HDPE covers for wastewater treatment lagoons, and HDPE patches thereon in service for further attachments

A method of attaching high density polyethylene (HDPE) patches at distributed locations on expansive sheet-form HDPE covers for wastewater treatment lagoons, which HDPE patches provide locally increased thickness to the HDPE cover in service as seats for attachment of further attachments to the HDPE cover;

• said method comprising the steps of:
• providing a planar workspace;
• bracketing the workspace with one elongated roller and a spaced other elongated roller;
• supplying an indefinitely expansive span of sheet-form HDPE in a roll on the one roller;
• taking up the sheet-form HDPE on the other roller whereby the sheet-form roll progressively translates across the workspace;
• providing a gantry generally parallel with the one and the other roller and intermediate thereof;
• propelling a traveling head along out and back trips on the gantry above the sheet-form HDPE below whereby the scrolling of the sheet-form HDPE establishes a relative X-axis for X-Y mapping of the placement of patches on the sheet-form HDPE while correspondingly the out and back trips of the traveling head establishes the relative Y-axis;
• and
• provisioning the traveling head to carry a motor to carry propel the traveling head for the out and back trips thereof, as well as to power a robotic arm which provides services including (1) pick, (2) place and (3) weld (or attach);
• wherein the robotic arm picks a patch from source stack of available packs, which stacks are carried by the traveling head, the robotic arm places the patch in a pre-programmed (or instruction signal sent) placement on the spread out sheet-form HDPE, and, robotic arm attaches the patch in place by chemical and/or thermal welding.