HPDE (high density polyetylene) is a firm and strong substance deviated from petrol. Unlike other polyetylenes, HDPE is heavy and firm. Approximately, 1.75 kg petrol is used to produce 1 kg HDPE raw material. HDPE is lighter then water and together with its durablitiy it becomes a preffered material for marine purposes.
HDPE can be shaped by molding and extrution methods. It can be processed in workshops and can be welded with special methods. It is difficult to combine with adhesives.
Although it looks like LDPE (low density poyetylene), HDPE is much more harder and molecular density of it is between 150000 – 400000. Its resistant to water and chemicals. HDPE’s mechanical spesifications are very good especially on impact and tension. With some additives, these resistanes are improved even better. Normally the tension resistance is like 225-350 kgf/cm2 and heat resistance is above 100 OC.
HDPE is widely used in pressure pipes, gas distribution pipes, liquid containers, machine and home appliance parts and in insulation. Lately, because of its resistance to water, it is also used in tank and boat manufacturing.
The advantages of HDPE in the boat manufacturing are;
• Since HDPE is very durable against aging and corrosion (minimum measured life is 50 years) , the life of the HDPE boat is more then the boats made of any other materials.
• Tension crack resistance and crack running resistance are high, the impacts remain minimum damage.
• HDPE is flexible and durable; the boats resist to worst weather conditions. Also, flexibility enhances the confort in the bad weather conditions.
• It is easier to assemble HDPE then steel, wood, aluminum or other composite materials.
• Polyethelene has anti-corrosion advantage.
• With the additives, HDPE does not become fragile at the low temparatures and resists at the high temperatures.
• It is not toxic and easy to clean. It is also water and dirt repellent.
• It is resistant to freezing. HDPE is not effected even the liquid it contains gets frozen.
• HDPE boats do not require painting or any care, especially the toxic cares.