US3587153A

US3587153A - Applicator

Info

Publication number: US3587153A
Application number: US871710A
Authority: US
Inventors: Charles Blickenderfer Jr; Harold E Erickson; Charles C Clapp
Original assignee: Weyerhaeuser Co
Current assignee: Weyerhaeuser Co
Priority date: 1965-08-20
Filing date: 1969-11-20
Publication date: 1971-06-28
Anticipated expiration: 1988-06-28
Also published as: DE1528154A1

Abstract

AN APPLICATOR APPARATUS FOR PLACING A PRDETERMINED AMOUNT OF MATERIAL EVENLY OVER AN UNEVEN SURFACE. THE APPLICATOR ROLL HAS A COVERING OF RESILIENT MATERIAL. THIS MATERIAL HAS AN OUTER BARRIER SURFACE AND AN INITIAL SHORE DUROMETER OF 60 OR LESS ON THE 00 SCALE. PREFERABLY, IT IS BETWEEN 60 AND

14 ON THE 00 SCALE. THE TRANSFER ROLLS ARE OF HARD MATERIAL. THE TRANSFER ROLL AND THE APPLICATOR ROLL BOTH ROTATE IN THE SAME DIRECTION CAUSING A SLIDING CONTACT BETWEEN THE ROLLS.

Description

United States Patent Inventors Charles Blickenderfer, Jr.

Puyallup; Harold E. Erickson, Federal Way; Charles C. Clapp, Tacoma, Wash.

Appl. No. 871,710

Filed Nov. 20, 1969 Patented June 28, 1971 Assignee Weyerhaeuser Company, Tacoma, Wash.

Continuation 01 application Ser. No. 7 746,694, July 2, 1968, now abandoned which is a continuation of application Ser. No. 481,305, Aug. 20, 1965, now abandoned.

APPLICATOR 12 Claims, 3 Drawing Figs.

US. Cl 29/132 1nt.CI B21b 31/08 Field of Search 29/ 1 30 Primary Examiner-Alfred R. Guest Attorneys.lohn M. Crawford and Patrick D. Coogan ABSTRACT: An applicator apparatus for placing a predetermined amount of material evenly over an uneven surface. The applicator roll has a covering of resilient material. This material has an outer barrier surface and an initial Shore Durometer of 60 or less on the 00 scale. Preferably, it is between 60 and 15 on the 00 scale. The transfer rolls are of hard material. The transfer roll and the applicator roll both rotate in the same direction causing a sliding contact between the rolls.

APPLICATOR Related Cases This is a continuation of application Ser. No. 764,694 filed July 2, 1968, which is a continuation of application Ser. No. 481,305, filed Aug. 20, I965 both abandoned.

This invention relates to an apparatus for applying adhesives and other materials to surfaces having varying thicknesses and varying surface characteristics, and specifically relates to an apparatus for applying adhesives to wood veneer sheets.

In the manufacture of plywood there are several requirements for the application of an adhesive to a veneer sheet.

The first requirement is that a metered quantity of adhesive be placed on the veneer sheet. The adhesives normally used are costly and any excessive adhesive that is used will result in a higher cost of plywood produced from the veneer.

An excess amount of adhesive on the veneers will also result in longer press times. The veneers are formed into plywood by being formed into unadhered crossed grain laminae and then being placed into a press which holds the veneers together and heats the veneers to set the adhesive and bond the veneers together. An excessive amount of adhesive will require a longer period of heating to activate the adhesive and remove moisture from the liquid adhesive. This also will result in greater costs in the manufacture of plywood.

Another requirement is to apply the adhesive over the entire surface of the veneer. This is difficult because the veneer has a tendency to curl, and also has surface irregularities such as knots which may protrude above'its surface. Therefore, it is necessary to have an applicator roll which will conform quickly to the varying surface characteristics of the veneer passing beneath it.

Therefore, it is an object of the present invention to provide an apparatus which will place a predetermined amount of material evenly over the entire surface of the object passing beneath it. It is a further object of this invention to provide an apparatus that can place material on the uneven surfaces and upon objects having varying thickness. It is a specific object of this invention to provide an adhesive applicator that will place a predetermined amount of adhesive evenly over the entire surface of a veneer sheet.

These and other objects will become readily apparent upon a reading of the following specification in conjunction with the attached drawings. While the apparatus will be discussed in conjunction with a specific application to veneer, it is obvious that the apparatus has broader application.

FIG. 1 is a perspective view of the applicator apparatus including the applicator roll.

FIG. 2 is a side elevational view partially in section showing the apparatus of FIG. 1.

FIG. 3 is a side elevational view partially in section showing the apparatus of FIGS. 1 and 2 modified for use in a conventional adhesive applicator in which both the top and bottom faces of core stock are glued simultaneously as it passes between the two applicator rolls.

The apparatus shown in FIGS. 1 and 2 is used to place adhesive on the upper face of veneer V passing on a conveyor beneath the applicator roll 10. The distance between the con veyor surface and the lower surface of the applicator roll allows the roll to contact the veneer passing beneath it. Usually, the roll would be adjusted to rest on the conveyor if no material is passing beneath it. The applicator roll has a central core 11, preferably of metal, which is covered with a resilient material 12.

The resilient material 12 must be capable of conforming quickly to the surface characteristics of the veneer passing beneath it so that the adhesive on the roll will be applied to substantially all of the veneer sheet passing beneath it. The material 12 must also have an outer barrier surface so that the portion of the applicator roll contacting the veneer sheet will have only a predetermined amount of adhesive thereon and will impart only a predetermined amount of adhesive to the surface of the veneer. It has been found that materials having these characteristics have an initial Shore durometer of 60 or less on the 00 scale and usually have a closed cell structure. Materials having an initial Shore durometer of under 60 on the 00 scale are preferred because of their better resiliency. The material most suitable for this application is a flexible, expanded modified polyvinyl chloride closed cell material having an initial Shore durometer of between 15 and 30 on the 00 scale. The material should be at least %thick.

The material 12 is attached to the core 11 with a cover adhesive 13. The materials of the cover and the core and the material being applied will determine the cover adhesive to be used. The cover adhesive should be one that is compatible with the materials forming the cover 12 and the core 11' so that the cover can be adhered to the core, and is compatible with the adhesive being applied to the veneer so that it will not be removed or otherwise be rendered nonadhering by the veneer adhesive.

The veneer adhesive is placed on the veneer by the applicator roll 10. The roll, which has a shaft 14 that is rotatably mounted in bearings 15, rotates in the same direction as the veneer passing beneath it and at a peripheral speed that is equal to the lineal speed of this veneer. Thus, the covering 12 contacts and presses down on the veneer to conform to the surface of the veneer and place the adhesive on this surface.

The veneer adhesive is spread on the applicator roll 10 by a metering roll 16, one of a pair of

metering rolls

16 and 17. Preferably these rolls have a solid metal core which is covered with a hard rubber. However, one or both of the rolls could be entirely of metal. These rolls have shafts l8 and 19 which are rotatably mounted in their

respective bearings

20 and 21.

The spreading of the veneer adhesive onthe applicator roll 10 by the metering roll 16 is caused by the two rolls rotating in the same direction so that they are moving in opposite directions at their point of contact, resulting in a sliding contact between the rolls. The metering rolls pick up adhesive as they move downwardly through the adhesive pool 22 or out of the pan 27 and carry a film outwardly from beneath the nip. It is obvious that the pan 27 may also be used in conjunction with the rolls I7 and 17a.

The predetermined amount of adhesive imparted to the veneer will depend upon the viscosity or flowability of the adhesive, and on the spacing between the metering rolls I6 and 17, and the speed of the

metering rolls

16 and 17. The applicator roll 10 must fit tight against the metering roll 16 and tight against the veneer on the conveyor to transfer the exact amount of glue required. The viscosity and the spacing will determine the amount of adhesive that will be transferred and the amount that will be recirculated. There is never a total transference of adhesive from the applicator roll to the veneer.

Preferably, the two metering rolls and the applicator roll are driven by the conveyor motor. Occasionally it is necessary to raise the applicator rolls 10 from the conveyor and the air pistons 25 are provided for this purpose. These pistons are also used to provide the necessary downward pressure of 20 p.s.i. at the glue line for a good glue transfer to the veneer.

In FIG. 3, the applicator apparatus is used in a conventional glue spreader which places adhesive on both sides of crosscore veneer. In this apparatus, the applicator rolls 10a and 10b have the same construction as applicator roll 10, and the metering rolls 16a and 17a and 16b and 17b have the same construction as metering rolls 16 and 17. The rolls 10a and 10b are tangential when no veneer is passing through. The apparatus performs in the same manner as that shown in FIG. 1 except that the applicator rolls 10a and l0b now perform the double function of applying adhesive to both sides of the veneer V and of moving the veneer through the apparatus.

While specific details of preferred embodiments have been set forth above, it will be apparent that many changes and modifications may be made therein without departing from the spirit of the invention. It will, therefore, be understood that what is described herein is intended to be illustrative'only, and is not intended to limit the scope of the invention.

We claim:

1. An applicator roll having an outer barrier surface which is resilient and has a maximum initial Shore Durometer of 60 on the scale.

2. The applicator roll of claim 1 in which said-roll is surfaced with a closed cell material.

3. The applicator roll of claim 2 in which said material is polyvinyl chloride.

4. In a plywood adhesive apparatus, the improvement of an adhesive applicator roll having an outer barrier surface which is resilient and has a maximum initial Shore Durometer of 60 on the 00 scale.

5. The apparatus of claim 4 in which said roll is surfaced with a closed cell material.

6. The apparatus of claim 5 in which said material is a modified polyvinyl chloride.

7. An applicator roll having an outer barrier surface which is resilient and has a maximum initial Shore Durometer in the range of 15 through 60 on the 00 scale.

8. The applicator roll of claim 7 in which said roll is surfaced with a closed cell material.

9. The applicator roll of claim 8 in which said material is polyvinyl chloride.

10. In a plywood adhesive apparatus, the improvement of an adhesive applicator roll having an outer barrier surface which is resilient and has a maximum initial Shore Durometer in the range of l5 through 60 on the 00 scale.

11. The apparatus of claim 10 in which said roll is surfaced with a closed cell material.

12. The apparatus of claim 11 in which said material is a modified polyvinyl chloride.