Which two thread types are commonly used and why?

Which two thread types are commonly used and why?

• A. Cotton thread and linen thread; chosen for softness.
• B. High-tenacity nylon or polyester thread; chosen to match fabric behavior and resist environmental exposure.
• C. Elastic thread and wool thread; chosen for stretch.
• D. Metallic thread and fishing line; chosen for visibility.

Answer: (B)

Threads used in parachute sewing must deliver high strength, low stretch, and good environmental resistance while behaving similarly to the fabric they join. High-tenacity nylon or polyester threads fit this need because they provide strong, abrasion-resistant seams that stand up to moisture, salt air, UV exposure, and temperature changes typical in field conditions. Nylon threads pair well with nylon fabric in terms of elasticity, while polyester offers excellent dimensional stability and moisture resistance, reducing seam creep under load. Together, these two thread types cover the common fabrics used in parachutes and keep seams reliable under demanding use. Cotton and linen absorb moisture and can rot or weaken in harsh environments, making them unreliable for parachute seams. Elastic or wool threads introduce excessive and unpredictable stretch, compromising seam integrity. Metallic thread and fishing line aren’t suited for standard sewing practices in parachutes due to snagging, corrosion concerns, and incompatibility with sewing equipment and fabric behavior.

Threads used in parachute sewing must deliver high strength, low stretch, and good environmental resistance while behaving similarly to the fabric they join. High-tenacity nylon or polyester threads fit this need because they provide strong, abrasion-resistant seams that stand up to moisture, salt air, UV exposure, and temperature changes typical in field conditions. Nylon threads pair well with nylon fabric in terms of elasticity, while polyester offers excellent dimensional stability and moisture resistance, reducing seam creep under load. Together, these two thread types cover the common fabrics used in parachutes and keep seams reliable under demanding use.

Cotton and linen absorb moisture and can rot or weaken in harsh environments, making them unreliable for parachute seams. Elastic or wool threads introduce excessive and unpredictable stretch, compromising seam integrity. Metallic thread and fishing line aren’t suited for standard sewing practices in parachutes due to snagging, corrosion concerns, and incompatibility with sewing equipment and fabric behavior.