Sandwich panel

Details Sandwich panel Sandwich panel

2000-11-17

2004-07-27

Morris, Terrel (Department: 1771)

Stock material or miscellaneous articles

Web or sheet containing structurally defined element or...

Composite having voids in a component

C428S318400, C428S319300, C428S319700, C428S317900

Reexamination Certificate

active

06767623

ABSTRACT:

This invention relates to a sandwich panel comprising
A. a core layer of polypropylene particle foam,
B. cover layers of fiber-reinforced polypropylene and also optionally
C. decorative layers.
Such sandwich panels are known, for example from DE-A 195 44 451. They are used for producing motor vehicle parts. Motor vehicle part production by stamping produces appreciable waste. It is an object of the present invention to recycle this waste.
We have found that this object is achieved, surprisingly, when the comminuted waste is added in amounts from 1 to 30% by weight in the production of foam panels from which new sandwich panels can be produced with only insignificantly inferior mechanical properties.
The present invention accordingly provides a sandwich panel as claimed in claim
1
. The invention further provides a process for producing a foam panel as claimed in claim
5
.
The polypropylene of the particle foam of the core layer can be a homopolymer or a copolymer with from 0.5 to 15% by weight of ethene and/or 1-butene. Its crystallite melting point is generally in the range from 120° to 170° C. The foam particles are produced by impregnating polypropylene minipellets with a volatile blowing agent in aqueous suspension and foaming by expansion. Foam extrusion is also possible. The particle size is customarily in the range from 2 to 8 mm, the bulk density in the range from 10 to 100 g/l.
The polypropylene of the cover layers is a homopolymer or a (graft) copolymer with maleic anhydride or acrylic acid. The cover layers preferably include from 10 to 60% by weight of glass, natural or polymeric fibers in the form of mats, nonwoven scrims, wovens or short fibers. Preference is given to glass mat reinforced polypropylene having a fiber content of from 20 to 50% by weight.
The decorative panels comprise a fiber web composed of polyester or polyamide, polymeric films or a foam film optionally laminated with a film. They may also be colored.


REFERENCES:
patent: 4866110 (1989-09-01), Lee
patent: 5122398 (1992-06-01), Seiler et al.
patent: 5164257 (1992-11-01), Haardt et al.
patent: 5180628 (1993-01-01), Haardt et al.
patent: 5514458 (1996-05-01), Schulze-Kadelbach et al.
patent: 5817420 (1998-10-01), Murakami et al.
patent: 5876534 (1999-03-01), Erhardt
patent: 5954403 (1999-09-01), Mock et al.
patent: 6253527 (2001-07-01), De Zen
patent: 2136773 (1995-05-01), None
patent: 2189319 (1995-05-01), None
patent: 37 22 873 (1989-04-01), None
patent: 195 44 451 (1997-06-01), None
patent: 19544451 (1997-06-01), None
patent: 0 657 281 (1995-06-01), None
patent: 0 771 644 (1997-05-01), None
patent: 5-154861 (1993-06-01), None
patent: 5-169479 (1993-07-01), None
Translation of DE 195 444 51, Molitor et al, Jun. 6, 1997, 5 pages.

Affiliated with

Also associated with

Rating

Sandwich panel does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Sandwich panel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sandwich panel will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3246725