| WO1994016144A1 | 1994-07-21 | |||
| WO1995016070A1 | 1995-06-15 |
| EP0606524A1 | 1994-07-20 | |||
| EP0122701A1 | 1984-10-24 | |||
| EP0389404A2 | 1990-09-26 |
| 1. | A forming apparatus for forming a web from a primary, a secondary, and a further source of stock, said apparatus comprising: a looped fourdrinier wire having an upstream and a downstream end; a primary headbox disposed adjacent to said upstream end of said fourdrinier wire for ejecting the stock from the primary source of stock onto said fourdrinier wire between said ends thereof so that a first ply of the web is disposed on said fourdrinier wire; a twin wire former disposed downstream relative to said primary headbox; said twin wire former including: a first and a second looped wire which cooperate with each other to define therebetween a twin wire forming section; said first wire also defining a preforming zone disposed upstream relative to said twin wire forming section; a secondary headbox disposed adjacent to said preforming zone for ejecting the stock from the secondary source of stock so that a second ply of the web is disposed on said preforming zone, the arrangement being such that said second ply is carried by said second looped wire toward and onto said first ply disposed on said fourdrinier wire; a further looped wire disposed downstream relative to said twin wire former, said further wire cooperating with said fourdrinier wire for forming therebetween a further forming section; and a further secondary head box disposed adjacent to said fourdrinier wire and upstream relative to said further forming section for ejecting stock from the further source of stock so that a third ply of the web is disposed on said second ply. |
| 2. | A forming apparatus as set forth in claim 1, wherein said looped fourdrinier wire defines an initial dewatering zone between said primary headbox and said twin wire former. |
| 3. | A forming apparatus as set forth in claim 1, wherein said twin wire former further includes: at least one vacuum auto slice disposed within said second looped wire. |
| 4. | A forming apparatus as set forth in claim 1, wherein said preforming zone is of generally linear configuration. |
| 5. | A forming apparatus as set forth in claim 1, wherein said twin wire forming section is of curved configuration. |
| 6. | A forming apparatus as set forth in claim 1, wherein said twin wire forming section is of curved configuration, said twin wire forming section curving from said preforming zone in a direction toward said fourdrinier wire. |
| 7. | A forming apparatus as set forth in claim 1, wherein said twin wire forming section is of curved configuration, said twin wire section curving from said preforming zone toward said fourdrinier wire, said twin wire forming section having a radius of curvature which progressively decreases from said preforming zone toward said fourdrinier wire. |
| 8. | A forming apparatus as set forth in claim 1, wherein said twin wire former further includes: a roll disposed within said second looped wire, the arrangement being such that said second looped wire is guided by said roll toward said fourdrinier wire so that said second ply is brought into intimate contact with said first ply disposed on said fourdrinier wire. |
| 9. | A forming apparatus as set forth in claim 1, further including: a curved inverted vacuum box disposed within said further looped wire. |
| 10. | A forming apparatus as set forth in claim 9, wherein said curved inverted vacuum box defines a curved surface for guiding said fourdrinier wire and said further looped wire away from said further looped wire and subsequently downstream, in a direction towards said further looped wire. |
| 11. | A forming apparatus for forming a web from a primary, a secondary, and a further source of stock, said apparatus comprising: a looped fourdrinier wire having an upstream and a downstream end; a primary head box disposed adjacent to said upstream end of said fourdrinier wire for ejecting the stock from the primary source of stock onto said fourdrinier wire between said ends thereof so that a first ply of the web is disposed on said fourdrinier wire; a twin wire former disposed downstream relative to said primary head box; said twin wire former including: a first and a second looped wire which cooperate with each other to define therebetween a twin wire forming section; said first wire also defining a preforming zone disposed upstream relative to said twin wire forming section; a secondary head box disposed adjacent to said preforming zone for ejecting the stock from the secondary source of stock so that a second ply of the web is disposed on said preforming zone, the arrangement being such that said second ply is carried by said second looped wire toward and onto said first ply disposed on said fourdrinier wire; a further looped wire disposed downstream relative to said twin wire former, said further wire cooperating with said fourdrinier wire for forming therebetween a further forming section; a further secondary headbox disposed adjacent to said fourdrinier wire and upstream relative to said further forming section for ejecting stock from the further source of stock so that a third ply of the web is disposed on said second ply; and a roll disposed within said second looped wire for guiding said second wire and said second ply into contact with said first ply. |
| 12. | 1 2. A method for forming a web from a primary, a secondary, and a further source of stock, said method comprising the steps of: ejecting the stock from the primary source of stock onto a fourdrinier wire so that a first ply of the web is disposed on the fourdrinier wire; ejecting the stock from the secondary source of stock so that a second ply of the web is disposed on a preforming zone defined by a first wire of a twin wire former, the twin wire former also including a second wire such that the first and second wires of the twin wire former define therebetween a twin wire forming section, the second ply being carried by the second wire towards and onto the first ply disposed on the fourdrinier wire; and ejecting stock from the further source of stock onto the second ply, the arrangement being such that a further looped wire disposed downstream relative to the twin wire former and the fourdrinier wire cooperate together to form therebetween a further forming section. |
The BelLiner former developed and sold by Beloit Corporation is a twin wire former for forming a second ply on a first ply formed on a fourdrinier wire. BelLiner is a common law mark of Beloit Corporation.
The BelLiner former has met with considerable success in the application of a middle ply particularly with low freeness furnish.
The present invention enables the use of higher freeness stock in the formation of a middle or second ply.
More specifically, the BelLiner former is a high basis weight capacity former and Applicant has discovered that when the BelLiner arrangement is provided with a preforming section, such an arrangement can be used for forming a second ply from high freeness furnish.
Additionally, when applying the aforementioned concept to an existing fourdrinier wire, the length of the initial dewatering zone of the fourdrinier wire was extended by reversing and rearranging the configuration of the BelLiner relative to the fourdrinier wire.
Therefore, it is the primary object of the present invention to provide a former which is particularly useful for forming a middle ply from higher freeness furnish.
Other improvements and advantages of the present invention will be readily apparent to those skilled in the art by referring to the detailed description contained hereinafter taken in conjunction with the annexed drawing.
SUMMARY OF THE INVENTION The present invention relates to a forming apparatus and method for forming a web from a primary, a secondary, and a further source of stock.
The apparatus includes a looped fourdrinier wire having an upstream and a downstream end.
A primary head box is disposed adjacent to the upstream end of the fourdrinier wire for ejecting the stock from the primary source of stock onto the fourdrinier wire between the ends thereof so that a first ply of the web is disposed on the fourdrinier wire.
A twin wire former is disposed downstream relative to the primary headbox, the twin wire former including a first and a second looped wire which cooperate with each other to define therebetween a twin wire forming section.
The first wire also defines a preforming zone which is disposed upstream relative to the twin wire forming section.
A secondary headbox is disposed adjacent to the preforming zone for ejecting the stock from the secondary source of stock so that a second ply of the web is disposed on the preforming zone. The arrangement is such that the second ply is carried by the second looped wire towards and onto the first ply disposed on the fourdrinier wire.
A further looped wire is disposed downstream relative to the twin wire former, the further wire cooperating with the fourdrinier wire for forming therebetween a further forming section.
A further secondary headbox is disposed adjacent to the fourdrinier wire and upstream relative to the further forming section for ejecting stock from the further source of stock so that a third ply of the web is disposed on the second ply.
In a more specific embodiment of the present invention, the looped fourdrinier wire defines an initial dewatering zone between the primary headbox and the twin wire former.
Also, the twin wire former further includes at least one vacuum auto slice which is disposed within the second looped wire.
The preforming zone is of generally linear configuration and the twin wire forming section is of curved configuration.
More specifically, the twin wire forming section curves from the preforming zone in a direction toward the fourdrinier wire.
In a specific embodiment of the invention, the twin wire forming section has a radius of curvature which progressively decreases from the preforming zone toward the fourdrinier wire.
The twin wire former further includes a roll which is disposed within the second looped wire. The arrangement is such that the second looped wire is guided by the roll towards the fourdrinier wire so that the second ply is brought into intimate contact with the first ply disposed on the fourdrinier wire.
A curved inverted vacuum box is disposed within the further looped wire, the arrangement being such that both the fourdrinier wire and the further looped wire are guided initially away from the further looped wire and subsequently downstream in a direction back towards the further looped wire.
Many modifications and variations of the present invention will be readily apparent to those skilled in the art by a careful consideration of the detailed description contained hereinafter taken in conjunction with the annexed drawings. However, such modifications and variations fall within the spirit and scope of the present invention as defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING Fig. 1 is a side elevational view of the former apparatus according to the present invention.
DETAILED DESCRIPTION OF THE DRAWING Fig. 1 is a side elevational view of a forming apparatus generally designated 10 for forming a web W from a primary, a secondary and a further source of stock 12, 14 & 16, respectively. The apparatus 10 includes a looped fourdrinier wire 18 having an upstream and a downstream end 20 and 22, respectively.
A primary headbox 24 is disposed adjacent to the upstream end 20 of the fourdrinier wire 18 for ejecting the stock from the primary source of stock 12 onto the fourdrinier wire 18 between the ends 20 and 22 thereof so that a first ply 26 of the web is disposed on the fourdrinier wire 18.
A twin wire former generally designated 28 is disposed downstream relative to the primary headbox 24.
The twin wire former 28 includes a first and a second looped wire 30 and 32, respectively which cooperate with each other to define therebetween a twin wire forming section 34.
The first wire 30 also defines a preforming zone 36 disposed upstream relative to the twin wire forming section 34.
A secondary headbox 38 is disposed adjacent to the preforming zone 36 for ejecting the stock from the secondary source of stock 14 so that a second ply 40 of the web W is disposed on the preforming zone 36. The arrangement is such that the second ply 40 is carried by the second looped wire 32 towards and onto the first ply 26 disposed on the fourdrinier wire 18.
A further looped wire 42 is disposed downstream relative to the twin wire former 28.
The further wire 42 cooperates with the fourdrinier wire 18 for forming therebetween a further forming section 44.
A further secondary head box 46 is disposed adjacent to the fourdrinier wire 18 and upstream relative to the further forming section 44 for ejecting stock from the further source of stock 16 so that a third ply 48 of the web is disposed on the second ply 40.
As shown in Fig. 1, the looped fourdrinier wire 18 defines an initial dewatering zone 50 disposed between the primary headbox 24 and the twin wire former 28.
Additionally, the twin wire former 28 includes at least one vacuum auto slice 52 which is disposed within the second looped wire 32.
The preforming zone 36 is of generally linear configuration.
The twin wire forming section 34 is of curved configuration with the twin wire forming section 34 curving from the preforming zone 36 in a direction as indicated by the arrow 54 towards the fourdrinier wire 18.
The twin wire forming section 28 includes a radius of curvature which progressively decreases from the preforming zone 36 towards the fourdrinier wire 18.
A roll 56 is disposed within the second looped wire 32 so that the second looped wire 32 is guided by the roll 56 towards the fourdrinier wire 18 so that the second ply 40 is brought into intimate contact with the first ply 26 disposed on the fourdrinier wire 18.
A curved inverted vacuum box 58 is disposed within the further looped wire 42. The arrangement is such that both the fourdrinier wire 18 and the further looped wire 42 are guided initially away from the further looped wire 42 and subsequently downstream in a direction towards the further looped wire 42 for further assisting the bonding of the third ply 48 onto the second ply 40. The arrangement is such that the second ply 40 is sandwiched between the first ply 26 and the third ply 48 so that a multi- ply web W is formed by the former 10.
In the operation of the forming apparatus 10 a web is formed from a primary, a secondary, and a further source of stock. The method includes the steps of 1) ejecting the stock from the primary source of stock 12 onto the fourdrinier wire 18 so that the first ply 26 of the web W is disposed on the fourdrinier wire 18; 2) ejecting the stock from the secondary source of stock 14 so that the second ply 40 of the web is disposed on the preforming zone 36 defined by the first wire 30 of the twin wire former 28.
The twin wire former 28 also includes the second wire 32 such that the first and second wires of the twin wire former 28 define therebetween the twin wire forming section 34, the second ply 40 being carried by the second loop wire 32 towards and onto the first ply 26 disposed on the fourdrinier wire 18; 3) ejecting stock from the further source of stock 16 onto the second ply 40, the arrangement being such that the further looped wire 42 disposed downstream to the twin wire former 28 and the fourdrinier wire 18 cooperate together for forming therebetween the further forming section 44.
The present invention permits the manufacture of a multi-ply board from higher freeness furnish while maintaining the length of an initial dewatering zone.