MANUFACTURE OF MULTI-LAYER FILTERS

FABRICATION DE FILTRES MULTICOUCHE

English Abstract

A device for the assembly of multi-layer filters comprises a plurality of roll
holding
means permitting rolls of filter material to unroll in parallel. A first
powered roller
is provided to gather a plurality of webs of filter material from the rolls in
a multi-layer
stack. A second powered roller downstream of the first powered roller to pull
the stack from the first roller, under tension. An opposed pair of sewing
machines
is positioned between the first and second powered rollers, to sew the stacks
of
webs along side edges. The sewing machines are provided with trimming blades
to
trim the outside margins of the sewn stacks. A third powered roller downstream
of
said second roller pulls the sewn stack away from the second roller under
tension.
The third powered roller is provided with measuring and cutting means to
measure
desired lengths of the sewn stack, and cut the stack into desired lengths.

Claims

CLAIMS
1. A device for the assembly of multi-layer filters comprising:
i) a plurality of roll holding means permitting rolls of filter material to
unroll in
parallel;
ii) a first powered roller to gather a plurality of webs of filter material
from said rolls
in a multi-layer stack;
iii) a second powered roller downstream of said first powered roller to
pull said stack
from said first roller, under tension;
iv) an opposed pair of sewing machines between said first and second
powered
rollers, to sew said stacks of webs along side edges, said sewing machines
being
provided with trimming blades to trim the outside margins of said sewn stacks;
and
v) a third powered roller downstream of said second roller, to pull the
sewn stack
away from the second roller under tension, said third powered roller being
provided with measuring and cutting means to measure desired lengths of said
sewn stack, and cut said stack into said desired lengths.
2. A device as claimed in claim 1, also comprising a take-up roller between
said second and
third powered rollers, to maintain tension in said stack while the cutting of
said stack in
desired lengths is performed.
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Description

CA 02910857 2015-10-30
MANUFACTURE OF MULTI-LAYER FILTERS
The invention relates to a method and apparatus for the production of multi-
layer filters.
The problem addressed by the present invention is how to attach multi-layers
of types of material
used to make premium air filters so that up to 12 or more layers could be
sandwiched together
and formed into rectangles for assembly into filters.
A faster and more efficient method would be essential to provide a
commercially viable filter.
The present invention describes a novel way of constructing a multi-layered
article of cloth
material. The inventor was investigating a way of securing various layers of
material so that they
were aligned in a rectangular shape so that the layers could then be attached
to a frame made of
rigid plastic. The cloth layers had to be secured to one another so as to act
as a unit once attached
to the frame.
The previous method for construction included; measuring and cutting each
rectangle of material
individually; then manually aligning each layer with the one below and running
a bead of glue
along each of the four sides. Then adding the next layer in the same fashion
until all the layers
were secured at their edges. This method was very time consuming. In search of
a more efficient
way to secure the layers, the inventor tried sewing them on a standard sewing
machine, but found
that keeping the layers aligned and flat was not feasible. This invention
describes the novel way
we found to secure the edges and maintain the flat seam using automated sewing
techniques. We
constructed a machine that joins multiple layers in a continuous automatic
sewing process. The
machine features two sewing machines facing each other (right and left feeds).
The layers are fed
into the machines automatic feed rollers from rolls (of material) mounted in
front of the sewing
machines. The distance between the sewing heads can be adjusted to whatever
the required width
of the rectangle. (any excess material is cut off by blades mounted on each
machine.) Automatic
feed rollers mounted after the sewing machines pull the material layers
through the sewing
process so as to keep the layer flat while being sewn. The second operation on
the same machine
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CA 02910857 2015-10-30
pulls the band of layers (now secured on two sides) through a second set of
feed rollers that have
a metering device that stop the band of layers at a desired length. Then a
rotating saw blade
specially designed to cut cloth and mounted on a track automatically slides
across the end of the
multi-layer band and severs it from the continuous band producing the desired
article. Namely a
rectangle of multi-layers fabric that is fully secured and can be handled
easily and is fit to
proceed to the next part of the construction process for the desired product
(a specialty air filter).
This process and machine represent a large increase in efficiency and speed of
construction of a
multi-layered article of cloth or any sewable product.
In a broad aspect, the present invention provides a device for the assembly of
multi-layer filters
comprising: i) a plurality of roll holding means permitting rolls of filter
material to unroll in
parallel; ii) a first powered roller to gather a plurality of webs of filter
material from said rolls in
a multi-layer stack; iii) a second powered roller downstream of said first
powered roller to pull
said stack from said first roller, under tension; iv) an opposed pair of
sewing machines between
said first and second powered rollers, to sew said stacks of webs along side
edges, said sewing
machines being provided with trimming blades to trim the outside margins of
said sewn stacks;
and v) a third powered roller downstream of said second roller, to pull the
sewn stack away from
the second roller under tension, said third powered roller being provided with
measuring and
cutting means to measure desired lengths of said sewn stack, and cut said
stack into said desired
lengths.
In drawings that illustrate the present invention by way of example:
Figure 1 is a side, partially schematic view of a device of the present
invention, for implementing
the method of the present invention.
Referring to the drawing, it will be seen that the present invention provides
a device capable of
holding a multitude of fabric rolls, parallel to each other, so that they can
be unwound together
by feeding the fabric from each into a roller 1 that grips the layers of
fabric, and pulls them
toward an oppose pair of sewing machines 2.
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CA 02910857 2015-10-30
The sewing machines 2 are positioned at the side margins of the fabric layers,
and can be
adjusted closer together, or further apart, as desired. Each sewing machine
head is also provided
with a trimming blade, so that as the fabric moves forward, and is sewn
together by the sewing
machines, it is also trimmed to a desired width.
The trimmed fabric then passes through a driven pair of puller rollers 3,
which provide the force
to pull the fabric through the sewing machine head. Then, the sewn fabric is
pulled by a take-up
roller 4, through a drive roller 5 that also functions to measure, by
conventional means, the fabric
as it is pulled through. At regular predetermined intervals, the measuring
device signals a cut-off
knife 6 or saw blade mounted on a track 7 adjacent the drive roller, to cut a
work piece, which
will consist of a predetermined length of multi-layer filter, sewn together
along its side edges.
The two remaining edges can then be sewn, if desired, and the finished filter
mounted in a frame
for use.
As can be appreciated from Figure 1, the present invention can utilize any
desired number of
layers of fabric, and the fabric may be selected for particular filtering
properties. For instance,
fabric layers may include:
1) glass fiber
2) synthetic fiber
3) natural fiber
4) activated carbon coated cloth
5) filter paper made from glass fibers
6) synthetic fibers treated with absorbent
and so on. It will be understood that any combination of layers, as required
or specified for a
particular filtering application may be combined by the manufacturing method
and device of the
present invention.
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