CA1070201A

CA1070201A - Moldable plastic orthopedic cast

Info

Publication number: CA1070201A
Application number: CA262,617A
Authority: CA
Inventors: Kenneth M. Holland; Milton F. Custer
Original assignee: Hexcel Corp
Current assignee: Hexcel Corp
Priority date: 1975-11-19
Filing date: 1976-10-04
Publication date: 1980-01-22
Also published as: DE2649699A1; FR2332001A1; NL7612923A; JPS5264192A; BE847404A; CH604733A5; SE427420B; IT1069962B; DE2649699C2; JPS5912294B2; FR2332001B1; GB1522399A; SE7611213L

Abstract

ABSTRACT OF THE DISCLOSURE
Orthopedic structures are prepared from a thermal softening resin (e.g. polycaprolactons) impregnated large mesh knit fabric carrier having relatively large diameter strands and having a relatively high weight ratio of the polycaprolactone or equivalent resin composition to the fabric carrier. The impregnated fabric can be formed in rolls which may be warmed above the softening temperature of the resin. The thermally softened impregnated fabric becomes highly flexible and pliant and may then be wrapped in multiple layers about the limb to be immobilized. The large knit fabric carrier allows for twisting of the fabric, forming and reforming, so as to obtain the desired shape and degree of support. The overlapping layers of impregnated fabric bond to each other during wrapping and whereafter the impregnated fabric rapidly cools to a hard structurally stable cast, which is porous so as to minimize maceration or other deletrious skin conditions from developing.

Description

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This invention relates to a bandage material for forming in place an orthopedic cast.
Orthopedic structures find wide use in the im-mobilization of limbs in aiding the healing process. In the maintenance of fixation of fractured bones, immobilization `
of inflamed or injured joints, in cases of disease or trauma `~ and for the support and immobilization of ligamentous and muscular structures in instances of sprains and strains, it is necessary to encase the limb in a partially or completely surrounding rigid form or cast. The immobilized limb may be encased in such rigid structure for long periods of time, frequently as much as 6 weeks or more~
There are t~o major considerations for a cast.
The first consideration concerns the formation of the cast. A satisfactory cast material should be easily handleable, ~ ~`
should not have properties which deleteriously affect the limb, particularly the skin~, should have a reasonable setting time or work life, so as to allow a reasonable period of time in which to mold the cast material about the limb, should be flexible during application of the limb ;~i so as to readily assume the shape of the limb, should be free of offe~sive`or noxious solvents or othar chemical~, and should set within a reIatively short time under rel-atively mild conditions. In addition, it is desirable that a minimum of equipment should be involved in formation of the cast. Also it is desirable that during the forming of the cast the mat~rial does not generate an uncomfortable `~
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exothermic reaction, and that upon drying, curing or setting ~ ~;
up it has negligible shrinkage factor. ;`

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The second consideration concsrns the properties of the cast after it is formed. Desirably, the cast should b~ of a light weight ma~erial so as to minimize the in-convenience to the wearer, porous so as to allow the under-lying skin to breathe and not become macerated or otherwise irritated, should have sufficient structural strength so as to retain its structure under normal usage, should ~e sufficiently sturdy to maintain the joint or limb in the immobilized position and protect the joint or limb from jars, and should be easily removable. An optimum cast should also be water-proof, (i.e., the impregnated fabric material itself should not absorb and retain water), be as x-ray transparent as possible, be highly impact a~d abrasion resistant, and should exhibit a versatility to be reformed, and repaired after the initial cast is formed in place.
Because of the numerous and varied requirements for an orthopedic ~ast material, none of the presently known immediately available cast materials provide all or sub-stantially all of the proper~ies indicated above.
In the prior art, U.S. Patent No. 3,692,023 issued September l9j 1972, to Phillips et al describes the use of polycaprolactone as a cast material employing permeable or porous base webs impregnated with a polymer. U.S. Patents Nos. 3,592,190 issued July 13, 1971, to Silverman, 2,301,426 is~ued July 13, 1971, to Silverman, 2,616,418 issued November 4, 1962, to Eberle, 3,420r231 issued January 7, 1969, to Edenbaumr 3149t444 issued January 20, 1970, to Laaksor 3r592rl90 issued July 13, 1971, to Silvermanr 3,604,413 issued September 14, 1971, to Burg et al. also illustrates various aspects of the prior art.

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he invention provides a bandage or wrapping of an ~' orthopedic cast comprising a large mesh flexible fabric carrier (e.g., large mesh cotton knit~ impregnated with a ;
polycaprolactone polymer (or other resin having substan-tially the same or equivalent property and behavioral characteristics as hereinafter more fully identified) to provide a relatively thick coating of the polymer while , retaining substantially large openings in the mesh. The resulting coated fabric is semi-flexible, capable of being ~'~ 10 wound into a cylindrical package, and upon heating above the ~' softening point of the polymer softens to a highly flexible , , or pliable and readily moldable web. The web is readily K:,` formable by the hands and may be applied without protective , covering and is not normally uncomfortable to the patient.
The formed orthopedic case rapidly cools to a hard durable ~ .
~, porous cast, which is light and stable under normal usage ;~ conditions. The cast is easily removed by utilizing conven-tional cast cutting or sawing techniques and equipment. -~
More specifically the invention is a bandage ;~ 20 material for forming,in place an orthopedic case, comprising a pliant fabric carrier comprising low density strands of relatively bulky and good heat insulating material and ,s~ defining openings of relatively large diameter; each strand `
~,; being coated and only partially impregnated with a polymer ~; 25 composition having a heat softening point of not less than ~ 125F and not greater than 165F; said polymer coated ,,, carrier defining openings having an area of not less than , .020 square inches and not greater than about .25 square ,. :
', inches; said partially impregnated bulky strands being 5 ` 30 formed with multitudinous air voids providing increased ,'' '~ insulating properties to said bandage material. '~

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Aspects of the invention are illustrated, merely ~: by way of example, in the drawings in which:
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Figure 1 is a fragmentary, full scale plan view o a cotton knit carrier before impregnation w.ith the resin according to this invention;
Figure 2 is the same as Figure 1 after impreg-nation with the resin and showing how the mesh openings need not necessarily be maintained in perfectly square or rec-tangular shape to provi.de a satisfactory bandage for forming an orthopedic cast.
Figure 3 is an enlarged view of the knit carrier shown in Figure 1.
Figure 4 is an enlarged view of the impregnated carrier shown in Figure 2. ~:
Figure 5 is a diagrammatic view showing one method of fabricating a resin impregnated bandage embodying the :
inventiOn ~ A novel hi~hIy advantageous material is provided ; for forming orthopedic casts. A fabric web is employed ~ .
having relatively large openings and reIativeIy heavy - s strands. Preferably, the strands are~of a loose weave or .;
knit, so as to be porous and subject to at least partial impregnation by the polymeric material. The web carrier . serves as a structural element in the final product and is coated with at least an equal weight of the polymeric , ~ , .
composition, and preferably a greater weight of the poly-:. 25 meric composition. .. In describing the subject invention, the elements -.
of the invention will be described as followso (I) the ~.
carrier material; (2) the polymeric composition; (3) a : ~ . .,;
:. method of preparing the orthopedic cast forming bandage; and :
(4) the orthopedic cast forming bandage. .

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Ca_ri~r Material Referring particularly to Figures 1 and 3, the carrier material i5 a flexible large mesh fabric, preferably knit, defining a lattice of relatively large openings 3. The smallest dimension of the openings will generally be at least .015 sq. in. and preferably a minimum of .022 sq.
in., about .034 sq. in. and generally not-exceeding .25 sq.
in., more usually not exceeding .050 sq. in. The openings may be of any configuration, such as square, polygonal, or the like. The opening shall be large enough so that in the finished product the polymer composition preferably does not form air impervious windows across the opanings.
The s~rands 2 of the carrier which define the the .:.
,:, openings are preferably formed of relatively coarse~ bulky, staple, pOrous, low density and thermal insulating material such as heavy yarn '`'' ''';
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of 5 to 15 twist and having a raw diameter of at least n.13 in., preferably about .015 in. and generally not exceeding .040 in., and when including the fluff or fuzz around the yarn strands at least .030 in., preferably a minimum of .050. in., about .075 in. ana generally not exceedinq .20n in. and more usually not exceeding .100 in.
Materials which may be used include cellulosic materials, such as cotton, synthetic materials, such as acrylates and nylon, or combinations thereo~. For the most part, organic materials are employed, rather than more thermal conductive inorganic materials, such as glass fibers.
Some significant factors concerning the material are that the material be a thermal insulator, that it provide struc-tural stability to the final product, that it allow for molding to form the orthopedic structure, that it is wett-able by the polymer composition, and that it is stable under normal usage. By way of more specific example, the low ., . ~ . , .
density strands of bulky Raschael type knits formed of ,.,~
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staple fibers of cotton and defining naturally occurring multitudinous voids provides a de~irable carrier material.
A knit of the Raschael type inherently provides a highly flexible carrier material~
Preferably, the material should be substantially free of additives which may interfere with the bond between the polymer and the fiber. Cellulosic materials are pre~
; ferably scoured to remove any binders or lubricants in-, hibiting the wetting properties of the polymer or other ~ possibly deleterious additives.
; Polymer Composition While for the most part, poly-~-caprolactone is ~ -commerically available and therefore the product of choice, ~ ~ 7 ~7~ ~

other compositions resembling the properties of the poly-caprolactone have been reported in the literature and to that extent could be employed to replace the poly-caprolactone. See the above U.S. Patent No. 3,692,023.
However, for the purposes of describing a preferred embod-iment of this invention, only the poly- -caprolactone i will be referred to and is to be considered illustrative of this family of polymers. For purposes of convenience, the formula set forth in the aforestated patent is repeated with its definitions as inclusive of the types of polymers which ~ may be employed.
''r These polymers are characterized by the recurring unit.

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wherein each R, individually, is selected from the class consisting of hydrogen, alkyl, halo and alkoxy; A is the oxy group; x is an integer from 1 to 4; y is an integer ; from l to 4; z is an integer of zero or one; with the pro-visos that (a) the sum of x + y ~ z is at least 4 and not greater than 7, and (b) that the total number of R variables , , :; which are substituents other than hydrogen perferably does not exceed 3 per unit. Illustrative R variables include methyl, ethyl, isopropyl, n-butyl, sec-butyl, t-butyl, hexyl, chloro, bromo7 iodo, methoxy, ethoxy, n-butoxy, n~
hexoxy, dodecoxy, and the like. It is preferred that each R, individually, by hydrogen, lower alkyl, e.g.
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methyl, ethyl, n-propyl, isobutyl, and/or lower alkoxy, e.g.
methoxy, ethoxy, propoxy, n-butoxy, and the like.
It is fur~her preferred that the total number of carbon atoms in the R constituents does not exceed twenty. ;~
The polymers which are employed will normally have a molecular weight of at least about 30,000 weight average molecular weight and preferably about 40,000 weight average molecular weight and will have reduced viscosities as reported in the aforementioned patent of at least above 0.3 and generally not exceeding about 15, commonly above about 0.5 and up to about 10.
Small amounts, generally not exceeding 15 weight `~ percent, more usually not exceeding 10 weight percent, and `~
preferably from about 3 to 8 weight percent of inert in-sulative fillers may be included in the polymer composition.
Such fillers include titanium dioxide, talc, magnesium or ' calcium carbonate, clay or other suitable inorganic or ;~ organic materials.
In the present invention the polymer should thermally soften at or above 125F, and below about 180 F, and preferably between 145 - 165F.
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Method ~f;M~ki g Orthopedio;Cast Fo~ingii~a~dage Turning now to Figure 5, a roll 10 of the appro-priate knitted or loose carrier woven webbing 12 is pro-vided. The web~ing 12 is passed under first tank roller 14 and immersed in coating solution 16.
Various coating solutions may be employed having varying concentrations of polymer and fillers. A convenient volatile solvent for the polymer is used, for example, a .
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.~ 201 halocarbon such as methylene chloride. A formulation which was found to be satisfactory is a mixture 95 weight percent PCL-700 a poly--caprolactone having a weight average mole-cular weight.of about 40,000 (available from Union Carbide) and 5 weight percent titanium dioxide. The composition is 5 mixed with methylene dichloride to provide a mix having from about 5% to 50~ solids and preferably 10% to 20% solids, the solids content generally being dictated by the workable viscosity required. It will be undexstood that coating , techniques may be employed, such as hot melt coatings, where 10 a 100% solids content is used.
. The initially coated webbing is then passed be-; tween ad.justable trunnion rolls 17 and past an air knife 18 :
'' and thence circuitously through oven 19 passing over rollers 20 adjacent the upper regions o the oven 19. The air knife 18 serves to blow out any polymer windows which may have : formed in passing.through the wet polymer solution 16, and ;;~ the air knife also assists in the drying of the polymer applied to the wet carrier 12. The webbing in passing through the drying oven 20 is dried at an elevated tem-.- . .
perature preferably around 180F. Where one coat does not glve a suffi¢iently thick and h~avy coating of polymer, the . knit fabric webbing 12, as' shown in Figure 5, is subjected :. to a repeat process of reimmersion in a polymer solution and ' .

`, subsequent drying. Corresponding parts of the equi,pment .'' ~! 25 involved.in the repeat process are numbered correspondingly ,~ to those parts.already described but are suffixed by the ., letter "a" to distinguish them in the drawings. : :

A release film of polyethylene or similar materials ~' from an unwind roll-22 may be~employed in forming the take- :

up roll 23 of the impregnated web 12 if the roller handage _g_ ~

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~i~70;2~1 layers adhere to each other during rolling or when the roll is heated to working temperature prior to its use in the making of an orthopedic cast as more specifically described hereinafter.
In the preferred embodiment the diameter of the impregnated strands 2a of the web 12 (and as shown in Figures 2 and 4) were measured in the range of between t ~ ` " ' approximately .010 in. to .260 in. and generally between ;~
.075 in. and ~160 in................................................. -~
The size of the openings 3a (as shown in Figures 2 and 4) of the impregnated web should generally be in a somewhat lower range of areas than given pre~iously with -respect to the dimension of the openings of the unimpregnated carrier material shown in Figures 1 and 3. The~smallest ~`
dimension of the coated opening will generally be at least ~;~ .010 sq. in., preferably a-minimum of .020 sq. in., about .026 sq. in., generally not exceeding .250 sq. in. and usually not exceeding .050 sq. in. The shape of the openings shown in the impregnated web are disclosed as being in the ~. ~
form of a non-rectangular parallelogram as distinguished ` from the near square shaped openings of the unimpregnated knit carrier of Figures 1 and 3. Such variation in shape between the uncoated and coated carrier may result from the . manner in which the carrier is handled during the coating process. In manufacturing the impregnated web according to the process described in reference to Figure 5 and without utilizing rather special web tracking and handling equipment ~. ,j ., it was found that the web could be better handled through ~' the impregnation and oven drying process by running the - 30 fabric with the strandæ oriented paral~lel and perpendicular .~ to the line of travel of the material through the-e~uipment.
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Where the carrier material is originally oriented in a diagonal direction with respect to the strandsl it may be desirable to cut the material on a bias and run it through the coating process so that the strands are substantially parallel and perpendicular inskead of diagonaI to the line of travel. Such an orientation will give a more rectangular finished product.
However, the disclosure of Figures 2 and 4 are ~ade to indicate that the orientation during coating is not important and that in order to provide an entirely satis-factory bandage it is not necessary that the openings be square or rectangular. It is impoxtant, however, that the openings after coating be of substantial area ranging for example between not less than .010 sq. in. to not more than .25 sq. in. and more preferably between .020 sq. in. and .050 sq. in. and around .026 sq. in.
As earlier noted it is important that the openings be large enough so that when a cast~is formed by spirally wrapping and overlapping the material around the injured limb, that air passages through the thickness of the cast will be maintained to permit~the underlying skin of the . ., patient to breathe and to permit volatilization and dissi-pation of moisture from the interior of the cast.
When utilizing a Raschael type knit carrier formed of low density, staple fiber, bulky cotton strands as hereinabove described, and by utilizing the process of / .
polycaprolactone polymer impregnation of said knit cotton carrier described in reerence to Figure 5, the following physical or mechanical characteristics of the impregnated web 12 (other than those characteristics alrea~y specified) ., ' have been observed: `
1. Although both the polycaprolactone pol~mer and the cotton yarn have individual specific gravities in excess of the specific gravity of water which would lead to the apparently obvious conclusion that a mere combination of ~;
the two material (i.e., impregnating the cotton yarn with the polymer) would re~ult in a structure that would sink water, the fact of the matter is that the final impregnated -~
; web 12 ~as herein described) will float on water indicating that the specifi¢ gravity of the combined materials is less than the mere sum of the specific gravities of the two materials (polymer plus cotton yarn) divided by 2.
The apparent explanation for this observable fact is that upon magnified visual inspection of the impregnated strands 2a shows the existence of air voids still existing in the body of the cotton year where complete wetting and filling by the polyer has not occurred. It is theorized and believe~, that this type of structure contributes materially :: .
to the utility and practical operability of the impregnated web as a~suitable orthopedlc cast bandage material. ~ore `~ specificaIly, it is know that air pockets fundamentally form .
relatively good heat insulating zones, and it is further known that the better the heat insulating qualities of a body the slower will be the rate of dissipation of stored heat therefrom. It i9 therefore reasoned that in respect of the intended and practical use of the present in~ention, the . .~ .
existence of air voids (heat insulating zones) in the web provides the unexpected advantages of providing a longer "working time" with the material and accounts for the fact . . .

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that a rolled bandage of such material can be imm~diately removed from a hot water bath of over 165F and handled comfortably in the ungloved and bare hands of a physician user without his experiencing any discomfort as might be expected in handling such a relatively heated object. r.rhe "working time", and as will hereinafter be described, is the time that a physician has to remove a bandage roll from a hot water bath and unwind it with skill and care in a still softened and pliant condition around a patient's limb to form and mold an orthopedic aast.
Contributing also to the heat insulating proper-ties of the impregnated web 12 (according to the present :~
invention) is the use of an organic carrier material, such : :
: as cotton, which inherently is a relatively good heat . .
insulator. In this connection, other resin impregnated .
-........... orthopedic cast bandages on the market today utilize a glass fabric carrier which is not only less x-ray transparent, but is a relatively good heat conductor and would not provide ~- the optimum advantages of heat insulating properties in the ` 20 environment of the present Invention as herein described.
. 2. The impregnated web 12 made according to the ` process, and using the polymer and fabric materials speci-;; fically described herein, has a measured or determinable ratio of approximately 4:1 polycaprolactone polymer weight ~ 25 to cotton yarn fabric weight, although this ratio may be ; varied substantially to produce reasonably satisfactory : .
bandages within the range of 2. to 5:1 resin weight to fabric carrier weight. :~.

Orthopedic Cast Forming Bandage and IJse Thereof A typical bandage formed from the impregnated and :`~

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dried web 12 manufactured according to the process herein~
above described in reference to Figure 5 of the drawings may .~ ~ .
be approximately 6 ~eet long and:3 inches-wide i~ roll form with a parting film of sheet polyethylene separating adja- ~ :
cent layers of impregnating fabric in the roll.
In using the bandage to make an orthopedic cast it ~ ;
is convenient simply to immerse the rolled bandage in a vessel of hot water at a temperature above the thermal so~tening point of the polymer. In a bandage utiliz.ing the preferred lQ poly-~-caprolacton~ polymer, the same has been found to :~
soften readily when introduced into hot water a* about 155- ~,Q
~ 165F. Approximately.two minutes in the hot water bath is .~ sufficient to bring the web to a readily moldable state.
While warm ai.r or oven heat or the like can be used at the heat source to soften the polymer, the.water bath is pre-ferred because of.its ability to rapidly a.nd uniformly . aontact and heat all areas of:the rolled bandage to uniform .` temperature... When removed fromlthe water, the bandage can be readily wrapped about a limb without requiring any protec~ive covering of~the:user's hands. When the usual `

-- no.rmal underlying stockinette or padding is employed, there is no discomfort on the part of the patient. The heat . ~.
softened and pliant ban~age can be twisted, gathered, :~
formed, re-formed, molded., rolled and unrolled as desired, there being ample time for the bonding hetween adjacent .. layers and the formation;of the cast. Any release fïlm may be peeled of and discarded as ~nwinding of the bandage :
. proceeds. The cast.may be allowed to cool and:if desired, :

.i the rate of cooling~.can be enha~ced-by~applying cold water ~; 30 compresses over the cast. :Air cooling or oth2r means is ''''' '.

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The resulting cast has a number of desirable features. It is sufficiently transparent to x-rays, so that close to skin quality x-rays can be achieved. This means S lower x-ray voltage may be employed as compared to other cast materials, such as plaster~ The cast is light weight and a strong structure can be achieved with as li~tle as 2 layers of the material. Chan~els are retained, so that the ., ' '~
skin is able to breathe through the cast and maceration over the normal period of time for which the cast is worn is not observed. Strong bonding is obtained between the layers of the webbingj so that the cast does not come apart. In addition, the cast can be immersed in water and because of ~` the porosity of the cast, the water will evaporate and the skin underneath the cast will retain its healthy condition.
By employing a heavy webbing with large openings t,~ .
and a relatively large proportion of polymeric composition, the polymeric composition remains moldable for a substan-tially long period of time. For example, a bandage roll of ~ -6 feet in length upon heating in water of about 125-165 will remain soft and bondable for a period of at least 30-45 j....................................................................... ;
~ seconds at room temperature. A cast made of wound series of 1 3 rolls for example will remain hand pressure moldable or ; formable as a mass of approximately 3-4 minutes a~ter application of the third roll. Thus, once the composition has reached its softening point, it lS easily workable over a reasonable time which is required in formin~ the cast and insuring the proper positioning. ~he heavy strands of the web provide structure to the material and remaln in place when positioned, so as to insure that on hardening the `

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immobilize~ limb is held in the desired position.
During use, the cast has good wet strength and does not deteriorate upon repeated immersions in water, such as during swimming or taking showers or baths. In addition, the cast is highly abrasion resistant and capable of sus-taining substantial impact. The cast provides pratection - for the injured limb and can be used in most situations normally encountered by the wearer.
Finally, the cast is readily removable as by cutting with a conventional vibrating sawtooth disc. A cast once formed in place over an injured limb can also be ~
readily reformed, repaired, and in many instances re-used. .
For example, i~ a patient complains of a discomforting localized pressure point exerted by the cast, the cast can be reformed by ease the pressure merely by applying to it hot towels (or other type of heat) to cause the impregnated : material to soften and be manually manlpulated and molded to desired configuration.
In situations where it lS ne-cessary to cut out a plug to form~a~window in a cast ~or~the physician to observe or treat an underlying wound, the plug cut-out plu~ may be readily~replaced simpIy by re-heating it and re-inserting it ::~
~ back in the window hole. If desired the plug can be more ~ .: ....
securely held in place by wrapping one or two layers o~ pre-softened new ba~dage material around the cast and overlying the re-inserted plugO -~

;~ It is also possible in some instances to re-use :.~i . .
,!,;1 either a single or double slit cast after its entîre removal from a limb. This can be done merely~by reheating in water ~ 30 or otherwise the removed cast parts and replacing and '' ' ., ~ .
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reforming them on the patient's limb, whereafter another layer or two of new bandage material can be wrapped around the original parts to hold them securely in place.
It will further be appreciated that the term orthopedic "casts" as used herein is also meant to include where applicable, the forming of splints and braces.
Further, although one manner of making and im-pregnating carrier 12 has been described in particular reference to Figure 5 of the drawings, it is contemplated that the fabric carrier can be impregnated by other well known processes such as by hot-melting the powderous resin on the carrier, or by powder coating the carrier by passing the carrier one or more times through a fluidized bed of resin powder one or more times, and after each pass heating - 15 the material to cause the powder to fuse and bond itself to the carrier strands. ;
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Although the foregoing invention has been des-cribed in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious ~ `
that certain changes and modifications may~be practiced within the scope of the appended claims.
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Claims

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

1. A bandage material for forming in place an orthopedic cast, comprising a pliant fabric carrier com-prising low density strands of relatively bulky and good heat insulating material and defining openings of relatively large diameter; each strand being coated and only partially impregnated with a polymer composition having a heat soften-ing point of not less than 125°F and not greater than 165°F;
said polymer coated carrier defining openings having an area of not less than .020 square inches and not greater than about .25 square inches; said partially impregnated bulky strands being formed with multitudinous air voids providing increased insulating properties to said bandage material.

2. A bandage material according to claim 1 wherein the openings are approximately .025 square inch.

3. A bandage material according to claim 1 wherein said fabric comprises a knit formed of fiber bulky strands having a raw diameter of between .013 in. and .040 in.

4. A bandage material according to claim 3 wherein the outside fluff diameter is between .030 in. and .20 in.

5. A bandage material according to claim 4 wherein the carrier is a cotton knit formed of staple fiber.

6. A bandage material according to claim 1 wherein said carrier comprises a Raschael type substantially cotton knit of staple fiber bulky strands.

7. A bandage material according to claim 1 wherein the polymer coated strands have a diameter between .010 to .260 in

8. A bandage material according to claim 1 wherein the coated strands have a diameter between .075 in.
and .160 in.

9. A bandage material according to claim 1 wherein the polymer composition comprises a solid crystal-line cyclic ester polymer having at least a major amount of recurring structural units of the formula:

wherein each R, individually, is selected from the group consisting of hydrogen, alkyl, halo and alkoxy; A is the oxy group; X is an integer from 1 to 4; Y is an integer from 1 to 4; Z is an integer of 0 or 1; provided that (a) the sum of X plus Y plus Z is at least 4 and not greater than 7, and (b) that the total number of R variables which are substituents other than hydrogen does not exceed 3.

10. A bandage material according to claim 9 wherein said polymer composition comprises in major propor-tion a poly-E-caprolactone polymer.

11. A bandage material according to claim 10 wherein the poly-E-caprolactone polymer has a molecular weight average of at least 30,000.

12. A bandage material according to claim 11 wherein the molecular weight of the poly-E-caprolactone is about 40,000.

13. A bandage material for forming in place an orthopedic cast, comprising a pliant fabric carrier com-prising a Raschael type substantially cotton knit of staple fiber bulky strands; each strand being coated and partially impregnated with a polymer composition having a heat soften-ing point of not less than 125°F and not greater than 165°F
and each coated strand having a diameter between about .010 to about .260 inches; said polymer coated carrier defining openings having an area of not less than about .020 square inches and not greater than about .25 square inches; said partially impregnated bulky strands formed with multitu-dinous air voids providing increased insulating properties to said bandage material.

14. A bandage material according to claim 13 wherein the polymer composition comprises in major pro-portion a poly-E-caprolactone polymer having a molecular weight average of at least 30,000.