PVC foam is a very popular and versatile foam core material used in composite structure manufacturing. Fibermax PVC foam is used in many aspects of daily life, from construction to medical devices, in boat building, public transportation and many more, due to its excellent mechanical and physical properties.
Fibermax PVC foam is made from a polymer, polyvinyl chloride, through polymerisation. The mix of polymer and air bubbles forms a consistent material, with increased volume many times over, while the weight remains low. Polyvinyl chloride contains chlorine (approximately 57% by weight,) carbon and hydrogen. Chlorine makes it compatible with many other materials, and also provides some fire retardancy. The chlorine atoms are bonded to every carbon chain, making PVC resistant to oxidation by atmospheric oxygen.
PVC foam is manufactured by mixing the polymer under certain conditions. Then the mixture is poured in a mold that is cured under heat and pressure. The resulting mass is de-molded, heated again with hot water and finally cured. The result is a block of foam containing closed cells that can be cut to different thickness sheets.
Fibermax PVC products consist of 50% to 95% air, resulting in a density of 55-200 kg/m2, and thereby can contribute to save valuable weight and raw material. It may be used with most types of resin like epoxy, vinylester and others and all types of fiber reinforcement like carbon, aramid, Kevlar, fiberglass, etc. Methods of fabrication include wet layup, vacuum bagging, vacuum infusion, RTM, RTM light, press molding, and autoclave.
Fibermax cross linked PVC has high physical properties, and exhibits good heat and solvent resistance. Its water absorption ranges from 0.07 to 0.03kg/mm2, tensile modulus from 45 to 180N/mm2, and tensile strength from 1.30 to 6.20N/mm2 depending foam’s density (higher values for higher density PVC foam.) Concerning shear strength, values begin from 0.8 N/mm2 till 3.5 N/mm2.
MAIN ADVANTAGES
PVC foam widespread use in advanced composites is due to its many advantages. The main benefits it provides are:
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High strength and stiffness to weight ratio
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Process friendly
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Rot resistance
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Resistance to solvents and most chemicals
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Very good fatigue properties
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Very good thermal insulation
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Good fire behavior
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Low water absorption
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Compatible to many resin systems including epoxy
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Low resin absorption
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Durability
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Ease of adhesion
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Shock absorbance
When processing PVC foam overlaid by prepreg, great caution should be taken to avoid outgassing.
PVC FOAM APPLICATIONS
As already mentioned Fibermax PVC foam is used in various applications. Some examples of the most popular fields of application are:
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Sporting goods: PVC foam is widely used to manufacture sporting goods like windsurf boards, kite boards, wakeboards, skis, racing car parts, beach rackets and many more.
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Aerospace: The need for high quality requirements, and to decrease life time costs, turned manufacturers' attention to PVC foam. Using PVC in aircraft construction has environmental impact, because building lighter composites results in less fuel consumption, less energy spent and increased payload. Aircraft interiors, cabin sidewalls, luggage bins, heads and galley ways, crew rest areas, partitions and seat shells are some of the components often manufactured by PVC foam.
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Transportation: Sandwich technology results in lighter designs which drive at less fuel consumption, higher payloads and positive impact in the environment. PVC foam is applied in structural parts like frames and train fronts, flooring, body side protection strips, dashboard and arm rests. The special fire retardant grades of Fibermax PVC foam is generally commonly used in many public means of transport as it protects against fire, smoke and toxicity.
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Marine: When building either a small boat or a luxurious yacht, the keys to success are weight, quality, cost and environmental impact. PVC foam is a lightweight material with superior mechanical properties, consistency and moisture resistance. For these reasons it is commonly used in marine applications (especially hulls, bulkheads, decks, hatches, interior parts e.g. floor, wall.)
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Subsea: Every application in subsea demands high performance equipment to preserve security, due to the fact that it is a really challenging environment. PVC is suitable for those applications because it is characterized by high strength, low weight and very good buoyancy.
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Radar and telecommunication industry: Lightweight, high strength, energy efficient, freedom in design, long lasting, are some of PVCs’ properties utilized by radar and telecommunication industry in manufacturing antennas, radomes, and in antenna tower construction.
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Wind energy: The need for long lasting and heavier turbine blades directed wind blade manufacturers to core materials and mostly PVC foam. The wind blades became bigger, stronger and stiffer, but are kept in relatively low weight. Consequently, PVC foam has helped to decrease the cost and increase efficiency of wind power installations.
HYBRID FOAM CONSTRUCTION
Higher densities of PVC foam have increased toughness at a respective weight penalty. The higher density foam makes a stronger but heavier product. Low density foam materials add little weight to the sandwich construction. However, they usually have more open cells which results in more resin absorption. The lower the density, the larger the cells are, and the worst the resin absorption problem. On the other hand, most of the times, the actual life expectancy of products proves to be different than in calculations made during the design. This can happen for many reasons, and also because the actual torture that the product is imposed to, varies from user to user. Other conditions, like weather in a certain region may also vary greatly affecting the life of the product. For example, an experienced athlete in wind force of 7bf may treat and load a sport product in a different way or manner than a beginner. This makes the choice of density of PVC foam somewhat chaotic.
In order to improve product quality with minimal weight penalty many manufacturers choose to use 2, 3 or more layers or areas of different densities of foam or core types. Higher densities are usually used close to the surface or skin of the product and also to certain points of mechanical load (e.g. close to metal fasteners.) This greatly improves impact, fatigue and delamination resistance with a much smaller weight penalty.
Fibermax PVC foam comes at different thickness, weight and panel size dimensions. Some of our readily available PVC foam products are listed below.
|
Type
|
Thickness
|
Spec. weight |
|
1
|
2 mm
|
100 Kg/m3
|
|
2
|
3 mm
|
60 Kg/m3
|
|
3
|
3 mm
|
80 Kg/m3
|
|
4
|
3 mm
|
100 Kg/m3
|
|
5
|
5 mm
|
100 Kg/m3
|
| 6 | 7 mm | 80 Kg/m3 |
| 7 | 8 mm | 80 Kg/m3 |
| 8 | 10 mm | 60 Kg/m3 |
| 9 |
10 mm
|
80 Kg/m3
|
| 10 | 10 mm | 100 Kg/m3 |
| 11 |
12 mm
|
60 Kg/m3
|
| 12 |
12 mm
|
80 Kg/m3
|
| 13 |
12 mm
|
100 Kg/m3
|
| 14 |
13 mm
|
80 Kg/m3
|
| 15 | 15 mm | 60 Kg/m3 |
| 16 |
15 mm
|
80 Kg/m3
|
| 17 |
15 mm
|
100 Kg/m3
|
| 18 |
20 mm
|
60 Kg/m3
|
| 19 |
20 mm
|
80 Kg/m3
|
| 20 |
20 mm
|
100 Kg/m3
|
| 21 |
20 mm
|
200 Kg/m3
|
| 22 |
25 mm
|
80 Kg/m3
|
| 23 |
25 mm
|
100 Kg/m3
|
| 24 |
25 mm
|
200 Kg/m3
|
| 25 | 30 mm | 60 Kg/m3 |
| 26 |
30 mm
|
80 Kg/m3
|
| 27 | 40 mm | 60 Kg/m3 |
| 28 |
40 mm
|
80 Kg/m3
|
| 29 |
50 mm
|
60 Kg/m3
|
| 30 | 50 mm | 80 Kg/m3 |
Also available with perforation & grooves, as well as in HT (High Temperature) type.
The perforation (with holes) and grooves (carved channels) are specifically designed and optimized to facilitate fast resin flow in the infusion/injection process. The perforation allows the resin to pass easily through the foam to the underside, while the grooves distribute the resin flow effectively.
The HT type is suitable for high temperature applications. For example, it can be used for autoclave prepreg sandwich curing at 120°C and 3 bar pressure. Higher temperature and pressure applications are possible, depending on the tolerance for potential partial collapse (collapse refers to a reduction in thickness without implying a loss of mechanical properties).
For any other type of PVC foam products and special orders (different thickness, weight) please contact us. However, those special products may be subjected to minimum order level.