make up natural cara make up make up tutorial make up korea make up minimalis make up artis make up mata belajar make up make up wardah alat make up makeup forever indonesia makeup artist jakarta tips make up barbie make up natural make up make up wajah make up pesta make up syahrini makeup mata makeup minimalis peralatan make up make up cantik make up mac make up kit jual make up make up sederhana perlengkapan make up gambar make up vidio make up cara makeup minimalis wardah make up make up pac make up glamour cara memakai makeup make up panggung harga make up make up modern make up alami make up dasar pixy make up make up muslimah make up oriflame make up jepang makeover cosmetic make up ultima make up sariayu grosir make up makeup fantasi makeup pesta tas makeup langkah make up make up pria make up malam alat makeup tahapan make up produk make up shading make up mak up make up kebaya make up jilbab make up inez make up simpel contoh make up cara ber makeup makeup wajah tanpa make up make up terbaru toko make up mac makeup indonesia make up soft urutan make up trik make up makeover makeup brand gusnaldi make up paket make up panduan make up jual makeup brush make up bagus alat2 make up make up gusnaldi aplikasi make up alat alat makeup dasar make up inez make up peralatan makeup make up wanita make up berjilbab make up tebal sejarah make up make up maybeline make up branded make up siang tata cara makeup reseller make up make up muslim make up maybelin warna make up tips make up artist rias make up make up mata make up artis belajar make up make up artist kursus make up kuas make up make up forever indonesia jual make up mac indonesia make up make up artist indonesia harga make up forever jual make up online make up pac make up forever jakarta make up oriflame jual make up forever make up online shop indonesia harga make up sekolah make up grosir make up harga make up maybelline jual make up murah make up terbaru mak up mac make up indonesia sofia make up make up kit murah mac makeup indonesia produk make up jual make up kit make up store indonesia make up forever academy jakarta toko make up online jual make up set jual make up mac make up beauty jual make up branded produk make up mac make up forever harga make up mac indonesia produk make up artis jual make up palette produk make up forever make up palette murah before after make up pengantin before after make up sendiri before n after hasil makeup contoh make up karakter contoh riasan pengantin before n after harga make up wisuda harga make up artist harga make up forever make up wisuda rias wisuda di jogja Daftar harga make up forever daftar harga make up mac daftar harga kosmetik make up forever makeup wisuda harga makeup wisuda kursus make up di yogyakarta kursus make up di jogja kursus make up jogja kursus make up yogyakarta kursus kecantikan di yogyakarta kursus kecantikan di jogja kursus make up artist di jogja kursus rias pengantin di jogja kursus rias di yogyakarta kursus tata rias di yogyakarta rias pengantin muslim jogja jasa kreasi jilbab wisuda yogyakarta jasa rias make up wisuda murah bagus bisa dpanggil tempat make uf di jigja yang bagus rias wisuda murah dan berkualitas yogyakarta pakar kreasi jilbab di jogja make uper natural yogya make up wisuda hijab area jogja make up dan kreasi jilbab yang bagus di jogja jasa make up natural untuk wisuda jogja makeup jogja make up jogja makeup yogyakarta make up yogyakarta makeup wisuda jogja make up wisuda jogja make up wisuda yogyakarta makeup wisuda yogyakarta
Search - People/Events
Search - Content
Search - Industry
Search - Forums
Search - Newsfeeds


Welcome, Guest
Username: Password: Remember me
If you have a question regarding coaxial, telephone, and building wire, power cable, insulation, extrusion, bunching, stranding, braiding, etc. post it here.

TOPIC: Excessive sparkouts

Excessive sparkouts 2 years 7 months ago #673

I run a high-speed THHN extrusion line (12/19 copper mainly). It's set up with 2 Davis-Standard extruders (they were meant to be nylon extruders, however, thus a very small barrel and screw) with a Microdia crosshead. The problem is this, the faster the line is ran the more sparkouts it generates. I'm currently running at 1000 FPM, on a line that will run 2500 FPM. This is a new set-up, and I personally think that the small nylon extruders can't provide a proper melt to the PVC at a high speed. Anyone have any thoughts on this?
The administrator has disabled public write access.

Re: Excessive sparkouts 2 years 7 months ago #674

Hello line108,

I guess the basic questions are:

- Do you have a pvc screw in the pvc designated extruder and are all the PID temperature controls on the whole line in good shape and calibrated?
- Is this screw in good shape and are the screw dimensions OK? (Especially the diameter over the screw flights.)
- Do you have indications of burning of the pvc embedded in the pvc extruder screen pack (This is created by excessive screw shear.) or on the screw itself?
- Are you near or over the Davis Standard projected output (Say in lbs per hour.) for (flexible?) pvc for that extruder/ screw combination?
- Do you have a nylon screw in the nylon extruder?
- Is the nylon extruder screw in good shape?

A dual pvc/nylon crosshead is quite tricky because of the different melt temperatures of the nylon and the pvc. As I recall, Microdia (Swiss) worked a long time developing such a crosshead. Be very sure that the pvc is not overheating and burning in the crosshead.

Presumably the nylon resin is not smoking when you are running at high speed.

Can you tell us the diameter and L/D ratio of the two extruders?

Kindest regards,
Peter J. Stewart-Hay
Stewart-Hay Associates
The administrator has disabled public write access.

Re: Excessive sparkouts 2 years 7 months ago #675

Thank you for your reply. I didn't clearly explain the set-up of this line. The crosshead is a "quick color change" system. It has two extruders flowing PVC through it at all times. There is a seperate extruder coating the PVC with nylon. The two extruders that feed the crosshead with PVC were originally nylon extruders, with a small barrel and screw. As we all know, PVC extruders are significantly larger. Is it possible for PVC to flow through a small extruder made for nylon and get a good melt at a high speed ?
The administrator has disabled public write access.

Re: Excessive sparkouts 2 years 7 months ago #676

Hello again,

You are not giving us any help with your problem. We cannot see what you see or understand what you are not telling us.

Regardless of the configuration of the two crossheads (One single for the nylon and one dual for the pvc base and the pvc color coat.), the fundamental problems still remain.

With any pvc extruder, one of the the most important things is to make sure that you are not burning the plastic by excessive shear inside the extruder or by heating the plastic to too high a temperature and burning it that way. Likewise, dead zones or areas of long residence time inside the extruder and crosshead are to be avoided.

The faster you turn the screw, the more chance there is of burning the pvc by screw shear, expecially over the screw flights. Moreover it is a really good idea to have a regular clean out of the extruders and crossheads scheduled to ensure there is no burned plastic stuck to the screw.

You should also be using screws designed for pumping pvc.

The temperature and burning concerns as described in my first reply are still appropriate and to the point. They are the starting point in your investigation.

Finally, we recommend you purchase the the Electrical Wire Handbook Set (Three books). You can buy it at At a member price of $59.00 it is definitely a bargain.

You have to evaluate your process and determine if indeed pvc burning is the issue. Good luck with your investigation.

Kindest regards,
Peter J. Stewart-Hay
Stewart-Hay Associates
The administrator has disabled public write access.

Re: Excessive sparkouts 2 years 7 months ago #677

Peter is correct in the main question of the screw design as you had mentioned that these were both designed as nylon extruders. A nylon screw will be significantly different from a PVC screw and would not process efficiently if running PVC. I would personally check the L/D of the PVC extruder and the screw configuration (compression ratio, # of flights of feed/transition/metering and actual flight depths) and then talk to a quality screw designer (check with your local screw manufacturer) to ensure you can process with that screw. I would say that if the 2 extruders are the same size and configuration, you will not be able to run very efficiently.

Your screen packs will be a good indicator of problems - if there are black specs there, you are making scrap. If there are unmelted pieces on the pack, likewise garbage.

Erik Macs
VP North American Machinery Sales
Fine International Corporation
148 Oak Street
Natick, MA 01760 USA
508-315-8200 fax: 508-315-3621
This email address is being protected from spambots. You need JavaScript enabled to view it.
The administrator has disabled public write access.
Time to create page: 0.286 seconds