Plastic and nonmetallic article shaping or treating: processes – Mechanical shaping or molding to form or reform shaped article – To produce composite – plural part or multilayered article
Patent
1992-05-04
1994-09-06
Woo, Jay H.
Plastic and nonmetallic article shaping or treating: processes
Mechanical shaping or molding to form or reform shaped article
To produce composite, plural part or multilayered article
264257, 264260, 264313, 264316, 2643288, 264510, B29C 4516, B29C 4513
Patent
active
053446011
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method of molding and in particular to a method of molding fiber-reinforced resin composite materials.
2. Description of the Background
Products and components made from high strength composites consisting of reinforcing fibers bonded in a matrix material system such as synthetic resin are continually finding new applications as their strength-to-weight advantages are realised and exploited. However, there are certain applications where the surface properties of the product cannot be achieved by the matrix material system employed in forming the component. Secondary coating processes, such as in-mold coating, can be used but in general these are restricted to thin coatings and they always complicate the production process and therefore add cost.
An example of such a product is an access chamber cover of the type described in European Patent No. 1047050. For this type of cover to be suitable for use in the highway it must have a top surface of sufficient thickness to contain a tread pattern and this surface must have exceptional wear and high friction properties. Such a surface coating requires the use of special resins in conjunction with the inclusion of aggregates, and it is very difficult to apply the secondary coating.
SUMMARY OF THE INVENTION
The method of the invention seeks to provide an improved manufacturing process which will allow the injection of two or more matrix material systems within a single moulding cycle of a component. Each matrix material system may, independently, have the ability to incorporate fibre reinforcement, aggregates, various fillers and the like.
According to the present invention there is provided a method of molding a composite article which comprises providing a mold adapted to receive a first matrix component for molding the article, inserting a membrane in the mold so as to define at least two contiguous volumes separated thereby, injecting the first matrix system on one side of the said membrane and injecting a second matrix system on the other side of the membrane.
Preferably the first matrix system has the characteristics required for the surface and, in effect, provides the surface coating on the finished composite article. It will preferably be a curable resin system and may contain fibre reinforcement, aggregates, various fillers and the like to give the necessary wear and surface friction properties.
The membrane acts as a boundry between the two volumes and allows injection of one matrix material system into the chosen volume confining it to that predetermined volume within the mould. The second matrix material may be injected into the other contiguous volume and the membrane is preferably adapted to allow one of the matrix systems to diffuse into the other so as to fuse, chemically combine or otherwise bond prior to or as part of the curing process for the article. The second matrix system may be a curable plastics resin system as used in our above mentioned European patent. The matrix component may be a cloth or batt of fibers, e.g. glass fibers, and may contain one or more foam inserts.
A membrane suitable for use on the method of the invention may be made in a number of different ways and the most suitable membrane will depend on the product and matrix material systems employed. Examples of suitable membrane systems are described below.
1) A membrane is formed from a woven, knitted or non-woven fabric with pore sizes of a predetermined value intended for use with matrix material systems of different viscosities. One volume can be injected with higher viscosity material which would be contained by the membrane after which the second volume is injected with the lower viscosity material which would penetrate the membrane and come into direct contact with the first material.
2) A membrane similar to that in paragraph 1 above maybe be coated and hence sealed with a thin film of nonporous material but the membrane or coating is dissolved by the second matrix material injected,
REFERENCES:
patent: 3087201 (1963-04-01), Williams et al.
patent: 3549477 (1970-12-01), Burgman
patent: 3761560 (1973-09-01), Newlove
patent: 4123488 (1978-10-01), Lawson
patent: 4435349 (1984-03-01), Dominquez et al.
patent: 4473208 (1984-09-01), Nava
patent: 4636422 (1987-01-01), Harris et al.
patent: 4714575 (1987-12-01), Preston
patent: 4758395 (1988-07-01), Zion
patent: 4781876 (1988-11-01), Kia
patent: 5034173 (1991-07-01), Altman et al.
patent: 5074771 (1991-12-01), Thakrar et al.
patent: 5089206 (1992-02-01), Kia
patent: 5132069 (1992-07-01), Newton
Smith Duane S.
Woo Jay H.
LandOfFree
Molding method using two different resins and a membrane does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Molding method using two different resins and a membrane, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Molding method using two different resins and a membrane will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1328056