Unitary injection molded filter
AssigneeSuratco Products Company
InventorRobert E. Stamstad
Life of this patent
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Abstract
A unitary injection molded filter is disclosed which includes a rigid frame of resin material to provide a rigid shape to the filter, and at least one screen of non-woven sheet resin material suspended on the frame and having formed therethrough a plurality of holes extending between the opposed side surfaces of the screen so as to form fluid passages therethrough. Each screen is integrally molded simultaneously with the frame.
Claims20
A unitary injection molded filter for separating small particulate matter from a fluid comprising:
- (a) a rigid frame of synthetic resin material to provide a rigid shape to the filter;
- and
- (b) at least one screen of non-woven sheet synthetic resin material with opposed smooth side surfaces made integral with the frame and having formed therethrough a plurality of holes extending between the opposed side surfaces of the sheet so as to form fluid passages therethrough, each hole having a minimum transverse width within the range of approximately 0.0005 inches to 0.01 inches, wherein the filter is formed by a process comprising injecting a quantity of thermoplastic resin material into a mold to simultaneously form the frame and the screen of the filter.
A method of forming a unitary injection molded filter for separating small solid particulate matter from a fluid comprising the steps of:
- (a) injecting a quantity of thermoplastic resin material into a mold which includes at least two mold parts with mold cavity surfaces, and at least one of the mold cavity surfaces including projections formed on it extending to the cavity surface of the opposed mold part for the formation of a plurality of holes through the filter, the mold forming a filter which includes a rigid frame to provide a rigid shape to the filter, and at least one screen of non-woven sheet resin material with opposed smooth side surfaces made integral with the frame and having formed therethrough the holes which extend between the opposed side surfaces of the sheet so as to form fluid passages therethrough, each hole having a minimum transverse width within the range of approximately 0.0005 inches to 0.01 inches, each screen being simultaneously and integrally molded with the frame;
- (b) allowing the formed filter to cool so that it will hold its form;
- and
- (c) opening the mold cavities and separating the filter from the mold cavities.
A mold for forming a unitary injection molded filter for separating small solid particulate matter from a fluid comprising:
- (a) at least one mold part defining a mold cavity surface formed by an engraving process, the surface including projections which project from an otherwise continuous smooth surface formed in the mold part for the formation of a plurality of holes through the filter, the projections having flattened tops and a minimum transverse width within the range of approximately 0.0005 inches to 0.01 inches;
- (b) at least one opposed mold part defining an opposed mold cavity surface including a continuous smooth surface which abuts against the flattened tops of the projections of the other mold for the formation of a plurality of holes through the filter, the mold forming a filter which includes a rigid frame to provide a rigid shape to the filter, and at least one screen of non-woven sheet resin material formed between said continuous surfaces of the mold and made integral with the frame with holes formed by the projections, the holes extending between opposed smooth side surfaces of the sheet so as to form liquid passages therethrough, wherein portions of the mold cavity in which the frame and the screens are formed are interconnected such that resin material can be injected to simultaneously mold the frame and screens.
Dependencies are inferred from the claim text.