Hi John:
> My question: we have a UL mark on a box we build. One of the requirements
> that the auditors check is flammability of materials. 2 parts give us
> trouble - a molded bezel and a plex screen. Both are materials purchased
> elsewhere by our fabricators. UL says either assemble a 'paper trail' that
> shows continuous control of the materials, or use a 'recognized
> fabricator' (read buck$) to make our parts. Neither fab. house is
> recognized or wants to be. UL is VERY evasive about the required
> documents for the 'trail'. Any one have this experience - and succeed?
Ahh, yes. The famous UL "paper trail" syndrome.
1. The 'paper trail.'
How do YOU know that the molded part is molded from
the resin you specified for the part? Do YOU know
how the fabricator tracks the resin from purchasing
to the finished part? How are YOU satisfied that your
fabricator is molding the part from the resin spec'd
on your part drawing?
Most of us (regardless of UL) require some sort of
documentation accompanying the molded parts. At the
very least, in order to accept the parts from the
fabricator, the parts must have some sort of
fabricator identification, order reference, and part
identification (usually our part number). This is
provided by the fabricator either pasted to the carton,
or a shipping document, or a paper inside the shipping
carton.
Officially, the resin is a UL-Recognized Component.
At your factory, the UL inspector must be able to
identify the molded part as being molded from the UL-
Recognized resin as specified in your end-product UL
FUS Procedure. Your contract with UL obligates you to
provide such identification.
You're lucky. Your UL guy will allow almost any paper
trail that includes the resin identification. So, all
you need to do is to ask your fabricators to add the
resin identification to the part identification document.
We've done this, and it works. But, its iffy. The
next UL inspector may be more strict and shut you down
because you don't have official UL traceability.
You COULD take the UL guy to the fabricator to verify
that the fabricator is using the correct material when
he molds your parts. Now THIS is spendy!
2. UL fabricators.
There are lots of UL fabricators throughout the world.
When I worked in Spain, we had no trouble finding and
using Spanish UL fabricators.
Once in a while, you will find a fabricator is not a
UL fabricator. My policy has been that we need the
fabricator to be a UL fabricator for traceability and
control of the molding compound. We'll continue buying
parts from him if he shows due diligence in obtaining
qualification under the UL program. Never have we had
a refusal.
If the fabricator requires us to pay for the UL
qualification, we say "yes," but also we say that we
own the qualification, and he can't sell UL parts to
anyone else. The fabricator doesn't take us up on
our offer.
Any fabricator who refuses to join the UL fabricators
program won't enjoy good growth in his business. Too
many of us require our fabricators to be UL. We won't
do business with him since his competition offers UL.
Being in the UL fabricators program levels the playing
field for fabricators. Its a standard for being a
fabricator.
3. Buck$.
Not true. The person or organization who told you this
was trying to get you off his case for applying for UL
fabricator.
A UL fabricator provides competitively priced products.
Not an issue.
As a general rule, UL simply documents the fabricator's
process by which he tracks the resins from purchasing to
the finished part. Then, the fabricator can use his UL
code to identify that the parts have the traceability.
If the fabricator's documentation is found by UL to be
deficient, you should think twice about using that
fabricator. It means he doesn't have adequate inventory
control to guarantee that the part will be molded from
the correct material.
The cost of the UL investigation for a UL Fabricator is
less than the cost of a full UL end-product investigation.
FUS costs are the same as you experience for your
products. No big deal.
4. Another way out.
You can set up your FUS so that the plastic material is
tested for the parameter required by the end-product
standard during each FUS inspection. In most cases,
the parameter is flame-rating.
You can set up a lab to do the flame test each time the
UL inspector shows up. You take a sample of each part
from the production-line and perform the flame test.
Easy. But UL will send an engineer to qualify your lab.
Or, you can arrange for UL to perform the test at their
labs. The UL guy selects a part from your production-
line, labels it, and you send it to the UL lab. A
month later, both you and the inspector get a copy of
the test results.
Costly. You'll probably spend as much for this service
over the life of the product as would the fabricator for
UL qualification. And, you may have problems with
inventory control when you take parts from the production-
line.
5. Take the parts out of your FUS Procedure.
A bezel is a part on the outside of the equipment. Its
usually attached to something else. Examine the safety
function of the bezel. It may simply be a "decorative"
part insofar as safety is concerned. If so, you may be
able to talk your friendly UL engineer into removing the
part from the FUS Procedure.
A good question. A long response. As you may discern, I
don't have much tolerance for fabricators who don't want to
join the UL program. If the fabricator wants to do business
with those of us who UL-certify our products, then he should
be in the UL program in order to satisfy his customers.
Best regards,
Rich
-------------------------------------------------------------
Richard Nute Product Safety Engineer
Hewlett-Packard Company Product Regulations Group
AiO Division Tel : +1 858 655 3329
16399 West Bernardo Drive FAX : +1 858 655 4979
San Diego, California 92127 e-mail: [email protected]
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