US 11,794,385 B2 · Integrally molded body

Abstract

The following configuration is adopted for the purpose of solving reduction in strength and rigidity at a weldline which is a problem of an injection molding body, and enabling free design such as thin wall molding or complex shape molding of the injection molding body. That is, there is provided an integrally molded body in which a substrate for reinforcement (a) having a discontinuous fiber (a1) and a resin (a2) and an injection molding body (b) having a discontinuous fiber (b1) and a resin (b2) are integrated, the substrate for reinforcement (a) covering a part or all of a weldline of the injection molding body (b) to be integrated with the injection molding body (b), the ratio of thickness Ta of the substrate for reinforcement (a) to thickness T of a weldline part of the integrally molded body satisfying relational expression: in a case of Ea≠Ebw, Ta/T≤((Ebw−√(Ea·Ebw))/(Ebw−Ea)) in a case of Ea=Ebw, Ta/T≤0.5 wherein, Ta: Thickness of substrate for reinforcement (a), T: Thickness of weldline part of integrally molded body, Ea: Flexural modulus of substrate for reinforcement (a) in width direction of weldline, and Ebw: Flexural modulus of weldline of injection molding body (b) in width direction of weldline.

Claims16

Dependent claims

An integrally molded body in which a substrate for reinforcement (a) having a discontinuous fiber (a1) and a resin (a2) and an injection molding body (b) having a discontinuous fiber (b1) and a resin (b2) are integrated,

the substrate for reinforcement (a) covering a part or all of a weldline of the injection molding body (b) to be integrated with the injection molding body (b),
a ratio of thickness Ta of the substrate for reinforcement (a) to thickness T of a weldline part of the integrally molded body satisfying relational expression:
in a case of Ea≠Ebw,
Ta/T≤((Ebw−√(Ea·Ebw))/(Ebw−Ea))
in a case of Ea=Ebw,
Ta/T≤0.5
wherein, Ta:
Thickness of substrate for reinforcement (a),
T:
Thickness of the weldline part of integrally molded body,
Ea:
Flexural modulus of substrate for reinforcement (a) in width direction of the weldline, and
Ebw:
Flexural modulus of the weldline of injection molding body (b) in width direction of the weldline,
wherein the substrate for reinforcement (a) covers a part of the injection molding body (b), such that when the integrally molded body is arranged such that a surface of the substrate for reinforcement (a) is placed in the horizontal direction and facing upward and projected from above, the substrate for reinforcement (a) having 50% or less and 5% or more of a projected area of the integrally molded body, and
wherein:
(i) the substrate for reinforcement (a) is in a form of a sheet or a tape of randomly dispersed discontinuous fibers (a1),
(ii) the substrate for reinforcement (a) is substantially isotropic, and
(iii) the substrate for reinforcement (a) does not have a weldline.

16 more elements

the substrate for reinforcement (a) covering a part or all of a weldline of the injection molding body (b) to be integrated with the injection molding body (b),
wherein the substrate for reinforcement (a) covers a part of the injection molding body (b), such that when the integrally molded body being arranged such that a surface of the substrate for reinforcement (a) is placed in the horizontal direction and facing upward and projected from above, the substrate for reinforcement (a) having 50% or less and 5% or more of a projected area of the integrally molded body,
a ratio Ea/Eb of flexural modulus Ea of the substrate for reinforcement (a) to flexural modulus Eb of the injection molding body (b) in a non-weldline part being 0.7 to 1.3, and
wherein:
(i) the substrate for reinforcement (a) is in a form of a sheet or a tape of randomly dispersed discontinuous fibers (a1),
(ii) the substrate for reinforcement (a) is substantially isotropic, and
(iii) the substrate for reinforcement (a) does not have a weldline.

4 more elements

Dependencies are inferred from the claim text.

Integrally molded body

Life of this patent

Integrally molded body

Life of this patent

Abstract

Claims16