Covering Wood and Steel Bunker Systems
The grain pile is covered with a reinforced poly tarp. Typical thickness is 12- or 14-mil woven or 6- or 8-mil string reinforced polyethylene. Custom tarps and mil thicknesses are available to meet individual needs and requirements.
The standard LeMar 12- or 14-mil reinforced polyethylene sheeting is manufactured through the use of a weaving process. First, narrow ribbons of high-density polyethylene film are weaved into a durable cloth. Then, both sides of the cloth are extrusion coated with an impermeable layer of low-density polyethylene: black on one side, white on the other or black on black. The white layer is designed to prevent heat buildup and condensation beneath the cover and contains special UV inhibitors to prevent premature aging. The black layer contains carbon black, which blocks light penetration and prevents damage from UV radiation. Finally, heat from the process permanently fuses the layers together, resulting in these versatile materials with superior resistance to tearing, stretching and puncture.
The economy 6- or 8-mil string reinforced polyethylene offers several advantages in different applications. With its 1000-denier polyester yarn, the Integra SRP series offers excellent tear strength at the yarn, and the open areas between the yarns provide outstanding elongation properties. These physical characteristics make the Integra SRP the appropriate material for a wide variety of applications.
String reinforced materials are manufactured using a blend of the best polyethylene resins formed into two skins. These skins act as the "bread" to the reinforced "sandwich," encapsulating a grid pattern of polyester yarn and a hot sheet of polyethylene to form a three layer product suitable for multiple applications. Once the raw goods are laminated together, the mill rolls are fabricated into custom-sized covers and liners. The finished panel is then rolled into a heavy-duty cardboard core and wrapped in a protective material for shipment.