Panel structure

A panel structure including plastic sheets arranged in layered relationship and including an upper sheet and a lower sheet, characterized in that:

• the upper sheet includes a planar main body portion and a plurality of spaced downwardly extending bosses opening in the upper face of the upper sheet and each including an annular side wall and a lower end;
• the lower sheet includes a planar main body portion and a plurality of spaced upwardly extending bosses opening in the lower face of the lower sheet and each including an annular side wall and an upper end;
• the annular side walls of at least some of the downwardly extending bosses of the upper sheet being fused to the annular side walls of upwardly extending bosses of the lower sheet to form fused interfaces between the side walls of the upwardly and downwardly extending bosses;
• each of the fused interfaces being formed of deformed portions of the annular wall of an upwardly extending boss and the annular wall of a respective downwardly extending boss;
• each of the fused interfaces thus formed extending along a relatively wide area of contact so as to define a relatively wide area of fused together contact between the respective upwardly and downwardly extending side walls.

A panel structure comprising:

• a first plastic sheet having a planar main body portion and a plurality of spaced downwardly extending hollow bosses opening in the upper face of the first sheet and each including an annular side wall and a lower end;
• a second plastic sheet having a planar main body portion and a plurality of spaced upwardly extending hollow bosses opening in the lower face of the second sheet and each including an annular side wall and an upper end;
• the lower end of each downwardly extending boss being fused to the upper face of the main body portion of the second sheet between adjacent upwardly extending bosses, the upper end of each upwardly extending boss being fused to the lower face of the main body portion of the first sheet between adjacent downwardly extending bosses, and the annular side walls of at least some of said downwardly extending bosses of said first sheet being fused to the annular side walls of upwardly extending bosses of the second sheet;
• a third plastic sheet positioned over and fused to the upper face of the first sheet in overlying relation to the boss openings in the upper face of the first sheet;
• and
• a fourth plastic sheet positioned under and fused to the lower face of the second sheet in underlying relation to the boss openings in the lower face of the second sheet.

A panel structure including four plastic sheets arranged in layered relationship and including an upper sheet, a lower sheet, an upper intermediate sheet positioned beneath the upper sheet, and a lower intermediate sheet positioned between the upper intermediate sheet and the lower sheet, characterized in that:

• the upper intermediate sheet includes a planar main body portion and a plurality of spaced downwardly extending bosses opening in the upper face of the upper intermediate sheet and each including an annular side wall and a lower end;
• the lower intermediate sheet includes a planar main body portion and a plurality of spaced upwardly extending bosses opening in the lower face of the lower intermediate sheet and each including an annular side wall and an upper end;
• the lower ends of the downwardly extending bosses are fused to the upper face of the lower intermediate sheet between adjacent upwardly extending bosses;
• the upper ends of the upwardly extending bosses are fused to the lower face of the upper intermediate sheet between adjacent downwardly extending bosses;
• the annular side walls of at least some of the downwardly extending bosses of the upper intermediate sheet are fused to the annular side walls of upwardly extending bosses of the lower intermediate sheet;
• the upper sheet is fused to the upper face of the upper intermediate sheet in overlying relation to the boss openings in the upper intermediate sheet;
• and
• the lower sheet is fused to the lower face of the lower intermediate sheet in underlying relation to the boss openings in the lower intermediate sheet.

A laminated plastic panel structure including first, second and third plastic sheets, characterized in that:

• the first sheet includes a planar main body portion and a plurality of spaced downwardly extending bosses opening in the upper face of the first sheet and each including an annular side wall and a lower end;
• the second sheet is positioned beneath the first sheet and includes a main body portion and a plurality of spaced upwardly extending bosses opening in the lower face of the second sheet and each including an annular side wall and an upper end;
• the lower ends of the downwardly extending bosses are fused to the upper face of the second sheet between adjacent upwardly extending bosses;
• the upper ends of the upwardly extending bosses are fused to the lower face of the first sheet between adjacent downwardly extending bosses;
• the annular side walls of at least some of the downwardly extending bosses of the first sheet are fused to the annular side walls of upwardly extending bosses of the second sheet;
• and
• the third sheet comprises a flat sheet fused to the upper face of the first sheet in overlying relation to the boss openings in the first sheet.