Pressure extrusion

Sir,
How to calculate the die and nozzle size for pressure insulation.

Hello Mr. Prasd;

The bore of the tip (nozzle, nipple) equals the largest cable core diameter plus say 0.015 inches (0.381 mm) radial clearance. The radial clearance depends on the variability of the core. (Telephone cable has a lot more variability than a stranded conductor.) I have actually seen extrusion foremen take the end of a cable core and slide an uninstalled tip over it to ascertain that the radial clearance is OK.

The die diameter is equal to the the largest diameter of the cable core plus twice the jacket thickness provided that the core is not oversize or significantly varying.. Later, the fudge factors can be carefully reduced with SPC.

Each cable company develops their own special charts from personal experience and with many years of experience.

Thank you for your reply.

I want to do tin coating in 0.25mm. How to calculate the tin kg per Kilometer.

REgards

Hello Again,

You did not tell us you were extruding tin and not plastic. I saw insulation in your initial question and thought you were extruding plastic.

Now you are talking about calculating a volume and weight of tin. Is this a new subject or is it related to your initial question? Anyway, the answer is:

The area of the outer diameter of the tin in mm minus the area of the inner diameter of the tin in mm gives you the cross section area of the tin in square mm.. Multiply this by one kilometer in mm to get the cubic millimeter volume of tin in one kilometer of cable. Then multiply that figure by the standard density of tin (7,31 grams per cubic cm) and you have your answer..A very easy thing to do on a good scientific calculator.

Dear Sir,
We are doing sheathing for flexible two core, lay length is 85 mm. While pressure sheathing the impression of the lay appears and make the sheathing uneven. core dia is 5.4 and outer thickness is 0.9 mm. Please suggest me for better toolings sizes.

Regards