GB2134007A - Method for coating adhesives and coating apparatus therefor - Google Patents

Abstract

The present invention relates to a method for coating adhesives and a coating apparatus for practicing this method. Melton dumbbells for tennis balls are coated in laminar form with an adhesive at the side thereof. There has not previously been a suitable method to coat them uniformly. The present invention provides a method for coating adhesives which comprises dipping one side of a laminar pack 6 of the articles to be coated which are placed on a conveying means into a first adhesive bath 5 and then dipping the other uncoated side of the pack into a second adhesive bath 5, followed by drying the laminar pack of coated materials. The present invention also provides a preferred adhesive coating apparatus for practicing this method. The present method can be applied to the coating of adhesives on the side of other laminar sheet packs. <IMAGE>

Description

SPECIFICATION Method for coating adhesives and coating apparatus therefor The present invention relates to a method for the coating of adhesives and to a coating apparatus for practicing this method.

When the side of felt pieces, etc., which are cut into the same shape such as melton dumbbell for tennis balls are to be coated with an adhesive, a method is commonly used in which the pieces are placed on one another in a laminar form, and the side of the laminate is coated with an adhesive by means of a brush or collar, or a method in which the whole laminate is dipped into an adhesive bath and removed, and after drying, the pieces are stripped one by one from the laminate.

In the former case, however, applying a sufficient amount of an adhesive by a single coating operation is so difficult that the coating/drying cycle has to be repeated. While the latter case has the disadvantage of causing non-uniform coating because both the amount of adhesive attached to the laminate and the degree of penetration of the adhesive vary depending upon the upper and lower positions of the laminate.

The present invention attempts to improve these defects.

Accordingly, the present invention provides a method for coating adhesives which comprises dipping one side of a laminar pack of the articles to be coated which are placed on a conveying means into a first adhesive bath and then dipping the other uncoated side of the pack into a second adhesive bath, followed by drying the laminar pack of coated materials.

The present invention also provides an apparatus for coating adhesives which comprises a conveying means for moving a laminar pack of articles to be coated and a laminar pack of coated articles, two adhesive baths arranged in parallel for dipping and coating the side of the pack of articles to be coated and a drying means for drying the pack of coated articles.

The present invention will be further described with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a pack of melton dumbbells for tennis balls; and Fig. 2 is a typical view illustrating one embodiment of an adhesive coating apparatus according to the present invention.

A pack (6) of melton dumbbells (1) for tennis balls placed on one another in a laminar form by means of end plates (2) and clamps (3) as shown in Fig. 1, is loaded sideways onto a conveying means, for example, two parallel chains (7), introduced into the first adhesive bath (4) containing an adhesive (5) through a suitable chain wheel (8), in which bath one side of the pack (6) is coated with the adhesive, and then introduced into the second adhesive bath (4') in which the pack (6') coated with the adhesive on one side is coated with the adhesive on the other uncoated side.

The pack (6") coated with the adhesive on the both sides is then dried for a pre-determined period of time in a drying means, for example, in a drying oven (9) equipped with the appropriate number of chain wheels, and sent for further treatment.

The depth of dipping and period of dipping time required for the pack to be treated in the adhesive baths (4) and (4') and the period of treating time in the drying oven (9), etc. are governed by the kind and material of the pack to be treated, the kind and concentration of the adhesive, the temperature of the adhesive baths, etc., and they are not particularly limited. It suffices to properly select them so as to attain uniform coating and penetration of the adhesive on the side of the pack to be treated.

A particularly preferred adhesive used in the method of the present invention is a latex adhesive containing a depolymerized latex as the main component thereof. By using this latex adhesive in this way advantages are obtained such that; the amount of the adhesive attached to the side of the articles to be treated on dipping and the degree of penetration of the adhesive can easily be regulated by the blending recipe of the adhesive; because of the thixotropic nature of the adhesive, uniform coating of the adhesive onto the side of the articles to be treated and the prevention of running and slipping during drying of the adhesive adhered to the side become possible. Furthermore an operation to strip the laminar pack coated with the adhesive on the side thereof of its component pieces becomes easy.

By the foregoing method of the present invention, the uniform and sufficient adhesion and penetration of the adhesive onto the side of a laminar pack of articles to be coated can be attained efficiently by the coating/drying cycle.

The method of the present invention is suitable for coating an adhesive onto the side of a laminar pack of felt pieces, etc., cut into the same shape, including pieces of melton dumbbell for tennis balls.

The present invention will be illustrated with reference to the following example.

EXAMPLE A latex adhesive was prepared by the following blending recipe: Solid Part by Part by Component Content (%) Dry Weight Wet Weight Depolymerized natural rubber latex 57 90 157.9 Low molecular weight polyisoprene latex 70 10 14.3 Zinc salt of 2-mercaptobenzothiazole 50 0.5 1.0 Zinc salt of diethyldithiocarbamic acid 50 0.5 1.0 Zinc oxide 50 3.0 6.0 2,2-Methylenebis(4-methyl-6-t-butylphenol) 50 1.5 3.0 Sulfur 50 0.4 0.8 Nonionic surfactant11 20 0.5 2.5 Anionic surfactant21 20 0.2 1.0 Carboxymethyl cellulose 4 1.0 25.0 Titanion dioxide 50 10.0 20.0 rI Emulbin W (aromatic polyglycol ether, produced by Bayer Co.).

21 Demol N (produced by Kao-Atlas Co.).

The pH of the latex adhesive thus obtained was adjusted in the range of from 8 to 10.6 to prepare an adhesive bath (bath temperature, 230C).

A laminar pack of eighty-five pieces of the commonly used melton dumbbell for tennis balls, as shown in Fig. 1, was loaded on a chain, and one side thereof was dipped for 8 seconds in the first adhesive bath arranged as shown in Fig. 2. After removing the pack from the bath, the uncoated side of the pack was then dipped for 8 seconds in the second adhesive bath, and after removing it, the adhesive-coated pack was dried for about 120 minutes in a drying oven kept at 500C.

The running and slipping of the adhesive during drying were not observed, and the melton dumbbell pieces could easily be stripped one by one from the pack after drying. Since every melton dumbbell piece has on its side a uniform coating film layer of the adhesive having a thickness of 0.8 mm, it could be stuck to a core ball with a uniform adhesive power without overflow of the adhesive.

Claims (10)

1. A method for coating adhesives which comprises dipping one side of a laminar pack of the articles to be coated which are placed on a conveying means into a first adhesive bath and then dipping the other uncoated side of the pack into a second adhesive bath, followed by drying the laminar pack of coated materials.

2. A method as claimed in claim 1 wherein the conveying means is a chain.

3. A method as claimed in claim 1 or claim 2 wherein the pack of materials to be coated is a pack of melton dumbbells for tennis balls.

4. A method as claimed in any one of the preceding claims wherein the adhesive is a latex adhesive containing depolymerized latex as the main component thereof.

5. A method as claimed in claim 1 substantially as hereinbefore described with reference to the Example.

6. Articles when coated by the method as claimed in any one of claims 1 to 5.

7. An apparatus for coating adhesives which comprises a conveying means for moving a laminar pack of articles to be coated and a laminar pack of coated articles, two adhesive baths arranged in parallel for dipping and coating the side of the pack of articles to be coated and a drying means for drying the pack of coated articles.

8. An apparatus as claimed in claim 7 wherein the conveying means is a chain.

9. An apparatus as claimed in claim 7 or claim 8 wherein the drying means is a drying oven.

10. An apparatus as claimed in claim 7 substantially as hereinbefore described with reference to and so illustrated in the accompanying drawings.