ASBESTOS TILE MANUFACTURE - CONTENTS: history & manufacturing processes of asbestos floor tiles, both asphalt & vinyl asbestos tile
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Asbestos floor tile manufacturing process & contents: this article describes how asphalt asbestos floor tiles & vinyl asbestos floor tiles were produced, their ingredients and the equipment used to make them.
We include data on athe estimaged production levels of asphalt-based flooring products in square feet by type and material. Our page top photograph illustrates popular and widely-installed Armstrong™ vinyl asbestos floor tiles.
This articles series about the manufacture & use of asbestos-containing products includes detailed information on the production methods, asbestos content, and the identity and use of asbestos-containing materials.
In the past few decades [into the 1950's ] there has been a gradual development
and increase in the use of tile. Vinyl floor tile and
asphalt floor tile can use as much as 30 to 50 per cent, by
weight, of asbestos shorts and floats. See Figure 4.1 below.
Shown at left, Sears vinyl-asbestos flooring. [Click to enlarge any image]
longer fibers are used; however, it is rare inasmuch as
they are more expensive and tend to interfere with producing
smoothly surfaced tiles. Asbestos is also used in the
manufacture of synthetic resin tile.
Resilient floor coverings identify such organic types as
asphalt tile, rubber tile, linoleum, and plastic tile. The nonresilient
floor coverings pertain to stone, brick, etc. The
original resilient floor coverings were developed during the
latter part of the Nineteenth Century by Frederick Walton.
The original covering was linoleum for use as a floor decking
on British naval ships. Asphalt tile was first made as amastic type of floor covering.
The mastic was troweled on
the floor. In 1917, the United States Navy used the mastic
as a deck covering over wood. The original mixes included
asphaltic binders, with fillers of asbestos; mixing was done
on a rubber mill.
Shown at left: Figure 4.1. View of asphalt tile floor with pattern. (Courtesy Armstrong Floor Div.)
It has been reported that the asphalt tile industry had its
beginning in 1920 when the asphalt roofing manufacturers
attempted to develop a material similar to slate shingles.
The material developed was not suitable for shingles, but it
started the asphalt floor tile business.
The term tile generally identifies tiles using asphalt materials as the principal binder; such organic resin binders
as vinyl are used too, because they permit the manufacture
of light-colored products. Vinyl asbestos tile competes with
Both of these markets are expanding , however,
the vinyl market is expanding faster. [That is to say, asbestos-based floor tile tile markets were still significantly expanding in 1959 - Ed.]
Asbestos Tile Production Growth Beginning From 1920
The first publicized installation of asphalt tile was in the
Western Union office in New York City (1920). By the end
of 1930 3 million sq yd was being produced annually.
Growth of Annual Production Rate of Asbestos-Flooring 1920 - 1952
Square Yards Produced
% Change from
1920 - first public building installation
Western Union Office, New York City
3 million square yards
4.5 million square yards
41 million square yards
+ 1000%, +12% greater than during WWII
61 million square yards
+ 148 %
90 million square yards
1952 (Vinyl asbestos tile)
40 million square yards
1952 (Vinyl, homogeneous)
40 million square yards
Adapted from original text, Rosato (1959) p88.
The [early] gradual
growth in asphalt tiling [in the 1930's] had a sudden expansion during
World War II, in both industrial and commercial applications. The growth in asphalt tile during World War II had been caused by shortages
of the important raw materials required for the more
standard flooring products. The military requirements activated
more development in the field of asphalt and vinyl
1936 it had reached 4 1/2 million sq yd per year. Approximately five per cent of the floor covering in 1940
was of asphalt tile. After World War II, the volume increased
to twelve per cent or approximately 41,000,000 sq
yd of asphalt tile. In 1949 with the post-war building boom,
there was an annual production of 61 million sq yd.
production of vinyl plastic tile in 1952 was approximately
35 million sq yd. Reports indicate that in 1952 vinyl plastic
tile production was approximately one-half of asphalt tile
production. See Table 4.1 for estimated production.
TABLE 4.1. Estimated Production of Asbestos-Containing Floor Tiles / Sheet Flooring
Asbestos & Other Floor Covering Production Levels in Square Yards, 1952
Square Yards Produced
Percent of Total Production
Vinyl asbestos tile
Adapted from Rosato (1959) (1950) Table 4.3 
TABLE 4.1. part 2: Asbestos FLooring Yard Goods & Tiles
Manufacturing Processes Used for Asbestos Floor Tiles
Figures 4.2 and 4.3 show some of the operations involving
the preparation and manufacture of tiles. The usual procedure
is to combine plasticized resin with filler for the resin
tile and asphalt with filler for the asphalt tile. Banbury
mixers are generally used to mix the basic material. In the
case of asphalt mixes, the. binder softens at moderately low
temperatures. A steam-heated jacket is generally used with
the mixer in order to soften the mix.
Pigments and other fillers are added during the mixing
operation. After the mixes are completel blended with
coloring matter, they are fed through calenders in order to
produce smooth sheets of specified thickness. Then, these
sheets are cut to proper size, prior to the material cooling
Asphalt Tile Material Contents
Asphalt floor tile was originally manufactured
with heavy asphalt solutions mixed with a very high percentage
of asbestos filler. The tiles were hardened by means
of solvent evaporation. Hot mixed asphalt solutions were
These tiles were black or extremely dark in color.
In order to obtain a different color, brown or intermediate
colors, gilsonite is used.
Figure 4.2. The original doughy mass for tile is a heavy caramel-like
sheet. Sheeting-mill operators pull it from the machine and lay it on
a conveyor belt, which will take it to the calender rolls for thinning out. (Courtesy Kentile, Inc.)
Gilsonite is usually approximately 90 per cent soluble in
carbon disulfide but its solubility in petroleum naphtha
varies from 10 to 60 per cent. It is miscible in all proportions with drying oils and with the resins commonly used in making
Unlike other asphalts, it can mix in almost
any proportion with waxes to form stable compounds.
Gilsonite alone is hard and brittle. It requires softening
in the manufacture of tile products. Soft asphalts or pitches
can be used to soften gilsonite.
A typical formula for dark
colored tile includes 40 parts by weight of asphalt or gilsonite,
60 parts of asbestos floats, 30 parts of powdered
limestone, and pigment as required.
Another typical mixture
includes 70 per cent asbestos fiber, 15 per cent gilsonite,
15 per cent vegetable pitch, and sufficient coloring.
vegetable pitch provides for the proper flow of the binder.
The nomenclature of asphalt tile is misleading. The original
asphalt tile contained a high percentage of asphalt;
however, modern asphalt tile contains very little or no
asphalt. Rather than the use of asphalt or gilsonite, most
of the binders used now are synthetic organic resins.
additives or plasticizers used with the resins are vegetable
or petroleum pitches. These synthetic binders produce a
brighter, lighter, and wider range of colors. Asbestos fillers
however, are still the main ingredient in asphalt tile.
Figure 4.3. Continuous flow of floor tile moving from mill at rear
through polished calender rolls on the production line—side view.
The coumarone-indene resins are the principal resins used
92 Asbestos Tile 93
in asphalt tile manufacture. They are readily fusible and
resistant to water and the alkalies which makes them well
adapted to tile manufacture.
When using coumarone-indene resins, the tile is brittle.
Plasticizers are required in order to soften the tile. A general
procedure is to mix vegetable and animal pitches in a
dispersion of the resin in oil.
For a light-colored tile a conventional
mixture is coumarone-indene resin of 22 parts,
cottonseed pitch of 20 parts, asbestos of 65 parts, powdered
limestone of 35 parts and pigments as required. Other mixes
include a two to one ratio of coumarone-indene resin with
the various pitches.
When marbleized tile is to be manufactured, the marbleizing
color is added to the mixture at the end of the mixing
operation. Generally this coloring matter is prepared in a
mixture which has a slightly higher melting point so that it
does not flow too readily when mixed with other compounds.
Summary of Typical Ingredients in Asphalt-Asbestos Floor Tile by Percent
Rosato cites another flooring material from the 1950's called asbetic flooring which was a mixture of ground mother rock and the shortest, otherwise unusable asbestos fibers.
Other sources such as the Rotterdam Convention PIC archive,  note that while vinyl-asbestos floor tile ingredient mixes varied by manufacturer, typically vinyl-asbestos floor tiles contained:
Asbestos - 5 - 25%
Binder - 15 - 20%
Limestone - 53 - 73% [note that some products used asbestos powder as filler]
Plasticizer - 5%
Stabilizer - 1 - 2%
Pigment - 0.5 - 5%
Short asbestos fibers may also be among the more hazardous if airborne. Asbestos was also used in a mixture with waterglass (a clear binder used in many chemical applications and even for cementing stove gaskets) as a hard binding compound.
Vinyl-Asbestos Tile Material Contents
Vinyl resin is the most important type of
plastic floor tile. The use of vinyl resin in floor coverings
started after World War II. These floor coverings can be
made in many different colors (light and dark).
Similar to asphalt tile, but generally more flexible, vinyl asbestos
tile has the largest volume of sales of the vinyl
flooring family. The annual production rate is estimated at
more than 80 million sq yd; the tile produced is usually 9
in. by 9 in. and
1/16 in. thick. Commercial installations usually
use 1/8 in. tile.
Shown at left, Ever-Wear vinyl-asbestos floor tiles.
Vinyl-asbestos tile is used above or below
grade on smooth wood or concrete base. As it wears, it gets
smoother and takes waxing very well. Its resistance to
scratching or marring and to strong detergents is excellent.
The batch type-continuous process type of flooring is
made by a combination batch type and continuous process.
It consists of vinyl-chloride vinyl-acetate copolymer resin
mixed with plasticizers, stabilizers, asbestos, limestone and
Varying types of intensive mixing equipment
are used to fuse these ingredients into a hot mass of
the base, or field color.
Then, this base can be decorated on
a two-roll differential speed mill by adding previously made
granules of the proper shapes and colors to produce the
A thick blanket of stock is cut from this mill when the
pattern is right; it is butted to the previous slab and fed
into a two-roll calender which squeezes it to what is almost
the required thickness. From this point, the process is continuous
as the sheet passes through a second and often a
third two-roll calender, cooling equipment and then a blanking
In the press, depending upon the width of the
sheet two rows of three to five tiles are die cut from the
sheet per stamping. The rest of the sheet travels back on an
overhead conveyor to the mixer, for immediate reworking,
while the tiles move along to be visually inspected for pattern,
color and surface appearance.
An entirely different approach to the processing of vinyl
resins into flooring materials is the use of vinyl plastisols or
organosols. These materials are dispersions of vinyl resins in
plasticizer (plastisols) or combinations of plasticizer and
volatile diluent (organosols).
These dispersions are of a fluid
nature; the methods for their application are based on their
flow characteristic, on their ability, when heated to 350°F
to fuse into the same tough resilient vinyl plastic that requires
the above-described heavy processing techniques.
Another application of asbestos with vinyl tile involves
the use of asphalt saturated asbestos felt applied under
1/8 in. thick tile. This felt underlay provides for smoother
Do Asbestos-Containing Floor Tiles or Sheet Flooring Also Contain Lead Contaminants?
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 Asbestos, its Industrial Applications, D.V. Roasato, engineering consultant, Newton MA, Reinhold Publishing Co., NY, 1959, Library of Congress Catalog No. 59-12535. We are in process of re-publishing this interesting text. Excerpts & adaptations are found in InspectApedia.com articles on asbestos history, production & visual identification in and on buildings.
 "Asbestos in Plastic Compositions", A.B. Cummins, Modern Plastics [un-dated, pre 1952]
 "Asbestos in Your Home," Spokane County Air Pollution Control Authority, Spokane WA 509-477-4727 www.scapa.org provides a one-page image, a .pdf file drawing of a house warning of some possible sources of asbestos in the home. The sources are not ranked according to actual risk of releasing hazardous levels of airborne asbestos fibers and the list is useful but incomplete.
 The US EPA provides a sample list of asbestos containing products epa.gov/earth1r6/6pd/asbestos/asbmatl.htm
 "Characterization of asbestos exposure among
automotive mechanics servicing and handling
asbestos-containing materials", Gary Scott Dotson, University of South Florida, 1 June 2006, web search 3/9/2012 original source: scholarcommons.usf.edu/cgi/viewcontent.cgi?article=3505&context=etd [copy on file as /hazmat/Automotive_Asbestos_Exposuret.pdf ].
 Asbestos Identification and Testing References
Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed
the basis for current work by asbestos identification laboratories.
Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
Pott, F., Staub-Reinhalf Luft 38, 486-490 (1978) cited by McCrone
 ASBESTOS IN YOUR HOME U.S. EPA, Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
 Asbestos products and their history and use in various building materials such as asphalt and vinyl flooring includes discussion which draws on ASBESTOS, ITS INDUSTRIAL APPLICATIONS, ROSATO 1959, D.V. Rosato, engineering consultant, Newton, MA, Reinhold Publishing, 1959 Library of Congress Catalog Card No.: 59-12535 (out of print, text and images available at InspectAPedia.com).
 "Handling Asbestos-Containing roofing material - an update", Carl Good, NRCA Associate Executive Director, Professional Roofing, February 1992, p. 38-43
 EPA Guidance for Controlling Asbestos-Containing Materials in buildings, NIAST, National Institute on Abatement Sciences & Technology, [republishing EPA public documents] 1985 ed., Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460 Copy on file as ASBESTOS IN YOUR HOME - U.S. EPA, Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
Basic Information about Asbestos, US EPA, web search 08/17/2010, original source: http://www.epa.gov/asbestos/pubs/help.html
"Handling Asbestos-Containing roofing material - an update", Carl Good, NRCA Associate Executive Director, Professional Roofing, February 1992, p. 38-43
EPA Guidance for Controlling Asbestos-Containing Materials in buildings, NIAST, National Institute on Abatement Sciences & Technology, [republishing EPA public documents] 1985 ed., Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
Copy on file as ASBESTOS IN YOUR HOME - U.S. EPA, Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
[copy on file as /hazmat/Vermiculite_US_EPA.pdf/ Current Best Practices for Vermiculite Attic Insulation - May 2003, U.S. EPA
[copy on file as] /hazmat/Vermiculite_Health_Canada.pdf] Vermiculite Insulation Containing Amphibole Asbestos - September 2009, Health Canada
Managing Asbestos in Place, How to Develop and Maintain a Building Asbestos Operations and Maintenance (O&M) Program, U.S. EPA, web search 01/20/2011, original source: http://www.epa.gov/asbestos/pubs/management_in_place.html
Asbestos Strategies, Lessons Learned about Management and Use of Asbestos: Report of Findings and Recommendations on the Use and Management of Asbestos, 16 May 2003, US EPA, web search 01/20/2011, original source: http://www.epa.gov/asbestos/pubs/asbstrategiesrptgetf.pdf
prepared by the: Global Environment & Technology Foundation, 7010 Little River Turnpike, Suite. 460, Annandale VA 20003
Other US EPA Publications on asbestos: web search 01/20/2011, see http://www.epa.gov/asbestos/pubs/pubs.html
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