Note: Descriptions are shown in the official language in which they were submitted.
- IL ~o~3~8
ACKC I~OU ~ D O F TH E I NVLNTl ON
The instant invention relates to a novel sterile packet I ~ ;
,, for sterili~ing medical instrumeni~:s and i~he like, and to the
,,method for sealing tl~e instrumen~ in the packet. ~lore par'ticu~
i' larly, this inventi3n relates to a composite packet having a ' , .
~ lltransparent face and an opaque face provi~ed witll interior and
: 'I exterior sterilization indicators, including means ~or preventing
~slippage durin~ s~erile deLivery o~ tlie ins~rument.
, While various sterile packs are co~riercially available, I ;
none inc'ludes the requisi~e com'bination of desirable qualities. `'`~
'`The optimal sterile packet should have lnterior and exterior
'~ sterilization indica~ors'; i~ should have a positive seal on all l;
sides to avoid con~amina~ion; it should lnclude means for pre- !
enting slippage o~ the instrument from the packet interior dur~
!l ing sterile delivery thereof; and the substrate of which the~pack
' is fabricated should be~suitably~ porous so as to permit the
llsterilization mediu~ to sterilize the enclosed instrument, but
pre~lude entry of microorganlsms therein. It is also deemed ``~
highly desirable to provide a sterile pack: that may~be opened .
and closed witbout contacting the interlor side walls ~hereof. '.`
Accordingly, a sterile pack wî~hi.n tlle scol~e o~ tlne 1
instan~ invention includes this com~ination ~f ~dvan~ages, includ~
. . jiing a novel sealing method~ Th~ pack periorms lligl-l.y satisfac~
,torily under conventional steam or ethylene oxide sterilization
procedures,
S~RY OF TH~ INVENTION
~: - ,, Generally speaking, in accordance with tlle invention,
~a sterile~pack blank is provided which comprises an enclosure
~5 3
¦determine~ ~y a su~s~rate o predetermined porosity and a discrete
¦plastic film overlying the porous substrate, The film and porous
substrate are adhesively connec~ed by a coliesive or self-sealing
adhesive. The porous substrate is prin~ed with a continuous
I adhesive track, while substan~ially an enti~e surface of the
¦ plastic film is adhesive coated. An end flap of the film is I ~
folded back upon itself along a fold line to provide access to ¦ ~ ;
¦Ithe enclosure interior. ~ter intro~uc~ion o~ ~n instrument into ¦
¦~the enclosure, ~he film end flap is hingedly connected to the ¦
!I substrate~ along respective adhesively coated areas thereof,
l¦according to the sealing method o the invention.
I
The adhesiye is characterized by the fact that it is
self-~dhering. Therefore, on~y interfaced areas of the film and
substrate that are respectively coated with the adhesive may be
¦ adhesively connected. The adhesive coating on ~he film is further
characterized by a predetermined tack value for thereby providing
for sterile delivèry of an instrument from the pack.
~¦ The porous substrate 1~ provided, respectively with
lexterior and interior~sterili2ation indicators. The indicators ¦
; comprise respective pairs of s~eam~and ethylene oxi~e sensitive
¦ inks, The exteriorly located indicators are in~edi.ately sensitive
i the
¦ to/s~erilizing ambienc ~of the pack, while the inte~iorly located
¦ indicators are sensitive/a sterilizi~ environment withLn che pack
I enclosuL-e .
- ¦ ~ ~ Accordlngly, it is an o~ject of this invention to~ j
provide a sterile pack having a novel construction.
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Another o~ject oE ~he inventi.on is to provide a steri;el
pack having internal and external indica~ors'for respective'ly~ ''
showing a sterile environment wi~hin the pack enclosure and a ¦
' sterile ambience for the pack.
Still another objec~ o the invention is to provide
a sterile pack which includes means for preventing slippage of
an instrument therefrom to tl~ere~y cna~le sterile delivery of ,~ ,~
i' the instrument from ~he pack. ~
;~,! Yet another object of the instan~ invenLion is to
provide a novel method ~or sealing the sterile pack a~ter the ' ,.
instrument is introduced therein.
'
Still other objects and advantages of the invention
~ will in part be obvious and'~ill in part be apparent from the
`~" ''¦ specification,.
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' The inveneion accordingly~comprises an article~of
" ,manufacture possessing the ~eatures~ properties,~and the relation
, , , .. ~ .
, of elements which will be exemplified in ~he article hereinafter
!i
' ~" described, and~the~;several steps for sealing the article and the
relation of one or more of such steps wlth respect to each o
the others thereo~ which will be exemplified in the metho~
hereinafter disclosed, and the scope of the tnvent;on will be
"indicated in the c~laims.
,i ' BRIEF DESCRIPTION 01~ TII~ ~KAWINGS
' For a fuller understanding~' of ~he invention, reference~
' is had~to the follo~'~in~ description taken in Lonnectlon wlth the~
accompanying drawings, in which~
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~ig, 1 i's a bottom ~lan view o a sterile pack within I
the scope of the instant invention;
li Fig. 2 is a top plan view of tlle em~odiment shown in
j~ Fig. 3 is a sectional view taken along line 3-3 of the
¦embodiment s~en in Fi~. 2;
Figs. 4-6 are detail views sequen~ially showing method
steps for seallng the pack after lntro~uc~ion oE the ins~rumen~
¦therein; ~ ~ ~ ;
i Fig. 7 is a sectlonal view taken along line 7-7 of ~ '
iFig. 6 showing an instrument sealed within the pacl;;~
Fig. 8 is a perspective view showing the manner of
~presentation o~ the instrument af~er sterilization;~and
~igs. 9 and 10 are'fragmentary details respec~ively ;~
showing gas and steam indicators provided on the pack.
. DESCRIPTION OF THE PREl;'ERRl~D ~2IBODI~IENT ~
:` I ~
¦ ~ Referring now to Figs.~1-3 and~7~ O,~a non-woven~sub-
strate ll, for~instance~of paper, paper board,fiber-bonded
syntheti¢ and the like of generally rectangùlar shape, is pro- --
~ided~with a~continuous printed a~dhesive ~rack L2 along the sur-
~ I face 13 thereof. Adhe~sive track 12 consisting oE an adhesive
-~ ¦12' is of substantially~'~uniform~width and,~ln goneral, runs~'
~ ~ lalong~the margin~o surface l3 of`~the substrate. At the top l4
,!, ~ , of the packet, su~stan~ially symmetrical segments 15, 15' of;the
track detour acutely~inwardly relative to top end~l4 of the
' packet and converge at~ a~vertex 16 ~for a purpose which will be
hereina~ter describ'èd. ~Provided-in substr'ate ll are resp ctive
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31 ~.8 :
pairs 17, 17' ~nd 18, 18' oL steriliza~ion indicators. One mem-
~ber 17, 18 of eacll respective pair of in.licators is located on I ~;
the surface 19 of substrate 11, and eacl~ corresponding member , :
17', 18' o~ the pair is located on the sur~ace 13 o~ subs.ra.e
1111. As seen in the F~gures., respe.^tive members of each pair.of I . ~ :-
: ~indicators overlie each other.
Overlyin,~, surface 13 of subsLLa~:c 11 is a ~liscre~e
, subs~antially rectangula~ section o~ ~ clear plastic ~ilm 20,
fabricated for instance of high or low densi~y polyethylene,
,Ipolypropylene or polyetheyleneterephthala.~e.The surface 21 thereof
which inter~aces with-surface 13 of su~strate 11 is substantially
complerely coa~ed with adhesive 12'. Overlapping adhesively
¦coated areas of substrate 11 and film 20 are adhesively connected
...
~` ~hereby determining an enclosure 22 into which access may be had 1 ~.
, through an inlet slot 2~
~ ~l At top end 14 of the pack, end wall 24.of film 20 is
:~ j'substan~ially uniformly foreshortened relative to end wall 25 :
jif substrate ll for a purpose which is hereinafter described
~ An end flap 26 of film 20 is ~olded back upon itself along a ! ;
:. l : .:
fold line 27 for thereby definin~access slo~23. ~.er intro-
I¦ duction of an instrument 28 into enclosure 22, ~lap 26 may be
; ~I hingedly connected to substrate 11, along respective adhesively -
coated areas thereof, according to~tbe sealing m~hod within the .
~scope oE the invention.
. Adhesive 12' is a cold or cohesive seal type commercially
,1 ~
- ~ .i svailable self-adhering a.-lhesive.~:~These adhesives are typic-ally
. ~ of the rubber la~ex type. Therefore, only con~only adhesively
- ~, coated areas of subs.~rate 11 and film 20 may be adhesively sealed.
1053~8~
In ~abricatill~ tl~e blanlc 29, as best seen in ~ig, 2, adhesive ¦
~rack 12 of su~sta~e 11 may be sealed a~ainst the adhesively ¦
coated surface 21 of ~ilm 20 by convell~ional mechanical me~ns.
The in~erior o~ surface 13 o~ subs~ra~e 11 is uncoa~e~ and ~hPre- !
fore presents a foreign subs~ance along i~s interface with adhes-
ively coated surEace 21 o film 20 which does not seal therewith,
thereby ~e~inin~ enclosure 22. ~nd ~lap 26 lS overcoate~ wi~h
adhesive 12' and there~ore remains ~ree because o~ ~lle collesive
character thereof, until it is pivoted outwardly into sealed
overlying relationship on track 12 of substrate 11. While the
cohesive cliaracter o`f ~dhesive 12' assures that no substantial
adhesion occurs between adhesively coated surface 21 of film 20
. ~ ,. .
and instrument 28 introduced into enclosure 22 of blank 29,
the adhesive 12' on surface 21 o film 20 is preferably character-¦
ized by a pxedetermined tack for inhibiting accidental slippage of
instrumen~ 28 rom the pack upon s~erlle presentation thereof,
for there~y assuring sterile delivery of instrument 28.
The statistical ;likelihood o~ success~ul sterile deliv-
ecy after sterlle presentaLion o~ instrument 28 is optimlzed wl~en
the tack value of a~hesivc 121 on sur~a~e 21 of ~ilm 20 is ~etwecn
about 0.5 to about 60.0 sec., and prefera~ly betweell about 2.5 ~! -
~and about 12.0 sec., as measured according to a mc~ ied version~
or~psTc-l4 (11/70~. The modiLicatLon was introduce~ to account
f~r ~ E -t ~h-- ins~r~e~ 28 I; o~en c~-,nlo s sce~
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tungsten steel and the like. According to the test method - `~
2 x 5 x 1¦16 inch stainless steel substrates, type 302, finish
No. 4 were provided. The test substrates were scrubbed with
surgical gauze saturated with diacetone~alcohol, wiped dry,
scrubbed a second time with surgical gauze saturated with
isopropyl alcohol, and air dried 2 x 2 inch paper masks were ;`~
cu~ (max. paper thLckness 0.002 inch) and rectangular windows
or slots of the dimensions, 1 x l ~ O.Ol inches, were provided -;
in the middle thexeof. ~
Strips, approximately 5 x(1.5 - 1.8)inches, of
àdhesive coated plastic film were CUt. The tes~ specimens were ~'
laLd on a flat surface~ adhesive side up, and a màsk was placed '`
over each specimen whereby the l x 1 windows therein covered '
respective test specimens. The masks were pressed onto
respective specimens with care taken to press only'the paper ~ ~
surfaces of the masks. ' ' ;~ ;
The specimens were lifted by their ends9 inverted and '~; ;
placed on respective test substrates, whereby the respective '
windows there~of were locat'ed at the approximate centers of the "
re~pective substrates. Each test specimen was pressed onto its -
substrate'by a mechanically operated roller having a rubber
covered wheeL. The roller weighed 4.5 ~ 0.1 lbs., had a ~'
diameter of 3.25 ~ 0.1 inches, and a width o~ 2 5 ~ 0,1 inches
The rubber surface was approximately 1/4 inches thick and had a .;~
durometer hardness value of 70-80, The roller was' moved over
the t'es~ specimens at a speed of 12 inches per minute, once
forward and once reversed. '
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10531Y13 1 ~ ~
A test weigllt consistin~ o~ a narrow metal strip ~: :
having a l ~ l/2 inch adllesive tape a~ached ~o an end thereo
was provided. ~ l/2 x l/2 inch por~ion oE the adhesive tap~
projected beyond the edge o~ the metal strip. ~he test weight,
including ~he adllesive weighed l ~ O.Ol grams.
Each test specimen was tril~led by cutting it across
the n rrow side exac~ly at the edge oE ~lle ~aper mask ~herein ;
and~excised portion was discarded~ The test weight was attached
to the edge o~ ~he mask a~ the center of the trimmed side oE ;
the test specimen. ~ ;
While holding ~he test weig~t ana pressing the mask ; ;
against the surface o~ the test substrate, the entire assembly
was inverted and horizontally-~mounted. The pressure securing
the test weigllt against the substrate was gently relieved to
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.i~ avoid imparl:ing a shoclc load~ on the specimen, and simultaneously : `~
the interval . -:
~ therewith a timer was actuatedO The timer recorded/until the`~ ;~
.~ ., entire area of tlle specimen~within the l x~ l~ window ;~Oe tlle mask
was disconnected Erom the substrate. Values~ were calculated as
set forth ln the PSTC-14 test method. ActuaL values recorded for ~ ;
,, the test specimens were, respec~ively, 2.5, 2.5, 3,0, 3.5j 4Oo,
. secon ds. `
. .~ 12.0, 1200, 15.5, 52 and~ 54/ The-adhesive cnmp~siti~n was a~ ~ ` :
;` , constant for all the ~tests performed.
'! It is a significant feature of t1~e inventi~oll that the :
~1 adhesive seal between substrate;ll and film 20 does not breach
during the 5terilization procedure. In general this
, feature relates to th- functiunal~relationshLp whic~ prevails-
... ... . ~ . ... . . .. ... .
11 iO53~8~ ~
i
: between the porosity of subs~rate ll and the adhesive value of
: adhesive 12'. Under typical sterilization conditions, a
: substrate porosity of between abowt lO and about 150 gurlies
and preferably from abou~ 18 to lO0 gurli.es provides highiy '.
: satisfactory results. The porosi~y, expressed in gurlies, is
measured on the Gurley-Hill S-P-S tester~ the units are ~i
seconds/lO0 ml. Higher porosities may render ~he sterile
enclosure accessible ~o microorganisms, and at lower porosities `
the integrity o~ the cohesive seal ma~`be fractured. Con-
: comitantly therewith, a cold seal adhesive having a peel
. strength of about lO.0 to about 18 oz. b.efore sterilization l.
~. and about 6.0 to about l4 oz. after sterilization .as determined j~~ by PSTC-l (last-revised ll/70) is ~ound to have'a satisfactory ,:
. adhesive value under typical steriLization conditions. For
. high-vacuum and/or pulsing type sterilization procedures, as
~ the porosity of the substrate is decreased, the adhesive value
.... or corresponding peel'strength of the adhesive must be pro~
portionately increased so as to avoid breaching the adhesive
~' seal in the pack. The peel strength o~.the adhesive may be
' ` . increased, for instance', by overcoating it wi.th a primer or 1~
.. by admixing a conventional adjuvant therewith. :
.~ Located above printed indicators l8, 18', as seen in
: Figs, l and lO is the legend STEAM, with a r.ecognition blank ~ .
. 30 printed adjacent theretoO When the sterilization procedure " ':
: ~: - to 'be employed utilizes steam, bIank 30 may be marked for thereby
directing the technician's attention as to the type of steriliza-
tion to be employed. Typically~'indicators 18, L8' may be a
:' ~
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: :
-10- '
:,
:`
li :lLOS3~L8~3 : ~-
¦I chemically ac~ive ink whicll cLlanges color aE~er a predetermined
! period of time upon exposure to pressure steam, such as/employed
in autoclave sterilization procedures. For instance, ~he ster-
ilization procedure may trigger a yellow to gray-black color
¦ chan~e in indicators 18, 18', Typical conditions of the color
I cycle are 4-5 minutes at 272 F. OL- 20 minutes at about 250 F.
i ii Under either set o~ conditions, sterilization must occur in the
- !I substantial a~sence o~ air, viz., 98 to 100% pure steam"
¦¦ Alternatively, located ~elow printed indicators 17,
¦ 17', as seen in Figs. l and 9, is the legend GAS,, with ~a recog-
¦ nition blank 31 printed adjacent theretoO When the sterilization
procedure to be employed utillzes a gas, for instance ethylene
oxide, blank 31 may be marked or thereby directing the~techni-
cian's attention as to the~type of sterilization to be employed.
¦¦ Typically, indîcators 17, 17l may be a chemically active ink
¦ which changes color after exposure to e~hylene oxide. For in- ~ ;~
; ~ ¦ stance, the s~erLlization procedure~may~trigger a red to green ~ ~ ;
~ ~color change in indlcators 17, L7'.-`A~typical`color change cycle ~ ~
. ~ , ~ , . .
¦ occurs at 130~ F., 50% RH,~600~to 700 mgs. oi ethylene oxide per ~ r' ' '
liter of sterilizing volume for about 1-3/4 hours. ~ `~
The pack is therefore adapted to function within any
I known
/steriLizing envlronment for¦which~its purpose;may be ~suited.
It iS~ moreover, a significant aspect of the invention~that
indicators 17' and 18' are printed on~the substrate sur~ace ~ I ~1
wi~bi ~be pack enclosure¦f r ~heleby ndic-~lng the ~re G ence~oL ¦
~ . . ~ ~
-. . . .. :: .. : . , ~- -, , . - ~-: .
)53~38 ~;
s~erilizing environn~ent witllin the enclosure. This feature safe-
¦ guards against the incidence of a color ~hange in exterior indi-
¦ cators 17 and ~8 be~ore a corresponding color change in indicator~
!1 17~ and 18' provides notice of a defective production sample, :
and prevents inadvertent ~oresllor~ening of the period of steril-
, ¦ ization. '
Referring now to Flgs. 2-7, in practice instrument 28
- l~ is introduced into blank 29 in the manner ~est seen in Figs. 2
and 3. The~instrument is introduced into enclosure 22 ~rom the , ~,
I bottom end 32 of the blank in the direction shown by arrow 33.
; I After ins~rument 28 is introduced into enclosure 22, the pack is
'', sealed irom bottom end 32 as best seen in Figs. 4-6. To seal
¦ the pack3 it is placed upon a~flat surface with film 20 facing
upwardly and bottom end 32 facing~away from the sealer. The
bottom end is manually sealed by placing index fingers under flap 1
26, thereby'rotating it 180 ar~ound fold~'line 27 until it~over- ¦
lies surface 13'of substrate ll;.~'As ~particularlv seen in Fig. 4,1 ~
the index fingers are centered`on fold line 27 and moved~toward I l;
respective edges of;¦the pack in the respective directLons illus- ,~
! tr~ated by arrows 34,~34~Lor~thereby formin~ the firs~ section
of the seal.
I As particularly seen in Fig. S,~the second phase of ; ~"~
- ~the~lseal is~obtained by replacing~he index fln~ers a~ tl~e mlddle
of score line 27 facing toward~lbottom end 32 and moving
~¦1 each index finger ~diagonally toward respective opposed
-~ 2r~ co~ tn~ ~2 ~ ~ b~ rro~ 35, 35~
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iO5318~ ~
To perEorm the final stage o~ t~e sealing operation,
'~ the index fingers a~e returned to their respective positions in
the middle of score line 27 and moved initially forwardly to the
edge o~ bottom end 32 and across the edge of bottom end 32 toward¦
the respective opposed corners ~hereof., Each side seal ls secured
,I by running over it with the flat of the index finger then the flat
;i of the inger nail or a smooth hard instrument,
.~ ,
` ~ As best seen în ~ig. 7, the pack is in condition ~or
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sterile treatment, A~ter the sterile treatmen~ has been effected
according to one of the heretofore prescribed procedures, sterile
presentation of instrument 28 may be had ~y gripping -
end ~alls 24 and 25 respectively-of film 20 and substra~e 11 by
, the thumb and ~ore~inger and applying opposed tensile ~orces
thereon until the opposed tensile forces break the adhesive seal ~:
ii between fiLm 20 and substrate ll at vertex 16 of track 12. The
~ .
'"! purpose for configuring track 12 ~hrough respective segments 15, `~
I5' is to provide a~l~ocus 16 on which opposed tensile forces may~
'' act over the smallest area to thereby concentrate the opposed
I ,'~orces for breaking~the seal,~ Upon breaking the seal, additional
~, fo~ce is exerted until the adhesive connections along segments
15, 15' of track 12 are breached. Due to ~heir conEiguration,
~, the opposed tensile forces concentrate upwardly alang the track
and thereby breach ehe seal w~ith minimum e~fort. Once the seal
. , ~ . .
,l is substantially breached there is a sterile presentation of
ostrument 28 ahd s~erlle delivery therect nay be had as desired.¦
~ 3 ~
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Thus, it is seen tllat steps of ~he sealing method
provide a secure seal, and once the bo~tom end of the pack is
adhesively sealed i~ is not reopened. On the other hand, after
completion o~ the sterilization procedure, the pack may be opened
with reasona~le facility ~rom ~he ~op end or s~erile presenta-
tion and delivery o the instrument. ~he ~acky interior sur~ace
of film 20 prevents slippage of the instrument during sterile
delivery thereoE. Tlle in~erior and exterior sterilization indi- ~ :
cators provide a double safety check for completion of the
sterilization procedure. It is also ~ound that the integrity
of the pack is maintained under various s-terilization procedures,
and wlthin the parameters set forth herein, ~he paclc construction¦
may be modlfied to accommodate variations in di~erent steriliæa-l ;
. . . '
tlon procedures.
It will thus be seen that the objects set forth above,
among those made apparent from the preceding~desçription, are ~ ;~
efficiently attained and, since certain changes may be made in
, j - I
~: ' the above constructions without departing from the spirit and
.' scope of the invention, it is intended that all matter contained
;j in tlie a~ove description or shown in ~he accom~anyin~ ~rawin~s
: i! shall be interpreted as illustrative and not in a lL~iting sense. ~:;
¦ ~ Ie i~s also to be~undersLood~tha~ the following clalms
.: l are inten~ed to cover all o the;generic and speciflc ~eatures
of the inven~ion herein~deseribed,~and all statements of the scope
i of the invention wllich, as a matter of language, might be said;
. to ~all therebetween.~
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