U.S. patent application number 13/500646 was filed with the patent office on 2012-09-27 for melt processable composition from recycled multi-layer articles containing a fluoropolymer layer.
This patent application is currently assigned to Arkema Inc.. Invention is credited to William J. Hartzel, Sean M. Stabler, Saeid Zerafati.
Application Number | 20120245238 13/500646 |
Document ID | / |
Family ID | 43857058 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120245238 |
Kind Code |
A1 |
Zerafati; Saeid ; et
al. |
September 27, 2012 |
MELT PROCESSABLE COMPOSITION FROM RECYCLED MULTI-LAYER ARTICLES
CONTAINING A FLUOROPOLYMER LAYER
Abstract
The invention relates to a composition that has been obtained by
the melt-process recycling of one or more multi-layer articles,
where the multi-layer articles are composed of at least one
melt-processible fluoropolymer layer. The composition of the
invention is a compatible blend of the different layers from the
multi-layer articles. The other layers of the multi-layer articles
are also melt-processible, and include one or more layers chosen
from: a) a melt-processible fluoropolymer of a different
composition, b) a non-fluoropolymer, and c) a barrier layer. The
composition is useful for forming an article in a melt-process
operation. The composition may be used by itself, may be blended
with other virgin or recycled materials, or may be used at low
levels with melt-processible polymers as a process aid.
Inventors: |
Zerafati; Saeid; (Villanova,
PA) ; Stabler; Sean M.; (Montoursville, PA) ;
Hartzel; William J.; (Cherry Hill, NJ) |
Assignee: |
Arkema Inc.
Philadelphia
PA
|
Family ID: |
43857058 |
Appl. No.: |
13/500646 |
Filed: |
September 23, 2010 |
PCT Filed: |
September 23, 2010 |
PCT NO: |
PCT/US10/49941 |
371 Date: |
May 24, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61249353 |
Oct 7, 2009 |
|
|
|
Current U.S.
Class: |
521/46 ; 525/104;
525/123; 525/165; 525/178; 525/199; 525/57; 526/254 |
Current CPC
Class: |
B29K 2027/12 20130101;
C08L 27/16 20130101; Y02W 30/622 20150501; B32B 27/34 20130101;
B29K 2029/00 20130101; B29B 17/02 20130101; B29L 2009/00 20130101;
B29K 2027/16 20130101; B29C 51/002 20130101; B32B 27/304 20130101;
C08G 59/1488 20130101; B32B 2250/24 20130101; B29L 2007/008
20130101; B32B 27/08 20130101; B29C 48/0017 20190201; C08L 2207/20
20130101; Y02W 30/62 20150501; B29K 2075/00 20130101; B32B
2307/7242 20130101; C08L 2205/03 20130101; B29B 7/002 20130101;
B29C 48/022 20190201; B32B 27/40 20130101; B29K 2029/04 20130101;
B29B 13/10 20130101; C08L 2205/035 20130101; B32B 27/306 20130101;
B29B 17/0042 20130101; C08L 27/16 20130101; C08L 29/04 20130101;
C08L 35/00 20130101; C08L 75/08 20130101; C08L 27/16 20130101; C08L
29/04 20130101; C08L 75/08 20130101 |
Class at
Publication: |
521/46 ; 526/254;
525/199; 525/178; 525/123; 525/165; 525/104; 525/57 |
International
Class: |
C08J 11/04 20060101
C08J011/04; C08L 27/20 20060101 C08L027/20; C08L 29/04 20060101
C08L029/04; C08L 75/04 20060101 C08L075/04; C08L 67/02 20060101
C08L067/02; C08L 83/00 20060101 C08L083/00; C08F 214/28 20060101
C08F214/28; C08L 77/00 20060101 C08L077/00 |
Claims
1. A melt processible polymer composition comprising a compatible
melt blend formed from one or more recycled multi-layer articles,
wherein said multi-layer article comprises at least one
melt-processible fluoropolymer layer.
2. The polymer composition of claim 1, wherein said multi-layer
article further comprises at least one other layer comprising a
melt-processible fluoropolymer having a different chemical
composition form the first fluoropolymer layer.
3. The polymer composition of claim 1, wherein said at least one
melt-processible fluoropolymer layer comprises a polyvinylidene
fluoride (PVDF) homopolymer or copolymer.
4. The polymer composition of claim 2, wherein all fluoropolymer
layers consist of a PVDF homopolymer or copolymer.
5. The polymer composition of claim 1, wherein said multi-layer
article further comprises at least one non-fluoropolymer layer.
6. The polymer composition of claim 5, wherein at least one
non-fluoropolymer layer is selected from the group consisting of
TPE (thermoplastic elastomer); thermoplastic vulcanates (TPV);
thermoplastic olefins (TPO); thermoplastic vulcanates (TPV)
containing grafted or reacted functional groups; thermoplastic
vulcanates that are polyamide based (PA based); thermoplastic
vulcanates that are thermoplastic polyester elastomer based;
acrylate rubbers; thermoplastic polyurethanes (TPU) based on either
polyesters or polyethers; polyesters and copolyesters; polyamides
and copolyamides; silicones; neoprene; nitrile rubber; butyl
rubber; polyamides, polyolefins; and chlorinated vinyls.
7. The polymer composition of claim 1, wherein said multi-layer
article further comprises at least one barrier layer.
8. The polymer composition of claim 7, wherein said barrier layer
is ethylene vinyl alcohol (EVOH) or poly(vinyl alcohol).
9. The polymer composition of claim 1 comprising 1 to 100 weight
percent fluoropolymer, 0 to 40 weight percent of a barrier polymer,
and 0 to 99 weight percent of a non-fluoropolymer, the total adding
to 100 percent.
10. The polymer composition of claim 9 comprising 20 to 90 weight
percent fluoropolymer, 5 to 25 weight percent of a barrier polymer,
and 25 to 75 weight percent of a non-fluoropolymer, the total
adding to 100 percent.
11. The polymer composition of claim 10 comprising 25 to 70 weight
percent fluoropolymer, 5 to 25 weight percent of a barrier polymer,
and 25 to 75 weight percent of a non-fluoropolymer, the total
adding to 100 percent.
12. The polymer composition of claim 1, wherein said recycled
multi-layer article(s) comprise at least one disposable
manufacturing system used in biomedical or pharmaceutical
production.
13. The polymer composition of claim 1, wherein said polymer
composition further comprises, in addition to said recycled
multi-layered articles from 5 to 50 weight percent of one or more
other melt-processible polymers compatible with said recycled
multi-layered articles.
14. The polymer composition of claim 1 comprising polyvinylidene
fluoride (PVDF) homopolymer or copolymer, and thermoplastic
polyurethane (TPU).
15. The polymer composition of claim 14, further comprising
ethylene vinyl alcohol (EVOH) barrier polymer.
16. A polymer article formed by a heat processing operation
comprising the polymer composition of claim 1.
17. The polymer article of claim 16, wherein said polymer
composition comprises the recycled melt blend as a process aid in a
matrix polymer, wherein the fluoropolymer weight percent in the
article is from 0.05 to 20 weight percent.
18. The polymeric article of claim 17, wherein said matrix polymer
is selected from the group consisting of a polyvinyl chloride
(PVC), polycarbonate (PC), polyamide or copolyamide,
polycarbonate/polyester blends, thermoplastic urethanes (TPU) and
polyolefins.
19. A process for forming a polymeric article from a recycled
multi-layer structure comprising the steps of a. forming a
multi-layer article, having each layer adhered to the adjoining
layer(s), wherein said multi-layer structure comprises an inner
fluoropolymer layer, and at least one other layer chemically
different from the fluoropolymer inner layer, b. washing and/or
sterilizing the multi-layer structure c. grinding the washed and/or
sterilized multi-layer structure into small pieces or flakes; d.
cleaning the pieces or flakes to remove non-polymeric materials and
other contaminants; e. Optionally screening or sizing the flakes or
pieces, and regrinding if needed to obtain the desired average
particle size; f. mixing or blending the flakes or small particles;
g. melting the flakes or small particles h. extruding the melted
flakes or small particles into pellets directly into final
articles; and i. thermoforming the pellets into final articles.
20. The process of claim 19, wherein the multi-layer of step a)
further comprises a barrier layer of ethylene vinyl alcohol (EVOH)
or poly(vinyl alcohol) (PVOH), and at least one elastomeric
non-fluoropolymer layer.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a composition that has been
obtained by the melt-process recycling of one or more multi-layer
articles, where the multi-layer articles are composed of at least
one melt-processible fluoropolymer layer. The composition of the
invention is a compatible blend of the different layers from the
multi-layer articles. The other layers of the multi-layer articles
are also melt-processible, and include one or more layers chosen
from: a) a melt-processible fluoropolymer of a different
composition, b) a non-fluoropolymer, and c) a barrier layer. The
composition is useful for forming an article in a melt-process
operation. The composition may be used by itself, may be blended
with other virgin or recycled materials, or may be used at low
levels with melt-processible polymers as a process aid.
BACKGROUND OF THE INVENTION
[0002] The worldwide consumption of plastics is around 400 billion
pounds a year--with only about 12% being recycled. There has been a
movement to increase the level of plastics recycling to reduce
landfill usage. While municipal waste has traditionally been the
main target for recycling, other type of plastic waste such as
those generated by industry is gaining more attention. Some
industries, such as the biopharmaceutical sector, are more
sensitive to the life cycle of their waste. In this market,
recyclability gains even more importance for the products that are
designed for one-time use.
[0003] The majority of the recycled plastics are single layer
bottles or films made from PET, HDPE, PVC or LDPE. Mixed plastic
waste is generally separated into the different chemical species
due to a lack of compatibility between many of these
materials--resulting in poor blend properties if blended. In
general, recycling of materials containing barrier layers such as
epoxies, ethylene vinyl alcohol (EVOH) or polyamides is not
practiced, mainly due to compatibility issues.
[0004] In addition to the single-layer polymer products, many
multi-layer polymer articles exist. The use of multiple layers
allows one to take advantage of the properties of each
polymer--such as chemical resistance, permeation resistance,
weatherability, and physical properties.
[0005] It is critical to performance that the various layers of a
multi-layer article adhere to one another. This adherence can occur
in many ways, including: compatibility or miscibility of the
polymers, with the multi-layer formation process generally
involving heat and/or pressure; the use of a tie layer (reactive or
non-reactive) or adhesive; a surface treatment of one or both
surfaces to increase interactions, such as by corona treatment,
plasma treatment, chemical etching or even physical abrasion; or by
adding functionality into one or both layers that can react
covalently with the other layer under processing conditions.
[0006] There is a trend in the pharmaceutical industry to reduce
the price of the medicine, move towards individualized drugs and
reduce the time for new drug development. Moreover, the FDA is
enhancing and modernizing the drug production regulations with a
push towards improved risk management. The general outcome of these
inputs is a move towards adoption of single use manufacturing
systems. These systems are typically made completely from plastics
and designed to replace stainless steel vessels, pipes and
components for production of drugs and batch processed medicines.
Currently, several companies manufacture systems with capacities
from 1 L to 10,000 L for cell growth, buffer preparation and drug
synthesis. These systems typically include bags, tubes, fittings,
stirrers and other components. Each of these articles has specific
requirements that would necessitate a multilayer structure in the
design of some components. It is estimated that several million
pounds of plastics will be used in these systems in the next
several yeas. The pharmaceutical industry is very particular about
the life cycle of their products and is very interested in
minimizing the landfill and/or incineration of these single use
systems. Moreover, some European regulation bodies are putting
emphasis on the life cycle of these disposable systems. Therefore,
there is a need to have a manufacturing system that would perform
the required functional tasks and be recyclable after it is
discarded. Currently the disposable manufacturing systems are
incinerated.
[0007] Recycling of a multi-layer material (article or scrap)
presents special issues, since the layers cannot be easily
separated before recycling. First, the whole multi-layer article
must be designed to meet specific requirements of high purity, and
resistance to permeation of gases and liquids. In the
biopharmaceutical industry there is also a need for a surface that
resists protein adhesion. Then, in addition, the article must also
be capable of being melt blended into a usable article. The
polymers in a recyclable multi-layer material must be compatible at
both a macro-level and a micro-level.
[0008] Compatibility in the polymer adhesion context is represented
by low interfacial tension. Specifically the polar component of the
surface tension plays a major role in the peeling strength and the
work of adhesion between polymers. Typically, the greater the
polarity difference, the greater will be the interfacial tension.
In addition to the interfacial tension, other factors such as
processing parameters and tooling design can affect the peeling
strength.
[0009] On a macro-compatibility level, the layers of the
multi-layer structure need to be compatible only on their surfaces.
However, during recycling, the polymers are melt blended in the
bulk and must also be compatible at a micro level when the
individual polymer chains contact each other. In polymer blends,
the important mechanical, transport and optical properties depend
on the size of the polymer phases, which in turn is dictated by
viscosity ratio, mixing intensity in the extruders and
compatibility of the components. In many instances, interfacial
area between the phases is the weak point in the polymer bland. In
these cases, the failure starts from this area and progresses
through the bulk of the material. Strength of this interface, to a
great extent is determined by the compatibility of the polymers in
the blend. Therefore, a compatible blend would have good surface
and processing aspect, reduced phase size, strong domain interface
and good melt behavior. For polymer blends compatibility is
represented by Flory interaction parameter. It can be shown that
Flory interaction parameter and interfacial tension are related to
each other.
[0010] Many multilayer films do not produce compatible polymer
blends. These demonstrate chemical bonding or compatibility at the
interface, to allow production of a multilayer film structure, but
not micro-scale compatibility that is good enough for an intimate
blend with proper morphology and phase size. In multilayer films in
which surfaces of the polymers are modified for adhesion, the bulk
of the layers would remain incompatible--resulting in a poor
recycled blend.
[0011] In multilayer films using a tie layer or adhesive, the tie
layer may act as a compatibilizer. However, the amount of tie layer
generally is not sufficient to provide total surface coverage of
the minor phase. Often the tie layer simply forms a separate phase
inside the most compatible polymer in the blend--resulting in large
incompatible polymer domains.
[0012] Functionalized or cross-linked layers may negatively affect
viscosity of the blend, making it difficult to reprocess. Ideally,
recyclable multilayer films are those in which all of the layers
are reasonably compatible with each other. The recycle of many
multi-layer films containing only low-performance plastics is
generally not worth the recycling cost, and may not produce
melt-blends from which useful articles can be formed.
[0013] There is a need for multilayer structures designed to have
a) excellent physical, chemical, purity, permeation resistance and
purity useful in high purity applications, b) layers that adhere
well together in the application, and c) are capable of being
recycled into useful articles--where the layers that are compatible
in a melt blend and the blend has good physical and processing
properties.
[0014] Compatibility is especially problematic when at least one
layer of a multilayer structure is a fluoropolymer. Fluoropolymers,
by their nature, are incompatible with, and difficult to adhere to
most substances.
[0015] Surprisingly, Applicant has now developed multilayer
structures in which the layers adhere well, have the excellent
properties for use in high purity applications, and are capable of
being recycled. One additional advantage of recycling the
multilayer structures of the invention is that fluoropolymers, and
other polymers used in these types of structures, can be relatively
expensive materials, and the articles formed from the recycled
blend can receive a performance benefit from the special properties
of the fluoropolymer and other high-performance recycled polymer
layers.
SUMMARY OF THE INVENTION
[0016] The invention relates to a melt processible polymer
composition having a compatible melt blend formed from one or more
recycled multi-layer articles having at least one melt-processible
fluoropolymer layer.
[0017] The invention further relates to an article formed from the
composition by a melt process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a micrograph showing the compatibility of a
melt-blend of a multi-layer film of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The invention relates to a multi-layered article containing
at least one melt-processible fluoropolymer layer, which can be
recycled into a useful article.
[0020] By "multi-layer article", as used herein is meant an
article, film or sheet having two or more layers. The article may
consist of 2, 3, 4, 5, 6 or more layers adhered together. Tie
layers and adhesive layers may be part of the structure, or the
different layers may adhere together without tie-layers or
adhesives.
Fluoropolymer Layer
[0021] One or more layers of the multi-layer structure are melt
processible fluoropolymers. In one embodiment, more than one layer
is a fluoropolymer.
[0022] The term "fluoromonomer" or the expression "fluorinated
monomer" means a polymerizable alkene which contains at least one
fluorine atom, fluoroalkyl group, or fluoroalkoxy group attached to
the double bond of the alkene that undergoes polymerization. The
term "fluoropolymer" means a polymer formed by the polymerization
of at least one fluoromonomer, and it is inclusive of homopolymers,
copolymers, terpolymers and higher polymers which are thermoplastic
in their nature, meaning they are capable of being formed into
useful pieces by flowing upon the application of heat, such as is
done in molding and extrusion processes. Fluoropolymers useful in
the present invention are those that are melt processable. Some
examples of fluoropolymers that are melt processable include, but
are not limited to polyvinylidene fluoride and it's copolymers
(PVDF and co-PVDF), ethylene tetrafluoroethylene (ETFE), ethylene
chlorotrifluoroethylene (ECTFE), fluorinated ethylene propylene
(FEP), tetrafluoroethylene-perfluorovinyl propyl ether (PFA), and
any combination of monomers where at least one of them is
fluorinated. These could also include EFEP (ethylene,
hexafluoropropylene, tetrafluoroethylene), PVDF copolymerized with
hexafluoropropylene, perfluorovinyl methyl or propyl ether,
ethylene, tetrafluoroethylene, vinyl fluoride, vinyl trifluoride,
ethylene, etc., as well as functional monomers such as maleic
anhydride, glycidyl methacrylate, etc. Some fluoropolymers that are
not part of the invention due to poor melt processability include,
but are not limited to, propylene chlorotrifluoroethylene (PCTFE),
polytetrafluoroethylene (PTFE) and polyvinyl fluoride (PVF).
[0023] Preferred fluoropolymers of the invention are the
homopolymer made by polymerizing vinylidene fluoride (VDF), and
copolymers, terpolymers and higher polymers of vinylidene fluoride
wherein the vinylidene fluoride units comprise greater than 70
percent of the total weight of all the monomer units in the
polymer, and more preferably, comprise greater than 75 percent of
the total weight of the units. Copolymers, terpolymers and higher
polymers of vinylidene fluoride may be made by reacting vinylidene
fluoride with one or more monomers from the group consisting of
vinyl fluoride, trifluoroethene, tetrafluoroethene, one or more of
partly or fully fluorinated alpha-olefins such as
3,3,3-trifluoro-1-propene, 1,2,3,3,3-pentafluoropropene,
3,3,3,4,4-pentafluoro-1-butene, and hexafluoropropene, the partly
fluorinated olefin hexafluoroisobutylene, perfluorinated vinyl
ethers, such as perfluoromethyl vinyl ether, perfluoroethyl vinyl
ether, perfluoro-n-propyl vinyl ether, and
perfluoro-2-propoxypropyl vinyl ether, fluorinated dioxides, such
as perfluoro(1,3-dioxole) and perfluoro(2,2-dimethyl-1,3-dioxole),
allylic, partly fluorinated allylic, or fluorinated allylic
monomers, such as 2-hydroxyethyl allyl ether or
3-allyloxypropanediol, and ethene or propene. Preferred copolymers
or terpolymers are formed with vinyl fluoride, trifluoroethene,
tetrafluoroethene (TFE), and hexafluoropropene (HFP).
[0024] Preferred copolymers are of VDF comprising from about 71 to
about 99 weight percent VDF, and correspondingly from about 1 to
about 29 percent TFE; from about 71 to 99 weight percent VDF, and
correspondingly from about 1 to 29 percent HFP (such as disclosed
in U.S. Pat. No. 3,178,399); and from about 71 to 99 weight percent
VDF, and correspondingly from about 1 to 29 weight percent
trifluoroethylene.
[0025] Preferred terpolymers are the terpolymer of VDF, HFP and
TFE, and the terpolymer of VDF, trifluoroethene, and TFE, The
especially preferred terpolymers have at least 71 weight percent
VDF, and the other comonomers may be present in varying portions,
but together they comprise up to 29 weight percent of the
terpolymer.
[0026] The polyvinylidene fluoride could also be a functionalized
PVDF, produced by either copolymerization or by post-polymerization
functionalization, such as KYNAR ADX from Arkema Inc. with grafted
maleic anhydride functionality. KYNAR ADX could be a blend or pure
grafted polymer. The use of a functionalized PVDF for the contact
layer could be useful in industrial applications where the highest
purity is not a major concern. However, in biopharmaceutical and
other application requiring high purity, the functional PVDF is not
as useful for direct surface contact, since some of the functional
monomers could leach out from the PVDF.
[0027] When the multi-layer article is composed only of
fluoropolymers, at least two chemically different fluoropolymers
must be present. Examples would include a PVDF homopolymer inner
layer/PVDF copolymer of PVDF and HFP/PVDF homopolymer outer layer;
a PVDF inner layer/KYNAR ADX/PVDF homopolymer outer layer; and a
PVDF/HFP copolymer inner layer and PVDF/HFP outer layer where the
ratios of PVDF to HFP are different in each layer.
Non-Fluoropolymer Layer
[0028] At least one layer of the multi-layer article is a
non-fluoropolymer. In a preferred embodiment the multi-layer
article contains one or more non-fluoropolymer layers. The
non-fluoropolymer layers are preferably compatible with the
fluoropolymer and should be melt-processible. Melt-processible
polymers useful in the invention, include, but are not limited to:
polyvinyl chloride (PVC), polymethylmethacrylate (PMMA)
homopolymers and copolymers, polyethylene (of all densities),
polybutylene, polypropylene, polyamides especially polyamides 6, 11
and 12 and the copolyamides thereof, functional polyolefins,
thermoplastic olefin (TPO), alkyl(meth)acrylate polymers and
copolymers, acrylonitrile butadiene styrene (ABS) terpolymers,
acrylonitrile-styrene-acrylate (ASA) terpolymer, polycarbonate
(PC), polyesters, poly(butylene terephthalate), poly(ethylene
terephthalate), MBS copolymers, high impact polystyrene (HIPS),
acrylonitrile/acrylate copolymers, poly ethylene terephthalate
(PET), acrylonitrile/methyl methacrylate copolymers, impact
modified polyolefins and impact modified PVC, or mixtures thereof.
In a preferred embodiment, the non-fluoropolymer layer(s) is
elastomeric. Useful elastomeric polymers are those having the
ability to return to their original shape when a load is removed.
Elastomeric polymers most useful in the elastomeric layer(s) of the
invention are those that can easily be melt-processible. Examples
of useful elastomeric polymers include, but are not limited to,
elastomeric polyamide TPE (thermoplastic elastomer), such as PEBAX
(Arkema Inc.); thermoplastic vulcanates (TPV) such as SANTOPRENE
(polypropylene-EPDM TPV produced by Advanced Elastomer Systems);
thermoplastic olefins (TPO) such as Engage (ethylene-propylene
polyolefin elastomer produced by Dow Chemical); thermoplastic
vulcanates (TPV) containing grafted or reacted functional groups
including maleic anhydride or glycidal methacrylate, such as
SANTOPRENE; thermoplastic vulcanates that are polyamide based (PA
based) or thermoplastic polyester elastomer based (such as HYTREL
produced by Dupont); acrylate rubbers such as SEBS
(styrene-ethylene-butylene-styrene copolymer produced by Shell,
thermoplastic polyurethanes (TPU based on polyesters or polyethers
in both aliphatic and aromatic versions); polyester type TPE such
as HYTREL; polyesters and copolyesters; polyamides and copolyamide;
fluoroelastomers (VITON from Dupont, KYNAR Ultraflex from Arkema
Inc), silicones, Neoprene, nitrile rubber, butyl rubber,
polyamides, polyolefins such as polyethylene and polypropylene,
chlorinated vinyls, such as PVC and flexibilized PVC where the
flexibililzed PVC is typically plasticized.
[0029] In one embodiment, the non-fluoropolymer layer(s) provides a
flexible article. By "flexible", as used herein, means a
multi-layer film of a thickness of 100 microns or less can be bent
or folded over a cylindrical rod having a diameter of 10 mm without
destroying the physical or optical properties of the film. A
multi-layer film of up to 200 microns can be bent or folded over a
cylindrical rod in a diameter of 100 mm without destroying the
physical or optical properties of the film. The multi-layer article
is not flexible if crazing, or other physical or optical change
occurs during these tests. For a multi-layer tube or pipe,
"flexible" means that the tube can be bent to a radius of 20 times
the tube or pipe diameter without the tube collapsing or being
pinched closed.
Barrier Layer
[0030] The multi-layer structure may contain at least one barrier
layer. Useful barrier layers include, but are not limited to
ethylene vinyl alcohol (EVOH) and poly(vinyl alcohol) which is
fully or partially hydrolyzed polyvinyl acetate. The barrier layer
is preferably present in films, reactors, bags, and other
multi-layer structures to improve permeation resistance to
CO.sub.2, O.sub.2, H.sub.2O, and other substances. Multi-layer
tubing, especially very flexible tubing such as that used in
peristolic pumps, may have no extra barrier layer present.
Tie Layers
[0031] One difficulty with constructing a multi-layer structure
with a PVDF is that few materials adhere well to PVDF. Adhesion can
be aided through the use of a functional polymer or a tie layer.
The functional polymer or tie layer may also serve as a
compatibilizer between polymers when recycled in a melt blend. In
one embodiment, a functional PVDF, such as maleic anhydride
functional PVDF available as KYNAR ADX from Arkema Inc., can be
directly adhered to the PVDF contact layer, and then can adhere to
many elastomeric compounds.
[0032] A tie layer can also be used to improve adhesion between
layers. The tie layer or layers are known in the art, and can be
selected depending on the elastomeric layer, and can include, but
are not limited to, one or more of the following materials: KYNAR
ADX, LOTADER (functionalized polyethylene from Arkema), OREVAC
(functionalized polyethylene or polypropylene from Arkema),
thermoplastic polyurethanes (TPU), CPE (chlorinated polyethylene),
functional tie layers (TPO--thermoplastic olefins), polyamides,
particularly amine terminated, fluoropolymers, polyolefins,
polymethylmetacrilate, and other acrylics. These materials can also
be blended in some cases to make a superior tie layer.
Properties/Construction of the Multi-Layer Film
[0033] The multi-layer materials of the invention can be formed in
a variety of ways, as known in the art, including but not limited
to coextrusion, and lamination, or other process capable of forming
a multi-layer material. Single layers to be used in lamination can
be formed by extrusion, cast film, blown film and oriented
film.
[0034] The multi-layer structure is preferably of high purity, has
a high resistance to O.sub.2, CO.sub.2, and H.sub.2O and has little
or no leaching into the interior of the structure (the side in
contact with fluids of gases). Ideally the material is also
weldable thermally, by radiation, or radio frequency; can be
sterilized; and has good low temperature properties. Sterilization
can occur by autoclave (steam sterilization), gamma sterilization,
radio frequent sterilization, ethylene oxide and other known
methods.
[0035] The multilayer material may be used in a final application
without modification, or can be formed into a useful objects such
as containers, fittings, tubes, filters, bags, catheters,
connectors, filters, membranes, and similar objects. Having a
fluoropolymer inner layer, the multilayer articles are especially
useful in high purity contact applications, such as for biological,
biomedical, pharmaceutical and chemical contact. Some examples
include an IV bag and tubes, or a bioreactor used for manufacture
or fermentation leading to sera, biologicals, and
pharmaceuticals.
[0036] A typical disposable manufacturing system is composed of
several components, including: [0037] 1) A bag, serving as the main
component of the manufacturing system and generally made by welding
multilayer films together. [0038] 2) Flexible tubing. One example
is a PVDF/TPU flexible tube: the inner layer being a thin layer
(3-500 microns, preferably 15 to 150 microns, and most preferably
25-75 microns) of PVDF and the thicker (250 to 1500 microns) outer
layer being TPU. This tube is flexible enough to be used directly
in peristolic pumps. [0039] 3) Connectors, impellers and
miscellaneous components. Connectors are welded to the bags and
facilitate the connection of the tubes. These connectors are
generally injection molded from PVDF and are welded to the bags. It
is important to note that the bags have PVDF layer on the exposed
surfaces, which makes direct welding possible. Other components of
these disposable systems such as stirrers and probe gates can also
be injection molded from PVDF.
[0040] In general, films used in the invention, and formed into
articles such as bags contain from 2 to 5 or more layers. The
overall thickness of the film is from 1 to 40 mils and preferably
from 3 to 15 mils. In one embodiment, a bag is made of a
PVDF/TPU/EVOH/TPU/PVDF composition, having a high purity
fluoropolymer with low surface tension on the inner layer, the bulk
of the structure's volume being TPU with good flexibility and
toughness and also acts as a tie-layer between the PVDF and EVOH.
Preferably the TPU is ester based without lubricants. The weight
percent of PVDF is from 10-100 wt %, preferably 10-90 wt %, and
more preferably 25 to 70 wt %, the weight percent of TPU being from
0 to 90 wt %, preferably from 10 to 80 wt %, and more preferably
from 30 to 70 wt %, and the weigh percent of EVOH is from 0 to 40%,
preferably 5-30 wt %, and more preferably from 5 to 25 wt %. The
percentages adding to 100%. Some preferred layer thicknesses for
this composition in mils (first number is the inner layer) are:
2/2/1/2/1, 1/2/1/2/1, and 2/2/1/2/2.
[0041] Other useful film constructions include: [0042] 1)
PVDF/TPU/EVOH/TPU/copolyester [0043] 2) PVDF/TPU/EVOH/polyamide
[0044] 3) PVDF/TPU/PVC
[0045] Tubes used in the disposable systems could be 2, 3, 4, 5 or
more layers. A typical tube would have a two layer PVDF/TPU
structure and could have inside diameters from lass than 1/32'' to
over 1''. The thickness of the tube depends on the application and
diameter. In the tube structure, PVDF could be from 1% to 99% and
preferably from 15 to 40 percent by weight of the tube. In the case
of two-layer structure, TPU provides the balance of the thickness.
For the tubes that include EVOH, the balance is provided by TPU and
EVOH.
Process of Recycling
[0046] An advantage of the present invention is that the whole
disposable manufacturing system (bag, tube, fittings, impeller,
etc) can be recycled, without a need to disassemble various parts
before recycling. A typical recycling process involves the
following steps. [0047] 1) In most applications, the system is
sterilized using autoclave or radiation before shipping out of the
lab. Systems are gathered and preferably pre-washed. [0048] 2) The
whole system is ground into small pieces or flakes using a grinding
machine. The size of the flakes could be controlled using various
methods but the most common way is by using screens and sieves. The
average size of the flakes is generally in the order of several mm
to facilitate the remaining recycling steps. [0049] 3) The flakes
are washed using water or a suitable solution. Metal, paper, ink
and other contaminants are separated using various methods. The
material is then dried and stored. [0050] 4) Flakes are fed into an
extruder with intensive mixing sections. A twin screw extruder is
preferable. Using this process, flakes are converted into pellets
suitable for conversion into a useful article. The compatibility of
the ingredients guarantee enough melt strength and stability for
stranding and pelletizing. In this step, compatibilizers can be
added if necessary. One useful compatibilizer is KYNAR ADX, a
maleic anhydride functionalized PVDF from Arkema Inc. [0051] 5) In
most cases, large quantity of pellets are tumble mixed to further
unify the average composition of the product. [0052] 6) These
pellets are used in thermoforming processes such as in extruders,
injection molding machines and other polymer processing equipments
to create pipes, tubes, films, injection molded, blow molded or
similar articles.
Articles Made of the Recycled Multi-Layer Structures.
[0053] A unique feature of the present invention is that compatible
melt blends of recycled materials can be formed from a broad range
of ratios of fluoropolymer to other components. This is important,
since the exact compositions and ratios of layer compositions in
fluoropolymer-containing disposable multi-layer materials will vary
from material to material. As noted above, connectors and impeller
will be primarily PVDF, tubing generally contains little or no
barrier layer, and even the bags can vary in composition depending
on the process in which they were used.
[0054] In the recycled melt blend, the weight percent of the
components is from 1 to 100, preferably 10 to 90, and more
preferably 25 to 70 weight percent fluoropolymer; 0 to 40 and
preferably 5 to 25 weight percent barrier material; and 0 to 90 and
preferably 25 to 75 weight percent non-fluoropolymer material; the
total adding to 100 percent. The fluoropolymer, non-fluoropolymer
and bather layer may be of a single composition, or may be a
combination of two or more different compositions and/or different
layers and materials.
[0055] In one embodiment, a manufacturing system having a
multi-layer bag of PVDF/TPU/EVOH/TPU/PVDF, plus multi-layer tubing,
and single composition stirrers and connectors is recycles into a
melt blend. The weight percentage of each component is 10 to 100,
and preferably 25 to 70 weight percent of PVDF; 0 to 90 and
preferably 30-70 weight percent TPU; and 0 to 40 weight percent and
preferably 5 to 25 weight percent of EVOH. From 1 to 60 weight
percent and preferably 15 to 30 weight percent based on the total
composition of a compatibilizer, such as KYNAR ADX polymer (a
maleic anhydride modified PVDF) could be added to the melt blend
before being formed into a final article. KYNAR ADX polymer can
have from 0.1% to 30% and preferably from 0.5% to 10% weight
percent of maleic anhydride graft or content. A blend of these
three materials in the above range has good melt processing and
melt strength behavior and can easily be converted to films and
tubes or injection molded parts. The morphology of the blend
exhibits interesting properties. For the systems with TPU as the
continuous phase, EVOH and PVDF exist as separate dispersed
domains. The size of the PVDF particles will be at least an order
of magnitude larger than the EVOH domains. Small domains of TPU can
be seen inside the PVDF region in higher magnifications. FIG. 1
shows a micrograph of a 30/60/10 blend of PVDF/TPU/EVOH on weight
basis. For systems with PVDF as the continuous phase, more complex
morphologies including a bull's eye structure of EVOH surrounded by
TPU in a matrix of PDVF are observed. Given the density difference
between PVDF and EVOH and TPU, the system needs to have at least 60
weight percent of PVDF to have a continuous PVDF phase. A
continuous PVDF morphology has major implications in terms of the
improvement of the permeation and chemical exposure.
[0056] The TPU/PVDF/EVOH blend has substantially better fuel
exposure and permeation properties than pure TPU. Exposure of the
blend to selected chemicals shows better chemical properties of the
blend compared to TPU. Examples 1 to 3 present these results.
[0057] The recycled blend could be used as 100% recycled material,
or could also be melt-blended with virgin materials to form
melt-processed final articles. The recycled blend of the invention
could also be formed into pellets or powder that could then be
transported to a melt-processing manufacturing site, and formed
into useful articles.
[0058] Another use for the recycled blend of the invention is as a
polymer process aid (PPA). The recycled blend could be extruded and
cut into pellets, or ground into flakes or powder, and added at low
levels with a melt-processible matrix polymer. The recycled blend
is used at a level calculated to provide from 0.01 to 25 percent,
preferably 0.02 to 20 percent, and most preferably from 0.05 to 15
percent fluoropolymer by weight in the final blend. The recycled
fluoropolymer blend would be useful as a process aid in a variety
of polymer systems, including, but not limited to polyvinyl
chloride (PVC), polycarbonate (PC), polycarbonate/polyester blends,
and thermoplastic urethanes (TPU). The PPA acts to decrease the
apparent melt viscosity of the matrix polymer. TPU is especially
difficult to melt process due to its stickiness, and the recycled
blend of the invention is especially useful as a process aid with
TPU. The fluoropolymer in the recycled blend as a process aid also
reduces the extruder back pressure and torque, reducing the
possibility of melt fracture and making the sizing of articles
easier. An advantage of using the recycled blend of the invention
as a process aid, is that not only is the melt-viscosity improved,
but the addition of even these low levels of fluoropolymer should
provide improved chemical resistance, weather resistance, reduction
of surface friction, and improvement of other surface
properties.
Example 1
[0059] Multilayer films were extruded with three different
materials having a five-layer construction. This construction is
based on KYNAR 2800 (PVDF copolymer with HFP from Arkema Inc.).
Table 1, below, describes the film.
TABLE-US-00001 TABLE 1 KYNAR 2800 Based Multi-Layer Film KYNAR
ELASTOLLAN EVALCA ELASTOLLAN KYNAR 2800-20 C85A10 H171b C85A10
2800-20 30 micron 30 micron 15 micron 30 micron 60 micron
[0060] The film was ground down to 1/8'' flakes. Per weight basis
the blend has approximately 62% KYNAR 2800, 30% ELASTOLLAN C85A10
(from BASF), and 8% EVALCA H171b (from Kuraray). These flakes were
then pelletized on a 18 mm Leistritz co-rotating twin screw
extruder. The screw used was specially designed for intensive
mixing. The KYNAR 2800 based multi-layer film pelletized very
easily. The pellets were then dried at 60.degree. C. for a minimum
of 2 hours in a vacuum drier. After drying, the pellets were
injection molded into ASTM D 638 Type I and IV tensile bars. The
bars were tested for tensile and elongation following ASTM D 639.
The Type I bars were converted to ASTM D 265 impact bars. The bars
were notched and tested at -40.degree. C. and -60.degree. C. in
accordance with ASTM D 265 notched impact. Table 2 illustrates the
tensile, elongation, and impact physical properties
TABLE-US-00002 TABLE 2 Tensile, Elongation, and Impact Physical
Properties 10% 10% Slope Slope Automatic -40.degree. C. -60.degree.
C. Threshold Stress at Threshold Strain at Young's Impact Impact
Stress Break Strain Break Modulus Resistance Failure Resistance
Failure Material (psi) (psi) (%) (%) (psi) (ft * lbf/in) Mode (ft *
lbf/in) Mode KYNAR 1445 2456 19.8 467.5 19322 2.519 Partial 5.812
Complete 2800 Multi- Layer Film Regrind KYNAR 3813 3870 9.7 367.3
106074 2.798 Complete 1.200 Complete 2800 Control ELASTOLLAN 522
1467 39.5 752.3 2505 -- No Break -- No Break C85A10 Control
[0061] The parts were then exposed to Fuel CE10a at 40.degree. C.
Weight and Length change measurements were recorded. Table 3
illustrates the weight and length change for 74 days of exposure
time.
TABLE-US-00003 TABLE 3 Weight and Length Change for Fuel Exposureat
40.degree. C. % Weight Material Gain % Length Gain 2800 Multi-Layer
17.78 6.14 Film Regrind KYNAR 2800 2.62 3.16 Control ELASTOLLAN
47.59 17.42 C85A10 Control
[0062] The parts were exposed to HCl (3n), Sulfuric Acid (>20%),
Bleach (50%), Ethylene Glycol (50%), Sodium Hydroxide (>20%) at
23.degree. C. Weight gain measurements were recorded. Table 4
illustrates the weight change for 45 days of exposure.
TABLE-US-00004 TABLE 4 Chemical Exposure at 23.degree. C., % Weight
Gain Ethyl- Sodium Sulfuric ene Hydrox- Acid, Bleach, Glycol, ide,
Material HCl, 3n 25% 50% 50% 30% 2800 Regrind 0.35% 0.14% 0.89%
0.82% 0.53% Film 2800 Control 0.05% 0.00% 0.03% 0.01% 0.00%
ELASTOLLAN -5.69%, -3.48%, 1.15% 0.82% -0.62% Control cracked
cracked
[0063] The pellets were dried and converted into tubes using a
1.5'' Davis Standard single screw extruder. The tubes processed
very easily. The tube had a 3/8'' outside diameter with a 0.040''
wall thickness. The tubes had a very smooth surface finish on the
outside as well as the inside. The tubes were tested for permeation
using Fuel CE10a at 40.degree. C. Table 5 illustrates the
normalized permeation results after 55 days of testing.
TABLE-US-00005 TABLE 5 Normalized Permeation in Fuel CE10a at
40.degree. C. Normalized Permeation Material Fuel (g *
mm/m{circumflex over ( )}2/day) 2800 Multi-Layer Film Regrind CE10a
714.52 KYNAR 2800 Control CE10a 1.60 ELASTOLLAN Control CE10a
1466.60
[0064] The pellets were dried and converted to a 7 mil film using a
1'' Killion extruder and a coat-hanger film die. The film processed
very well. Table 6 shows the tensile and elongation properties in
machine and transverse directions.
TABLE-US-00006 TABLE 6 Tensile and Elongation Properties 10% Slope
10% Slope Automatic 1% Stress at Strain at Threshold Threshold
Stress at Strain at Young's Secant Yield Yield Stress at Strain at
Break Break Modulus Modulus Thickness Direction (psi) (%) Yield
(psi) Yield (%) (psi) (%) (psi) (psi) (in) Machine 4632 47.3 4373
27.8 4544 55.3 32650 32352 0.00787 Transverse 1243 26.1 1173 16.3
1009 97.5 17859 17944 0.00757
[0065] Graves tear testing properties are shown in Table 7 in
machine and transverse directions.
TABLE-US-00007 TABLE 7 Graves Tear Properties Extension Transverse
at Tear Maximum Maximum Resistance Thickness Direction Load (gf)
Load (in) (gf/mil) (in) Machine 1188.61 0.067 156.99 0.0076
Transverse 2629.01 0.085 358.27 0.0073
Example 2
[0066] Multilayer films were extruded with three different
materials having a five-layer construction. This construction is
KYNAR 2500 based. Table 8, below, describes the film.
TABLE-US-00008 TABLE 8 KYNAR 2500 Based Multi-Layer Film KYNAR
ELASTOLLAN EVALCA ELASTOLLAN KYNAR 2800-20 C85A10 H171b C85A10
2500-20 30 micron 30 micron 15 micron 30 micron 60 micron
[0067] The film was ground down to 1/8'' flakes. Per weight basis
the blend has approximately 62% KYNAR 2800, 30% ELASTOLLAN C85A10,
and 8% EVALCA H171b. These flakes were then pelletized on a 18 mm
Leistritz co-rotating twin screw extruder. The screw used was
specially designed for intensive mixing. The 2500 based multi-layer
film pelletized very easily. The pellets were then dried at
60.degree. C. for a minimum of 2 hours in a vacuum drier. After
drying, the pellets were injection molded into ASTM D 638 Type I
and IV tensile bars. The bars were tested for tensile and
elongation following ASTM D 639. The Type I bars were converted to
ASTM D 265 impact bars. The bars were notched and tested at
-40.degree. C. and -60.degree. C. in accordance with ASTM D 265
notched impact. Table 9 illustrates the tensile, elongation, and
impact physical properties, as measured by ASTM D 639.
TABLE-US-00009 TABLE 9 Tensile, Elongation, and Impact Physical
Properties 10% 10% Slope Stress Slope Strain Automatic -40.degree.
C. -60.degree. C. Threshold at Threshold at Young's Impact Impact
Stress Break Strain Break Modulus Resistance Failure Resistance
Failure Material (psi) (psi) (%) (%) (psi) ASTM (ft * lbf/in) Mode
(ft * lbf/in) Mode 2500 1457 3970 17.9 884.8 17433 D 256 2.519 No
break 5.812 Complete Multi- Layer Film Regrind KYNAR 3813 3870 9.7
367.3 106074 D 256 2.798 Complete 1.2 Complete 2800 Control
Elastollan 522 1467 39.5 752.3 2505 D 256 -- No Break -- No Break
C85A10 Control
[0068] The parts were then exposed to Fuel CE10a at 40.degree. C.
Weight and Length change measurements were recorded. Table 10
illustrates the weight and length change for 74 days of exposure
time.
TABLE-US-00010 TABLE 10 Weight and Length Change for Fuel Exposure
at 40.degree. C. Material % Weight Gain % Length Gain 2500
Multi-Layer Film Regrind 16.70 6.14 KYNAR 2800 Control 2.62 3.16
ELASTOLLAN C85A10 Control 47.59 17.42
Example 3
[0069] Considering that the recycled material could include tubes
and/or connectors that have different ratios of ELASTOLLAN C85A10
to KYNAR 2800. We ran a series of tests and varied the ratios of
the ELASTOLLAN C85A10, KYNAR 2800, and EVALCA H171b. The series of
tests showed good properties of the blends regardless of the
composition. Table 11 shows the compositions tested and Table 12
shows the physical properties of each composition as measured by
ASTM D 639 and impact resistance as measured by ASTM 256.
TABLE-US-00011 TABLE 11 Compositions of each blend Composition (Wt.
%) Composition (Vol. %) KYNAR ELASTOLLAN EVALCA KYNAR ELASTOLLAN
EVALCA Blend 2800 C85A10 H171b 2800 C85A10 H171b 1 100 0 0 100 0 0
2 75 15 10 67 20 13 3 60 30 10 50 37 12 4 30 60 10 22 67 11 5 15 75
10 11 79 11 6 0 100 0 0 100 0
TABLE-US-00012 TABLE 12 Physical Properties of each Composition 10%
10% Slope Stress Slope Strain Automatic -40.degree. C. -60.degree.
C. Threshold at Threshold at Young's Impact Impact Stress Break
Strain Break Modulus Resistance Failure Resistance Failure Blend
(psi) (psi) (%) (%) (psi) (ft * lbf/in) Mode (ft * lbf/in) Mode 1
3813 3870 9.7 367.3 106074 2.798 Complete 1.2 Complete 2 3043 4907
9.3 581.1 89810 4.799 Complete 3.032 Complete 3 2035 5070 15.8
821.7 30637 -- No Break 5.457 Complete 4 1111 2436 25 868.9 8285 --
No Break 2.61 Partial 5 854 3873 27.3 888.6 2755 -- No Break -- No
Break 6 522 1467 39.5 752.3 2505 -- No Break -- No Break
[0070] Chemical exposure was performed on some of these blends.
They were exposed to HCl (3n), Sulfuric Acid (25%), Bleach (50%),
Ethylene Glycol (50%), Sodium Hydroxide (30%) at 23.degree. C. for
45 days. Weight change is being observed after 45 days, Table 13
shows the results of weight change.
TABLE-US-00013 TABLE 13 Chemical Exposure at 23.degree. C., %
Weight Change Sulfuric Ethylene Sodium Acid, Bleach, Glycol,
Hydroxide, Material HCl, 3n 25% 50% 50% 30% 2800 Control 0.05 0.00
0.03 0.01 0.00 50/40/10 0.33 0.21 1.39 1.24 -0.66 ELASTOLLAN -5.69,
-3.48, 1.15 0.82 -0.62 Control cracked cracked
Example 4
[0071] We added 20% by weight of KYNAR ADX 285, which is PVDF with
maleic anhydride functionality included in the chain, to a material
blend as a compatibilizer. The KYNAR ADX blend is very similar to
the KYNAR 2800 based multi-layer film in Example 1 structure, but
with the addition of KYNAR ADX 285. Table 14, describes the
composition of the materials in the blend.
TABLE-US-00014 TABLE 14 Weight % Composition of Material KYNAR
ELASTOLLAN EVALCA Material 2800 ADX285 C85A10 H171b 2800
Multi-Layer 64 0 29 7 Film Regrind KYNAR ADX 40 20 32 8 Blend
[0072] The compounds were injection molded into tensile ASTM D 639
type I tensile bars. Tensile and Elongation as well as notched cold
temperature impact was performed on these bars. The physical
properties are shown in Table 15 as measured by ASTM D 639 and ASTM
256.
TABLE-US-00015 TABLE 15 Physical Properties Comparing to the
Addition of KYNAR ADX Automatic -40.degree. C. 10% Slope Stress at
10% Slope Strain at Young's Impact Threshold Break Threshold Break
Modulus Resistance Failure Material Stress (psi) (psi) Strain (%)
(%) (psi) (ft * lbf/in) Mode 2800 Multi 1457 3970 17.9 884.8 17433
-- 70% No Layer Film Break Regrind 2.519 30% Partial 40/20/32/8
2118 5749 18.2 664 29229 -- 100% No Break
[0073] Chemical exposure testing was performed for both materials
for duration of 45 days at 23.degree. C. Table 16 illustrates the
results.
TABLE-US-00016 TABLE 16 Chemical Exposure Testing, % Weight Change
Ethylene Sodium HCl, Sulfuric Bleach, Glycol, Hydroxide, Material
3n Acid, 25% 50% 50% 30% KYNAR 2800 0.35% 0.14% 1.89% 0.82% 0.53%
Regrind Film 40/20/32/8 0.49% 0.30% 1.05% 0.84% -0.16%
Example 5
Comparative
[0074] A known multi-layer structure consists of LOTADER AX8840
(Arkema Inc.), HDPE DOW DGDB-2480 NT, and KYNAR ADX120 (Arkema
Inc.). For example a film of this structure that is 10 mils thick
would have a 1.5 mil layer of LOTADER, 3.5 mils of HDPE, and 5 mils
of KYNAR. When calculated by weight this is equivalent to 10%
LOTADER, 25% HDPE, and 65% KYNAR ADX.
[0075] A 10/25/65 by weight blend of LOTADER AX8840, HDPE, and
KYNAR ADX was made on a 18 mm Leistritz twin screw extruder with a
screw designed for intensive mixing. The blend was injection molded
into ASTM D 638 type I tensile bars and ASTM D 256 impact test
specimens and tested at 23.degree. C. Below are the results for the
mechanical testing as compared to the control of HDPE and
KYNAR.
TABLE-US-00017 TABLE 17 Mechanical Properties Weight % Loading
Elongation Impact KYNAR Elongation at at Break Strength LOTADER
HDPE ADX 120 Yield (%) (%) (ftlb/in) 0 100 0 9.9 17.6 2.91 0 0 100
8.7 52.8 1.45 10 25 65 8.6 9.9 1.44
[0076] As can be seen, the properties of the blend are below the
properties of the controls. Moreover, severe craze, whitening and
crack would occur when an extruded strand or tensile bars are
simply bent.
[0077] The next step in the evaluation is to make film on a three
roll stack cast film line. Making quality film was not possible.
The blend lacked melt strength and would tear very easily. Severe
gross phase separation and plate out was also observed during the
process.
[0078] In this case, both the mechanical properties and the
processibility of the blend are worse than the individual
components.
Example 6
Nylon Example
[0079] Two films were produced using the same components; KYNAR
2800, ELASTOLLAN C85A10, EVALCA H171b, and BESNO TL. The first film
was a multilayer film of weight percent and thickness shown below
and the second film was a single layer film having identical weight
percents of the contents in the multilayer. The multilayer film is
transparent; the melt blended film is opaque. Pelletization of the
blend and manufacturing of the blended film was performed without
any processing issues. Below is a description of the structure.
TABLE-US-00018 TABLE 18 Film Structures KYNAR ELASTOLLAN EVALCA
BESNO 2800 C85A10 H171b TL CG 5C 08-859 Film Weight % 48% 16% 8%
28% Layer Thickness 2 1 1 2 (mils) Melt Blended Film Nylon Blended
Film 48% 16% 8% 28%
[0080] The two films were made of similar thickness and tested for
tensile and graves tear in the machine and transverse directions.
Below are the results.
TABLE-US-00019 TABLE 19 Tensile Properties in Machine Direction
Machine Direction Stress Automatic Film at Strain at Stress at
Strain at Young's Identification Yield Yield Break Break Modulus
Thickness # (psi) (%) (psi) (%) (psi) (in) CG 5C 3886 5.8 7399
475.5 134052 0.006 08-859 Film Nylon 2236 9.4 4001 387.0 68909
0.006 Blended Film
TABLE-US-00020 TABLE 20 Tensile Properties in Transverse Direction
Transverse Direction Stress Automatic Film at Strain at Stress at
Strain at Young's Identification Yield Yield Break Break Modulus
Thickness # (psi) (%) (psi) (%) (psi) (in) CG 5C 3960 5.3 6799
470.9 143314 0.006 08-859 Film Nylon 1008 2.3 1926 347.4 63701
0.006 Blended Film
TABLE-US-00021 TABLE 21 Tear Resistance in Machine Direction
Machine Direction Maximum Extension at Tear Load Maximum Resistance
Thickness Film Identification # (gf) Load (in) (gf/mil) (in) CG 5C
08-859 Film 2886 0.108 450 0.006 Nylon Blended Film 1285 0.019 196
0.007
TABLE-US-00022 TABLE 22 Tear Resistance in Transverse Direction
Transverse Direction Extension at Tear Maximum Maximum Resistance
Film Identification # Load (gf) Load (in) (gf/mil) Thickness (in)
CG 5C 08-859 Film 2503 0.195 482 0.005 Nylon Blended Film 2668
0.239 409 0.007
* * * * *