Kendall Co. v. Tetley Tea Co.

• Decision Date: 17 April 1950
• Docket Number: Civ. No. 6984.
• Citation: 89 F. Supp. 897
• Parties: KENDALL CO. v. TETLEY TEA CO., Inc.
• Court: U.S. District Court — District of Massachusetts

89 F. Supp. 897

KENDALL CO. v. TETLEY TEA CO., Inc.

Civ. No. 6984.

United States District Court, D. Massachusetts.

April 10, 1950.

As Amended April 17, 1950.

H. L. Kirkpatrick and Edgar H. Kent of Fish, Richardson & Neave, Boston, Mass., for plaintiff.

T. Clay Lindsey, Hartford, Conn., George P. Dike, Boston, Mass., George P. Towle, Jr., Boston, Mass., for defendant.

SWEENEY, Chief Judge.

In this action the plaintiff seeks an injunction against and damages for an alleged infringement of its Patent No. 2,277,050, which was applied for on August 31, 1940, issued on March 24, 1942, to Reed and Ryan, and assigned by them to the plaintiff. The defendant denies infringement and asserts the invalidity of the patent on several technical grounds which will be discussed hereinafter. The claims in suit are Nos. 1, 2, 3, 5, 12, and 14, and claim 4 by reference. Throughout this opinion there will be references to a patent numbered 2,277,049, which is a parent application to the one in suit. It must be clearly understood that 2,277,049 is not in suit in this action.

These claims relate to an infuser made of an unwoven, thermoplastically bonded fabric. The Tetley Tea Company, Inc., which manufactures the accused tea bags, is only a nominal defendant, the real defendant being C. H. Dexter & Sons, Inc., of Windsor Locks, Connecticut, which supplies the Tetley Tea Company with the material from which the accused tea bags are made. Dexter openly conducted the defense of this action and has undertaken to indemnify Tetley for any losses accruing as a result of it. While the action does not involve "all of the tea in China" it does directly involve the major portion of the tea bag industry, all of which is supplied by the defendant Dexter with its fabric.

Findings of Fact

The plaintiff is a large manufacturer of gauzes and surgical dressings, and controls other corporations such as Bauer & Black. With the advent of chemical fibers such as nylon and vinyon, this company, in common with many of its competitors, saw the possibility of producing a fabric which needed to be neither spun nor woven, thus eliminating two expensive steps in the process of textile fabrication. Plaintiff's first attempt to solve this problem involved the use of fibres of cellulose acetate which were made adhesive by union with a solvent in a "wet process". This was unsuccessful. Plaintiff was successful when it used a "dry process" and introduced the acetate into the mass of textile fibers, prior to their being carded into a web. Cellulose acetate fibers are latently thermoplastic, by which it is meant that they tend to coalesce and to adhere to themselves (and to any other fibres present in the web) when subjected to heat and pressure. Therefore, by passing this carded web through heated calendar rolls it became a fabric possessing tensile strength without having been spun and woven. Furthermore, plaintiff discovered that this fabric continued to retain latent thermoplasticity so that several such unified webs could be superposed, one upon another, and again run through heated rolls, with the result that a thicker and stronger laminated fabric ensued. Finally plaintiff learned that the amount of thermoplastic fiber in the webs of such a laminated fabric could be varied so that one surface would contain a high thermoplastic concentration and the other surface a low one. Thus the adhesive character of the fabric under the application of heat and pressure could be varied on each surface.

However, heat sufficient to cause the acetate to become usefully adhesive scorched it because the point at which it becomes adhesive is very close to its deterioration point. Therefore, plaintiff needed a plasticizer, the function of which would be to lower the temperature at which the acetate fibers would become adhesive. Plaintiff, which was not in a position to manufacture a plasticizer eventually found what it needed in plasticizers provided by the Monsanto Chemical Company, called Santicizers. The laboratory notes of Reed, one of the co-patentees, indicate that in September of 1936 plaintiff produced a strong, bonded fabric which did not scorch when heated, composed of thermoplastic fibers (cellulose acetate), non-thermoplastic fibres (bleached cotton), and Santicizer No. 8. This fabric was covered by Letters Patent No. 2,277,049 (hereinafter called "049"), applied for November 6, 1939, and issued to the plaintiff on the same date as the patent in suit. The application which resulted in 049 was a continuation of one filed in July, 1935, Serial No. 30,022, which was a disclosure substantially the same as that made in 049. The trade name given this fabric was "Webril".

Prior to February of 1937 Reed and other researchers for plaintiff discovered that Webril was porous and that the degree of its porosity could be varied according to the percentage of thermoplastic fiber contained within it. Plaintiff knew that when immersed in water although all other fiber-to-fiber bonds in Webril bonds were loosened, those caused by thermoplastic adhesion remained firm. By varying the amount of plasticizer in the fabric its critical temperature of thermoplastic adhesion could be established above that of boiling water so that, when immersed in boiling water, the fabric would not disintegrate. All of these were prime necessities in the development of a fabric for an infuser to be used in a liquid, such as for making tea, and with the acquisition of this knowledge plaintiff, prior to February of 1937, conceived of using Webril in a tea bag infuser.

In February of 1937 Ryan began work with plaintiff, and there is no evidence to disprove the proposition that he contributed to the further development of Webril as it took place after that date. Plaintiff at this time had a fabric which was porous, which retained tensile strength in water, even when the water boiled, and which could be manufactured cheaply because it was chemically bonded and neither spun nor woven. To reduce to practice Reed's idea of using it as a tea bag, Webril had to be produced in a form which was tasteless, non-toxic, and heat-sealable. Initially toxicity and bad taste were prevented by kier-boiling the fabric in an alkali solution. This increased the cost of manufacture, weakened the fabric's tensile strength by 15%, and regenerated the cellulose acetate with the result the Webril lost its thermoplastic property and could not be heat-sealed. Kier-boiling had been necessary because all plasticizers thus far used in Webril, when an attempt was made to adapt it to food infusers, degenerated in water which gave the water a bad taste. Reed was not sure that such plasticizers were non-toxic, despite the fact that Monsanto, which manufactured the plasticizers used by Reed, guaranteed them to be non-toxic. Further obstacles to be overcome before the goals of freedom from bad taste and toxicity were reached required the selection of a particular type of bleached cotton and the assurance that the water used to process this cotton was pure. Finally, to perfect a Webril tea bag it was necessary to determine the correct proportion of each of the three elements — cotton staple, thermoplastic fiber, and placticizer — to include in the web to make it perform most efficiently.

In order to elminate kier-boiling, and to permit Webril to remain heat-sealable, non-toxic, and tasteless, Ryan and Reed selected Santicizer E-15 as its plasticizer when used in a tea bag. Although Reed had known of this Santicizer and used it in Webril before 1937, he had not used it in a fabric which had been tested for use as a tea bag, or if he had done so, he had not assured himself that the fabric was non-toxic and tasteless in virtue of the use of E-15, evidence of which is the fact that he had kier-boiled all such fabrics before Ryan began to work on the problem. Ryan also helped in the solution of the other problems to be solved, i.e. the selection of a proper type of bleached cotton, the evolution of a process for producing it which used sufficiently pure water, and the selection of the proper proportion of the three elements in Webril to make it useful as a tea bag. The adaptation of Webril to a tea infuser was accomplished in September of 1939 and the suit patent was applied for in August of 1940, about a year later.

The defendant's answer has raised four issues: (1) whether the suit claims possess invention; (2) whether the patentees abandoned them; (3) whether the patentees are the original inventors, 35 U.S.C. A., § 35; and (4) whether the defendant has infringed upon plaintiff's claims.

Invention

The claims in suit can be summed up by the following analysis. They cover a fabric or sheet material containing fibers which are heterogeneously intermingled, unspun, water-insoluble and bonded. The bond is caused by latently adhesive fibers which are distributed discontinuously and substantially throughout the sheet material, which do not become coalescent at temperatures equaling that of boiling water, and which are concentrated more highly on one surface of the sheet material than on the other. As a result, this sheet material is highly pervious to air and to liquids but prevents sifting of dry particles of solids. Thus, when made into an envelope it is useful for enclosing a material to be infused in a liquid. The suit claims cover this material only when it is made into such an envelope by uniting the marginal portions of two sheets of this material thermoplastically. Claim 14 (which incorporates claim 4) of Letters Patent No. 2,277,050 (hereinafter called "050"), which is representative of this disclosure, reads as follows: "An infuser comprising a porous envelope for enclosing a material adapted to be infused in a liquid, a substantial portion at least of said envelope consisting essentially of an unwoven sheet material composed of unspun fibers and a water-insoluble binder distributed in a discontinuous form substantially...