Edexcel GCSE Design and Technology · 1DT0
Specification 6.7.3 · Paper 1
Revise: Fabrication and Assembly MethodsA sealed seam prevents leakage through the join. Compatible synthetic materials such as PVC can be welded: heat and pressure soften or melt their surfaces, which unite as they cool. This produces strong, airtight or waterproof joins for inflatables and outdoor products without needle holes.