A laminated waterstop strip used in the construction of buildings
that is placed on the top of a surface of a hardened concrete layer
of footing, prior to pouring of an additional layer, and is made
to have a number of granular layers held with adhesive between each
of the layers, and having in the range of 30 to 60 individual granular
layers so that the waterstop has a height of in the range of one-half
to one inch. The waterstop strip is made up of bentonite granules,
preferably, which are adhered to a fabric layer for support, an
adhered layer on the exterior of the fabric layer, with a quick
release paper on the exterior of the fabric layer. A light weight,
synthetic fiber mesh for providing weather resistance, tear resistance,
and retention properties is placed over the upper layer of particles.
The waterstop strip is made in a batch process before being cut
into strips by utilizing a reciprocating multi-station adhesive
and particle dispensing carriage that will move back and forth across
a desired size sheet of fabric until the number of layers of particles
and adhesives have been built to the desired level and the adhesive
forms an elastomeric matrix to retain the particles together.
What is claimed is:
1. A waterstop strip comprising a base sheet of open mesh porous
flexible material, supporting a layer consisting essentially of:
a plurality of individual layers of particles which hydrate and
swell in the presence of liquid and which dehydrates as the liquid
dries, and a separate network of adhesive in interstitial spaces
to form a matrix between particles and between individual layers
of particles, the adhesive and the particles being built up to in
the range of 1/2 to 1 inch in thickness measured normal to a base
an overlying open mesh layer on the exterior of said built up layer
of particles, said strip having substantial interstitial spaces
that are filled with air to permit compressing the strip under exterior
forces while being held together by the matrix of adhesive, the
adhesive comprising elastomeric solids which remain flexible to
permit conforming to irregular shapes as the strips compress and
which hold the particles together during repeated hydration and
2. The strip of claim 1, wherein said strip has a width of approximately
3. The strip of claim 1, wherein said mesh base sheet is sufficiently
porous so an adhesive layer passes through the mesh to the exterior
thereof, and a removable release paper over the adhesive layer on
the exterior of the base sheet.
4. The strip of claim 1 wherein the particle size ranges between
10 and 50 U.S. Standard mesh size.
5. The strip of claim 4 wherein the adhesive is between 15% and
30% of the total weight of the strip and is substantially uniformly
distributed across the thickness of the strip.
6. The strip of claim 5, wherein the plurality of adhesive layers
comprise adhesive layers each having a thickness of in the range
of one to two mils.
7. The strip of claim 1, wherein the strip is constructed of an
adhesive overlying the built up layers of particles, and the overlying
mesh layer being adhered to the layer of adhesive on the exterior
of the built up layer of particles.
8. A narrow, elongated liquid stop strip for interspersing between
portions of building material consisting essentially of an open
mesh porous base layer having adhesive deposited over the mesh and
extending through to the exterior to provide an exposed adhesive
surface, a plurality of individual layers or particles which hydrate
and swell in the presence of liquid and which dehydrate as the liquid
dries, and adhesive layers alternately formed with particle layers
over the mesh base layer to form a matrix of adhesive between particles
and the individual layers of particles, the adhesive and particle
layers being built up to a thickness to provide waterproofing between
the portions of building material, an overlying open mesh layer
on a surface of said built up layers of particles opposite from
the base layer, said liquid stop strip having substantial interstitial
spaces which are filled with air to permit compressing the strip
under exterior forces while being held together by the matrix of
adhesive, the adhesive comprising elastomeric solids which remain
flexible and hold the particles together during repeated hydration
9. The narrow elongated liquid stop strip of claim 8, wherein the
overlying open mesh layer is embedded in a layer of adhesive applied
to the exterior of the immediately adjacent layer of particles.
BACKGROUND OF THE INVENTION
The present invention relates to a thick waterstop layer utilizing
bentonite or bentone (modified bentonite) particles, embedded in
layers of adhesive that will keep the particles in position after
repeated exposure to liquids that cause swelling. The waterstop
provides a conforming liquid stopping layer in seams or joints between
poured concrete layers.
Reference is made to a water barrier sheet shown in U.S. Pat. No.
4,693,923, which is made up of a plurality of individual layers
of bentonite adhered to each other and to an underlying impervious
sheet. Patent '923 illustrates adhesive spray bars and material
feed hoppers usable in a new arrangement for making the strip of
the present invention, and thus reference to this patent provides
details of adhesives that are usable, as well schematic illustrations
of adhesive feed controls and on and off controls. However, the
device shown in U.S. Pat. No. 4,693,923, does not produce a thick
layer of particulate bentonite, in the range of one-half to one
inch thick, economically.
It has also been found that the ratio of adhesives to particles
should be more when the material is used as a waterstop strip, and
in the present invention, which provides an extremely thick waterstop
strip made up of individual layers of bentonite adhered together
with adhesive, a higher concentration of adhesive is desired. Further
maintenance of void spaces between the bentonite particles is desirable
to provide for conformability when the waterstop strips are compressed.
Additionally, U.S. Pat. No. 4,837,085 illustrates a prior waterstop
strip, and illustrates the type of application to which the improved
waterstop strip of the present application will apply.
Further, the use of overlying mesh fabrics, and also support mesh
fabrics for bentonite has been known.
In each of these situations, however, the thickness of the layers
of bentonite particles, is substantially less. Use of selected bentonite
size particles permits the building up of a strip of substantial
thickness to provide for full hydration in concrete work at the
interface between two pourings, and interstitial spaces which make
the strip able to conform to irregular concrete surfaces such as
might be formed by workmans foot print or a chip from the concrete
SUMMARY OF THE INVENTION
The present invention relates to a liquid proofing or liquid stop
strip that is utilized primarily in interfaces between two types
of building materials, or between two separate layers of building
materials of the same type. The strip is made of layers of particles
embedded in layers of adhesive with a high concentration of adhesive
forming a rubber like (elastomeric) support for retaining the particles.
The adhesive is in the interstitial spaces between particles and
surrounding the particles. The adhesive material forms an elastomeric
matrix supporting the particles without degradation ever after repeated
cycles of liquid content expansion of the particles and subsequent
drying out and reduction in size. The adhesive does have openings
whereby water gaining access to the particles to cause swelling,
or can be a water based emulsion which will emulsify to open up
A thick layer of particles and adhesive is supported with a fabric
layer preferably a synthetic woven fabric, on which a base of adhesive
is applied and then alternate layers of bentonite or treated clay
(liquid swellable) particles and adhesives are placed in sequence
to form a matrix. The fabric will also carry an external layer of
pressure sensitive adhesive, covered with a release paper so that
the support layer can be placed onto a surface, such as the upper
surface of a concrete footing, and it will be retained in place
until the subsequent pour of a wall on top of a footing. The waterstop
strip also has a use where materials are placed on top of supports
because of its ability to conform and compress while providing for
the desired effects of waterproofing known from the use of bentonite.
The waterstop strip is made to have, as stated, a plurality of
layers of bentonite or bentone particles and adhesives, built up
into the range of 30 to 60 granular layers, with the corresponding
number of adhesive layers. The top layer of particles is covered
with adhesive, preferably an extra layer of adhesive, and then an
overlaying with a light mesh that is quite open and will embed into
the adhesive to protect against abrasion, and also to tend to hold
the strip together. Bentonite swells in water, while bentones, which
are treated bentonite particles, will react and swell from hydrocarbon
liquid compounds. The bentones can be used for leak proofing hazardous
The waterstop strips are made first into a sheet that will later
be cut into strips, and comprises a fabric sheet having adhesive
and a release paper on one side. The fabric sheet is laid onto a
support surface underlaying a traveling carriage. The carriage has
dispensing hoppers for laying down individual layers of non-hydrated
bentonite or other liquid swellable particles, and also has spray
bars providing a layer of adhesive to be applied onto the underlying
surfaces of the sheet as the carriage moves. At least two material
hoppers are used, along with three spray bars that are suitably
controlled for providing suitable adhesive layers. The traveling
carriage is made to reciprocate back and forth across the underlying
fabric sheet, on each path of the carriage laying down two individual
layers of bentonite or bentone particles that extend transversely
across the entire fabric sheet. The spray bars also extend across
the entire sheet so there is adhesive between each layer of particles
that insures a desirable final product.
The waterstop product is built up by reciprocating the carriage
15 times to 30 times depending on the number of particles and thickness
that are desired, after which the upper surface of the bentonite
or other material particle layers is coated with adhesive and an
open mesh protective fabric is put into position on the top side
of the underlying sheet. The sheet and particles are then rolled
up and cut into strips to form the waterstop strips of the present
invention that have a substantial height and width of about 1 inch.
The cover fabric is generally a light weight polypropylene mesh
to provide a suitable appearance to the exterior or exposed surface
of the bentonite or bentone particles, as well as providing for
a retention of the particles and tear resistance of the particle
bed forming the water proofing strip.
The rolls are shipped to the job site where the release paper is
removed, and the adhesive on the bottom supporting fabric can then
be adhered to a supporting surface to hold the strip in place.
The use of a multiple pass applicator having multiple depositing
stations and reciprocating this applicator relative to the support
fabric, and thus to the material that is being deposited, simplifies
manufacturer and permits the use because of the individual placement
of larger particles of bentonite, than the dust size particles that
have been used in various applications before. U.S. standard mesh
of 10 to 50 mesh size particles are preferred, which eliminates
the dust that has a great saving, not only in adhesive cost, but
also in handling problems, such air borne dust. The larger particles
also enhance the formation of an adhesive matrix that holds each
individual particle in place, but yet, upon wetting, the particles
hydrate or swell and exert pressures capable of sealing gaps against
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational, schematic view of a apparatus utilized
for making the waterstop material of the present invention;
FIG. 2 is a sectional view taken as on line 2--2 in FIG. 1;
FIG. 3 is a fragmentary enlarged schematic representation of the
device of FIG. 1 showing bentonite particles being laid onto an
underlying fabric sheet;
FIG. 4 is a schematic view taken substantially in the same position
as FIG. 3 showing the assembly moving in an opposite direction;
FIG. 5 is a schematic block diagram simplified representation of
a control system usable with the present invention by way of illustration
FIG. 6 is a schematic representation of the location of the sensors
and sensor activating elements on the device shown in FIG. 1;
FIG. 7 is a side view of a typical waterstop material made according
to the present invention; and
FIG. 8 is an enlarged view of particles in an adhesive matrix.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First referring to FIGS. 7 and 8, the waterstop strip made according
to the present invention is shown in vertical cross-section. The
strips may have a width of substantially 1 to 2 inches and as shown,
would have a height of about the same amount. The waterstop strip
10, in its finished form comprises a support mesh fabric sheet 11
that can be made of a suitable woven synthetic fabric. The sheet
11 is a mesh fabric that preferably is porous. This fabric has a
layer of adhesive 12 extending to the bottom (exterior) side thereof,
covered with a release paper 14, which can be removed, as partially
shown in FIG. 7, so that the adhesive layer 12 can be placed against
and adhered to a concrete surface that is to be protected by the
waterstop strip. This layer 12 can be deposited as the first layer
of adhesive deposited from above because of the open mesh of the
fabric sheet. The strip is built up of a plurality of individual
layers of initially non-hydrated liquid swellable particles (called
waterstop particles). The bentonite particles used are of the type
that hydrate (swell) in the presence of water. Sodium montmorillinite
is suitable. Treated clays are selected to hydrate in other liquids.
The particles can thus also be a smectite-type clay that is modified
to be organophilic, as exemplified by U.S. Pat. No. 4,434,076 or
the types of clays shown in U.S. Pat. No. 2,531,427, or other type
of organophilic minerals or clays.
Other particles which swell in presence of liquid hydrocarbons
include clays modified with methyl tri-tallow or di-methyl, di-tallow,
according to known methods, which will swell in aliphatic hydrocarbons.
Aliphatic hydrocarbons are straight chain carbon components, such
as gasoline, kerosene, jet fuel and other petroleum products.
Clays modified with di-methyl benzyl tallow, a di-methyl tallow
propoxy or ethoxy will swell in aromatics including benzene and
other selected six carbon ring components.
Clays modified with methyl di-tallow benzyl quaternary compounds
will swell in both aliphatic hydrocarbons and aromatics. Swelling
of the clays may be improved in both mediums by the use of silane
coupling agents, zirco-aluminates, chrome aluminates (such as Volan
from DuPont Chemical Company), organotitanates, and other materials
of like nature. Adding a dispersing or complexing agent will improve
effectiveness or quaternary ammonia groups to cause swelling.
Ketones also are useful for modifying bentonite particles to make
bentones for waterstop particles for making waterstop strips.
Typical layers are shown at 16, and 17, and then are built up to
the height desired, generally comprising between 30 and 60 layers
of the selected mesh size particles, preferably in the range of
10 to 50 United States Standard Mesh (2.0 mm down to 297 microns).
The strip is built up to the desired height, as stated in the range
of 1/2 to 1 inch, and then is covered with a very fine fabric or
mesh indicated generally at 20 which is held in place with adhesive
as will be described. The mesh serves to protect the outer layers
of the particles, as well as provide for a neat appearance. This
cover fabric can preferably be of a fine non-woven polypropylene
fabric available as a landscape fabric or similar fabric. The layers
of particles are interspersed with layers of adhesive. This adhesive
is indicated in the spaces between the particles 21, and is generally
shown at 22. The adhesive is applied at a substantial rate so that
a continuous layer of adhesive is deposited and even when the adhesive
flows into She interstitial spaces there will remain a coating on
top of the previously deposited layer of particles sufficient for
adherence, but not blocking all liquid passage, which liquid passage
is necessary for hydration of the particles. The adhesive is sprayed
or deposited in position over a prior layer of particles and immediately
prior to applying each individual layer of particles.
The adhesives indicated in U.S. Pat. No. 4,693,923 are suitable
for manufacturing this waterstop device, but preferably the adhesive
will include a water emulsion base. The acrylic type adhesives also
mentioned in U.S. Pat. No. 4,693,923 are suitable, as are the acetate
types of adhesives. The acrylic based adhesives are emulsifiable
in water when applied and the solids form an elastomeric matrix
of when applied at the rates disclosed, after the water has evaporated.
The adhesives have a consistency which permits spraying under pressure
and uniform application.
The known adhesives that are suitable for use with bentonite or
bentones, can be sprayed under pressure or dispensed by gravity
in a suitable manner for application. The types of application devices
are shown in U.S. Pat. No. 4,693,923 and the same considerations
for application and selection of adhesives are present in the process
of manufacturing the waterstop strip disclosed herein.
The machine for making the waterstop strip is illustrated in FIGS.
1 through 6, and as shown comprises a support table 30 that is mounted
below a traveling gantry or carriage 32. The gantry comprises a
support frame 34 that has suitable support legs 36 mounting onto
carriages illustrated at 38 that are supported in a pair of tracks
40. The tracks 40 in turn are supported within the building housing
the table 30 at a location above the table. Alternately, the gantry
or carriage can be mounted on wheels that would run on a floor surface.
The gantry is made to reciprocate in opposite directions along the
tracks 40 as indicated by the double arrow 41.
Table 30 is made of a suitable size so that a sheet of the fabric
11 can be laid in position. A length of the fabric sheet 11 in the
range of 10 to 15 feet would be usable and a width in the range
of 4 feet would be suitable. The support frame 34 is used to support
the particle or material applicator mechanisms 42. The granular
material dispensing devices and adhesive dispensing devices can
be of the same type shown in U.S. Pat. No. 4,693,923. They are supported
in a different arrangement in the present device. The applicator
frame 32 is a traveling or reciprocating frame that can be manually
or automatically controlled.
The carriage 32 includes a first adhesive applicator bar or spray
bar 44A, which is called "A1" in subsequent discussions.
The spray bar 44A is supported with a suitable support 46 from the
frame 34, and it receives material from an adhesive tank 48A, that
can be of any desired design. Tank 48A is used for providing a discharge
of suitable adhesive to the transversely extending bar 44 (it extends
across the width of the fabric sheet that is supported on the table).
The adhesive spray bar 44A, is supplied with adhesive material through
an electric solenoid valve 50A, that is controlled as will be described.
A second adhesive spray bar 44B, also designated A2, is supported
on the frame 34, and is positioned between the granular material
dispensing devices 51A and 51B, as will be explained. The spray
bar 44B is held with a support 46B from the frame 34 and a tank
48B provides suitable adhesive through a solenoid control valve
A third adhesive applicator bar 44C is provided on an opposite
end of the frame 34 from the bar 44A, and will be referred to subsequently
as adhesive applicator A3 as well. This applicator has an adhesive
tank 48C that is also supported from the frame 32. The spray bar
44C can be supported from the frame with a support 46C. The control
of adhesive is with a solenoid valve 50C, which, when on, will provide
adhesive to be sprayed downwardly onto the sheet supported in table
30 as the carriage 32 travels back and forth.
The carriage 32 is power driven in a suitable manner from a motor
indicated generally at 52, which is a reversible, variable speed
motor that can be controlled in the process as needed to provide
the necessary depositing of the layers of individual particles.
At each end of the tracks 40, schematically shown, are support
bars 54 and 56 respectively, that support proximity detectors as
will be explained, for controlling operations by providing signals
when sensing surfaces on the various components pass the proximity
detectors. The proximity detectors are used for individually operating
each of the valves 50A, 50B and 50C. The frame 34 also, as stated,
provides support for a pair of granular material applicators 51A
and 51B which are used for dispensing non-hydrated (dry) waterstop
particles onto the fabric held and supported on the table 30. The
applicators comprise hoppers that contain bentonite or Ketone particles
(particles which swell in presence of liquids) with feeding devices
56A and 56B at the lower ends thereof. Suitable material dispensers
that control material flow are electric solenoid operated, and are
indicated at 58A and 58B, respectively. These material dispensers
are referred to as M1 (51A) and M2 (51B) subsequently.
Additional hoppers can be provided if desired, but the double hopper
and the reciprocating drive provide for an arrangement that is suitable
for relatively rapidly building up the number of layers of particles
necessary for the waterstop strip of the present invention.
The reciprocating drive is operated by a programmable logic system
or control which is designed with normal digital controls or analog
controls as desired. The unit can have manual overrides.
The support bar 54 includes a first proximity detector 58 which
is an "end right" detector a second proximity detector
59 which is a "stop right" detector and a third proximity
detector 60, which is a "start right" detector. These
detectors are used for controlling the dispensing as well as the
motor 52 as the carriage 32 travels back and forth.
The support bar 56 includes an "end left" proximity detector
61, a "stop left" proximity detector 62, and a "start
left" proximity detector 63. The support bars 54 and 56 are
positioned adjacent the ends of the unit, beyond the start and stop
edges of the sheet 11 that is being provided with the coating of
adhesive and swellable waterstop particles, so that the carriage
32 can travel the desired distances beyond the start and stop edges,
and provide the same number of particle layers on the fabric sheet
30 adjacent each end of the sheet.
Each of the individual adhesive spray or dispenser bars, and each
of the waterstop material hoppers is provided with a sensing surface
on the sides of the units that are shown schematically at 64 as
small patches. These are metal sensing surfaces that are mounted
in a suitable location and orientation to provide the necessary
signal to the proximity detectors and control circuitry for turning
on and off the solenoid valves and material metering devices, as
well as reversing motor 52.
The sensing surfaces are metal plates mounted onto an insulating
base, so that when they pass next to an aligned proximity detector,
a true actuator signal will be obtained when they pass the proximity
detectors. Proximity switches or detectors are conventional items,
and the lay out of the sensing surfaces on the carriage is shown
schematically in FIG. 6, and is provided in connection the simplified
logic diagram of FIG. 5. The adhesive spray or dispenser bars, are
again labeled, A1, A2 and A3, and the individual sensing surfaces
are horizontally aligned with the proximity detectors at the right
end and left end of the tracks, respectively.
Aligning with the end right proximity detector 58 that indicates
the right end, is a sensing surface 70 which is at the left hand
end of the frame 34, and this is the only sensing surface that aligns
with that particular proximity detector. In regard to the proximity
detector 59, there are four sensing surfaces aligning with such
detector including a sensing surface 71A that is on the spray bar
44C (A3), a sensing surface 72 which is on the material dispenser
51B (M2), a sensing surface 73, which is on the adhesive dispenser
44B (A2), and a sensing surface 74, which is on the material dispenser
The adhesive dispenser 44A has no sensing surface aligning with
the "stop right" proximity detector 59.
The alignment with the proximity detector 60 includes a sensing
surface 72A, on material dispenser M2 or 51B, and a sensing surface
73A that is on the A2 adhesive dispenser, an alignment surface 74A,
which is on the material dispenser 51A (M1) and a sensing surface
75A which is placed on the adhesive dispenser 44A (A1).
The proximity detector 61 at the left end of the track or table
30 aligns horizontally with an end sensing surface 76 that is on
the right hand end of the frame 34, as shown in FIG. 1. That will
come close to the proximity detector 61, when the frame 34 has moved
all the way to the left.
Aligning with the proximity detector 62 is a sensing surface 75B,
that is mounted on and is used to control the dispenser 44A (A1);
a sensing surface 74B that is on the material dispenser 51A (M1),
a sensing surface 73B which is on the adhesive dispenser 44B (A2);
and a sensing surface 72B which is on the material dispenser 51B
(M2). Horizontally aligning with the proximity detector or switch
63 is a sensing surface 74C, that is on the material dispenser 44A
(M1), a sensing surface 73C which is on the adhesive dispenser 44B
(A2); a sensing surface 72B which is on the material dispenser 51B
(M2), and a sensing surface 71B, that is on the adhesive dispenser
As the carriage 32 moves back and forth, each time a sensing surface
passes the respective proximity detector, the detector will provide
a pulse or will be turned on, and then this signal indicating the
presence of the sensing surface, will discontinue after the surface
has passed the detector. This provides a pulse type signal and in
the overall logic circuit shown in FIG. 5, these pulses are provided
to conventional counters. The simplified circuit in FIG. 5 does
not include many of the set and reset functions, or other known
circuitry for making counters operate. Suitable power will be provided,
The number of passes of the carriage back and forth also is controlled
by the logic circuit shown in FIG. 5, as indicated very schematically.
The main "on" switch 80 provides power to a motor controller
81, that controls the motor 52, and which can be reversed to reverse
the motor 52. The motor 52 also can be speed controlled. A main
counter 82 is used for initializing and setting the controller to
turn on the motor 52. This will be also set so the motor resets
the carriage 52 to its start position at the right hand side of
the table 39, with the sensing surface 70 just clearing the "end
right" detector 58.
When the carriage 32 is traveling to the left, in a first pass,
as shown in FIG. 3, a layer of adhesive 86 is laid down from the
adhesive dispenser 44A (A1) and a first layer of bentonite particles
is laid down as shown at 88 in FIG. 3 on top of the layer of adhesive,
and supported on the fabric 11. The first layer of adhesive can
be the adhesive that is used with the release sheet in that She
adhesive will pass through the openings in the base fabric (mesh)
sheet. A second layer of adhesive 90 is applied over the particles
88, by the dispenser 44B (A2) and the second layer of particles,
indicated at 92 is laid down over the adhesive layer 90 from the
material dispenser 51B (M2). The adhesive dispenser 44C (A3) is
not operating in this mode, and the unit will continue to travel
to the left until, referring to FIG. 1, sensing surface 75B for
A1 passes proximity switch 62, which is the "stop left"
side. This will provide a signal to a counter 94 which is indicated
at D3 in FIG. 5, providing a signal along the line 94A to the off
control for valve 50A controlling the dispensing of adhesive from
spray bar A1.
As the carriage continues to travel to the left, the signals from
the stop left detector will be activated by the passage of sensing
surface 74B. The start left detector 63 will be locked out of the
circuit until a signal is received indicating the passage of the
entire frame 34, so the sensing surface 74C will not cause any signal
at this stage, nor will the sensing surfaces 73C, 72C or 71B.
When the signal from the sensing surface 74C is received, it will
provide a pulse from the detector 62 to the out-put 94B of counter
94 which will in turn, turn off the dispensing control for particle
or granular material dispenser 51A (M1). When sensing surface 73B
passes the stop left proximity detector switch 62, a pulse from
this detector will trigger the counter D3 one more step, so that
line 94C, provides a signal for turning off the valve 58B for adhesive
material dispenser A2. Finally, as the carriage 32 continues to
move to the left, sensing surface 72B will pass the proximity detector
62 and provide another trigger signal to the counter 94, providing
a signal on line 94D to turn off the solenoid control 58A (M1) for
the material dispenser 51B. These solenoid controls are represented
as blocks in FIG. 5, schematically.
Then, as the carriage continues to pass to the left, the sensing
surface 76 at the very right hand end of the frame 34 will move
pass the stop left proximity detector 62 providing a signal that
is an end left signal from the proximity detector 61.
The end left signal will be used for reversing the drive motor
52 through controller 81, and also will be used to provide a signal
to disable the stop left detector 62 and enable the start left detector
63. A time delay may be provided between the stop and start signals.
As the carriage 32 then moves toward the right, the first sensing
surface that will move past the start left detector, will be sensing
surface 71B that provides a signal from detector 63 to counter D1
indicated at 95 and provide an output on the first output line 95A
to turn on the valve 50C controlling the adhesive spray bar 44C
(A3). Then, A3 will start dispensing a layer of particles of material
as shown at 96 in FIG. 4, that will be on top of the layer of particles
92. As will be further explained, the particulate material dispensers
will be activated so that dispenser 51B (M2) will provide a layer
of particles 98 over the adhesive layer indicated at 96. The second
adhesive spray bar 44B will be dispensing adhesive indicated at
100 above the newly dispensed particle layer 98. The first material
dispenser 51A will be dispensing a layer of particulate waterstop
material 102 on top of the adhesive dispensed by bar 44B indicated
at 100. The adhesive applicator spray bar 44A will not be operating
as the unit moves to the right.
When the sensing surface 72C passes the proximity detector 63,
counter 95 will be triggered and a second line 95B will be provided
with a signal to the on side of the electric solenoid valve M2 for
dispenser 51B, and turn on this material dispenser to provide for
dispensing the layer 98 of waterstop particles.
The carriage will continue to be driven by the motor 52 to the
right, and sensing surface A3 will pass the detector 63, which provides
a pulse energizing the line 95C to turn on the solenoid valve 50B
for adhesive dispenser 44B (A2). Sensing surface 74C passes the
detector 63 in sequence, as the carriage moves to the right, and
this will clock the counter 95 to provide a signal on line 95D to
turn on the valve or dispenser for the particulate material dispenser
51A (M1). The particle layer 102 will be dispensed, and since the
adhesive applicator bar or spray bar 44A is not operating, the carriage
will continue to move toward the right until it again comes to a
position where the sensing surface 71A will pass the stop right
proximity detector 59 providing a signal to the counter 108 (D4)
so that a signal on line 108A goes to the off terminal of the solenoid
valve 50C turning off the adhesive dispenser 44C (A3). The sensing
surface 72 will pass the stop right proximity detector 59 causing
a signal on line 108B to turn off the solenoid control for material
dispenser M2. Sensing surface 73 will pass the proximity detector
59, clocking the counter 108 one more time to provide a signal on
line 108C to turn off the solenoid valve 50B for material dispenser
44A (A2) and the sensing surface 74 will then pass the proximity
detector 59 to clock the counter 108 to provide a signal on line
108D to turn off the material dispenser 51A (M1).
The carriage unit will continue to travel until the end sensing
surface at the left end of the frame 34 indicated at 70 passes the
end right proximity detector 58 which provides for the signals that
will reverse the motor 52, and disable the proximity detector 59
and enable the detector 60, as well as disabling the "start
left" detector 63 and enabling detector 62. It should be noted
that the signal from detector 61 would be used to disable the detector
60 at an appropriate time. In reverse direction, then, the sensing
surface 75A passes the start right signal switch 60 that controls
the counter 112, and in sequence, the sensing surfaces 74A, 73A
and 72A clock the counter 112 to energize sequentially lines 112A,
112B, 112C, and 112D, to sequentially turn on the adhesive applicator
A1, the particulate waterstop material dispenser 51A, the adhesive
applicator A2, and the particulate waterstop material dispenser
51B. Adhesive dispenser 44C is not turned on.
The carriage 32 then will reciprocate back and forth for a number
of counts that can be set with a count setter at 114 leading to
the counter 82. When the count of counter 82 is complete the controller
for the motor 52 will be shut off, and then the final overlay of
the fine fabric will be placed on the waterstop (after 30 to 60
layers of material). On the final pass, the starting adhesive dispenser,
which is normally turned off, will be activated to provide an adhesive
layer on top of the last bentonite layer.
The counter 82 is made so that it decrements by counts of one,
each time the end left or end right proximity detectors provide
a signal. When the counter reaches the end of its count, such as
in the range of 60 counts when 30 layers of particles are to be
applied, then the counter indicates that the set of instructions
is over, and it can shut down the system. One count short of the
end of the counter set that is set with the thumb wheel 14 can provide
a signal to activate the leading spray bar, without activating any
of the other spray bars or the material dispensing controls, such
as that shown in the drawing to activate spray bar A1, and provide
a single layer of adhesive over the last layer of particles that
is deposited. Alternatively, the trailing spray bar can be activated
on the last pass, as discussed. This provides for automatically
placing an upper layer of adhesive that will hold the loose woven
mesh fabric that is used as a cover in place.
A truth table for the electric solenoid and actuators A1, A2, A3
and M1 and M2 is represented below as Table 1, illustrating the
control counts of counters D1-D4.
TABLE 1 ______________________________________ Turned on by: Turned
off by: ______________________________________ A3 D1 = 1 D4 = 1
M2 D1 = 2, D2 = 4 D4 = 2, D3 = 4 A2 D1 = 3, D2 = 3 D4 = 3, D3 =
3 M1 D1 = 4, D2 = 2 D4 = 4, D3 = 2 A1 D2 = 1 D3 = 1 ______________________________________
It should be also noted that the rate of application of the granular
waterstop material can be provided through suitable rate controls
116 and 118, on the material dispenses.
The waterproofing material of fabric with the built up layers of
bentonite is rolled into a bulk roll, and subsequentially slit into
one inch wide strips to be used as the waterstop strips.
The labor utilized with the reciprocating carriage is substantially
reduced. The control provides for a good control of adhesive and
particles so that each particle layer has a generous layer of adhesive
on top to hold the particles together well, and from a non-deteriorating
matrix of adhesives. A one to one granular layer to adhesive layer
ratio, that is one layer of adhesive to one layer of granules, is
important to prevent de-lamination which can occur if two dry granular
layers are applied without an adhesive layer between them to bond
the layers together, as the waterstop strip hydrates and then dehydrates
in use. A layer of adhesive in the range of 1 mil to 2 mils in thickness
is provided. The adhesive emulsion is liquid so that it flows into
interstitial spaces for forming a matrix of elastomeric material
that can cycle between hydration and drying of the particles.
There are substantial interstitial spaces or air voids around the
granules that will increase as the emulsion carrier or solvent for
the adhesive evaporates, which provides a matrix of elastomeric
solids that stretch and give, but which do not deteriorate from
use. The strip has a resilient, compressible character, so that
the waterstop strip can compress to conform to irregular surfaces,
as well as change in internal size.
A device that has mesh size and 10 to 50 U.S. Standard mesh size
granules is also desirable in manufacture because of the elimination
of dust as well as having substantial void volume.
It should also be noted that various types of logic controls can
be utilized, and that these are merely representative of a schematic
arrangement that will show that the gantry can be reciprocated.
As shown in FIG. 4, the frame 84 can be supported on upright posts
120 that are mounted on wheels 121, and the wheels 121 then can
be driven from the motor 52. The wheels 121 can be mounted on floor
supported rails, or other guides.
The individual solenoids 50A, 50B, 50C, and controls 58B and 58A
can be manually operated, and also the motor 52 can be manually
operated and reversed in direction. Manual controls 126 include
individual switches 127 for controlling the solenoids and the motor
52. The motor has forward, reverse and "on" buttons. The
on and off sequencing can be done manually. In some instances, such
as the last pass, the trailing adhesive spray tube may be operated,
to add a layer of adhesive over the exterior layer of granules.
The top layer of adhesive helps to bond the waterstop strip together
and holds the additional loose fabric or open mesh that is placed
on the exterior of the waterstop strip. The adhesive is applied
in a concentration of 15% to 30% of the strip weight, so a high
adhesive content is provided for the matrix.
In applications where the waterproofing strip is left in standing
water before a wall is poured, for example, it may be desirable
to seal the strip side surfaces with a slowly water degradable adhesive.
The layer would be applied to coat the side after the strip is slit
from the sheet. It can be done manually while the strip is rolled.
The adhesives would be selected to keep liquid away from the swelling
particles initially, but which would open or degrade with time so
the leakproofing action would be available when needed.
It should be also noted that the program can provide safety features
such as a delay during the reversal of the frame member 34, and
the block out of right travel functions during left travel and vice
versa. Further, blocking out of the start proximity detectors when
the stop detectors are being activated can be carried out utilizing
the signals that indicate "stop right" and "stop
left" for the carriage.