Garden hose
Plasticised PVC forms flexible tube layers around a reinforcing braid.
Material
Flexible PVC hose layers: PVC
Material selection rationale
- Flexible compound
- Lets the hose curve and coil for storage.
- Continuous tube
- Carries water along an uninterrupted inner passage.
- Reinforcement shares the load
- Flexible PVC provides tube surfaces while the braid helps limit expansion under pressure; the braid is not created by vinyl-chloride polymerisation.
How it becomes a product
- Extrude the liner: PVC compound is shaped into an inner tube.
- Reinforce and cover: A textile braid is added and an outer PVC layer formed around it. The reinforcement is enclosed by the outer compound; adhesion and layer geometry affect resistance to delamination and kinking.
Preparation routes
Vinyl chloride route
Free-radical addition polymerisation. Vinyl chloride molecules link into PVC chains. The resin is then formulated differently for rigid pipes and flexible coverings. The original double bond is consumed, while the C–Cl bonds remain in the repeat unit. Flexible and rigid PVC can therefore have the same polymer origin.
An initiator starts chain growth. Stabilising additives and, for flexible formulations, plasticisers are separate from the monomer. Plasticiser acts mainly by altering chain mobility; it is not a second polymerising feedstock.
- PVC: monomer production, polymerisation and usesChemical Industry Education Centre, University of York
From ethene to vinyl chloride
- Ethene + Chlorine → 1,2-Dichloroethane
Direct chlorination adds chlorine across ethene's double bond.
- 1,2-Dichloroethane → Chloroethene
Industrial cracking removes hydrogen chloride, leaving the double bond in vinyl chloride.
- PVC: monomer production, polymerisation and usesChemical Industry Education Centre, University of York
Sources
- Select Hose: flexible PVC and reinforcing braidHozelock
- PVC: monomer production, polymerisation and usesChemical Industry Education Centre, University of York