"'
`Consumer and
`tit~
`~ >t;\f#J Corporate Affairs Canada
`
`Consommation
`et Corporations Canada
`
`(11)
`
`(A) No.
`
`1189 434
`(45) ISSUED 850625
`
`(52) CLASS
`
`154-69
`
`4
`(51) INT. CL. B32B 13/12,31/12
`
`(19) (CA) CANADIAN PATENT (12)
`
`(54) wallboard Made from Gypsum and Plastic Facing
`Material
`
`(72) Bruce, Robert B.~
`Hartel, Alfred;
`Leeming, Peter A.,
`Canada
`
`(73) Granted to BPB Industries Public Limited Company
`U.K.
`
`(21) APPLICATION No.
`
`3.96, 368
`
`(22) FILED
`
`820216
`
`No. OF CLAIMS
`
`11 - NO DRAWING
`
`Canada
`
`DISTRIBUTED BY THE PATENT OFFICE, OITAWA.
`CCA·27 4 (11 ·82)
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 1
`
`
`Consumer and
`tit~
`~ >t;\f#J Corporate Affairs Canada
`
`Consommation
`et Corporations Canada
`
`(11)
`
`(A) No.
`
`1189 434
`(45) ISSUED 850625
`
`(52) CLASS
`
`154-69
`
`4
`(51) INT. CL. B32B 13/12,31/12
`
`(19) (CA) CANADIAN PATENT (12)
`
`(54) wallboard Made from Gypsum and Plastic Facing
`Material
`
`(72) Bruce, Robert B.~
`Hartel, Alfred;
`Leeming, Peter A.,
`Canada
`
`(73) Granted to BPB Industries Public Limited Company
`U.K.
`
`(21) APPLICATION No.
`
`3.96, 368
`
`(22) FILED
`
`820216
`
`No. OF CLAIMS
`
`11 - NO DRAWING
`
`Canada
`
`DISTRIBUTED BY THE PATENT OFFICE, OITAWA.
`CCA·27 4 (11 ·82)
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 1
`
`
`
`1189434
`
`FIELD OF THE INVENTION
`
`This invention relates to a new improved
`
`gypsum wallboard product and to a novel method of making
`
`the improved gypsum wallboard product. More particu-
`
`5
`
`larly, this invention is directed to a gypsum wallboard
`
`product that is produced using water vapour permeable
`
`synthetic polymeric facing materials enclosing a gypsum
`
`core.
`
`10
`
`Gypsum wallboard is traditionally manufactured
`
`BACKGROUND OF THE INVENTION
`
`by a continuous process wherein a slurry of calcium
`
`sulphate hemihydrate, water, water reducing agents,
`
`bonding agents, set control agents and anti-burning
`
`agents is deposited on a lower, continuously advancing
`
`15
`
`web of paper, and an upper, continuously advancing web
`
`of paper is laid over the slurry. The paper and gypsum
`
`slurry are passed between parallel horizontal upper and
`
`lower forming rolls and integrated into a continuous
`
`flat envelope of paper enclosing the unset gypsum. The
`
`20
`
`continuous product thus formed is conveyed on a
`
`continuous moving belt until the slurry has set. The
`
`strip or sheet is then cut to form boards of prescribed
`
`length, after which they are passed through an oven or
`
`kiln to be dried until the excess water in the gypsum
`
`25
`
`board has evaporated.
`
`In the production of gypsum wallboard it is
`
`customary to use multi-ply paper facing materials which
`
`are generally manufactured from waste paper grades or
`
`other pulp sources, employing conventional papermaking
`
`30
`
`techniques. Wallboard paper liners produced by
`
`-
`
`1 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 2
`
`
`
`1189434
`
`conventional papermaking processes possess a number of
`
`inherent properties or characteristics which detriment(cid:173)
`
`ally affect the final gypsum wallboard product. One
`
`such property is the difference in tensile strength
`
`5
`
`between the machine direction of the paper (the
`
`direction of the paper as it travels through the paper
`
`making machinery) and the cross (lateral) direction
`
`(right angle to the machine direction). Typically the
`
`machine direction tensile strength is three to four
`
`10
`
`times stronger than the cross (lateral) directional
`
`strength. This imbalance of paper strength properties
`
`results in a finished gypsum board product with dis(cid:173)
`
`similar directional strength characteristics. Since a
`
`minimum specification degree of strength must be
`
`15
`
`achieved by the gypsum board, regardless of paper
`
`direction, the board and paper strength requirements are
`
`necessarily determined by their weakest direction. As a
`
`result of this anisotropy of the paper, and in compen(cid:173)
`
`sation of the imbalance, a relatively thick paper liner
`
`20
`
`(thicker than necessary in the in machine-line direc(cid:173)
`
`tion) must be used if minimum strength requirements are
`
`to be met.
`
`A further disadvantage of wallboard paper
`
`liners is their susceptibility to abrasion surface
`
`25
`
`damage on the face of the wallboard due to the rela(cid:173)
`
`tively soft fibrous nature of the cellulosic ingredients
`
`of the paper and to the relatively weak chemical forces
`
`which hold the fibres together. A coating of some type
`
`is always required to increase the resistance of this
`
`30
`
`product to damage after application.
`
`In spite of this
`
`-
`
`2 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 3
`
`
`
`1189434
`
`protective coating, the gypsum wallboard face still has
`
`relatively poor resistance to abrasion and impact force.
`
`This deficiency is most detrimental to the product for
`
`applications in high occupancy buildings such as banks,
`
`5
`
`offices, and the like. To overcome this problem, gypsum
`
`wallboard is commonly covered with a decorative poly(cid:173)
`
`vinylchloride plastic film applied to the gypsum
`
`wallboard surface.
`
`Production of an abrasion and impact resistant
`
`10
`
`wallboard by substituting a plastic film for the wall(cid:173)
`
`board paper liner in the primary manufacturing process
`
`is generally not possible since the plastic film is
`
`impermeable to water vapour thereby making it impossible
`
`to dry the wallboard. Normally, an abrasion resistant,
`
`15
`
`impact resistant, vinyl covered wallboard (known
`
`generically as vinyl board) is produced by a secondary
`
`manufacturing operation in which the decorative vinyl
`
`film is adhesively laminated to the face surface of the
`
`gypsum wallboard. This ancillary operation substan-
`
`20
`
`tially increases the cost of the finished wallboard
`
`product.
`
`The degree with which paper products undergo
`
`changes in physical properties upon adsorption or
`
`absorption of water can also affect the manufacture and
`
`25
`
`use of conventional gypsum board. The manufacturing
`
`process is affected by the adsorbed water content of the
`
`paper being used. This in turn is dependent on several
`
`factors such as time since manufacture, storage
`
`conditions, and the like. The rate of water absorption
`
`30
`
`into the paper from the gypsum slurry is also a function
`
`-
`
`3 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 4
`
`
`
`1189434
`
`of many parameters and is of great importance in the
`
`production of a quality gypsum board product. Paper
`
`expansion due to the effect of the water absorption by
`
`the paper must be taken into account if a gypsum board
`
`5
`
`of correct dimensions is to be obtained. Considerable
`
`effort has been made to overcome these problems using
`
`sizing agents during paper manufacture.
`
`The effect of water adsorption and subsequent
`
`paper expansion also limits the types of applications
`
`10
`
`considered acceptable for some gypsum board products.
`
`Under conditons of high humidity, for example, the use
`
`of a low caliper (9.5 mm) gypsum board for ceiling
`
`applications can result in the gypsum board sagging
`
`between the support structures. One major factor
`
`15
`
`contributing to this effect is the expansion of the
`
`paper liner such that it no longer supports the core.
`
`This problem can be especially serious if the gypsum
`
`board product is held at ceiling level using support
`
`tracking, etc. rather than by direct attachment using
`
`20
`
`nails or screws.
`
`SUMMARY OF THE INVENTION
`
`We have discovered that certain types of water
`
`vapour permeable plastic (synthetic polymeric) film or
`
`sheeting can be used instead of wallboard paper liners
`
`25
`
`to produce a decorative gypsum wallboard with excellent
`
`abrasion, impact and sag resistance properties.
`
`Surprisingly, the plastic films can be used in the
`
`primary gypsum wallboard manufacturing process and the
`
`· wallboard can be satisfactorily dried without detriment
`
`30
`
`to the bond between the plastic facing material and the
`
`-
`
`4 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 5
`
`
`
`gypsum wallboard core. Furthermore, achieving the
`
`production of a gypsum wallboard with a decorative
`
`plastic finish without processing through a secondary
`
`laminating operation has been entirely unexpected to
`
`5
`
`those skilled in the art of wallboard manufacture.
`
`The plastic films comprise a family of spun-
`
`bonded polymers such as poly-olef ins which family is
`
`produced by first spinning continuous strands of the
`
`polymers, such as high-density polyethylene into a very
`
`10
`
`fine, interconnected web of fibres and then bonding the
`
`fibres together with heat and pressure. The product
`
`after bonding displays a good printing or coating
`
`surface, high opacity, and toughness to a degree unique
`
`among sheet or film products of similar weight.
`
`15
`
`The invention is directed to a gypsum wall-
`
`board product which comprises a gypsum core, at least
`
`one side of which is substantially covered by a water
`
`vapour permeable synthetic polymeric web which may be
`
`composed of spunbonded polymeric filament or spunbonded
`
`20
`
`polyolefin filament.
`
`In the product according to the invention., the
`
`polyolef in may be polyethylene and particularly high(cid:173)
`
`. density polyethylene. The spunbonded polyolefin
`
`filament sheeting or film may be a product available
`
`25
`
`from DuPont of Canada Limited in association with the
`
`trade mark TYVEK.
`
`The invention is also directed to a process
`
`for the preparation of a gypsum wallboard product
`
`comprising spreading a fluid gypsum hemihydrate slurry
`
`30
`
`between two substantially parallel vapour permeable
`
`.?
`- -:t- -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 6
`
`
`
`1189434
`
`sheets, at least one of which is synthetic polymer, and
`
`allowing the gypsum hemihydrate to set and bond to the
`
`sheets.
`
`In the process, the product may be passed
`
`through an oven to remove excess water in the gypsum
`
`5
`
`board. The polymeric sheeting or film may be composed
`
`of spunbonded polyolefin filament, for example, high
`
`density polyethylene filament.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`Gypsum wallboard samples were prepared in the
`
`10
`
`laboratory using spunbonded olefin liners. The board
`
`products were evaluated in a number of standard testng
`
`procedures using a regular, paper lined gypsum board as
`
`a control sample.
`
`The following examples demonstrate the
`
`15
`
`properties of this new product and the process by which
`
`it is made.
`
`Example 1
`
`A laboratory board sample 1/2 inch (12.7 mm)
`
`thick was prepared using the spun bonded polyethylene
`
`20
`
`sheeting in the following manner. A piece of Tyvek*
`
`1085 sheeting (spunbonded high density polyethylene} was
`
`cut with dimensions 14-1/2" (368. 3 mm) by 28" ( 711. 2
`
`mm). The specific product used was uncoated Tyvek*, but
`
`other sheeting manufactured in the same manner with the
`
`25
`
`same range of properties would be suitable. This
`
`material was folded and creased at positions 3/4" {19.05
`
`mm) and 1-1/4" (31.75 mm) from each of the 28" edges to
`
`form an envelope similar to that used in the conven(cid:173)
`
`tional gypsum board process. This envelope was then
`
`30
`
`clamped in a laboratory board forming apparatus. A
`
`- 6 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 7
`
`
`
`1189434
`
`piece of liner of dimensions 11-3/4" (298.5 mm) by 28"
`
`(711.2 mm) was also clamped in the laboratory board
`
`forming apparatus such that it would form the back face
`
`of the laboratory board. Double sided adhesive tape was
`
`5
`
`applied to the bottom sheeting along a 3/4" (19.05 mm)
`
`wide strip to come into contact with the upper liner
`
`sheet upon sample preparation.
`
`The slurry to be used in preparation of the
`
`board sample was prepared as follows:
`
`a surfactant foam
`
`10
`
`solution (173 ml at 0.7% by weight Cedepal* FA406
`
`foaming agent) was premixed for one minute using two
`
`Hamilton Beach Scovill Mixers (Model 936-2SA) at high
`
`speed (86.5 ml in each mixer cup). While mixing the
`
`foam, a mixture of calcium sulphate hemihydrate (1563 g)
`
`15
`
`and ground gypsum accelerator (1.13 g) was added to the
`
`bowl of a Hobart* Model N-50 mixer containing 1042 ml of
`
`water, 3.63 g of paper pulp, 1.62 g of Lemar D*
`
`superplasticizer and 11.34 g of starch. The mixture was
`
`stirred at low speed for 2 seconds and the premixed foam
`
`20
`
`was added to the bowl. The entire mixture was stirred
`
`at high speed for 30 seconds. The resultant slurry was
`
`poured onto the bottom sheet of the laboratory board
`
`apparatus and the top sheet rolled into place using a
`
`heavy steel roller.
`
`25
`
`30
`
`Upon setting, the apparatus was dismantled and
`
`the sample was trimmed to a length of 16" (406.4 mm).
`
`This sample was then dried in a circulating air oven at
`
`115°C for 60 minutes, and then at 40°C overnight.
`
`Performance Tests
`
`The laboratory board sample prepared according
`
`* Trade Marks
`
`- 7 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 8
`
`
`
`to the procedure in Example 1 above was compared to a
`
`sample of commercial 12. 7 nun board by performing the
`
`following tests:
`
`Comparison of Spun-bonded Polyethylene Covered
`Gypsum Board to Commercial Gypsum Board
`
`5
`
`Commercial
`Gypsum
`Board
`
`Tyvek*
`1085
`Board
`
`Test
`Method
`Reference
`
`Thickness (mm)
`
`Weight(kg/10om2)
`
`10
`
`Breaking Strength (N)
`Cross
`Machine
`
`Nailhead Pull
`Resistance (N)
`
`Humidified
`Deflection (mm)
`
`12.7
`
`899
`
`225
`776
`
`487
`
`25
`
`12.7
`
`934
`
`250
`250
`
`507
`
`5
`
`15
`
`Impact Resistance
`(joules/mm)
`
`0.356
`
`0.783
`
`Bond (N/76 mm)
`Peak
`Plateau
`
`Durability (mm/100
`revolutions)
`
`35
`13
`
`24.5
`22.0
`
`0.254
`
`0.001
`
`1
`
`1
`
`1
`1
`
`1
`
`1
`
`2
`
`3
`3
`
`4
`
`20
`
`25
`
`30
`
`Reference 1
`
`Test Methods
`
`Canadian Standards Association A82.20.3-M
`
`1977.
`
`Reference 2
`
`Canadian Government Specifications Board
`
`41-GP-24.
`
`Reference 3
`
`Measurements of bond of the liner to the core
`
`were performed by cutting a 3 inch (76.2 mm) wide
`
`* Trade Marks
`
`-
`
`3 _;
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 9
`
`
`
`11.89434
`
`portion of board 12 inches (304.8 mm)
`
`long, scoring one
`
`side, breaking the core and using an Instron testing
`
`apparatus to measure the force required to pull the
`
`liner away from the core at 90°C. The peak value
`
`5
`
`corresponds to the maximum force required, whereas the
`
`plateau value corresponds to the flat section of the
`
`bond strength curve immediately after the peak.
`
`Reference 4
`
`Durability was measured using a Tabor* Abraser
`
`10
`
`equipped with CS-10 abrasion wheels. The measurements
`
`were performed using the 250 g arms as load to the
`
`abrasion wheels. After 1000 revolutions, the samples
`
`were measured using a micrometer at four locations
`
`inside the abrasion ring and four locations immediately
`
`15
`
`adjacent to the abrasion ring. The difference between
`
`the average of these two sets of data was reported.
`
`Example 2
`
`To demonstrate the improved characteristics of
`
`R gypsum board product of reduced thickness, samples
`
`20
`
`were prepared using Tyvek* 1073 sheeting in which the
`
`overall thickness was 6.35 mm.
`
`The procedure used was
`
`the same as outlined in Example l except the spacers in
`
`the moulding table were 6.35 mm thick, the bottom liner
`
`was 35.6 cm wide and creased 19.1 mm and 25.4 mm from
`
`25
`
`each 71.1 cm edge, and the foam solution was added
`
`directly to the water rather than premixing using the
`
`Hamilton Beach mixer.
`
`The board samples produced were then tested
`
`and compared to commercial 12.7 mm board as shown by the
`
`30
`
`following Table. As can be seen from these results, the
`
`* Trade Marks
`
`-
`
`9 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 10
`
`
`
`1189434
`
`spunbonded olefin sheeting product offered several
`
`advantages over the conventional 12.7 mm board. The
`
`data indicates that the product would be suitable for
`
`ceiling tile applications.
`
`5
`
`Comparison of Spun-bonded Polyethylene Covered
`Gypsum Board to Commercial Gypsum Board
`
`Property
`
`Commercial
`Gypsum
`Board
`
`Tyvek*
`1073
`Board
`
`'I'est
`Method
`Reference
`
`(Sample No.)
`
`(A)
`
`( B)
`
`( 1)
`
`( 2)
`
`10
`
`'rhickness (mm)
`
`12.7 12.7 6.35 6.35
`
`Weight(kg/100m2)
`
`899
`
`879
`
`626
`
`804
`
`Breaking Strength (N)
`Cross
`Machine
`
`Nailhead Pull
`Resistance (N)
`
`225
`776
`
`487
`
`103
`
`231
`
`15
`
`Humidified
`Deflection (mm)
`
`18
`
`5
`
`Surface Water
`Resistance (g)
`
`Impact Resistance
`(joules/mm)
`
`2.1
`
`1.1
`
`0.356
`
`0.712
`
`1
`
`1
`
`1
`
`1
`
`1
`
`1
`
`2
`
`20
`
`25
`
`30
`
`Test Methods 1 and 2 as described in Example 1.
`
`As will be apparent to those skilled in the
`
`art in the light of the foregoing disclosure, many
`
`alterations and modifications are possible in the
`
`practice of this invention without departing from the
`
`spirit or scope thereof. Accordingly, the scope of the
`
`invention is to be construed in accordance with the
`
`substance defined by the following claims.
`
`* Trade Marks
`
`- 10 -
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 11
`
`
`
`1189434
`
`The embodiments of the invention in which an
`
`exclusive property or privilege is claimed are defined
`
`as follows:
`
`A gypsum wallboard product which comprises a
`
`gypsum core substantially covered by a water vapour
`
`permeable synthetic polymeric web.
`
`2.
`
`A product as defined in Claim 1 wherein the
`
`polymeric web is spunbonded polymeric filament.
`
`3.
`
`A product as defined in Claim 1 wherein the
`
`polymeric web is spunbonded polyolefin filament.
`
`4.
`
`A product as defined in Claim 3 wherein the
`
`polyolefin is high-density polyethylene.
`
`5.
`
`A product as defined in Claim 4 wherein the
`
`product is intended for use as ceiling tile.
`
`6.
`
`A product as defined in Claim 3, 4 or 5
`
`wherein the spunbonded polyolefin filament web is a
`
`spun bonded polyolefin sheeting or film.
`
`7.
`
`A product as defined in Claim 1, 2 or 3
`
`wherein only one face of the product is composed of
`
`synthetic· polymeric sheeting or film.
`
`8.
`
`A process for the preparation of a gypsum
`
`wallboard product comprising: spreading a fluid gypsum
`
`hemihydrate slurry between two substantially parallel
`
`vapour permeable sheets or film at least one of which is
`
`a synthetic polymer, and allowing the gypsum hemihydrate
`
`to set and bond to the sheets.
`
`9.
`
`A process as defined in Claim 8 wherein the
`
`product is passed through an oven to remove excess water
`
`in the gypsum board.
`
`/(
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 12
`
`
`
`10.
`
`A process as defined in Claim 8 or 9 wherein
`
`the polymeric sheeting or film is of spunbonded
`
`polyolef in filament.
`
`11.
`
`A process as defined in Claim 8 or 9 wherein
`
`the polymeric sheeting or film is of spunbonded
`
`high-density. polyethylene.
`
`BARRIGAR & OYEN
`Patent Agents for
`the Applicant
`#280 - 505 Burrard St.
`Vancouver, B. C.
`V7X 1M3
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 13
`
`
`
`ABSTRACT
`
`This invention relates to a new improved
`
`gypsum wallboard product and to a novel method of making
`
`the improved gypsum wallboard product. The gypsum
`
`wallboard product comprises a gypsum core substantially
`
`enclosed within a water vapour permeable synthetic
`
`polymeric sheeting. The invention also relates to a
`
`process for the preparation of a gypsum wallboard
`
`product comprising spreading a fluid gypsum hemihydrate
`
`slurry between two substantially parallel vapour
`
`permeable polymeric sheets and allowing the gypsum
`
`hemihydrate to set and bond to the sheets.
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 14
`
`
`
`S UBSTITUT,E
`REMPLACEMENT
`there are NO DRAWINGS
`
`il n'y a PAS DE DESSJNS
`
`Louisiana-Pacific Corporation, Exhibit 1025
`IPR of U.S. Pat. No. 8,474,197
`Page 15
`
`
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