DuPont Plastic Film Glazing

Thanks to Alan for providing the following material on thin film glazing materials from DuPont.

Hi Gary,

I did some research of Teflon, Tedlar, and Tefzel that I thought you might be interested in.  After numerous calls and emails to DuPont reps and techs, below is not necessarily the last word, but it is what I have come up with, so far.     

Teflon was recommended by one DuPont person for solar glazing, Tefzel by another.  Both are available in widths up to 60".  Both can be seamed if they are ordered coated.  If coated, it will have a C in the designation (example: Teflon FEP 100C, or Tefzel 200CLZ).  Apparently both are long life, and both hold up to hot water.  Both allow some vapor transmission through them (as do most plastics).  Thicker films have less vapor transmission.  In terms of ‘wetting’, both bead up water much more than normal materials.  I am trying to get some samples.  It will be interesting to see if they can help disperse water across a painted collector like the thin poly did.        

 TEFLON (FEP) specs:  http://www2.dupont.com/Teflon_Industrial/en_US/assets/downloads/h55007.pdf   (optical specs on page 8)

Available in widths up to 60”

The types recommended by DuPont techs were FEP 100 (not coated) or FEP 100C (coated 1 side for seaming and adhering)

  

TEFZEL (ETFE):  http://www2.dupont.com/Teflon_Industrial/en_US/assets/downloads/h96518.pdf  (optical specs on page 23)

Available in widths up to 60”.

The types recommended by DuPont techs were 200 LZ or 200 CLZ.coated version for seaming/gluing.   

 

 

Tefzel  ETFE

Teflon  FEP 100

200 LZ

200 CLZ (treated)

Non treated

C  (treated)

1 mil

2 mil

1 mil

2 mil

1 mil

2 mil

1 mil

2 mil

$/lb.  

$45.63/lb

40.58

52.53

46.71

40.85

35.01

52.57

42.15

Sq.ft/lb.

110sq.ft/lb

55

110

55

90

45

90

45

$/sq.ft.

$.415/sq.ft

.738

.478

.849

.454

.778

.584

.937

$/sq.ft. w/5%

surcharge *

$0.44/sq.ft

.78

.50

.89

.48

.82

.61

.98

Tensile

6000 psi @ 70F ,  1500 psi @ 300F

3000 psi @ 70F,  500 psi @ 300F

Working temp

302 F

400 F

Solar transmis

Possibly 94% (from page 23 chart)

96%

Infared transmission

Varies – mostly well over 50%

See page 23 of site above.

Varies – mostly under 35%

See chart page 8 of site above.

 

TEDLAR (PVF): http://www.dupont.com/tedlar/techdata/pdf/h49719-1.pdf

According to two different DuPont reps. current availability of clear Tedlar is restricted for PV use.  One tech said it did exhibit some cracking problems at the edges on solar collectors.  Another tech was saying 6 year life for Tedlar.  At least one type of Tedlar has UV inhibitors that deplete to 50% in about 6 years.  Techs and sales reps steered back to FEP or ETFE.  

I hope to receive samples and do a little more testing.  I like that Tefzel might do better on creating greenhouse effect.  At the moment I am thinking for a trickle collector, one might do worse than use polycarbonate outer glazing at $1 to $1.50 and 1 or 2 mil Tefzel for an inner film that would lay directly on the collector surface with water trickling behind.  A key factor will be if Tefzel or Teflon can disperse water well like the thin polyethylene did.  I am trying to get some samples to test this.  

 

 

1/27/07 Updated 1/31/07