GB2068268A

GB2068268A - Liquid paste coating apparatus

Info

Publication number: GB2068268A
Application number: GB8003446A
Authority: GB
Original assignee: Isowa Industry Co Ltd
Current assignee: Isowa Corp
Priority date: 1980-02-01
Filing date: 1980-02-01
Publication date: 1981-08-12
Also published as: GB2068268B

Abstract

A device for spreading paste on paperboard comprises a supplier for supplying liquid paste 21, a roller 3 for spreading the liquid paste on crests of core paper CP to be pasted with linerboard LB a member for controlling the volume of the liquid paste, a paste-feeding member 4 provided under the supplier downwardly inclinedly toward the paste- spreading roller to define a passage for the liquid paste, at least a pair of movable end plates 11 provided in the forward end of the paste- feeding member and defining a certain clearance between the upper surfaces thereof and the paste- spreading roller 3, and a feed portion defined by the end plates to communicate with the passage. The width of the feed portion is adjustable by movement of the end plates in conformity with the width of the core paper CP between minimum effective width and maximum effective width. <IMAGE>

Description

SPECIFICATION Device for spreading paste on paperboard in a corrugated board manufacturing apparatus The present invention relates to a device for spreading paste on paperboard in a corrugated board manufacturing apparatus, and more particularly, to a device for spreading paste on crests of core paper corrugatedly supplied from a pair of stepped heating rollers to be pasted with linerboard.

In a conventional corrugated board manufacturing apparatus, pasting for core paper is conducted by a roll turning system in which liquid paste having low viscosity is taken up by dipping by a paste-spreading roller to be spread on crests of the corrugated core paper, which is then pasted with linerboard. Therefore, it has been desired that the liquid paste spread on the crests of the corrugation is impasted to gel to have high viscosity by heat from the stepped heating rollers while the core paper is moved toward the linerboard.

However, in a conventional device, a predetermined volume of the liquid paste is constantly stored in a tank placed in the vicinity of the stepped rollers, and therefore the liquid paste is exposed to heat radiation from the stepped rollers, leading to gelation and deterioration of the paste which cannot be satisfactorily taken up by dipping by the pastespreading roller.

Further, the effective width of the pastespreading roller is in conformity with the maximum width in varieties of sizes of the core paper, and thus, in case the outer periphery of the paste-spreading roller is continuously in contact with the liquid paste stored in the tank, the roller takes up the liquid paste by dipping in full width thereof during rotation. Because of this, when core paper which is smaller in width than the paste-spreading roller is used, excessive paste runs over both sides of the core paper leading to inferior pasting of the core paper, spreading of the paste to the outer peripheries of the stepped rollers and a press roller, sticking of the core paper and the linerboard to the rollers and exfoliation and breakage of the core paper and the linerboard.

In consideration of the disadvantage, there has been provided a device in which a pair of partitions are movably placed in the paste tank to adjust the width of the paste-spreading roller which is in contact with the liquid paste stored in the tank in conformity with the width of the core paper to be pasted (Japanese utility model publication No. 41-21028).

In this device, however, the liquid paste stored between the partitions is still exposed to heat radiation from the stepped rollers, resulting in deterioration of the paste, and further, tends to run over the partitions to be spread on the outer peripheries of the rollers, resulting in exfoliation and breakage of the core paper and the linerboard.

The object of the present invention is to overcome the aforementioned disadvantages of the prior art by providing a device for spreading paste on core paper in a corrugated board manufacturing apparatus which can prevent deterioration of the paste by heat and improper spreading of the paste on the core paper and spread the minimum required volume of the paste having appropriate properties on the core paper to facilitate efficient manufacturing of corrugated board of good quality.

In the device according to the present invention, liquid paste is continuously fed from a supplier such as a pump and a nozzle and flows through an inclined passage downwardly into a feeding portion at which a continuously rotating paste-spreading roller takes up the paste by dipping. Since the paste is in a flowing condition, no deterioration such as gelation will occur in the paste even if the same is exposed to heat radiation from stepped rollers for corrugatedly moulding the core paper.

Further, the feeding portion provided in the forward end of the passage includes a pair of feeding end plates which are movable with respect to the axial centre of the paste-spreading roller for adjusting the width of the feeding portion in conformity with that of the core paper to be pasted. Therefore, the device according to the present invention can be applied to various sizes of core paper with minimum required volume of the paste, and thereby prevents excessive spreading of the paste on the core paper and the outer peripheries of rollers, and further preserves the core paper and the linerboard from breakage.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a roughly illustrated side elevational view of a corrugated board manufacturing apparatus to which a paste-spreading device according to the present invention is applied; Figure 2 is a longitudinal cross sectional view on a larger scale of the paste-spreading device; Figure 3 is a partially fragmentary cross sectional view taken along the lines Ill-Ill in Fig. 2; Figure 4 is an illustrative top plan view showing members provided in the vicinity of the core paper; Figure 5 is a transverse cross sectional view showing a modification of the paste-feeding members; Figure 6 is a transverse cross sectional view showing another modification of the pastefeeding members; and Figure 7 is a perspective view showing still another modification of the paste feeding members.

Referring to Fig. 1 of the drawings, there is shown a corrugated board manufacturing apparatus which includes a press roller 1 for supplying linerboard LB, a pair of stepped heating rollers 2 for supplying core paper CP while corrugatedly moulding the same and a base plate 4 for feeding liquid paste P (Fig.

2). The base plate 4 is formed by a rectangular flat plate which is greater in width than a paste-spreading roller 3 oppositely provided against one of the stepped rollers 2. As shown in Fig. 2, the base plate 4 is supported by a pair of unevenly parallel supporting shafts 5 and 6 located along the axial direction of the paste-spreading roller 3 through a pair of brackets 7, and is downwardly inclined toward the paste-spreading roller 3. At the centre of the forward end of the base plate 4, there is provided a feed plate 8 having effective width E2 for the paste P along the axial centre of the paste spreading roller 3 and downwardly inclinedly extending below the roller 3 (see also Fig. 4).

A pair of side plates 9 are provided symmetrically about the longitudinal axis of the base plate 4 so that they are movable in contact with the upper end thereof. Each of the side plates 9 is formed by an extremely thin flat plate, the thickness of which is, for example, 0.5 mm. Along the longitudinal outer sides of the side plates 9, there are provided a pair of side walls 10 for preventing leakage of the liquid paste P, and plates extending from the forward ends of the side walls 10 and each having three open end portions which form feeding end plates 11.

Each of the feeding end plates 11 has an effective width E 1 which is half the size of that of the feed plate 8 and extends under the paste-spreading roller 3 defining a certain clearance C of, for example 2 mm between the upper surface thereof and the outer periphery of the roller 3 (See Fig. 2). The outer open end of each feeding end plate 11 functions as a release portion 1 2 for the liquid paste P.

As shown in Fig. 4, a passage 1 3 for the liquid paste P defined by the base plate 4 and the side plates 9 and a feeding portion 14 formed by the feed plate 8 and the feeding end plates 11 are identical in width, which is adjustable between minimum width W 1 in which the side plates 9 are fully closed about the centre of maximum effective outer surface O of the paste-spreading roller 3 and maximum width W2 in which the side plates 9 are fully opened in conformity with the varieties of the core paper CP between the minimum width W 1 and the maximum width W2.

Since, when the side plates 9 are fully opened, parts of the feed plate 8 and each feeding end plate 11 are overlapped, the effective width E2 of the feed plate 8 is shorter than its actual length, and the effective width E 1 of each feeding end plate 11 is identical with the actual length thereof.

Further, since one of the supporting shafts 6 is vertically movable, the angle of the base plate 4 and the side plates 9 and the width of the clearance C are respectively adjustable.

A support 1 5 and a press member 16 are placed in contact with the lower and the upper surfaces of each side plate 9 respectively for proper location thereof and are connected with each other by a bolt. An extension 1 7 provided integrally with the support 1 5 is projected under the rear end of the base plate 4 to be tightened by a clamp screw 1 8 having a lever 1 9 to fix the side plate 9 in the predetermined position. By virtue of this, each side plate 9 is replaceably provided with respect to the base plate 4 and is smoothly slidable in any direction by guidance of the support 15.

A pump 21 is provided above the rear end of the base plate 4 to continuously pump up the liquid paste P from a tank 20 which is separately provided under the stepped rollers 2 and to supply the liquid paste P to the base plate 4 and the side plates 9 from a nozzle 22 downwardly extending therefrom. The nozzle 22 is, for example, rectangular in section and smoothly curved in the longitudinal direction and a port 23 thereof is faced transversely to the passage 1 3. A cover 24 of proper size is replaceably mounted to the port 23 at need, to adjust the width of the port 23.

A receptacle 25 is provided under the paste-spreading roller 3 and the forward end of the base plate 4 to collect the liquid paste P falling from the feed plate 8 and the feeding end plates 11 and return the same to the tank 20 through a pipe 26. The receptacle 25 may be in the form of a funnel.

A roller 27 is provided to face the pastespreading roller 3, and the space therebetween is adjustable to control the volume of the liquid paste P with respect to the core paper CP.

Such control of the volume of the liquid paste P, adjustment of inclination of the base plate 4 and adjustment of movement of the side plates 9 are all achieved based on graduations.

In operation with narrow core paper satisfactory pasting of which is difficult to achieve and of which the width is the minimum width W 1, each clamp screw 1 8 is loosened and then tightened to fully close the side plates 9 and conform the passage 1 3 and the feeding portion 14 to the minimum width W 1. In this condition, the liquid paste P supplied from the nozzle 22 to the rear ends of the side plates 9~ by continuing operation of the pump 21 flows down through the passage 1 3 into the feeding portion 14.

Following the aforementioned setting of the effective width of the feeding portion 14, the effective minimum width 0 1 of the outer surface 0 of the paste-spreading roller 3 is determined, and thus the paste-spreading roller 3 rotating reversely to the direction of flow of the liquid paste P continuously dips up the liquid paste P flowing into the feeding portion 14 within the range of the minimum width 0 1 of the outer surface 0 thereof.

In such operation, unused liquid paste P falls from the feeding end plates 11 into the receptacle 25 to be returned to the tank 20.

When excess volume of the liquid paste P flows into the feeding portion 14, the overflown paste is discharged from the release portion 1 2 of each feeding end plate 11 into the receptacle 25 so that the liquid paste P in the feeding portion 14 is continuously kept at a fixed volume and ceaselessly keeps flowing.

Under this condition, the paste-spreading roller 3 smoothly takes up by dipping the required minimum volume of the liquid paste P.

The liquid paste P thus dipped up is controlled in volume while passing through the roller 27 and fed to the paste spreading roller 3, and uniformly spread successively to the tops tof the core paper CP corrugatedly moulded by the stepped rollers 2.

Then the crests tand the linerboard LB are pasted with each other to form single corrugated board of good quality.

The liquid paste P falling from the roller 27 is returned to the side plates 9 and reused.

In operation with core paper having the maximum width W2, the side plates 9 are fully opened so that the passage 1 3 defined by the side plates 9 and the base plate 4 and the feeding portion 14 defined by the feeding end plates 11 and the feed plate 8 are in conformity with the maximum effective width W2.

In this condition, the liquid paste P supplied from the nozzle 22 flows through the passage 1 3 into the feeding portion 1 4 to be continuously dipped up by the paste-spreading roller 3 within the maximum width W2 and spread successively to the crests t of the corrugated core paper CP.

Thus, the width of passage 1 3 defined by the side plates 9 is determined so that the feeding portion 1 4 is aligned in effective width with the core paper CP, leading to smooth and uniform pasting by the pastespreading roller 3.

Attention is now drawn to Figs. 5 to 7, in which modifications of the paste-feeding members are shown.

In Fig. 5, the base plate 4 is provided thereon with a pair of inner side plates 9A and a pair of outer side plates 9B having the side walls 10 is superposed on the inner side plates 9A. The inner and outer side plates 9A and 9B are both slidable along the base plate 4 with respect to the axial centre of the pastespreading roller 3 and can be overlapped with each other to adjust the effective width of the feeding portion 14.

In Fig. 6, there are provided side plates 9 and 9' each having one of the side walls 10, the side plates 9 and 9' being different in width and overlappingly slidable to adjust the effective width, with respect to the passage 1 3 defined by the side plates 9 and 9' and the feeding portion 1 4 defined by the feeding end plates 11, between the minimum in the fully-closed condition as shown in full lines and the maximum in the fully-opened condition as shown in phantom lines.

Further, in Fig. 7, there are provided a trapezoidal stationary plate 9C having the side walls 10 and defining the passage 13, a feed plate 8' secured to the forward end of the plate 9C and a pair of feeding end plates 11' slidably mounted op the feed plate 8' to define the feeding portion 1 4 communicating with the passage 1 3. The end plates 11' have blocks 28 at the forward outer ends thereof to define the release portions 1 2.

In either of the aforementioned modifications, a means such as a slit and a bolt, a dovetail and a bolt and a turnbuckle having a handle can be employed for proper location of the side plates 9A, 9B, 9 and 9' and the movable feeding end plates 11'.

Further, the device according to the present invention can be used for various kinds of composition board other than the single side corrugated board.

While the invention has been described with reference to a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the scope of this invention which is defined by the appended claims.

Claims

1. In a corrugated board manufacturing apparatus, a device for spreading paste on crests of corrugated core paper to be pasted with linerboard, said device comprising, a supplier for supplying liquid paste; a roller spacedly provided from said supplier to face to said crests of said core paper for spreading said liquid paste thereon; a means provided opposite to said paste-spreading roller for controlling the volume of said liquid paste; a paste-feeding means provided under said supplier downwardly inclinedly toward said pastespreading roller to define a passage for continuously flowing said liquid paste supplied from said supplier; at least a paiiof end plates oppositely provided in the forward end of said paste-feeding means defining a certain clearance between the upper surfaces thereof and said paste-spreading roller, said end plates being movable with respect to the axial central of said paste-spreading roller; and a feed portion defined by said end plates and communicating with said passage, the width of said feed portion being adjustable by move ment of said end plates in conformity with the width of said core paper between minimum effective width and maximum effective width.

2. A device as claimed in claim 1 wherein said feed portion is further defined by a plate provided at the centre of the forward end of said paste-feeding means to communicate with said passage, said pair of end plates being slidably mounted on said plate.

3. A device as claimed in claim 1 or 2, wherein said paste-feeding means comprises a rectangular flat base plate and side plates provided on both sides of said base plate symmetrically about the longitudinal axis thereof, and said passage is defined by said flat base plate and said side plates.

4. A device as claimed in claim 3, wherein said side plates are movable in contact with the upper end of said base plate, and are provided with a pair of side walls along the longitudinal outer sides thereof.

5. A device as claimed in claim 3 or 4 wherein said base plate is supported by a pair of unevenly parallel supporting shafts through a pair of brackets.

6. A device as claimed in claim 1, wherein said paste-feeding means comprises a rectangular flat base plate, a pair of inner side plates provided on both sides of said base plate, and a pair of outer side plates superposed on said inner side plates, said inner and outer side plates being both slidable along said base plate to be overlapped with each other to adjust said width of said feed portion.

7. A device as claimed in claim 1, wherein said paste-feeding means comprises a pair of plates which are different in width and overlappingly slidable to adjust said effective width with respect to said passage and said feed portion both defined by said plates.

8. A device as claimed in claim 1, wherein said paste-feeding means comprises a stationary plate defining said passage, and said feed portion is further defined by a plate provided at the forward end of said stationary plate to communicate with said passage, said pair of end plates being slidably mounted on said feed-portion defining plate.

9. A device as claimed, in any one of the preceding claims, further including a tank connected to said supplier for storing said liquid paste, a receptacle provided under said paste-spreading roller and said feed portion for collecting said liquid paste falling from therebetween, and a pipe connecting said receptacle to said tank for returning said collected liquid paste to said tank.

10. In a corrugated board manufacturing apparatus, a device for spreading paste on crests of corrugated paper to be pasted with linerboard, said device being substantially as hereinbefore described with reference to Figs.

1 to 4 of the accompanying drawings.

11. In a corrugated board manufacturing apparatus, a device for spreading paste on crests of corrugated paper to be pasted with linerboard,said device being substantially as hereinbefore described with reference to Figs.

1 to 4 as modified by Fig. 5 of the accompanying drawings.

1 2. In a corrugated board manufacturing apparatus, a device for spreading paste on crests of corrugated paper to be pasted with linerboard, said device being substantially as hereinbefore described with reference to Figs.

1 to 4 as modified by Fig. 6 of the accompanying drawings.

1 3. In a corrugated board manufacturing apparatus, a device for spreading paste on crests of corrugated paper to be pasted with linerboard, said device being substantially as hereinbefore described with reference to Figs.

1 to 4 as modified by Fig. 7 of the accompanying drawings.