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

A method of attaching high density polyethylene (HDPE) components at distributed locations on expansive sheet-form HDPE substrate serving as covers for wastewater treatment lagoons;

• said method comprising the steps of:
• providing a production machine;
• loading an HDPE substrate and an HDPE component into the production machine wherein the component is suspended over a weld area characterized on the substrate;
• the production machine extending a heater plate to an intermediate position between the substrate and the suspended component, and over the weld area projected on the substrate, and under a counterpart weld area projected up under the component;
• the production machine pressing a bottom surface of the heater plate onto the weld area of the substrate as well as pressing the counterpart weld are of the component onto a top surface of the heater plate to allow a heat soak into both the weld area of the substrate and the counterpart weld area of the component to pre-heat the substrate and the component;
• the production machine retracting the heater plate retracted from the intermediate position between the substrate and the component, and the substrate and the component being separated apart;
• the production machine next pressing the pre-heated component and pre-heated substrate together to conjoin the respective weld areas thereof to fuse the substrate and the component together;
• and
• the production machine then releasing the compression on the substrate and the component whereby the fused assembly of the substrate and the component is completed.