SURFACE PROPERTIES
- SEALING
- STERILIZATION
- VACUUM METALISATION
- PRINTING
- ELECTRICAL
PROPERTIES
- CO-EFFICIENT OF
FRICTION
CHECKING OF SURFACE
PROPERTIES WITH NEW FILMS
- When new films are
designed based on blending they undergo change.
- Therefore any newly
designed film which is proposed for this
applications must undergo check of such properties.
ENVIRONMENTAL
PROTECTION
- Environmental
protection keeps desirable components inside the
package and keep undesirable components out.
- This often requires
some level of barrier to substances such as
moisture, oxygen, chemicals and aromas.
PHYSICAL & THERMAL
DEMANDS TO PRODUCE PACKAGE
- The physical
protection is achieved through use of sufficiently
rigid or protective package structure that can
withstand physical and thermal demands while
producing package.
- But still meet
better surface properties for appealing
SEALING
Heat sealing capability
is usually specified by
- Seal strength
- Hot tack strength
- Seal initiation
temperature
* (Strength of hot seal
after cooling for 0.1 sec.)
100% hot tack strength is important in vertical form
fill and seal equipment while contents are dropped
into bags while seal is still hot.
ADDITION OF TOPAS ON
PE IMPROVES THE PROPERTIES
CHARACTERISTICS OF
COC (TOPAS)
TOPAS is a trade name
of COC (Cyclic Olefin copolymer).
- High transparency
and gloss
- Excellent moisture
and aroma barrier
- Variable glass
transition temperatures from 65 °C to 178 °C
- High stiffness and
strength
- Easy to extrude and
thermoform
- Compatibility with
polyfins
- Excellent
biocompatibility and inertness
- Resists hydrolysis,
polar organics, acids and alkalis
|
PROPERTIES OF TOPAS
|
Property |
Unit |
Test Method |
9506F-04 |
8007F-04 |
8007F-400 |
6013F-04 |
|
Density |
kg/m3 |
ISO
1183 |
1020 |
1020 |
1020 |
1020 |
|
Melt Volume Rate (MVR)
* at 230°C, 2.16 kg
load
* at 190°C, 2.16 kg
load |
cm3/10
min |
ISO 1133 |
6.0
1.0 |
12.0
2.0 |
11.0
2.0 |
1.0
- |
|
Melt Flow Rate
* at 230°C, 2.16 kg
load
* at 190°C, 2.16
kg load |
g/10 min |
* |
5.5
0.9 |
11.0
1.9 |
10.1
1.8 |
0.9
0.1 |
|
Water absorption (23°C - sat) |
% |
ISO
62 |
0.01 |
0.01 |
0.01 |
0.01 |
|
Thermal Properties |
|
|
|
|
|
|
|
Glass transition temperature ((10°/min) |
°C |
ISO
11357 -1, -2, -3 |
65 |
78 |
78 |
138 |
|
Test specimen production (film) |
|
|
|
|
|
|
| Type
of extrusion |
|
|
cast |
cast |
cast |
cast |
|
Thickness of specimen |
µm |
|
70 |
70 |
70 |
70 |
|
Mechanical
Properties (film) |
|
Tensile modulus |
|
|
|
|
|
|
|
- machine direction
- transverse
direction |
MPa |
ISO-527-3 |
1700
2000 |
2200
1800 |
2100
1700 |
2400
2250 |
|
Tensile strength at
break |
|
|
|
|
|
|
| -
machine direction
- transverse
direction |
MPa |
ISO-527-3 |
55
55 |
57
50 |
55
50 |
55
45 |
|
Elongation at break |
|
|
|
|
|
|
| -
machine direction
- transverse
direction |
% |
ISO-527-3 |
2.9
3.6 |
2.9
3.0 |
3.4
3.4 |
2.4
2.2 |
|
Elmendorf tear strength |
|
|
|
|
|
|
| -
machine direction
- transverse
direction |
% |
ISO-6383-2 |
230
240 |
225
230 |
-
- |
9
9 |
| Dart
Drop Impact Strength, F50 |
|
ISO-7765-1 |
<36 |
<36 |
- |
<36 |
|
Optical
Properties (film) |
|
Gloss 60° |
% |
ISO
2813 |
>100 |
>100 |
>100** |
>100 |
|
Haze |
% |
ISO 14782 |
<1 |
<1 |
<2** |
<1 |
|
Barrier
Properties (film) |
|
Water vapor permeability (38°C, 90% RH) |
g-100 µm/(m2-day) |
ISO 15106-3 |
0.8 |
0.8 |
0.8 |
1.3 |
|
Oxygen permeability (23°C, 50% RH) |
cm2-100
µm/((m3-day-bar) |
ASTM D3985 |
170.0 |
200.0 |
- |
280 |
* Calculated from ISO
1133 MVR using a melt density of 0.92
** Haze level will
depend on processing conditions.
The above values are
representative values and not guaranteed values for
quality or design purpose
EFFECTS
-
TOPAS (COC) which is
added maintain high modulus of 65 to 78oC.
-
This adds significant
seal strength at temperature, where PE has low
strength and modulus.
-
When COC is blended with
PE it broadened the seal temperature range.
-
Fig. shows a typical
case where the seal range of pure LLDPE is extended
and seal strength is also noticeably higher.
SEALING SHOULD BE AT
OPTIMUM MODULUS
-
TOPAS (a specified grade
seals itself as a seal initiation temperature 105oC
(defined as seal temperature where 8.8 N seal
strength is achieved.
-
Seal strength of the
TOPAS-TOPAS seal is similar to that of LDPE-LLDPE.
-
It also has good hot
tack strength.
-
High modulus of TOPAS
means the seal may not be as tough as that of other
materials, although seal will be hermetic.
-
Therefore blending is
required with PE.
|
