When evaluating a canvas sealing machine, you must prioritize the sealing width and speed. For industrial canvas, a sealing width of 20mm to 50mm is standard. Look for machines with adjustable temperature controls (up to 600°C-700°C) to accommodate different canvas thicknesses and materials like PVC, PE, or DHPE. Additionally, ensure the machine features automatic cooling systems to prevent overheating during continuous operation and high-precision pressure rollers to ensure a leak-proof, airtight seal.