Basic components used in asbestos based formed or molding products: this article series about asbestos plastics & molded materials describes the history, manufacturing process & uses of asbestos plastics and molded materials such as asbestos reinforced handles, the Vanguard rocked nose cone, automobile parts & housings, electronic equipment (radar scanner), asbestos-filled Teflon, rocket motor parts, plastic drop tanks for the Hawker Sea Hawk, and hundreds of other products.

Asbestos Plastic Components & Makeup

How Asbestos Fabrics & Fillers Were Combined with Phenolics to Form Molded Plastic Products

By the use of asbestos fillers, phenolics can be made into many standard forms to meet the design requirements of high-impact strength, tensile strength, electrical insulating qualities, heat resistance, chemical resistance, moisture resistance, and wear resistance.

Figure 9.3. Automobile air-conditioning housing made of polyester premix compound containing 55 per cent asbestos. - Courtesy Houston Reinforced Plastics Co. [Click to enlarge any image]

For laminated or molded items, asbestos fabrics, papers, felts, mats, loose fibers and yarns are used.

The fabrics used are generally of heavy construction and low cost which meet National Electrical Manufacturing Association (NEMA) requirements.

The asbestos papers used for combination with phenolics include low-cost, low-strength paper products as well as such specialty paper products as Quinterra* and Novabestos.**

* Johns-Manville Corp.
** Raybestos-Manhattan, Inc.

The specialty grade papers, which are also more expensive, have been developed specifically for rigid electrical requirements. Table 9.2 provides for general information concerning asbestos felts.

Notes to the table above

Significant data for modern readers is that the asbestos content in these felt product ranges from 80% t0 99%! - Ed.

In molding compounds, short asbestos fibers such as "shorts and floats" can produce attractive surface finishes and satisfactory molding properties. Long asbestos fibers tend not to produce highly attractive surface finishes and have inferior flowing characteristics. To remedy these problems, shorter asbestos fibers are generally mixed with the long fibers.

Increasing filler content increases the viscosity of the resin systems. For example an unfilled polyester resin system with a viscosity of 2,500 centipoises at 75°F would increase to 60,000 centipoises with 20 per cent asbestos filler. Actually thick and stiff putties or pastes can be made with a high percentage of asbestos fillers in the various resin systems.

In many of the past applications, asbestos reinforced or filled plastics were not evaluated as basically structural materials. However, in the past decade there have been tremendous strides with regard to reporting and developing high strength and high modulus asbestos base plastics by industry. These types of plastics are gradually entering into such diversified fields as automotive parts, electronic parts, chemical equipment, aircraft, and missiles.

Note: significant data for modern readers is that the asbestos content in these felt product ranges from 80% t0 99%! - Ed.

See also VULCANIZED RUBBER & ASBESTOS PRODUCTS

Question: was asbestos used in the plastic coating on bicycle baskets?

My mother refurbished this weekend an old bicycle basket (age unknown). It was made of steel coated with relatively thick, plastic-like material (perhaps about 1-2 mm thick, and a good deal of visible rust through the coating). She scraped off this "plastic" with a metal scraper, and then painted the basket (picture of freshly painted basket attached).

I don't know which year the basket was manufactured. I came to think that such coating might contain mixed-in asbestos. Is that probable?

The scrap is now under the terrace tables at our cabin. The children use to play on the terrace in the summer. It was hard to get to under the terrace, but we have collected some of the scrap pieces, see attached picture.

- Anonymous by private email 1 July 2019

Reply: research on use of asbestos and asbestos waste as filler in plastics and plastic coatings

Use of asbestos in the plastic used to coat wires such as bicycle baket is not an application that I've come across, but asbestos was used in some plastic coatings - probably for more demanding and more critical applications.

The primary use of a bicycle basket plastic coating is to resist rust and corrosion.

A Google Scholar search for that application of asbestos did not produce any findings.

However a patent search does find applications in which plastic was modified by adding asbestos. Take particular note of Aldo 1954 and Greider 1944.

• Aldo, Castellani. "Continuous plastic waterproof coating in bituminous glass asbestos for buildings and application process thereof." U.S. Patent 2,695,257, issued November 23, 1954.
• Duffy, James J. "Metal plating of substrates." U.S. Patent 3,620,834, issued November 16, 1971.
  Excerpt: ... can be used in the unfilled condition, or with fillers such as glass fiber, glass powder, glass beads, asbestos, talc and ...
• Greider, Harold W., and George A. Fasold. "Plastic composition." U.S. Patent 2,354,593, issued July 25, 1944.
  Excerpt:
  
  As an example of a fibrous mineral filler suitable for use in the practice of this invention, reference may be made to the dust-like asbestos which is a by-product of the asbestos milling industry. A typical grade of this asbestos dust-like material is that which results as a by-product of the milling of asbestos rock for the recovery of asbestos fiber of ordinary commercial lengths, by the Quebec Asbestos Corp, of East Broughton, P. 6)., Canada.
  
  The asbestos dust by-product referred to is of such finely-divided character that all will pass a 20-mesh standard testing sieve, about 85% by weight will pass a 48-mesh testing sieve, about by weight will pass a IOU-mesh testing sieve, about 50% will pass a 200 mesh testing sieve, and about 35% will pass a 325- mesh testing sieve.
  
  This material has heretofore had no commercial use and has been regarded as worthless waste. For purposes of brevity, the particular material described by way of exemplification will be referred to as waste asbestos or asbestiform waste. The particle size range and gradation of particle size in this material are especially suitable for use in the practice of this invention.
• Hartzell, Rowland S., and Gene Gerek. "Asbestos-foam laminates." U.S. Patent 3,522,140, issued July 28, 1970.
  Excerpt: The product can be adhered to various wood, metal or plastic substrates to provide … 1. A coated asbestos-foam laminate comprising asbestos sheet material coated on one major
• Michaels, Alan Sherman. "Coated asbestos and method of making and using same." U.S. Patent 3,519,594, issued July 7, 1970. in citing other patents:
  Excerpt: ... Coupling agents for chrysotile asbestos and thermoplastic …
  
• 1976-01-27, Lion Yushi Kabushiki Kaisha, Process for preparing plastic coated metal powders …
  
• 1982-09-02, 1992-12-15, Union Carbide Chemicals & Plastics Technology Corporation
• Xanthos, M., and R. T. Woodhams. "Polymer encapsulation of colloidal asbestos fibrils." Journal of Applied Polymer Science 16, no. 2 (1972): 381-394.

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• ASBESTOS PLASTIC COMPONENTS
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• ASBESTOS PLASTIC PROPERTIES
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• VULCANIZED RUBBER & ASBESTOS PRODUCTS

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