Prepreg; GRI 2(b); GRI 3(b); HQ 087721; HQ 951321; Heading 7019
Active· CBP ruling HQ 951151· Issued 1992-08-05
Ruling text
HQ 951151
August 5, 1992
CLA-2 CO:R:C:M 951151 EJD
CATEGORY: Classification
TARIFF NO: 3921.90.40
J. F. Fritz
Customs Liaison
Norman Krieger, Inc.
P.O. Box 92599
Los Angeles, California 90009
RE: Prepreg; GRI 2(b); GRI 3(b); HQ 087721; HQ 951321; Heading
7019
Dear Mr. Fritz:
This is in response to your letter of December 31, 1991, to
Customs in New York, concerning the tariff classification of a
commodity referred to as prepreg under the Harmonized Tariff
Schedule of the United States (HTSUS). Your letter was referred
to this office for a response.
FACTS:
Prepreg is a composite material that is manufactured by
Multi-Layer International Inc. in the Philippines and is composed
of "E" grade (electrical) glass fabric, brominated epoxy resin,
dioyanex 200 and dimethyl formamide. It is, in essence, a woven
electrical grade fiberglass fabric, coated by a white colored
plastic which is impregnated with a brominated epoxy resin which
is used as a dielectric or insulator in printed circuit boards.
The process by which prepreg is made is a reel to reel
technique, wherein woven fiberglass is unwoven from a mill roll
and immersed in a bath which thoroughly saturates the glass. It
is then passed through a forced air oven where the solvents are
devolatilized, and then rewound to rolls of suitable length.
The saturating bath consists of a solid epoxy resin and curing
agent blended with appropriate solvents. The resultant varnish
is homogeneous, medium viscosity solution.
The glass fabrics employed are available in a number of
styles, although the chemical composition of the glass does not
vary. The difference among the styles has to do with the glass
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filament diameter, the number of filaments which comprise each
strand, and the number of strands used in the weaving process.
ISSUE:
What is the proper classification of prepreg under the
HTSUS?
LAW AND ANALYSIS:
Merchandise is classifiable under the Harmonized Tariff
Schedule of the United States (HTSUS) in accordance with the
General Rules of Interpretation (GRIs). GRI 1 states in part
that for legal purposes, classification shall be determined
according to the terms of the headings and any relative section
or chapter notes, and provided the headings or notes do not
require otherwise, according to GRIs 2 through 6.
GRI 2(b) provides that a reference to a material in a
heading shall be taken to include mixtures or combinations of
that material with other materials and that any reference to
goods of a given material shall be taken to include goods partly
of that material; if goods consist of more than one material,
then classification will be according to GRI 3.
GRI 3(a) requires that where two or more headings describe
the merchandise, the more specific will prevail; or if two or
more headings each refer to part only of the materials in the
goods, then classification will be by GRI 3(b). GRI 3(b) states
that the material or component which imparts the essential
character to the goods will determine their classification.
After reviewing the file on this matter, by memorandum
dated May 5, 1992, the Customs Office of Laboratories and
Scientific Services has furnished us with the following
information.
* * * In the instant prepreg case, (as in the case
of the other two) [HQ 087721 and HQ 951321] we are of the
opinion that the primary purpose of the fiberglass is to act
as a carrier for the resin and as a reinforcement material
for the finished product. The fiberglass material's
insulative and thermal properties simply make it more
suitable for usage in the product than any other
reinforcement fabric. Consequently, the major physical
characteristics of the prepreg are given by the epoxy resin
and not the fiberglass.
-3-
Pursuant to GRI 2(b), the merchandise is described by and
prima facie classifiable under heading 3921, HTSUS, as other
sheets and film of plastics, and heading 7019, HTSUS, as articles
of glass fibers. Therefore, it must be determined whether the
glass cloth or brominated epoxy resin gives the merchandise its
essential character.
In Headquarters Ruling Letter (HQ) 087721, March 5, 1992,
Customs dealt with the classification of polyimide prepreg. In
this case the formulation of the prepreg was different than the
instant prepreg only in that the impregnating and coating resin
is an epoxy rather than a polyimide. In HQ 087721, Customs
determined
that polyimide plastics is a very specialized type of
plastics with unique insulating and heat resistent
properties. As such, while it appears that the glass fiber
fabric in the instant merchandise has similar properties,
those properties merely make the glass fiber fabric more
suitable as a carrier for the polyimide plastics material.
On the basis of all the information that we have available,
it appears that it is the polyimide plastics which provides
the primary insulative attributes to the prepreg.
Accordingly, it is the polyimide plastics which imparts the
essential character to the imported merchandise[.]
Further, in Headquarters Ruling Letter (HQ) 951321, July 28,
1992, Customs dealt with the classification of epoxy prepreg. In
this case the formulation of the prepreg is essentially identical
to the prepreg in the instant case. In this ruling, Customs
Office of Laboratories and Scientific Services furnished us with
the following information.
The prepreg product under consideration is used to
manufacture a product which is known as an electrical
laminate, a product in which epoxy resins are commonly
found. Epoxy resins have gained wide acceptance in
electrical applications due to their exceptional
combination of properties such as toughness, adhesion,
chemical resistance and superior electrical properties.
Epoxy resins which are used to produce electrical
laminate sheets, such as the prepreg, are present due
to its excellent electrical properties as well as its
adhesive properties.
Information in the file shows that the prepreg
layers are used to separate layers of copper foil
and/or printed circuits in the construction of multi-
layer printed circuit boards. Therefore, it appears
that the prepreg is being used not only for its
excellent insulative (electrical) properties but also
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for its adhesive properties and its ability to cure to a
rigid infusible machineable (engineering plastic) state.
These characteristics are given to the prepreg
by the epoxy resin and not the fiberglass component.
Therefore, although the prepreg would probably not be
excluded from Heading 7019 and directed to Chapter 39 by
Exclusionary Note (a) to that Heading, the prepreg sheet in
its cured state most definitely would.
We note that fiberglass is an excellent insulative
material in its own right. However, in the case at
hand, it appears that the fiberglass material is used
as a carrier for the epoxy resin in its precured state
and acts as a reinforcement material in the finished
product. * * * It appears that in the case of the
prepreg, fiberglass fabric is used as the carrier and
reinforcement agent because it is a highly non-
conductive material and it is more resistive to heat
than ordinary fabrics of organic composition. Based on
our experience with plastics sheeting materials, we
are of the opinion that the primary purpose of the
fiberglass is to act as a carrier for the prepreg and a
reinforcement material for the finished product. The
fiberglass material's insulative and thermal properties
simply make it more suitable for usage in the product than
any other reinforcement fabric.
In view of the above, and other product information, we are
of the opinion that the essential character of the subject
composite good is derived from the brominated epoxy resin
material.
GRI 3(b) requires that the prepreg is properly classified
under subheading 3921.90.40, HTSUS, which provides for "[other
plates, sheets, film, foil and strip of plastics...[o]ther...
[o]ther," with a rate of duty of 4.2 percent ad valorem.
HOLDING:
The subject prepreg is classifiable under the provision for
other flexible plates, sheets, film, foil, and strip of plastics,
in subheading 3921.90.40, HTSUS.
Sincerely,
John Durant, Director
Commercial Rulings Division
Source: rulings.cbp.gov — ruling 951151, retrieved 2026-10-12T05:26:17Z, republished verbatim. This digest is informational; only CBP issues binding rulings.