Extruded boards of plastics (semi-finished); extruded boards of plastics for further manufacture; extruded plastics (semi-finished products); extruded plastics for use in manufacture; laminated plastic materials for use in manufacture; laminated plastic sheets for use in manufacture; plastic in sheet form for use in manufactures; plastic laminate sheets for use in manufacture; plastic laminates (sheets and panels) for use in manufacture; plastic laminates for use in manufacture; plastic sheeting for use in manufacture