Physical and Thermal Properties

1. General Physical Properties

Table 1 summarizes the physical properties of Lumirror™.
The thickness of each sample used for measurement was #25 (25 μ).

Table 1. Lumirror™ General Physical Properties
Property Measurement Value Unit Measurement Method
Density 1.40
(1.390 to 1.408)
g/cm2 JIS K 6760 - 71
(n–Heptane, CCI4)
Melting Point 263 °C With heating stage
Observed using a microscope
Specific Heat 0.32 cal/g/°C  
Heat Transfer Coefficient 3.36 × 10-4 cal/cm/sec/°C  
Moisture Expansion Coefficient 1.2 × 10-5 cm/cm/%RH  
Thermal Expansion Coefficient 1.5 × 10-5 cm/cm/°C ASTM D 696- 70
Refractive Index 1.66   ASTM D 542 - 70
(Abbe, 20°C)
Light Transmittance 85 % JIS K 6714 - 58
Flammability Oxygen index 25   JIS K 7201 - 72

2. Change in Hygroscopic Rate Based on Relative Humidity

Fig. 1 shows the changes in the hygroscopic rate as the amount of humidity Lumirror™ is exposed to increases.
Measurements were taken at 25°C.

Fig. 1. Changes in Lumirror™ Hygroscopic Rate Based on Relative Humidity

3. Water Absorption Rate for Various Product Numbers

Fig. 2 shows the water absorption rate of various Lumirror™ product numbers when immersed in 20°C water for 24 hours and when immersed in 100°C boiling water for 2 hours.
The measurement method is the Federal Test Method Std. NO. 406 Method 7031.

Fig. 2. Changes in Water Absorption Rate Based on Lumirror™ Product Number

4. Drying Curve

Lumirror™ was dried at 120°C until it reached a state of equilibrium, and then it was allowed to achieve sufficient equilibrium at room temperature in either 80% RH or normal humidity. After, the change in weight and the change over time were measured and recorded for both #75 (75 μ) and #188 (188 μ) as the samples were once again dried at 120°C. The results of these measurements are shown in Fig. 3.

Fig. 3. Lumirror™ Drying Curve

5. Moisture-related Dimensional Stability

Fig. 4 shows the dimensional change of Lumirror™ as it is exposed to increasing humidity.
The moisture expansion coefficient of Lumirror™ is calculated from Fig. 4 as follows.
1.2 × 10-5 cm / cm / %RH

Fig. 4. Dimensional Changes to Lumirror™ Based on Moisture

6. Thermal Dimensional Stability

Fig. 5 shows the dimensional change of Lumirror™ #50 (50 μ) as it is exposed to temperatures from room temperature up to around 100°C.
The thermal expansion coefficients of Lumirror™ around room temperature are as follows.
The measurement method is ASTM D 696-70.
MD (Vertical): 1.2 × 10-5 cm / cm / °C
TD (Horizontal): 1.6 × 10-5 cm / cm / °C

Fig. 5. Dimensional Changes of Lumirror™ Due to Relatively Low Temperatures

7. Heat Shrinkage for Various Product Numbers

Table 2 shows the heat shrinkage for various Lumirror™ product numbers at 150°C for 2 hours.
The measurement method uses a reading microscope in accordance with JIS C 2318-72.

Table 2. Heat Shrinkage for Various Lumirror™ Product Numbers
Thickness MD (Vertical) TD (Horizontal)
Product No. μ
#661.61.2
#991.51.2
#12121.30.2
#16161.50.5
#25251.31.0
#38381.30.4
#50501.20.2
#75751.20.3
#1001001.20.3
#1251251.20.7
#1881881.30.7
#2502501.20.7
#3503501.20.7

8. Changes in Heat Shrinkage Rate Based on Temperature

Fig. 6 shows the heat shrinkage rate of #50 (50 μ) Lumirror™ at temperatures from 90 to 190°C.
The measurement method is JIS C 2318-72.

Fig. 6. Changes in Lumirror™ Heat Shrinkage Rate Based on Temperature

9. Water Vapor Permeability for Various Product Numbers

Table 3 shows the water vapor permeability for various Lumirror™ product numbers.
The measurement method was JIS Z 0208-73 with measurement conditions of 40°C and 90% RH.

Table 3. Water Vapor Permeability for Various Lumirror™ Product Numbers
Thickness Water Vapor Permeability
Product No. μ g / m2 / 24hr / 0.1mm
#664.5
#12127.5
#25256.9
#38385.3
#50508.8
#75759.2
#1001006.3

10. Comparison of Water Vapor Permeability with Other Films

Even among the various plastic films available, Lumirror™ has an extremely low water vapor permeability.
Table 4 shows the water vapor permeability of various plastic films for the purpose of comparison.
Lumirror™ has the same degree of permeability as polyethylene film.
The measurement method was JIS Z 0208-73 with measurement conditions of 40°C and 90% RH.

Table 4. Water Vapor Permeability of Various Plastic Films
Film Sample Thickness Water Vapor Permeability
μ g / m2 / 24hr / 0.1mm
Lumirror™256.9
TORAYFAN™ BO *221.2
High pressure polyethylene305
Stretched polycarbonate2535
Soft polyvinyl chloride3523
Stretched vinyl chloride, vinylidene chloride copolymer301.5
Polyvinyl alcohol20240
Cellulose triacetate135410
Moisture-proof cellophane3211
  • Toray biaxially oriented polypropylene film

11. Comparison of Gas Permeability with Other Films

Even among the various plastic films available, Lumirror™ has an extremely low gas permeability, exhibiting excellent characteristics for food packaging, etc. Table 5 shows the oxygen, nitrogen, and carbon dioxide gas permeability of various plastic films for the purpose of comparison.
The measurement method was ASTM D 1434-72 at a measurement temperature of 25°C. For any film, the permeability is in the order of carbon dioxide, oxygen, and nitrogen, with a ratio of 3 to 5, 1, and 1/6 to 1/3.

Table 5. Gas Permeability of Various Plastic Films Units: cc(NTP)/ m2 / 24hr / 0.1mm / atm
Film Gas Permeability
Oxygen Nitrogen Carbon Dioxide
Lumirror™ 19 4.2 74
TORAYFAN™ NO *1 860 160 2670
TORAYFAN™ BO *2 400 84 1300
High pressure polyethylene 2000 720 8900
Low pressure polyethylene 520 180 2270
Stretched polystyrene 1140 180 5640
Stretched hard polyvinyl chloride 24 5.1 63
Stretched vinyl chloride, vinylidene chloride copolymer 17 - 91
  • 1 Toray unstretched polypropylene film
  • 2 Toray biaxially oriented polypropylene film

12. Comparison of Organic Solvent Vapor Permeability with Other Films

Table 6 shows the organic solvent vapor permeability of Lumirror™ and various other plastic films.
The measurement method was JIS Z 0208-73 at a measurement temperature of 40°C.

Table 6. Organic Solvent Vapor Permeability of Various Plastic Films Units: g / m2 / 24hr / 0.1mm
Film Organic Solvent Vapor Permeability
Acetone Ethyl
Alcohol
Toluene Ethyl
Acetone
n–Heptane Carbon Tetrachloride
Lumirror™ 0.77 0.42 0.50 9.70 0.69 0.71
TORAYFAN™ NO *1 29.0 2.20 1300 216 1440 4540
TORAYFAN™ BO *2 1.02 1.02 661 85.5 865 2020
High pressure polyethylene 202 19.1 1080 457 1540 4670
Stretched hard polyvinyl chloride 4330 0.44 611 2220 0.52 0.27
Stretched vinyl chloride,
vinylidene chloride copolymer
512 0.39 358 493 0.45 8.1
  • 1 Toray unstretched polypropylene film
  • 2 Toray biaxially oriented polypropylene film

13. Thermal Degradation Stability

Lumirror™ features excellent thermal degradation stability.
The maximum usable temperature for Lumirror™ is generally 150°C. When planning to use it for long periods of time, 130°C or less is recommended.
Figures 7 and 8 show the changes in tensile strength and elongation of Lumirror™ after heat treatment at a typical temperature along with the heat treatment time.
The thickness of each sample used for measurement was #38 (38 μ).

Fig. 7. Changes in Lumirror™ Tensile Strength Based on Heat Treatment Time
Fig. 8. Changes in Lumirror™ Tensile Elongation Based on Heat Treatment Time

14. Heat Resistant Life

With the initial tensile strength and elongation of Lumirror™ being 100%, Figures 9 and 10 show the amount of time taken for those values to drop to 50% and 10% (representing the change in lifespan) based on temperature.
The thickness of each sample used for measurement was #50 (50 μ).

Fig. 9. Lumirror™ Tensile Strength Heat Resistant Life
Fig. 10. Lumirror™ Tensile Elongation Heat Resistant Life

Lumirror™ Technical Information