Method of making a panel structure and pallet utilizing same

A method of forming a twin sheet plastic panel structure comprising:

• forming a first plastic sheet by heating the sheet to a heated, flowable state and thermoforming the heated, flowable sheet to include a generally planar main body portion having inner and outer surfaces and a plurality of spaced hollow bosses opening in the outer surface of the main body portion and each including an annular side wall portion extending inwardly from the inner surface of the main body portion and an inner wall portion at the inner end of the annular side wall portion;
• forming a second plastic sheet by heating the sheet to a heated, flowable state and thermoforming the heated, flowable sheet to include a generally planar main body portion having inner and outer surfaces and a plurality of spaced hollow bosses opening in the outer surface of the second sheet main body portion and each including an annular side wall portion having a height substantially equal to the height of the annular side wall portions of the first sheet bosses and extending inwardly from the inner surface of the second sheet main body portion and an inner wall portion at the inner end of the side wall portion;
• and
• with said sheets still in a heated, flowable state, bringing said sheets together to fuse inner wall portions of said first sheet bosses to the inner surface of said second sheet main body portion at locations between adjacent second sheet bosses, fuse inner wall portions of said second sheet bosses to the inner surface of said first sheet main body portion at locations between adjacent second sheet bosses, and fuse the annular side wall portions of some of said sheet bosses to the annular side wall portions of some of said second sheet bosses;
• the configurations of the side wall portions of the first and second sheet bosses providing an interference fit as between the side wall portions of the first and second sheet bosses when the sheets are brought together so that the fusion of the first and second sheet side wall portions occurs along a relatively wide area adjacent the initial line of contact between the first and second sheet annular side wall portions.

A method of forming a twin sheet plastic pallet comprising:

• forming an upper plastic sheet by heating the sheet to a heated, flowable state and thermoforming the heated, flowable sheet to include a generally planar main body portion having upper and lower surfaces and a plurality of spaced hollow bosses opening in the upper surface of the main body portion and each including an annular side wall portion extending downwardly from the inner surface of the main body portion and a bottom wall portion at the lower end of the annular wall portion;
• forming a lower plastic sheet by heating the sheet to a heated, flowable state and thermoforming the heated, flowable sheet to include a plurality of planar main body portions having upper and lower surfaces and a plurality of spaced hollow bosses opening in the lower surface of the lower sheet main body portion and each including an annular side wall portion having a height substantially equal to the height of the annular side wall portions of the upper sheet bosses and extending upwardly from the upper surface of the second sheet main body portion and a top wall portion at the upper end of the side wall portion;
• and
• with said sheets still in a heated, flowable state, bringing said sheets together to fuse the annular side wall portions of some of said upper sheet bosses to the annular side wall portions of some of said lower sheet bosses;
• the configurations of the side wall portions of the upper and lower sheet bosses providing an interference fit as between the side wall portions of the upper and lower sheet bosses when the sheets are brought together so that the fusion of the upper and lower sheet side wall portions occurs along a relatively wide area adjacent the initial line of contact between the upper and lower sheet annular side wall portions.

A method of forming a twin sheet plastic pallet comprising:

• forming an upper plastic sheet by heating the sheet to a heated, flowable state and thermoforming the heated, flowable sheet to include a generally planar main body portion having upper and lower surfaces and a plurality of spaced hollow bosses opening in the upper surface of the main body portion and each including an annular side wall portion extending upwardly from the lower surface of the main body portion and a bottom wall portion at the lower end of the side wall portion;
• forming a lower plastic sheet by heating the sheet to a heated, flowable state and thermoforming the heated, flowable sheet to include a generally planar main body portion having upper and lower surfaces and a plurality of spaced hollow bosses opening in the lower surface of the lower sheet main body portion and each including an annular side wall portion having a height substantially equal to the height of the annular side wall portions of the upper sheet bosses and extending upwardly from the upper surface of the lower sheet main body portion and a top wall portion at the upper end of the annular side wall portion;
• and
• with said sheets still in a heated flowable state, bringing said sheets together to fuse bottom wall portions of said upper sheet bosses to the upper surface of said lower sheet main body portion at locations between adjacent lower sheet bosses, fuse top wall portions of the lower sheet bosses to the lower surface of said upper sheet main body portion at locations between adjacent upper sheet bosses, and fuse the annular side wall portions of some of said upper sheet bosses to the annular side wall portions of some of said lower sheet bosses;
• the configurations of the side wall portions of the upper and lower sheet bosses providing an interference fit as between the side wall portions of the upper and lower sheet bosses when the sheets are brought together so that the fusion of the upper and lower sheet side wall portions occurs along a relatively wide area adjacent the initial line of contact between the upper and lower sheet annular side wall portions.