Topic: controling of the guage varience of a coextruded
amara Member
Posts: 1 From: Registered: May 2005
posted May 20, 2005 07:32 AM
There is a lldpe/ldpe coextruded machine in my company.most of time we are catering the wide variety of customer. most customers ask the film from us with low thickness tolerene (eg film with the thickness tolerence +/- 5).but most of time i falier to supply with this tolerence. These are my questions 1) what is the standarded method of takeing the thickness varience 2)what is the world accepted tolerence. I want to make them educated with a proof evidence awaiting promt reply
Posts: 10 From:Newcastle England Registered: Oct 2003
posted May 20, 2005 10:49 AM
A lot depends on what gauge of material you are extruding.Standard method of measuring sheet variation is generally with a Beta or thickness gauge that will give you are range of +-1 micron. If you do not have a Beta Gauge then a standard hand held micrometer will do with about 5 readings taken across the sheet and averaged. I work with sheet between 300 micron and 1000 micron and the standard is +- 5% below that it goes to +- 7% don't Know if it is world accepted tolerance but is fairly standard here in the UK
Posts: 373 From:McHenry, IL USA Registered: Nov 2002
posted May 21, 2005 07:53 AM
NOTE: Since you are speaking about FILM, you are speaking about materials < 10 mils in thickness. SHEET however is > 10 mils, and can have much tighter controls in thickness.
Your process needs to be defined further for a rational answer; * What gauge controls do you now have? * What is the +/- % precision of your extruder motor controls? * How now do you determine what tolerances you think your delivering? * Do you have taper-tension controls on your winders.
These questions go on & on until you tell us what your now doing, and what you now have.
posted May 20, 2005 07:32 AM
posted May 20, 2005 10:49 AM