CA1200798A - Disposable polyester pressure container - Google Patents

Abstract

ABSTRACT

A pressure vessel 10 constructed of biaxially oriented polyethylene terephthalate and application for the same. The application involves use of the PET
pressure container 10 as a fluid dispensing device 1, with a bladder 12 contained therein, whereby said device is disposable after a single use. The fluid dispensing device 1 is useful in domestic applications involving the application of various chemicals to lawns, gardens, automobiles, and the like, as through a driving fluid source, e.g., home water pressure, forcing the contained fluid out of the device 1. The disposable feature of the device 1 eliminates the necessity for storage in the home or garage of containers containing chemical residues.

Description

9~3 D~SPOS~BLE PO~YESTER PRESSUR~ CONT~INER

TECHNICAL ~IELD
The i~lvention relates to pressure containers.
Specifically, ~he invention relates to a disp~able pressure container cons~ructed of biaxially orientated polyethylene terephthalate (PET) which has an internal bladder and is useful in the dispensing as well as in the diluting of fluids via the application of low to moderate gas or hydrostatic pressure to either said P~T
container or said bladder.

BACKGROUND ART

Disposable pressure contaîners are widely used for a varie~y of applications requiring internal pressures above atmospheric. Generally, disposable containers of the known art ha~e been constructed of metal such as s~eel or aluminum.
The use of plastics for such construction has heretofore been avoided due in part to the generally lower tensile strength of plastics when compared to metals, other than for use as beverage bottles.
Heretofore, in applications utilizing pressure containers, the disposable pressure con~ainer is used to store a propellant gas which in turn provides the drîving force for the application of the content~.
30 - When gas pressure is used, there is always the danger ~ container rupture and su~sequent pPrsonal injury.
U. S. Pa~ent No. 3 9 733,309 relates to biaxial-ly orientated bottles, but does not relate to a pressure container having a bladder therein, an inlet tube, an outlet tube, etc. Hence, it is not pertinentO

DISCLOSURE OF INVENTION
In light of the foregoing, it is an object of an aspect of the instant invention to provide a polyes-ter pressure container.
An objec-t of an aspect of the invention is to provide a polyester pressure container, as above, which is disposable.
An object of an aspect of the invention is to provide a polyester pressure container, as above, which is corrosive resistant.
An object of an aspect of the invention is -to provide a polyester pressure con-tainer, as above, in which the polyester is biaxially oriented P~T.
An object of an aspect of the invention is to provide a polyester pressure container, as above, in which said container con-tains a flexible or a flexible and expandable internal bladder.
An object of an aspect of the invention is to provide - a polyester pressure container, as above, in which said container contains a device for dispensing, as well as dispensing and diluting, material contained within said container.
An object of an aspect of -the invention is to provide a polyes-ter pressure container, as above, which can be used, for example, in domestic applications and for dispens-ing of water miscible chemicals by using domes-tic wa-ter pressure.
Various aspects of this invention are as follows:
A disposable container, comprising:
a biaxially orientated polyethylene -terephthalate container, said container having a bladder therein, said bladder being made of a flexible material;
including an inle-t means for receiving a driving fluid, and an outlet means for dispensing a fluid contained in said container;
including said opening in said container, and including a cap, said cap covering said opening, said inlet means and said outle-t means extending -through said cap;
including a mixing means for diluting sald dispensable fluid upon discharge from said con-tainer, at a uniformed dilution ratio du;lng utiliza-tion of said container, said dilution ratio being from about 1 percen-t to abou-t 99.9 percent by weight.
A process for making a disposable plastic container, comprising the steps of:
10biaxially forming a polye-thylene terephthalate container, inserting a flexible bladder into said biaxially orientated polye-thylene tereph-thala-te container;
positionlng an inlet means for receiving a driving fluid;
15posi-tioning an outle-t means permitting said dispensable fluid to be dispensed from said container;
forming said biaxially oriented polyethylene terephtha-- late container by blow molding, utilizing a mixing device with said container, said mixing device uniformly diluting said dispensable fluid upon dispensing -thereof, said dispensing being at a dilution ratio of from 1 percent to 99.9 percent by weigh-t.
BRIEF DESCRIPTION OF DRAWINGS
For a better understanding of the objects, techniques, and structure of the invention, reference is made -to the following detailed description and accompanying drawings wherein:
Fig. 1 is a cross-sectional side view of one embodiment of the invention in which a bladder is used to force liquid out of a press~re container;
Fig. 2 is a cross-sectional side view of the same embodiment with -the bladder par-tially filled;
Fig. 3 is a cross-sectional side view of another embodiment of the invention also utilizing a bladder, 35Fig. 4 is a cross-sectional side view of a third embodimen-t which, in addi-tion to a pressure con-B

'7 ~4-tainer and a bladder, ~ltili~.es an ori~ice; and Fig, 5 is a cross-sectl~onal s~de view of yet another embodiment of the invention utilizin~ a pressure container, bladder, and orifîceO

BEST ~ODE FOR CAR~ING OUT THE nrVENTION
_ _ .
FigS. l through 5 depict sev~ral embodiments utilizing the novel pressure container of the instant invention. In all of these embodiments, a flexible, or a flexible and expandable bladder are used to dispense fluido The embodiments differ in the ~anner in which the liquids are dispensedO
Referri.ng now in particular to Figso 1 and 2, it is seen that a liquid dispensing device is des;gnated generally by the number 1. The pressure container 10, preferably spherical in shape, receives inlet and outlet conduits 18 and 20, respectively, through which flow the fluids used in operation o the dispenslng deviceO
The pressure container 10 is constructed of polyethylene terephthalate, hereinafter abbreviated as PETo By PET i~ is meant that no copolymer or other constituent is utilized. Such a compound is generally referred to by the art as pure PET.
The PET resin utilized in making the contain~
er is made according to conventional methods and pro-cedures using conventional catalysts and reaction condi-tionsO Such method and procedures of resin production are well known to the art and do not orm part of ~he present invention.
The PET pressure container of the present in-vention need not be refilled and can therefore be di.s-carded after one useO Hence, it ~s termed disposable.
The PET used in construction of ~he pressure container 10 should have a high tensile strengthO Such tensile strength is obtained through the use of a ~ 7~ ~

process known as biaxial orientation~ In this conven-tional blow molding pxoces.s, a prefox~e~ PET parison of general cylindri:cal shape is fixst stretched along its longitudinal axis and ~hen along its radial axis to form the desired shape of the ~iaxially orientated PET container. In the embodiments describ~d herein, the pressure container 10 is spherical, which, as is well known in the art, is the geometrical shape which . can withstand the greatest amount of pressure for a given internal volume. However, it is to be understood that pressure containers having shapes other than spheri-cal can also be utilized.
The inlet conduit 18 and the outlet conduit 20 respectively enter and exit the pressure container 10 through container port 11 and are maintained in place as through cap 13. A pressure tight seal is maintained between said inlet and outlet ports and the eontainer port 11 by appropriate means as through cap 13. The cap may be attached to container port 11 in any conventional manner as,through threads~ mechanical engagement, adhesive, etc.
The inlet and outlet ports 18 and 20 are of conyentional design having end connections or fasteners suited to particular applications~ In the em~odiments described herein, the inlet conduit 18 has an end fastener l9 suitable for attachment to a hose, e.g., a garden hose, said garden hose supplying the necessary hydraulic pressure to operate the liquid dispensing device 1. The end connection 21 of the outlet conduit 20 may also be of such deslgn as to permit connection to a domestic garden hose, or of other design permit-ting a variety of pressure source attachments to be appended for dispensing of liquids contained within dispensing deYice 1.
Bladder 12 is made out of any generally fluid-impervious material which is flexible. The ~terial can also be expandable; that îs, stretchable, e.g., rubber. Examples of suitable ~aterials include polyester, polyethylene, polyvinyl chloride, ru~ber~
and the like. The bladder is attached to the inlet or outlet tube in any conventional manner, for example, as by a hose clamp, etc. Alternatively, it may be attached to cap 13 in any ccnventional manner and to either tube 18 or 20 therein. As shown in Fig. 1, the bladder is attached by a screw hose clamp 25. The tube can have a shoulder 27 thereon to retain the bladder. One form of a bladder is a collapsed bladder; that is, a bladder which extends the full length or depth of container 10 but is folded, pleated, or otherwise exists in a col-lapsed condition as shown in Fig. l.
The li~uids dispPnsing device 1 operates in the manner illustrated in Figs. 1 and 2. In Fig. 1, t is seen that the bladder 12, attached to the inlet conduit 18, is much smaller than the internal volume of the pressure container 10. A driving fluid 14 enters the bladder 12 through inlet conduit 18 and thereby enlarges or inflates the collapsed bladder 12~
As said bladder expands, dispensable fluid 16 contained in the container, is forced out of outlet conduit 20.
Fig. 2 shows bladder 12 in its non~collapsed state occupying a large percentage of the internal volume of the pressure container 10. The bladder in the embodi-ment will enlarge until it bears against the inside of container 10. Throughout înflation, little pressure is borne by the bladder wall or surface since the pres-sure difference is usually small or nil, and hence the bladder wall thickness need not be extraordinarily thick.
The pressure container 10 must be capable of withstanding the positive pressure of driving fluid 14.

Such fluid,may be a co~pressed gas or prefer~bly a liquid. The use of a liquid such as home wa~er re~
duces t~e am~nt o danger ~ould ~he container rup-ture, as compared to the use of a gas. The biaxially o~ientated PET container is thus pro~Jided wlth a suf-ficient thickness to safely withstand encountered pressures~
A common utilization of the container is in association with municipal water systems, which generally have a pressure o~ from about 50 to about 100 psi.
Generally, for home or yard use, a size of from about 1 to about 7 gallons is suitable.
Fig. 3 shows a second embodiment of the in-vention in which the dispensable fluid 16 is contained within the bladder 120 Desirably, the initial bladder size is that of the container so that as mNch as possi-- ble of dispensing fluid is contained by the bladder.
The principal for dispensing of the fluid is the same as in the previous embodiment, except that here the , driving fluid 14 is contained directly within the pressure container 10. The pressure of the driving fluid 14 forces the bladder 12 to contract and thereby dispense the fluid contained wlthin through outlet tube 20.
Figs. 4 and 5 show other embodiments uti-lizing a mixing device or head 30. Unlike Figs. 1,

2 and 3, the dispensing fluid is diluted in these em-bodimen~s. Here, as in the previous two embodiments, dispensable fluid 16 can be contained directly within pressure con~ainer 10 or within bladder 12. In either case, the driving fluid 14 enters mixing device 30, which in ~hese em~odiments is a tube 22 having an ori-fice 24 therein, where the flow is divided between inlet cond~it 18 and orifice 240 The sizing of the orifice 24 regulates the proportion of the driving fluid 14 ~lo~n~ thro~h ~a~d oxif~ce and thxough the inlet conduît 18 ~nd thus the ~ou~ of dilution~ The amount o* dilu~on can vary from li~tle or nil, i~e,, about 1 percent by weight, to ~ery ~uch, i~e,, abou~
39,9 percent of diluting fluid by weight.
The dispensable fluid 16 which passes through the outlet conduit 20 and into the mi~ing device 30 is combined with the driving fluid 14 which passes through orifice 24. This arrangement is useful in those situations in which it is desirable to dilute dispensable fluid 16 prior to applicationO For example, a liquid fertilizer may be applied to a lawn or a garden by attachment of a domestic water hose to the inlet conduit 18 of the container and the fert~lizer dispensed thereby. In so doing, the portion of the water passing through the orifice 24 is intimately mixed with the dispensing fluid as it passes out of the outlet conduit 20. Since the pressure at the inlet of the orifice 24 and the inlet conduit 18 are relatively equal, the relative proportions of dispens-ing fluid and water exiting the mixing head 22 is not appreciably affec~ed by normal fluctuatlons in the hydrostatic pressure of the water liner feeding the înlet conduit 18. Thereby, a uniform or constant ratio of dispensing fluid and water is usually maintained.
The mixing device 30 and orifice 24 are of conventional design and materials. Like the inlet and outlet conduits 18 and 20, the mixing device 30 may contain end connections 26 and 28 suitable for secure-

3~ men~ to domestic garden hose or other devices supply-ing a driving fluid 14 and dispenslng the fluid 16.
The orifice 24 may be interchangeable with orifices having different diameters or configurations to ~ary the percentage of driving fluid 14 which passes there-throughO It is appreciated that the orifice 24 may ¢3'7~1~

also be replaced by a plug which completely eliminates ~lo~through, di~ec~ing all the dri~ing fluid into the inlet conduit 18. In this design, the embodiments described in Figs o 4 and 5 are essentially ident;cal to those embodiments shown in Figs. 1 through 3. In lieu of an orifice type-mixer, lt is to be und~rstood that any conventional diluting device can be used.
The size of container can vary greatly de-pending upon the desired amount of fluid contained thereinJ application, and the like~ The dispensing fluid can be a fertilizer, a pesticide, a herbicide, a sealant, a paint, etc. The container, after dispense-ment via any driving fluid, e.g., water, air, etc., can be discarded thereby alleviating any necessary cleaning, storage, etcO An importan~ feature of the present invention is that container 10 preferably is filled wi~h a non pressurized dispensing fluid and, thus, reduces, if not eliminates, the possibility of an explosion as exists in ordinary spray cans~ The only time con~ainer 10 is subjected to pressure is thus during the dispensing of the fluid therein. Another advantage of the present invention is that the cap and inlet and outlet condui~s can all be moldable as one integ~al unît. The same is true when a mixing head is utilized. Thus, these components c.ln be readily and inexpensively made. The invention will be better under-stood by reference to the following examples.

EXAMPLE I
(Non-Mix ng) A fi~e gallon PET sphere was blow molded from a parison by procedures that are standard in the in-dustry. The resulting sphere was then fitt d with a cap with inlet and outlet connections. A bladder within the sphere was a~tached to the outlet connection and filled with the liquid to ~e dispensed. A domestic 'J'~

water hose was attached to the inlet connection and water pressure at appr~ximately 7Q psi applied to the sphere. The pressure caused the bladder to contract and force the dispensable liquid through the outlet con-nection without mixing the two liquids.

EXAMPLE II
(Non-Mixing) The bladder within the sphere previously described was attached to the inlet connection and the sphere was filled with the liquid to be dispensed. A
domestic water hose was attached to the inlet connection and approximately 70 psi water pressure was applied to the bladder causing it to expand and force the dispensa-ble liquid within the sphere through the outlet connec-tion without mixing the ~wo liquids.

EXAMPLE III
(Mixing~
~he fiYe gallon sphere as heretofore described was fitted with a cap with an inlet and outlet connec-tion. A bladder within the sphere was attached to the outlet and filled with a dispensable liquid of known concentration~ The cap contained an orifice connecting the inlet and outlet. When water from a domestic hose at approximately 70 psi was applied to the inlet con-nection, the inlet water passin~g through the orifice was mixed with the dispensable liquid being discharged as the bladder contracted, i~e., the inlet was divided into two streams. One stream pressured the sphere and forced the dispensable liquid fro~ the bladder into the second stream which passed through the orificeO The water through the orifice and the dispensable liquid from the bladder con~erged at the discharge point re-sulting in a mixt~re of water and dispensable liquid~

3'7~

The concentration of the dispensa~le l;quid in the water was determined by analysis of the mixture, Several orifice sizes were tested and thP degree of dilution was confirmed by analy~is~

EXAMPLE I~
(~ing) The five gallon sphere as described in Example III was :Eilled with dispensable li~uid of known concentration~ A bladder was attached to the inlet inside the sphere and domestic water at approxi-mately 70 psi was applied to the inlet connection. As the water pressure was applied, the bladder expanded forcing the dispensable liquid within the sphere through the outlet connection. The water passing through ~he orîfice and the dispensable liquid convert2d at the discharge resulting in a mixture, the concentration o~
which was confirmed by analysis o:E the mixture. Several orifices were tested and the amount of dilution was confirmed by analysis, From the foregoingj it can be seen that the objects of the invention have been satisfied by the embodiments presented hereinabo~eu While in accordance with the patent statutes, only the best mode and pre-ferred embodiments of the invention have been presented and described in detaiL, it is to be understood that the invention is not limited thereto or thereby. Accord-ingly, for an appreciation of the true scope and breadth of the invention, reference should be had to the appended claims.

3~

Claims (8)

The embodiments of the invention in which an exclusive property of privilege is claimed are defined as follows:

1. A disposable container, comprising:
a biaxially orientated polyethylene terephthalate container, said container having a bladder therein, said bladder being made of a flexible material;
including an inlet means for receiving a driving fluid, and an outlet means for dispensing a fluid contained in said container;
including said opening in said container, and including a cap, said cap covering said opening, said inlet means and said outlet means extending through said cap;
including a mixing means for diluting said dispensable fluid upon discharge from said container, at a uniformed dilution ratio during utilization of said container, said dilution ratio being from about 1 percent to about 99.9 percent by weight.

2. A disposable plastic container, according to claim 1, wherein said container is spherical.

3. A disposable plastic container according to claim 1, wherein said bladder is made from a material selected from the group consisting of a polyester, a rubber, a polyethylene, a polyvinyl chloride, and the like.

4. A disposable plastic container according to claim 3, wherein said mixing means is a tube having an orifice therein.

5. A disposable plastic container according to claim 4, wherein said inlet means is attached to said tube upstream to said orifice, and wherein said outlet means is attached to said tube downstream from said orifice.

6. A disposable plastic container according to claim 5, wherein said bladder is attached to said inlet means.

7. A disposable plastic container according to claim 6, wherein said bladder is attached to said outlet means.

8. A process for making a disposable plastic container, comprising the steps of:
biaxially forming a polyethylene terephthalate container, inserting a flexible bladder into said biaxially orientated polyethylene terephthalate container;
positioning an inlet means for receiving a driving fluid;
positioning an outlet means permitting said dispensable fluid to be dispensed from said container;
forming said biaxially oriented polyethylene terephthalate container by blow molding;
utilizing a mixing device with said container, said mixing device uniformly diluting said dispensable fluid upon dispensing thereof, said dispensing being at a dilution ratio of from 1 percent to 99.9 percent by weight.