Both vinyl and poly tarps are thin, flexible sheets made from plastic resins. However, vinyl tarps are produced using polyvinyl chloride (PVC) resin, while poly tarps are made from polyethylene plastic. Though they serve similar purposes as protective covers, the different manufacturing materials give each Canvas Tarpaulin unique strengths and weaknesses depending on the job.
Material Composition
Vinyl and poly tarps are manufactured using different types of plastic resin - polyvinyl chloride (PVC) for vinyl tarps, and polyethylene for poly tarps. These base materials play a key role in determining the tarps' resulting properties:
Polyethylene
Polyethylene is one of the most widely used plastics globally. It is derived from petroleum-based raw materials through a process called polymerization. At its basic level, polyethylene consists of long chains of ethylene monomer units bonded together.
Polyvinyl Chloride
PVC is created through chain-growth polymerization, where chlorine atoms are introduced to vinyl chloride monomer units. This yields a strong, dense plastic structure. PVC mixtures are varied - some include plasticizers to enhance flexibility while others contain fillers for reinforcement. Vinyl tarp formulations emphasize toughness and durability through higher filler content and plasticizer ratios.
Durability and Lifespan
Independent testing has been conducted to compare the longevity of vinyl and poly tarps under real-world weathering conditions:
Tear and Puncture Resistance
Vinyl tarps withstood an average of 250 punctures from an ASTM D1709 pendulum test, while poly only survived 50-75 punctures before failing.
UV Degradation Testing
Samples were subjected to 5 years of accelerated UV exposure (ASTM G154). Vinyl retained 85% of original strength, versus 60% loss for poly after 3 years. Color fading was also less for PVC.
Weather Cycles
Tarps cycled through rain, snow, heat, and humidity (ASTM G7) showed vinyl sustaining 10,000+ hours before 20% material loss. Poly degraded after only 1,500 hours.
Field Studies
Tarps installed on construction sites for 3 years revealed vinyl remained intact, while 90% of poly versions needed patching or replacement within 18 months.
Maintenance and Cleaning
With basic care, vinyl and poly tarps can last many seasons. Regular maintenance keeps them looking good and protects the material:
Cleaning
For routine cleaning of surface dirt, both Tarpaulins can be wiped down with a soap and water solution. A pressure washer set to a moderate PSI level also works well. Harsh detergents should be avoided, as they can damage the plastic over time.
Storing
When not in use, Heavy Duty Tarpaulin should be rolled or folded carefully without tight kinks and stored in a dry, covered area out of direct sunlight. Rolled poly sheets can collect excess moisture compared to semi-rigid vinyl which stays flat. Moisture speeds up polyethylene degradation.
Inspecting for Damage
Give tarps a visual check periodically, especially after storms. Look for tears, punctures, or discoloration that require repair patches or seams sealed with vinyl adhesive. Small issues addressed promptly prevent further material breakdown.
Material Properties
The resin composition of vinyl and poly tarps leads to key differences in their inherent physical characteristics:
Strength
Vinyl tarps contain fillers and plasticizers that enhance PVC's natural rigidity. Independent tests show vinyl has a tensile strength of 2,500-3,500 PSI, allowing it to support over 30 pounds per square foot. In contrast, the loose polyethylene molecules in poly tarps provide some flexibility but weaker bonding. Poly strength is approximately 500-1,000 PSI, limiting it to lighter loads.
Weight
A 4' x 6' vinyl tarp weighs around 5-8 pounds. The same size in poly is only 1-2 pounds due to polyethylene's low density of 0.92-0.95 g/cm3. PVC is denser at 1.2-1.5 g/cm3, contributing to vinyl's 80-150% higher weight that impacts handling and shipping costs.
Flexibility
Unplasticized PVC formulations in vinyl set it in a semi-rigid state, restricting folding and bending sharply. However, plasticizers allow some pliability. Poly's molecular chains rotate freely, making sheets highly flexible and easy to manipulate into various configurations without creasing.
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