Patent ID: 11880083
Assignee: CORNING RESEARCH & DEVELOPMENT CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 12:
13. A method of preparing an optical fiber cable, comprising the steps of:
preparing a foam composition comprising a polymer component of 70% to 100% by weight of a thermoplastic elastomer (TPE) and 0% to 30% by weight of low density polyethylene, wherein the TPE has an unfoamed tensile modulus of at most 10 MPa at 100% secant as measured according ASTM D638; and
extruding a foamed tube comprising the foam composition around a stack of optical fiber ribbons so as to form a subunit having a central bore providing from 5% to 15% of free space around the stack along a length of the foamed tube wherein the foamed tube is characterized by at least one of,
a closed-cell morphology having pores with an average effective circle diameter of 300 μm or less;
a compression set of no more than 20% as measured after compression to a strain of 50% for ten hours and after four hours of recovery time using a parallel plate compression fixture on a dynamic mechanical analyzer; or
a compression modulus of less than 3 MPa when measure at 50% strain as measured according to ASTM 3574.