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airpop® is a clever solution for many packaging challenges. airpop® has many unique properties.

airpop® contains 98% air and just 2% solid material. It is extremely light yet highly impact resistant and therefore an excellent shock absorber. airpop® is not affected by moisture, does not rot, is fungal proof and resistant to UV radiation. airpop® is available in many colours and due to its insulating properties is extremely suitable for use at higher and lower temperatures. This durable material is extremely hygienic, not hazardous to health and is 100% recyclable, therefore very environmentally friendly. Due to its flexible properties, products can be supplied in airpop® in any three-dimensional design. Even the smallest details are possible, which guarantees complete form and design freedom.

The properties of airpop®

  • Light weight
  • Retains its shape
  • Excellent insulation
  • High shock absorption
  • Insensitive to moisture
  • Hygienic
  • Complete three-dimensional freedom of design
  • Durable, rot free, fungal proof and resistant to UV radiation
  • Not hazardous to health
  • Environmentally friendly and completely recyclable (contains 98% air)
  • Extremely competitively priced
  • New: airpop® HT, temperature resistant to 120º C
Total three-dimensional design freedom
Due to the various production techniques, airpop® packaging can be made to any desired three-dimensional design. Extremely small details can be realised using airpop®, which means complete design freedom.

The pearl among packaging materials
airpop® is a material that has been used for decades on a wide scale for a highly diverse range of purposes. airpop® thanks this popularity in part to its innumerable positive material properties. Moreover, airpop® is relatively inexpensive, so that one can without doubt describe it as a versatile material with one of the most favourable price/performance ratios in the packaging sector. For this reason and due to the characteristic ‘pearl structure’ of the material, airpop® is also referred to as ‘the pearl among packaging materials’. Read the information below for more material information and technical details.

Simple production process
The technology used to produce airpop® is actually very simple. Liquid monostyrene is made from petroleum. It is then converted in a number of production steps into the raw material for airpop®: expandable polystyrene. This comprises small, glass-like spheres, which contain a minute quantity of the blowing agent pentane. The pentane, which is comparable to natural gas, is heated by steam that causes the spheres to expand and become the well-known airpop® pearls that are up to 50 times larger than their original volume. The blowing agent escapes from the pearls and the numerous minute cells in each pearl draw in air. When the feather-light and elastic pearls are heated, once more using steam, and compressed in a mould, they melt into a homogeneous moulded product: the airpop® packaging. During the contour cutting process, a block moulder first melts the individual airpop® pearls into a homogeneous airpop® block, after which hot wires in series cut out the desired packaging in a completely automated process.

A single piece of airpop® packaging consists of thousands of pearls, which give it its ‘pearl structure’. The air, as it were, is encapsulated in the pearls and cannot escape. This is how these ‘shock absorbers’ bring a product safely to its final destination.

Total three-dimensional design freedom
Due to the unique production techniques used to make airpop® packaging, the choice they offer and the possibility to create even the smallest details, airpop® packaging can meet every desired three-dimensional design. This means complete freedom of design, an advantage that benefits the packaging industry later in the handling and packaging process.

The positive properties of airpop®
When choosing the type of raw material and the production process, account must be taken of the specifications that the final product must meet. Table 1 below shows the general material properties you can expect of airpop® in various densities (volumetric weight). It also shows, among other things, the excellent insulating value, but also airpop® insensitivity to moisture and the firmness of the material. Table 2 gives an overview of the resistance of airpop® to chemical substances.
Table 1: Material properties of airpop®

Types

Unit

airpop® 20

airpop® 25

airpop® 30

Volumetric weight

kg/m3

20

25

30

Thermal conductivity coefficient (measured at + 10°C)

W/(m·K)

0.033-0.036

0.032-0.036

0.031-0.035

Compressive strength at 10% deformation

N/mm2

0.11-0.16

0.15-0.20

0.20-0.25

Permitted compressive strength for packaging calculations

N/mm2

0.039

0.055

0.071

Flexural strength

N/mm2

0.15-0.39

0.22-0.47

0.33-0.57

Notch impact strength

N/mm2

0.12-0.17

0.15-0.20

0.21-0.26

Tensile strength

N/mm2

0.17-0.35

0.22-0.40

0.30-0.48

E-modules (crushing test)

N/mm2

3.4-7.0

5.6-9.2

7.7-11.3

Temperature resistance

- Short term

°C

100

100

100

- Long term at 5,000 N/m2

°C

80-85

80-85

80-85

- Long term at 20,000 N/m2

°C

80-85

80-85

80-85

Thermal linear expansion coefficient

1/K

5-7·10-5

5-7·10-5

5-7·10-5

Heat capacity

J/(kg·K)

1210

1210

1210

Moisture absorption when completely submerged

- After 7 days

% (vol-%)

0.5-1.5

0.5-1.5

0.5-1.5

- After 28 days

% (vol %)

1.0-3.0

1.0-3.0

1.0-3.0

(1 N/mm2 = 1 MPa)

Table 2: airpop® resistance to chemical substances

airpop®

Salt solutions (seawater)

+

Soap and surfactants

+

Bleaching agents including chlorine and hydrogen peroxide solutions

+

Diluted acids

+

Hydrochloric acid 35%, nitric acid up to 50%

+

Anhydrous acids such as evaporating sulphuric acid and 100% formic acid

Sodium hydroxide, caustic potash and ammonia solution

+

Organic solvents including acetone, acetic acid, petrol, xylene, thinners and trichloroethylene

Saturated aliphatic hydrocarbons

Liquid paraffin and vaseline

±

Diesel oil

Petrols

Alcohol including methanol and ethanol

±

Silicone oil

+

+ Resistant: airpop® does not break down, even when exposed for a longer time.
± Provisionally resistant: airpop® can shrink or suffer surface damage when exposed for a longer time.
– Not resistant: airpop® shrinks to a greater or lesser degree or dissolves.

Little material, a lot of protection
Synprodo BV is continually striving to create the optimum packaging. This means: packaging that meets all of the individual functional and economic requirements and packaging that consists of the least possible material, while still offering good protection. This is possible, as airpop® has excellent shock-absorbing properties. The material is relatively very strong, still rather pliable and at the same time particularly stable.

The buffer efficiency of airpop® is one of the best of all packaging materials. Tables 3 and 4 shown here show several standard values related to the protection of your product by airpop® packaging. It is easy to calculate the required buffer thickness of airpop® packaging using the formula and the details given in Table 5.
Table 5 drop test
Table 4: Drop height
PS Hard foam, Density 20 kg/m3, Weight dependence 28-50 kg, Buffer efficiency C=2.5

Drop height 50 cm

Drop height 100 cm

G

Material thickness in mm

Required buffer surface in cm2/kg

G

Material thickness in mm

Required buffer surface in cm2/kg

20

63

5.3

20

125

5.3

25

50

6.7

25

100

6.7

30

42

8

30

84

8

40

31

10.7

40

63

10.7

50

25

13.3

50

50

13.3

60

21

16

60

42

16

80

16

21.3

80

31

21.3

100

13

26.6

100

25

26.6








The buffer efficiency of several types of plastic

Table 5: G value

G

x

t

=

C

h


G = Desired G value
t = Buffer thickness
h = Drop height
C = Buffer efficiency

The buffer efficiency of several types of plastic

  • airpop® 20: C = 2.5
  • EPE: C = 3.0
  • EPP: C = 2.7
G VALUE GROUPS
  • 20-35 G: highly vulnerable, including precision/measuring instruments and computers
  • 40-75 G: vulnerable, including electromechanical equipment, audio and video equipment, word processors and calculators
  • >75 G: less vulnerable, including household equipment, refrigerators and washing machines
The behaviour of airpop® when exposed to fire: favourable when compared to other materials
Just like card, corrugated cardboard and paper, airpop® can burn. The relative speed at which these packaging materials burn does not differ much (see Table 6 below). However, research has shown that, contrary to what is often thought, the toxicity of the combustion gases emitted by burning airpop® is clearly lower than that of the combustions gases emitted by many natural materials. As early as 1980, TNO’s Centrum voor Brandveiligheid (Fire Safety Centre) concluded that the toxicity of the combustion gases of burning airpop®, even in an uncontrolled fire, is less than the gases emitted by natural materials such as wool, cork and even wood.
Table 6

Thickness (mm)

Speed (cm/s)

airpop®

10

1

Paper

0.05-0.16

5.0-1.2

Card

0.5

0.5-0.7

Corrugated cardboard

3.2

0.7

Walnut veneer

0.6

1.4-1.7

Wood

2

0.6-0.8

Other research has also shown that airpop® compares favourably to other materials in this respect (Table 7).
Table 7: Released volume fractions (ppm) at various temperatures
Sample Combustion gases

300 °C

400 °C

500 °C

airpop®

Carbon monoxide

50*

200*

400*

Monostyrene

200

300

500

Other aromatic compounds

Parts

10

30

Hydrogen bromide

0

0

0

Pine

Carbon monoxide

400*

6,000*

12,000*

Aromatic compounds

Chipboard

Carbon monoxide

14,000**

24,000**

59,000**

Aromatic compounds

Parts

300

300

Expanded cork

Carbon monoxide

1,000*

3,000**

15,000**

Aromatic compounds

Parts

200

1,000

* = smouldering/glowing ** = as flame – = not detected