Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Patent
1996-06-28
1998-09-08
Crispino, Richard
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
156227, 156229, B01D 2907, B01D 2931, B31F 5300
Patent
active
058040145
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a process for producing a filter insert comprised of filter material having a number of fold walls arranged in a zigzag-shaped continuous fold, adjacent fold walls being connected to one another and resting on one another at least in part by means of an adhesive spacer, wherein the a strip of the filter material is provided with indentations which determine positions of fold edges; the adhesive spacers are applied to at least corresponding areas of those parts of the strip of filter material which will become adjacent fold walls when the filter insert is complete; and the strip of filter material is folded at the indentations. The invention additionally relates to an apparatus for carrying out the process.
Filter inserts of the above types are used to remove contamination from a fluid flowing through a filter, particularly air or industrial gasses, but theoretically liquids as well. At present, filter elements consisting of a micro fibre fleece, particularly glass fibres, are predominantly used in air filters.
In order to increase the effective filter area relative to the inflow surface of the air filter which forms a filter element or filter area, the filter medium is folded in a zigzag shape so as to produce a number of folds adjoining one another via fold edges, which are located at an acute angle to the walls of the folds and through which the medium to be purified flows at right angles to the direction of the fold edges.
As a result of the depositing of material, and particularly the settling of larger particles, on the inflow side of the filter, turbulence in the inflowing fluid, slight irregularities in the folds, etc, inhomogeneities may occur in the fluid flow as the fluid flows through the filter, thereby subjecting the fold arrangement to strong mechanical alternating stresses and possibly bringing about deformation of the fold arrangement.
In order to hold the folds at a specified distance from one another and mechanically stabilise the fold arrangement of the filter insert, the folds are therefore provided with projections protruding from the plane or the told walls, as described for example in U.S. Pat. No. 3,531,920 or, according to another special embodiment, in German Patent Document DE 41 26 126 A1, in such a way that the projections of adjacent fold walls abut on one another and the fold walls support one another. In order that the fold walls are directed at an inclined angel to the incoming fluid, ie. the fold layers are substantially triangular in cross section, the projections must also be approximately triangular or trapezoidal in cross section.
These arrangements have proved suitable for filter inserts with a fold height up to about 100 mm, with relatively tightly packed folds. Beyond this fold height and with larger fold spacings, however, the depth of impression required is so great that, with conventional filter materials, there is the risk of the folds being punched through, thereby unacceptably increasing the number of rejects.
It is also known from German Patent Document DE 40 38 966 to place separate spacers with the same function on the fold walls or to insert such spacers therein. The spacers may be adhesive aggregates, particularly in fibre form, as mentioned as a possibility in the specification referred to above or as illustrated in German Patent Document DE 30 37 019 A1. In addition to acting as spacers, they also have the effect of connecting the fold walls and thus further increasing the rigidity of the filter insert.
The adhesive is applied before the folding of the filter material onto the flat strip, and the fold walls are adhered by the contact of the adhesive threads with one another during the folding operation. This solution is therefore only suitable for very densely packed folds. In addition, the fold layers formed in this way tend to have a meandering configuration in cross section, which does not lead to optimum flow qualities.
German Patent Document DE 39 03 730 A1 describes how an adhesive thread which
REFERENCES:
patent: 3531920 (1970-10-01), Hart
patent: 4111733 (1978-09-01), Periers
patent: 4798575 (1989-01-01), Siversson
patent: 5028331 (1991-07-01), Lippold
patent: 5066400 (1991-11-01), Rocklitz et al.
patent: 5290447 (1994-03-01), Lippold
Crispino Richard
Detroit Holding Limited
LandOfFree
Process for providing a filter insert does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for providing a filter insert, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for providing a filter insert will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1278378