Composition
and properties of insulation and jacket compounds for the production of
PVC cables and wires
H. Ernst
1. Market Data
The production of PVC cables and wires represents an important sector
within the PVC processing industry. Worldwide, approximately 1,600 KT
PVC have been processed for this application. This amount corresponds
to a share of about 8% of total PVC use. In Western Europe, the use of
PVC for this sector comes to about 432 KT; 8.5% of the total PVC use,
or 25% of the total P-PVC use.
In 1993, cable industry use of PVC in the Federal Republic of Germany
amounted to approximately 120 KT, or about 9% of the total use of PVC.
Due to the start of a recession, this is a reduction of 15% as compared
to 1992. In assuming that the average dosage of stabilizer is 2.5 phr,
the total worldwide stabilizer consumption (without lubricants) for the
production of PVC cable and wire is estimated to be about 40 KT.
This may be a somewhat conservative estimate, since in Western Europe
commonly used stabilizer /lubricant packages result in a higher dosage.
2. Areas of application
P-PVC is used primarily for low voltage cable and electrical cable up
to 10 KV. P-PVC has been proven effective in insulation and jacket compounds
for telecommunication and electrical wiring as well.
Use in high frequency applications is not possible due to high dielectric
constants (ªr) and relatively high (in comparison to nonpolar material)
dissipation factor (tan ä).
The highest permissible operating temperature in wires for P-PVC insulation
jacket compounds is generally around 70°C.
In using special filler and plasticizer, compounds can be produced for
operating temperatures in wires of up to 90°C. Length of use is reduced
with even higher temperatures. A temperature of 105°C may not be exceeded.
The most important raw materials and processing aids for the cable industry
as well as their influence on mechanical and electrical properties should
be presented herein. For the processor, recommendations and formula constellations
with regards to valid norms will be given.
3. Formula design
A PVC formula for the production of insulation and jacket compounds for
wire and cable generally consists of the following components:
- PVC
- plasticizer and extender
- filler
- pigment
- stabilizers and co-stabilizers
- lubricants
- special additives
(flame retardants, pest control agents, UV-absorber, etc.)
3.1 PVC
For the production of wire and cable compounds, primarily homo-polymeric
PVC is used which is produced by suspension.
Emulsion PVC types are not suitable, since water absorption, resulting
from emulsifier present, contributes to poorer electrical values. Due
to its particle nature, mass PVC polymerisates exhibit a less favorable
ability to absorb plasticizer than suspension PVC. They also have a limited
availability with higher K values. For these reasons, it can be ruled
out as a raw material for the cable industry.
The traditionally used K value lies at around 70. This K value represents
a compromise between easy processing and mechanical properties desired
in the final product. A K value of 75 or above offers better mechanical
values, but requires higher processing temperatures, thus needing a larger
amount of stabilizer. These types of PVC are only employed in compounds
for use at higher operating temperatures.
Lower K values, such as 60, are utilized because of their good flow properties
in injection moulding of electrical plugs. Further criteria which PVC
must fulfill for use in the cable industry are:
- porous particle structure
- high plasticized absorption
- free of contaminant particles
- good plastification properties
- low percentages of volatile components
- low electrolyte content
Listed in Table 3 are the typical properties which a suspension PVC for
the production of wire and cable should exhibit.
Table 3: Typical values for S-PVC use din the production of wires and cables (see attached files)
3.2 Plasticizers and
extenders
PVC formulas for the production of insulation and jacket compounds for
wire and cable always contain plasticizer, since PVC, if it were used
alone, would be too rigid and brittle. These are some of the requirements
placed on plasticizers for the cable industry:
- high compatibility with PVC
- good plastification properties
- low volatility
- good ageing properties
- electrolyte-free
The selection of a suitable plasticizer must be oriented towards the production
parameters as well as the requirements on the final product. Mainly Phthalate
acid esters such as DOP, DINP and DIDP are utilized as primary plasticizers.
The stand out on the basis of their broad area of use and good mechanical
and electrical properties. For high temperature compounds, like Yl 7 and
Yl 8, as well as YM 4 one should use the low volatile plasticizers Di-isotridecylphthalate
(DITP) or Trimellitates like TOTM (Trioctyltrimellitate).
PVC compounds which need low temperature resistance can best be prepared
in combination with Phthalic acid esters with dicarboxylic acids such
as Dioctyladipate (DOA), Dioctylazelate (DOZ) or Dioctylsebacate (DOS).
Oil or migration resistant compounds can be obtained by using polymeric
plasticizers or plasticizing polymers or elastomers such as CPE, EVA or
NR.
Flame retardant compounds often contain esters of Phosphoric acid or chlorinated
paraffin and are often combined with Antimony trioxide and/or Aluminum
hydrates.
For price optimization of formulations, extenders such as aromatic hydrocarbons
and chlorinated paraffin are used. Extenders have only a limited compatibility
with PVC and possess no or very little plasticizing effect. The use of
ESO can be advantageous in supporting the stabilizing effect of Ca/Zn
or Ba/Zn stabilized compounds.
Plasticizers used in the cable industry are often prestabilized with phenolic
antioxidants (0,3 - 0,5 % bisphenol A) in order to improve ageing properties.
This must be taken into consideration when designing a formulation.
The amount of plasticizer used is dependent upon its plasticizing capability
and the desired rigidness / flexibility of the final product. The desired
electrical properties such as volume resistivity are a function of the
plasticizer content. An increase in the amount of plasticizer leads to
a worsening of the electrical properties.
A summary of properties and applications of relevant plasticizers for
the cable industry can be found in Table 4.
Table 4: Properties of primary plasticizers for the cable industry (see attached files)
DOP = Dioctylphthalate
DINP = Dlisononylphthalate
TOTM = Trioctyltrimellitate
DIDP= Diisodecylphthalate
DITP = Diisotridecylphthalate
Note: trimellitates are also available as esters of straight chain C8 - C10 alcohols or esters of straight chain C7 - C11 alcohols.
DOP good all-round
properties Tl 1,TI2,YI3, TM 1, TM2, YM 3
DINP, DIDP
less volatile than DOP otherwise similar like DOP, and Yl 4, YM 5
DITP, TOTM
good ageing properties extremely low volatility Yl 7, Yl 8, YM 4
Special plasticizer
Esters of dicarboxylic acid (DOA, DOZ, DOS) secondary plasticizer for cold resistivity cold resistant compounds
Esters of phosphoric
add
primary plasticizer negative effect on photo-, thermal stability flame
retardant formulas especially combined with Sb203
polymeric plasticizers, polymers or elastomers (CPE, EVA, NBR) nonmigrating,
resistant to oil and mineral spirits, low volatility poor plastification
average cold resistivity compounds with high requirements on migration
epoxy plasticizer (ESO) synergistic improvement of thermal and photo-stability when combined with Ca/Zn or Ba/Zn co-stabilizer
Extender
chlorinated paraffin
(40 - 50% Cl)
good electrical properties, nonflammable, especially combined with Sb2O3,
negative effect on thermal and photo-stability and cold resistance price
optimization flame retardant
aromatic hydrocarbons
limited compatibility poor light stability price optimization
Table 5: Plasticizer for Insulation and Jacket compounds for wire and
cable. (see attached files)
3.3 Filler
Fillers are used in insulating and jacket formulas for wire and cable
to reduce the price of the compound and to improve electrical as well
as other properties.
Jacket formulas especially often contain high amounts of filler. Heat
transfer properties are positively influenced by fillers. Thermal conductivity
is increased.
Fillers, above all Calcium carbonate, can provide favorable effects on
flow and processing behavior of the PVC mass.
Primarily Calcium carbonate types (CCN) such as chalk, limestone and marble
of various fineness are deployed.
Their surfaces can be treated or untreated. Treated surfaces lead to a
reduction of plasticizer absorption of the filler material.
When cable is to be laid in acidic ground, if at all possible, Calcium
carbonate should not be used since it can react chemically with acids.
Calcium carbonates, like Aluminium hydrates, increase the Oxygen index
and in a fire can bind released Hydrochloric acid.
In doing so, they contribute in reducing the fire damages caused by Hydrochloric
acid.
Hydrated Aluminum silicate is used primarily in high temperature resistant
compounds to improve electrical properties. The use of noncalcified types
is not advisable, since they often contain Sulphur compounds which, in
the presence of Lead compounds, cause Sulfide discolourations. The utilization
of calcified hydrated Aluminum silicate also has a detrimental effect
in that abrasion on machine parts is increased.
Table 6: Typical properties of fillers for the production of Insulation and Jacket compounds for wire and cable.
Additions of highly
dispersed pyrogenic Silica acid serve as ion "traps" and reduce
plate-out and blocking tendencies.
Typical values of the most important filler materials are listed in Table
6.
3.4 Pigments
Pigments not only provide distinguishing colour of core blends, but also
colouration of jacket compounds. Except in the cases where the compounds
are black, Titanium dioxide is used as a colour "carrier". One
must keep in mind, that Titanium dioxide influences the dielectrical constant
(ªr). Also one must keep in mind, that when following the current trend
of using Ca/Zn instead of Lead primary stabilizers, Ca/Zn stabilizers
do not exhibit any pigmenting effects. In some cases where the stabilizer
has been changed, a correction of the pigment system is necessary.
3.5 Lubricants
In using external lubricants in PVC formulations for insulation and jacket
compounds, sticking of the PVC melt on hot metal surfaces of the processing
equipment can be reduced. Further advantages are gained with increased
production rate and the improved nature of the extrudate surface.
The use of internal lubricants is, in general, not necessary, since the
internal friction between the PVC molecular chains in already sufficiently
reduced by the plasticizer content. Cable formulations contain neutral
Lead stearate as a co-stabilizing lubricant; a primarily external lubricant,
as well as Calcium stearate; which is more of an internal lubricant. Fatty
alcohols, waxes, paraffin and low molecular weight polyethylene are also
used for additional lubrication. It is not advisable to use fatty acids
(i. e. stearic acid) since it may react with the basic components of the
Lead compound and thus lead to an alteration of the rheological properties
as well as the stability. Nonpolar lubricants such as paraffin and PE
waxes only slightly influence the electrical values. In Table 7, the most
important lubricant groups are listed which are utilized for PVC insulation
and jacket compounds for wire and cable.
3.6 Special Additives
3.6.1. Flame retardants
Antimony trioxide (Sb2O3) is an especially effective flame retardant for
thermoplastics containing Halogens. Its use has come under debate due
to possible carcinogenic effects. Antimony trioxide is available in various
qualities and with varying degrees of whiteness. A standard quality is
quite often good enough for use
Table. 7: Lubricants for PVC insulating and jacket compounds for cables and wires.
in PVC insulation
and wiring. In order to avoid on-the-job hygienic problems, Antimony trioxide
is mostly used in granulated or pasted forms. It can also be delivered
in an already processed stabilizer/lubricant package. Generally, the dosage
is 3 -5 phr. As far as toxicity is concerned, Aluminum hydrate (AKOH);,)
offers a less hazardous alternative. Dosage is however considerably higher
than Antimony trioxide and lies generally 20-30 phr.
3.6.2. Flame retardant plasticizer
The flame retardant properties of chlorinated paraffin and Phosphoric
acid esters were already discussed in the section, "Plasticizer".
They are commonly combined with the flame retardant fillers mentioned
in 3.6.1. In using chlorinated paraffin, one must use substitute the primary
plasticizer with twice as much chlorinated paraffin to ensure the same
degree of plastification. The Oxygen index (LOI) is often given as an
expression of inflammability. This unit represents how much Oxygen must
be present in the surrounding atmosphere so that the compound in general
will bum. The LOI lies at about 25 for flexible PVC in general. Specially
designed flame retardant compound can achieve values of 33. The Oxygen
index alone is however not enough to fully express the flammable nature
of wires and cable. In this case, the following tests would have to be
consulted: VDE 0472, part 804 with procedures A and B; VDE 0472, part
804. VDE 0472, part 813 serves as the valid reference for corrosive-ness
of gases released during fire.
3.6.3 Pest control agents (Rodenticide)
These additives serve to protect the cable against damage done by rodents.
Their effectiveness is unclear, since their ability to actually protect
the cable is very difficult to prove. Baerlocher offers Barostab PV 300,
a product based on Lead naphthenate.
3.6.4 UV-Absorber
Carbon black is known for effectively providing protection against light.
Since not all
wires and cables in exterior applications are black, other solutions have
been requested. In brightly coloured or transparent compounds, the familiar
UV-Absorbers based on Benzotriazole, Benzophenone or Oxanilide can be
used. Baerlocher has the UV-absorber Baerostab B 200 P in its program.
This product is based on a derivative of Oxanilide and has no influence
on the colour of the PVC compound.
3.6.5 Biocide
Biocides should serve to protect the PVC compounds, and above all the
plasticizer, from attack and degradation by fungus and microorganisms.
In this case, OBPA (10',10'-0xybisphenoazine) is frequently used. OBPA
is available on the market already dissolved in plasticizer.
3.7 Stabilizers and co-stabilizers
3.7.1 Lead compounds
Except for a few special applications, PVC insulation and jacket compounds
for wire and cable are, at this time, almost always stabilized with basic
Lead compounds.
This will probably change in the future, since attempts are underway to
replace the toxic heavy metal compounds in PVC with Calcium/Zinc stabilizers.
New compounds of this type will be discussed in the second part of this
unit.
3.7.1.1 Individual Lead component stabilizers for insulation and jacket
compounds
High quality insulation and jacket compounds contain basic Lead primary
stabilizers such as:
- tribasic Lead sulfate
- tetrabasic Lead sulfate
- disbasic Lead phthalate
- polybasic Lead fumarate
Previously, dibasic Lead carbonate (white lead) was also utilized by the
cable industry but has been replaced to a large extent by the previously
mentioned products because of its disadvantage of CO2, cleavage. The primary
Lead stabilizers are combined with costabilizers such as dibasic Lead
stearate, phenolic antioxidants, polyols as well as neutral Lead stearate
and Calcium stearate.
Whereas basic Lead sulfate is primarily utilized for Tl 1, Tl 2, Yl 3,
Yl 4, Yl 5, TM 1, TM 2, YM 5 types of compounds, basic Lead phthalates
and polybasic Lead fumarate can also be used for high temperature core
and jacket compounds of the type Yl 7, Yl 8 and YM 4.
The properties of the Lead primary and costabilizers are listed in Table
8.
In order to avoid work-related health concerns, the above stabilizers
are also available in low-dusting granulate form. "E" products
(rod-shaped granulates) contain approximately 10% low melting lubricant
which serves as a granulating process aid. "SMS" products (flakes)
and "TX" products (pastilles), which are produced through the
melting process, contain about 15 - 20% lubricant as melting process aid.
The Baeroblend products contain, aside from their Lead components, approximately
30% PVC and up to 5% DOP as carrier material. In Table 9, possible delivery
forms of low-dusting individual Lead components are listed.
In order to achieve a homogeneous distribution, granulates require hot
mixing in fast mixers at temperatures from 90 -120°C. Baeroblend types
are also suitable for cold mixing in slow mixers.
3.7.1.2 Stabilizer/Lubricant packages for the Cable Industry
Baerlocher has developed a series of stabilizer/lubricant packages for
an efficient production of wires and cables which allow the manufacturer
to produce high quality articles without having to add additional costabilizers,
antioxidants or lubricants. If the customer wishes, the additive system
is available in a form other than the one introduced (i. e. with added
Antimony trioxide). The currently available standard compounds are summarized
in Table 10.
The selection of a suitable type should be made by taking into consideration
the specific properties of the final products and equipment.
At this time, it should be carefully pointed out that UV rays can cause
discolouration in products which contain tetra or polybasic Lead salts
as a stabilizer system. For this reason, Baeropan 296 KA, 297 KA, 770
KA, 750 KA, 4926 KA as well as Baeroblend 7775/1 KA are not recommended
for photo sensitive applications in light colours.
Table 8: Properties of Lead primary and costabilizers (see attached files)
Table 9: Low-dusting delivery forms of Lead single component stabilizers (see attached files)
Table 10: Additive compounds for the extrusion of PVC insulation and jacket compounds for wire and cable. (see attached files)
BAEROPAN Stabilizer/lubricant
packages for insulation and jacket compounds
BAEROPAN 292 KA
Standard insulation and jacket package with a low percentage of lubricant
and good thermal stability. It is especially suited for higher stabilized
core insulation as no problems with overlubrication are present, even
at higher dosages, which could negatively influence the output or the
surface characteristics.
BAEROBLEND 294 KA
Highly effective stabilizer/lubricant package based on Lead sulfate with
very good thermal stability. Broad application spectrum of highly filled
core and jacket compounds up to 10 KV formulations.
BAEROPAN 295 KA
Highly effective stabilizer/lubricant package based on Lead sulfate. Broad
application spectrum like Baeropan 294 KA, however with somewhat reduced
lubrication.
BAEROPAN 296 KA
Standard stabilizer/lubricant package based on tetrabasic Lead sulfate
with the highest thermal stability. Broad application spectrum of highly
filled core and jacket compounds up to 10 KV formulations.
BAEROPAN 297 KA
Highly effective stabilizer/lubricant package based on tetrabasic Lead
sulfate. Broad application spectrum like Baeropan 296 KA but with somewhat
reduced lubrication.
BAEROPAN 770 KA
Effective stabilizer/lubricant package based on Lead sulfate/fumarate.
With regards to thermal stability and electrical properties, it is the
most effective product in the Baeropan series based on Lead sulfate for
cable extrusion. Due to its low percentage of lubricant, this compound
is especially suitable for highly stabile core insulation.
BAEROPAN 3600 KA
Universally applicable cable compound for insulation and jacket applications.
Due to its elevated percentage of lubricants, good lubrication can be
achieved with low dosages even in the presence of untreated filler.
BAEROPAN stabilizer/lubricant
package for formulations containing chlorinated paraffin and flame retardants
BAEROPAN 440 KA
Stabilizer/lubricant package which was especially developed for the extrusion
of cable insulation compounds containing chlorinated paraffin. Due to
its well-balanced lubrication, it possesses a broad application spectrum.
BAEROPAN stabilizer/lubricant
package for extrusion with high drawdown
BAEROPAN 4926 KA
Highly lubricated cable compound with good thermal stability. It is especially
suitable for the extrusion of telephone cores and also highly filled jacket
compounds with untreated filler as well as cable jackets with sturdy wall
strength.
BAEROPAN stabilizer/lubricant
packages for high temperature resistant formulations
BAEROPAN 1974 KA
Lead compound based on Lead phthalate, which was designed especially for
the high requirements of the 90°C and 105°C PVC compounds. The dosage
for the Yl 8 core compounds is approximately 12 phr. Additional lubricants
or antioxidants are not necessary.
BAEROPAN 1978 KA
The additive compound Baeropan 1978 KA based on Lead phthalate represents
a version of Baeropan 1974 KA with an optimized lubrication system. The
tendency towards lubricant exudation, as seen after long storage, is lower
than with Baeropan 1974 KA.
BAEROPAN 750 KA
Stabilizer/lubricant package based on Lead sulfate/fumarate with excellent
thermal stability and good lubrication especially for Yl 8 core compounds.
This is the only compound for high-temperature resistant formulations
available in pastille form.
BAEROBLEND additive
concentrates for insulation and jackets formulations
BAEROBLEND 7294 KA
PVC/stabilizer concentrate based on Lead sulfate which is a highly dispersible
form.
able" and can be transported pneumatically or mechanically. Due to
its delivery form, Baeroblend 7294 is also suitable for cold preparation
in slow mixers. Stability and lubrication correspond roughly to Baeropan
294 KA.
BAEROBLEND 7775/1 KA
PVC/stabilizer concentrate based on Lead sulfate/fumarate, which is has
a low-dusting, lightly dispersible form. Baeroblend 7775/1 KA has good
free-flowing properties, is "silo able" and can be transported
pneumatically or mechanically. Based on its special delivery form, Baeroblend
7775/ 1 KA is also suitable for cold preparation in slow mixers.
Low-dusting delivery
forms of additive compounds
These additive compounds are available under the name Baeropan MC in powder
form and can also be delivered in pre-weighed individually sealed EVA
bags for specific mixer size.
They can be added into the fast mixer without being opened and dissolve
without any residue.
These low-dusting additive systems
Baeropan E - rod-shaped granulate
Baeropan SMS - flakes
Baeropan TX - pastilles
require fast running
mixed aggregates with suitable friction and mixing temperatures of 90
- 120 °C in order to achieve a homogeneous distribution in the mixture.
The Baeroblend products are available as lightly dispersible, low-dusting
additive compounds. In this case. they are additive concentrates with
PVC as a supporting base which prove suitable for cold processing in slow
mixers.
The low-dusting delivery forms of Baerostab, Baeropan and Baeroblend types
are recommended specially for installations where weighing in automated.
They are "silo-able" and conveyable. The manufacturer is thus
allowed to handle the material in a hygienic manner.
A summary of the properties of the low-dusting delivery forms can be found
in table 11.
Table 11: Properties of low-dusting Lead stabilizers and Lead compounds (see attached files)
Formulation proposals for Lead stabilized PVC insulation and jacket compounds according to VDE 0207
Insulation compound,
Tl 1 and Tl 2
100.00 S-PVC,K70
50.00 DOP
65.00 Calcium carbonate
3.50 Lead compound, Sulfate basis, e.g. Baeropan E 292 KA
X pigment
Insulation compound,
Yl 4
100.00 S-PVC,K70
43-52 DIDP
30.00 Calcium carbonate
5.50 Lead compound, Sulfate basis, e.g. Baeropan TX 296 KA
X pigment
Insulation compound,
Yl 8
100.00 S-PVC, K 70-90
43.00 TOTM
10.00 calcified hydrated aluminium silicate
12.00 Lead compound, Phthalate basis, e.g.MC1978KA
X pigment
Jacket compound,
TM 1 and TM 2
100.00 S-PVC, K70
52.00 DOP
70-80 Calcium carbonate
3.50 Lead compound, Sulfate basis, e.g. Baeropan E 292 KA
X pigment
Jacket compound,
YM 4
100.00 S-PVC, K 70-90
53.00 TOTM
15.00 Calcium carbonate
3.50 calcified hydrated aluminium silicate
10-12 Lead compound, Phthalate basis, e.g. Baeropan MC 1978 KA
X pigment
Plugs (injection
moulding)
100.00 S-PVC, K70
95.00 DOP
50.00 Calcium carbonate
5.00 Lead compound, Sulfate basis, e.g. Baeropan TX 3900 KA
X pigment
Gusset compounds
100.00 S-PVC, K70
100.00 DOP
400.00 Calcium carbonate
2.00 Lead compound, Sulfate basis, e.g. Baeropan E 292 KA
0-1.00 external lubricant
Transparent insulation
compound
100.00 S-PVC, K70
55.00 DOP
4.00 Barostab LSA
4.00 Barostab UBZ 171 T
Testing of PVC insulation
and jacket compounds for wire and cable
The requirements placed upon insulation and jacket compounds are summarized
in DIN VDE 0207, parts 4 and 5. It concerns a series of standardized compound
types which carry the names Yl 1, Yl 2, Yl 3, Yl 4, Yl 7, Yl 8 for insulation
compounds and YM 1, YM 2, YM 3, YM 4 and YM 5 for jacket compounds. The
compounds Yl 1 (TI 1),YI2 (TI2),YM1 (TM 1), and YM 2 (TM 2) are harmonized
within the realms of CENELEC/TC 20. Test procedures are set in DIN VDE
0472.
New label for Lead
compounds
As stated in the revision of the EU directive for "Classification
and Labeling", Lead compounds are to receive a new label as of May
1st, 1994.
This change involves all Lead compounds containing more than 0.5% Lead
compounds, regardless of physical delivery form. The new hazard classification
requires the label, "poisonous" as well as the additional R61
sentence "can harm unborn children".
Since this change in the labelling is not based on new toxological data,
no changes in workplace concentration limits and handling are needed.
The effectiveness
of Lead primary compounds
Lead primary compounds possess varying degrees of effectiveness. This
is dependent upon their basicity, which in return is expressed by the
active Lead content, or also by residual acid. Lead primary compounds
can not be utilized by themselves, but always in combination with Lead
salts (neutral and dibasic Lead stearate) as costabilizer.
Organic Lead primary compounds such as dibasic Lead phthalate and polybasic
Lead fumarate exhibit extremely good ageing properties. For that reason,
they are the preferred stabilizers for high-temperature resistant cable
and wires types such as Yl 7 and Yl 8 and as well as YM 4.
As an illustration, trials were run with a simple insulation and jacket
compound as well as with a formulation for high-temperature resistant
insulation.
The tests were performed on milled sheets, which were run for 10 minutes
at 180°Conthe mill.
The HCI stability was measured at 200°C, as according to VDE 0472.
tensile strength
percentage elongation at break oven ageing
weight loss through
evaporation thermal pressure resistivity
thermal shock process
thermal stability
direct current resistivity
specific insulation resistance
DIN VDE 0472, part 602
DIN VDE 0472, part 602
DIN VDE 0472, part 303, ageing "A"
DIN VDE 0472, part 612
DIN VDE 0472, part 609
DIN VDE 0472, part 608
DIN VDE 0472, part 614
DIN VDE 0472, part 510
DIN VDE 0472, part 502
Table 12: Test Methods for PVC insulation and jacket compounds (see attached files)
3.7.2 Calcium/Zinc
compounds
Lead stabilizers provide a number of advantages, above all:
- excellent thermal stability
- good electrical properties
- easy processing
- excellent resistance to ageing
- unmatched price/performance ratio.
For decades these products have proven themselves in the production of
cable and wire, but have recently come under increasing ecological attack.
Strict injunctions are currently in the planning stages in the USA for
environmental protection which will effectively eliminate any possibility
of depositing Lead-contaminated waste. Thus, manufacturers are forced
to switch to Lead-free stabilizing systems.
Interest is also growing in Western Europe to do without Lead stabilizers;
not only in the cable industry, but in other branches of the PVC industry.
Baerlocher prepared itself for this trend which one had seen long in advance.
Baerlocher can now offer a series of Lead-free alternatives. These new
systems, in general, can be placed into the "family" of Ca/Zn
compounds, even if many of these products contain other metals such as
Magnesium and Aluminum.
It should be pointed out the these stabilizer systems, despite their lower
densities (1.5 - 2.0 g/cm3), are more expensive than Lead systems.
As of now, Ca/Zn stabilizers are available for all cable types up to VDE
0207 Yl 5 as well as YM 5. At this time, there is no economical Ca/Zn
solution for high-temperature applications such as Yl 8 or YM 4.
Baerlocher had introduced into the market more than a decade ago one of
the first stabilizer/lubricant packages based on Ca/Zn, BAEROPAN MC-KA
2. This product was recommended for use in Sulphur resistant jacket compounds.
The stabilizer systems which are offered nowadays provide considerably
more effectiveness than those initial Ca/Zn stabilizers.
Here, some standard stabilizer/lubricant packages:
BAEROPAN MC-KA 42
BAEROPAN MC 8367 KA and BAEROPAN MC 8425 KA
BAEROPAN MC-KA 42
Ca/Zn stabilizer/lubricant package for insulation and jacket blends of
wire and cable. Excellent effect on heat stability. Especially suited
for compounds of the types Tl 1, Tl 2, TM 1 and TM 2. Dosage, depending
upon requirements, 3 - 5 phr.
A lubricant-free variation of this product, Baeropan MC-KA 62, is available.
This product does not show any signs of over-lubrication even at higher
dosages. Use of BAEROPAN MC-KA 42 and BAEROPAN MC-KA 62, in comparison
to Lead stabilizers, can lead to higher water absorption, and thus worsen
electrical values.
BAEROPAN MC 8367 KA
Ca/Zn stabilizer/lubricant package with good thermal and ageing resistance.
Limited tendency to water absorption. No problems with overlubrication
occur, even at higher dosages. Dosage: 4.0 - 9.0 phr, depending on requirements.
BAEROPAN MC 8425 KA
Effective product of the BAEROPAN Ca/Zn stabilizer/lubricant series. Aside
from very good dynamic stability, good colour hold and good ageing properties,
BAEROPAN MC 8425 KA exhibits practically no change in electrical values
after storage in water. Due to the sparse use of external lubrication,
no problems with overlubrication are present, even at higher dosages.
Dosage: 4.0 - 9.0 phr, depending on requirements.
Fig 14: Standard Ca/Zn stabilizer/lubricant packages for wire and cable. (see attached files)
Formulation proposals
for Ca/Zn stabilized insulation and jacket compounds, as defined by VDE
0207
Insulation, Tl 1 and Tl 2
100.00 S-PVC, K70
50.00 DOP
65.00 Calcium carbonate
3.50 BAEROPAN MC-KA 42
X pigment
Insulation compound, Yl 4
100.00 S-PVC, K70
43-52 DIDP
0.0-10.00 ESO BAROSTAB LSA
30.00 Calcium carbonate
6.00 BAEROPAN MC 8367 KA or BAEROPAN MC 8425 KA
X pigment
Jacket compound,
TM 1 and TM 2
100.00 S-PVC, K70
52.00 DOP
70.0 - 80.00 Calcium carbonate
3.50 BAEROPAN MC-KA 42
X pigment