continuous saucer-like part as shown in Figure 9 or _ ~ _ J ~ 6~37~
may be stepped radially at several sections as shown in Figure 10.
As a modification of this bottle, the frusto-conical raised-up portion 21 may be formed lmdulately by forming continuous recessions and ridges alter-nately as shown in Pigure 11. Also, stepped portions 25 may be formed at the recessions 23 as showm in Figure 12. In still other modifications, the stepped portions 25 may be provided in both recessions 23 and ridges 24 as shown in Figure 13 or only in the ridges 24 as shown in Figure 14.
Further, a plurality of protuberant ribs 28 may be formed radially from the central part of the bottom wall, as viewed from above, on the interior of the lower portion of the bottle, as shown in Figure 8. In this case, the strength of the bottle bottom is further increased if the protuberant ribs are so provided as to extend to the slant 21a of the raised-up portion 21 and also to the lower part of the bottle barrel portion 3.
Thus, in the thin-walled bottle according to Figures 8 to 1~, since a stepped region is formed at the lower end of the raised-up portion, the sur-face area of the raised-up portion is more enlarged than in the case of other embodiments, resulting in increased degree of stretching of the bottom wall and elevated rigidity of the bottom wall owing -to the rib fwnction. For further in-creasing strength of the bottom wall of the bottle, the protuberant ribs are formed at the pertinent area.
Now, a fifth bottle is described with reference to Figures 15 to 17.
The bottom portion 29 of the ~hin-walled bottle is provided with continuous jagged ribs 30 arranged radially from the center of the bottom and undulatory in sectional shape. These ribs 30 are so arranged that their height is zero at the center of the bot~le bottom but gradually increases toward the ou~er peri-phery, and the outer side of the bottom portion of each said rib 30 is designed 1 ~ 6~ 37~) to form a ground-engaging section 30a for allowing upright standing of the bottle.
Additional ridged ribs 31 are formed at the bends of each undulation formed by the ribs 30 on the inside of the bottom portion of the bottle, said ribs 31 extending down to the lower part of the bottle barrel portion. Although no ribs 31 are provided at the central part o-f the bottle bottom portion, they may be formed extending along the full vertical length of the bottle barrel portion. Where no impediment is given to use of the bottle, the ribs may be also provided on the external surface of the bottle to further increase its strength.
~or forming the above-described thin-walled bottle, a tubular inter-mediate 33 having the ridges 32 is subjected to blow molding in a blow molding die in the same way as Example 1, thereby forming a bottle having the radial ribs 30 at the bottom.
The thus made thin-walled bottle is extremely enhanced in strength of its bottom portion by dint of the ribs 30 at the bottom and the ridged ribs 31 at the bottom and barrel portion of the bottle. l`he ridged ribs on the interior of the bottle are pro~ided as the ridges formed on the interior of the intermedi-ate remain as they are after blow molding, but when the ridged ribs are formed on the exterior of ~he bottle, blow molding of the bottle becomes easier as there is no need of giving consideration to formation of the ridged ribs on the interior of the bottle. In this case, the grooves corresponding to the ridged ribs to be formed are provided in the molding die.
Reference is now had to Figure 18. In this bottle, the bottom portion 34 of the bottle is bulged out spherically downwards. Since the bottle is un-able to stand upright by itself, there is required a supporting leg member 35 ~ ~fi'~37~J
that fits with the bulging bottom portion of the bottle. It will be seen that the top protuberant portion 3~ of said leg member 35 fits with the corresponding annular stepped portion 37 fo-rmed at the lower part of the bottle.
There are also provided on the interior of the bottle bottom portion 34 a plurality of ridged ribs 38 arranged radially from the center of the bottom portion. If necessary, such ridged ribs 38 may be extended all the way to an upper part of the bottle.
In this bottle, because of the spherical configuration, the bottom portion of the bottle is very tough and also blow molding is facilitated.
Referring to Figures 19 to 22~ in this bottle, the central part of the bottom portion 39 of the bottle is bulged inwardly of the bottle to form a frusto-conical raised-up portion 40 and the slant 41 thereof is formed undulate-ly as shown in Figure 20. If the undulation on the slant 41 is formed extending to the ground-engaging section 42 of the bottle bottom and to the lower part of the bottle barrel portion 3, the lower portian of the bottle is made more strong.
For increasing strength of the lower portion of the bottle, additional ridged ribs 43 are formed at the crests of the respective waves or at the bends between the waves in addition to said undulation extending from the slant 41 to the ground-engaging section 42 of the bottle bottom and to the lower part of the bottom barrel portion 3. The length of such ridged ribs 43 may be suitably de-termined depending on the desired bottle strength. Said ribs 43 are usually formed on the interior of the bottle, but where no impediment is caused in use of the bo~tle, such ribs may be formed on the outside of the bottle.
This thin-walled bottle can be formed in the same way as Figure 1 but by using a blow molding die having the undulatory hollows at the part correspond-ing to the lower portion of the bottle.
_ 9 _ ~ 3 ~i4~7~) ~ lso~ this thin-walled bottle is increased in degree of stretch at the lower portion of the bottle because of its undulatory configuration and hence enlarged sur:Face area. Further, the bends between the waves can function as ribs, so that this bottle, although thin-walled, can well withstand high pressure under which a carbonated drink is charged thereinto. The frusto~conical rising at the bottle bottom, coupled with said undulatory configuration, can further enhance the stretch ratio.
If the thin-walled bottle of this invention is made from a saturated polyester resin, there is no likelihood of seepage of any harmful substance such as solvent in use and also no poisonous gas is evolved when the discarded bottle is burned.
This application is a division of application Serial No. 339,303 filed on November 6, 1979.
This i-nvention relates to an intermediate preform used to prepare a thin-walled synthetic resin bottle, particularly one formed with ribs at its bottom and/or other parts, and a method of producing such bottle.
Heretofore, glass bottles have been commonly used as containers for carbonated or refreshing drinks. However, because of their heavy weight, such glass bottles entail high transportation cost and also are inconvenient to handle.
Generally, the container cost and transportation cost account for a substantial portion of the price of such drinks, so that reduction of these costs can great-ly influence the total price of the product.
In order to overcome such problems, attempts have been made to use a bottle made from a synthetic resin which was reduced in wall thickness by means of biaxial orientation and which was formed cylindrical at its barrel portion and also bulged out spherically downwards at its bottom wall. Such a bottle although thin-walled, is provided with sufficient strength because of the biaxial orientation. However, since the bottom wall of the bottle is bulged out spherically downwards, the bottle can not be placed upright stably unless a skirt-like support member is additionally provided to the bottle bottom portion.
This results in an increased cost and marred external appearance, and also if such support member is improperly fitted, the bottle may tilt and, during auto-mated filling of the bottle with a liquid, the bottle mouth might be dislodged from the filling nozzle, thus causing improper charging of the liquid.
Provision of a bulged leg portion at the periphery of the bottle bottom wall may be used for effecting proper standing of the bottle, but in such case, insufficient strength is provided to the bottle bottom portion because the ~ ~6~370 under side of the leg portion is excess;vely lessened in wall thickness, thus making the bottle easily breakable.
In application 339,303 is described a synthetic resin thin-walled bottle in which at least one other part than the neck portion is biaxially oriented to thin the wall thickness and which has a barrel portion circular in cross-section shape, characterized in that the bottom portion comprises a frusto-conical portion extruding inwardly into the bottle, and has a plurality of radial ridged ribs in the ground-engaging section of the bottom between the lower end portion of the frusto-conical portion and the lower end of the barrel portion.
In application 339,303 is ~urther described a method of producing a synthetic resin thin-walled bottle having a frusto-conical portion at the bottle bottom comprising: forming, by injection molding, an intermediate provided with a plurality of radial ridges at least at its bottom portion; heating the inter-mediate to a temperature at which biaxial orientation can occur; setting the heated intermediate in a blow molding die; and subjecting the intermediate to blow molding in the die, thereby to form a thin walled bottle having radial ribs at a ground~engaging section formed between the lower end of a substantially circular cross-section barrel portion, and an inwardly projecting frusto-conical bottom portion.
This invention provides an intermediate used for molding a synthetic resin thin-walled bottle, said intermediate being of a bottomed and tOp-Open tubular configuration and biaxially oriented to form a thin-walled bottle, characterized in that said intermediate is provided at least at its bottom portion with a plurality of ridges extending radially from the center of said bottom portion.
Brief Descr~ion of the D awings Figure 1 is a partially cut-away sectional view of a synthetic resin 3 7 ~) made thin-walled bottle according to onc embodiment of the invention in applica-tion 339,303;
Pigure 2 is a sectional view taken along the linc II - II of Figure l;
Figure 3 is a cross-sectional view of a bottle which is a modified version of the invention in application 339,303;
Figure 4 is a sectional view of an intermediate used in maki.ng the bottle of Figure l;
Figure 5 is a partially cut-away sectional view of a thin-walled bottle also according to application 339,303;
; 10 Figure 6 is a partially cut-away perspective view of a further thin-walled bottle in accordance with application 339,303;
Figure 7 is a sectional view of an intermediate used in making the bot-tle of Figure 6;
Figure 8 is a sectional view of another ~hin-walled bottle according to application 339,303;
Figures 9 and 10 are bottom views showing the different bottom con-figurations of the bottle of Figure 8;
Figures 11, 12~ 13 and 14 are sectional views of the principal parts of the bottles which are modified versi.ons of the bottle of Figure 8;
Figure 15 is a partially cut-away view of a different thin-walled bottle according to application 339,303;
Figure lG is a sectional view of an intermediate used in making the bottle of Figure 15;
Figure 17 is a bottom view of the bottle of Figure 15;
Figure 18 is a partially cut-away view of an alternative thin-walled bottle according to application 339,303;
~ ~ B 4 3 7 0 Figure 19 is a partially cut-away view o~ a further different thin-walled bottle according to application 339,303;
Figure 20 is a view taken along the line XX - XX of Figure 19 in the direction of arrows;
Figure 21 is a sectional view of the principal parts of a bottle which is a modification of the bottle of Figure 19; and ~ igure 22 is a sectional view taken along the line XXI1 - XXII of Figure 20. Whilst this invention is concerned with the intermediates used primarily, its understanding is facilitated by considering all of these figures.
Consider first Figures 1 to 4. It will be seen that the biaxially oriented synthetic resin thin-walled bottle 1, from bottom upwards, a bottom wall 2, a cylindrical barrel portion 3, a shoulder portion 4 and a neck portion 6. The neck portion is provided with an ex~ernal thread S to be engaged with a cap. ~s for the material for the bottle of this invention, saturated poly-ester resin is preferred, but it is also possible to use other synthetic resins, such as polypropylene, vinyl chloride, etc., which are capable of increasing the mechanical strength of the bottle by biaxial orientation.
The bottom wall 2 of the bottle 1 is centrally shaped inwardly of the bottle to form a frusto-conical portion or mountain-shaped rising 7. Thus, the underside of the bottom portion between the lower edge of said po~tion 7 and the lower end of the barrel portion 3 forms the ground-engaging section 8.
On the inside of this ground-engaging section are provided a plurality of ridged ribs 9 which are arranged radially as viewed from above as shown in Figure 2.
In case the wall thickness of the bottle is made extremely thin, the outer end of each of said ribs 9 is extended along the axial line to an upper part oE the bottle barrel portion.
Such a bottle may be formed in the following way. First, a bottomed and top-open tubular intermediate 11 is formed by injection molding from a syn-thetic resin which can be biaxially oriented. The neck portion 1~ of this tubular intermediate 11 is provided with an external thread 13 so that it can immediately serve as the neck of the bottle. ~n the inside o~ the bottom portion 1~ of said tubular intermediate 11 are provided the ridges 15 such as shown in ~igure 4. Such ridges 15 are provided in plurality in radial arrangement from the center of the bottom, but no such ridge may be provided in the central part because of formation of the frusto-conical raised-up portion 7. The thus formed intermediate 11 is heated to a temperature at which b]ow molding can be accom-plished, and then it is set in a blow molding die and while blowing compressed air thereinto, the interior side of the bottom portion 14 of said intermediate is pushed down by a push-down bar or other means to effectuate biaxial orienta-tion. The molding die used here is one which has an internal configuration which allows formation of the desired external shape of the thin-walled bottle 1.
In case the additional ridges 16 are provided around the lower part of the intermediate 11, there will be formed the protuberant ribs 9, 17 on both inside and outside of the bottle as shown in Figure 3 to ~urther increase the bottle strength.
Thus, the bottle is of cylindrical shape with small wall thickness, but being biaxially oriented, it has high mechanical strength and is light in weight. Also, since an inwardly projecting frusto-conical portion 7 is provided at the bottom, the bottle can well withstand the internal pressure which de-velops with a carbonated drink is charged into the bottle under high pressure, and even if the raised-up portion 7 should be deformed under such internal pres-3 ~ 0 sure, the bot-tle bottom does not swell out spherically downwards as in the case of a flat-bottom bottle~ and hence hori~ontality of the ground-engaging portion 8 of the bottle will not be impaired. Therefore, the bottle will not tilt when it is placed uprightly, and further, since a plurality of ribs 9 are provided radially (as viewed from above~ on the inside of the ground-engaging section 8 of the bottom wall, the strength of the lower portion of the bottle is increased to provide an extremely high impact strength at accidental drop of the bottle.
Referring to Figure 5, there is shown a second bottle where the ridged ribs 9a formed at the bottle bottom portion ex*end to the slant of the frusto-conical portion 7 and also to the lower part of the barrel portion 3 of the bottle thereby to increase resistance against buckling load at the lower section of the bottle barrel portion.
A third bottle is shown in Figures 6 and 7. In this bottle, the ribs 9b are formed extending along the full axial length of the barrel portion as shown in Figure 6, whereby the buckling strength is greatly increased.
There are also provided ring-shaped annular constrictions 18 around the lower part of the barrel portion 3. This can increase stretch ratio of the barrel portion 3 while elevating its strength owing to the rib function.
The intermediate used in this bottle is provided with long strips of ridges 19 which extend along the axial line of the tubular intermediate 11.
Such ridges 19 may be provided on the outer periphery of the intermediate 11.
In Figures 8 to 14 is shown a fourth bottle. In this case, *he bottle bottom portion 20 has its central part bulged out inwardly of the bottle to form a frusto-conical raised-up portion 21~ with the base part of said raised-up po-rtion 21 being stepped to form a gentle rising portion 22. This portion 21 may be either formed into a continuous saucer-like part as shown in Figure 9 or _ ~ _ J ~ 6~37~
may be stepped radially at several sections as shown in Figure 10.
As a modification of this bottle, the frusto-conical raised-up portion 21 may be formed lmdulately by forming continuous recessions and ridges alter-nately as shown in Pigure 11. Also, stepped portions 25 may be formed at the recessions 23 as showm in Figure 12. In still other modifications, the stepped portions 25 may be provided in both recessions 23 and ridges 24 as shown in Figure 13 or only in the ridges 24 as shown in Figure 14.
Further, a plurality of protuberant ribs 28 may be formed radially from the central part of the bottom wall, as viewed from above, on the interior of the lower portion of the bottle, as shown in Figure 8. In this case, the strength of the bottle bottom is further increased if the protuberant ribs are so provided as to extend to the slant 21a of the raised-up portion 21 and also to the lower part of the bottle barrel portion 3.
Thus, in the thin-walled bottle according to Figures 8 to 1~, since a stepped region is formed at the lower end of the raised-up portion, the sur-face area of the raised-up portion is more enlarged than in the case of other embodiments, resulting in increased degree of stretching of the bottom wall and elevated rigidity of the bottom wall owing -to the rib fwnction. For further in-creasing strength of the bottom wall of the bottle, the protuberant ribs are formed at the pertinent area.
Now, a fifth bottle is described with reference to Figures 15 to 17.
The bottom portion 29 of the ~hin-walled bottle is provided with continuous jagged ribs 30 arranged radially from the center of the bottom and undulatory in sectional shape. These ribs 30 are so arranged that their height is zero at the center of the bot~le bottom but gradually increases toward the ou~er peri-phery, and the outer side of the bottom portion of each said rib 30 is designed 1 ~ 6~ 37~) to form a ground-engaging section 30a for allowing upright standing of the bottle.
Additional ridged ribs 31 are formed at the bends of each undulation formed by the ribs 30 on the inside of the bottom portion of the bottle, said ribs 31 extending down to the lower part of the bottle barrel portion. Although no ribs 31 are provided at the central part o-f the bottle bottom portion, they may be formed extending along the full vertical length of the bottle barrel portion. Where no impediment is given to use of the bottle, the ribs may be also provided on the external surface of the bottle to further increase its strength.
~or forming the above-described thin-walled bottle, a tubular inter-mediate 33 having the ridges 32 is subjected to blow molding in a blow molding die in the same way as Example 1, thereby forming a bottle having the radial ribs 30 at the bottom.
The thus made thin-walled bottle is extremely enhanced in strength of its bottom portion by dint of the ribs 30 at the bottom and the ridged ribs 31 at the bottom and barrel portion of the bottle. l`he ridged ribs on the interior of the bottle are pro~ided as the ridges formed on the interior of the intermedi-ate remain as they are after blow molding, but when the ridged ribs are formed on the exterior of ~he bottle, blow molding of the bottle becomes easier as there is no need of giving consideration to formation of the ridged ribs on the interior of the bottle. In this case, the grooves corresponding to the ridged ribs to be formed are provided in the molding die.
Reference is now had to Figure 18. In this bottle, the bottom portion 34 of the bottle is bulged out spherically downwards. Since the bottle is un-able to stand upright by itself, there is required a supporting leg member 35 ~ ~fi'~37~J
that fits with the bulging bottom portion of the bottle. It will be seen that the top protuberant portion 3~ of said leg member 35 fits with the corresponding annular stepped portion 37 fo-rmed at the lower part of the bottle.
There are also provided on the interior of the bottle bottom portion 34 a plurality of ridged ribs 38 arranged radially from the center of the bottom portion. If necessary, such ridged ribs 38 may be extended all the way to an upper part of the bottle.
In this bottle, because of the spherical configuration, the bottom portion of the bottle is very tough and also blow molding is facilitated.
Referring to Figures 19 to 22~ in this bottle, the central part of the bottom portion 39 of the bottle is bulged inwardly of the bottle to form a frusto-conical raised-up portion 40 and the slant 41 thereof is formed undulate-ly as shown in Figure 20. If the undulation on the slant 41 is formed extending to the ground-engaging section 42 of the bottle bottom and to the lower part of the bottle barrel portion 3, the lower portian of the bottle is made more strong.
For increasing strength of the lower portion of the bottle, additional ridged ribs 43 are formed at the crests of the respective waves or at the bends between the waves in addition to said undulation extending from the slant 41 to the ground-engaging section 42 of the bottle bottom and to the lower part of the bottom barrel portion 3. The length of such ridged ribs 43 may be suitably de-termined depending on the desired bottle strength. Said ribs 43 are usually formed on the interior of the bottle, but where no impediment is caused in use of the bo~tle, such ribs may be formed on the outside of the bottle.
This thin-walled bottle can be formed in the same way as Figure 1 but by using a blow molding die having the undulatory hollows at the part correspond-ing to the lower portion of the bottle.
_ 9 _ ~ 3 ~i4~7~) ~ lso~ this thin-walled bottle is increased in degree of stretch at the lower portion of the bottle because of its undulatory configuration and hence enlarged sur:Face area. Further, the bends between the waves can function as ribs, so that this bottle, although thin-walled, can well withstand high pressure under which a carbonated drink is charged thereinto. The frusto~conical rising at the bottle bottom, coupled with said undulatory configuration, can further enhance the stretch ratio.
If the thin-walled bottle of this invention is made from a saturated polyester resin, there is no likelihood of seepage of any harmful substance such as solvent in use and also no poisonous gas is evolved when the discarded bottle is burned.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An intermediate used for molding a synthetic resin thin-walled bottle, said intermediate being of a bottomed and top-open tubular configuration and biaxially oriented to form a thin-walled bottle, characterized in that said intermediate is provided at least at its bottom portion with a plurality of ridges extending radially from the center of said bottom portion.
2. An intermediate according to Claim 1, wherein said ridges are formed extending to the side wall of the intermediate.
3. An intermediate according to Claim 1 or 2, wherein said ridges are formed on the interior and/or exterior of the intermediate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000429480A CA1164370A (en) | 1978-11-07 | 1983-06-01 | Synthetic resin made thin-walled bottle and method of producing same |
Applications Claiming Priority (14)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13741978A JPS5564039A (en) | 1978-11-07 | 1978-11-07 | Bottle made of saturated polyester resin and having small thickness but large size |
| JP53-137419 | 1978-11-07 | ||
| JP14569078A JPS5571244A (en) | 1978-11-24 | 1978-11-24 | Bottle made of twooaxissextended synthetic resin |
| JP53-145689 | 1978-11-24 | ||
| JP14568978A JPS5571243A (en) | 1978-11-24 | 1978-11-24 | Bottle made of twooaxissextended synthetic resin |
| JP53-145690 | 1978-11-24 | ||
| JP53-149871 | 1978-12-04 | ||
| JP14987178A JPS5579235A (en) | 1978-12-04 | 1978-12-04 | Bottle made of twooaxissextended synthetic resin and method of manufacturing said bottle |
| JP15331378A JPS5579238A (en) | 1978-12-11 | 1978-12-11 | Bottle made of twooaxissextended synthetic resin |
| JP53-153313 | 1978-12-11 | ||
| JP15825378A JPS5571245A (en) | 1978-12-18 | 1978-12-18 | Innprocess product for making bottle of twooaxissextended synthetic resin |
| JP53-158253 | 1978-12-18 | ||
| CA000339303A CA1153323A (en) | 1978-11-07 | 1979-11-06 | Synthetic resin made thin-walled bottle and method of producing same |
| CA000429480A CA1164370A (en) | 1978-11-07 | 1983-06-01 | Synthetic resin made thin-walled bottle and method of producing same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1164370A true CA1164370A (en) | 1984-03-27 |
Family
ID=27570249
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000429480A Expired CA1164370A (en) | 1978-11-07 | 1983-06-01 | Synthetic resin made thin-walled bottle and method of producing same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1164370A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9650170B2 (en) | 2014-12-10 | 2017-05-16 | Colgate-Palmolive Company | Container with arcuate sidewall panels |
-
1983
- 1983-06-01 CA CA000429480A patent/CA1164370A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9650170B2 (en) | 2014-12-10 | 2017-05-16 | Colgate-Palmolive Company | Container with arcuate sidewall panels |
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