Physical performance requirements for fire hose linings

The lining of fire hose usually requires uniform thickness, smooth inner wall, no adhesion, no wrinkling, waterproof, mildew resistance, low temperature resistance and aging resistance, and has a certain strength and elasticity. Some hose lining must also have oil resistance, high temperature resistance, chemical corrosion resistance and other properties. The lining thickness is generally 0.5 ~ 2.0 mm.

In terms of physical properties, the requirements are as follows: the tear strength of NR and synthetic rubber lining is not less than 8.30MPa, and the tear elongation is not less than 400%; The tensile strength of the latex lining is not less than 12.41MPa, and the tensile elongation is not less than 700%. Styrene butadiene rubber (SBR), neoprene rubber (CR), EPDM and NBR/PVC alloys in synthetic rubber are commonly used as fire hose lining.

(1) PVC lining. PVC lined water belt is cheap and light, with good weather resistance and certain oil resistance, and the production process is simple, very suitable for mass production and a variety of occasions for a large number of applications. The physical properties of the lining generally require that the tensile strength is not less than 8.30MPa and the tensile elongation is not less than 400%. The soft transparent PVC material commonly used in the market can be selected. The hardness of its Shore type A is generally 55 ~ 65 degrees, the tensile strength is not less than 13.00MPa and the tensile elongation is not less than 450%. In addition, the fire retardant PVC material should be selected for the special fire retardant requirements.

(2) TPU lining. TPU lining has higher strength, better elasticity, wear resistance, low temperature resistance, corrosion resistance, oil resistance and aging resistance. The physical properties of TPU lining are generally required to have a tensile strength of not less than 13.80 MPa and a tensile elongation of not less than 400%. There are many TPU brands available, which can basically meet the requirements. TPU is divided into polyester, polyether and polycarbonate. At present, Chinese fire hose manufacturers basically use polyether type TPU to produce high quality TPU fire hose.