Balanced crimp substrate reinforcement for molded products
A rubber molded product such as a brake cylinder diaphragm with a balanced elongation substrate reinforcement in both the warp and fill directions incorporated therein is provided. The fabric substrate reinforcement is woven without size and overfed after the weaving process leading to balanced crimp and elongation in the length and width directions. The fabric member is also woven with a reduced number of weft threads to start, but which are added back by overfeeding to further render the fabric elongation more isotropic in at least the warp and fill directions. The reinforcement substrate is placed in the mold along with the molding material and formed into the desired shape to assist in shape retention and overall structural stability. A method of forming a molded product including a balanced crimp reinforcement substrate is also provided.
1. A rubber molded brake diaphragm defining a bowl shaped portion, and consisting of a substrate reinforcement configured to improve shape retention and overall structural stability of the brake diaphragm by defining a fabric, circular in shape and of sufficient size to match a size of the bowl, with isotropic elongation in both a warp and weft directions, and a resorcinol-formaldehyde adhesion promoter, wherein the isotropic elongation is the result of weaving without size, reducing a number of weft yarns relative to a number of warp yarns woven, and overfeeding to increase a ratio of the warp yarns relative to the weft yarns by 5-10% in a manufacturing process of the substrate reinforcement, wherein a modulus of elongation for the warp and fill directions is defined as between 950-1050 kPa, and wherein the incorporation of the substrate reinforcement defining the aforementioned isotropic elongation results in a rubber brake diaphragm with a manufacturing scrap rate of less than 20%.
2. The brake diaphragm of claim 1 , wherein the ratio of the warp yarns relative to the weft yarns overfed in a manufacturing process of the substrate reinforcement is 9%.
3. A combination of a rubber molded brake diaphragm and a fabric substrate reinforcement, the combination consisting of,
a rubber molded brake diaphragm defining a bowl-shaped portion; and
a substrate reinforcement configured to improve shape retention and overall structural stability of the brake diaphragm by defining a fabric, circular in shape and of sufficient size to match a size of the bowl, with isotropic elongation in both a warp and weft directions, and a resorcinol-formaldehyde adhesion promoter;
wherein the isotropic elongation is the result of weaving without size, reducing a number of weft yarns relative to a number of warp yarns woven, and overfeeding to increase a ratio of the warp yarns relative to the weft yarns by 9% in a manufacturing process of the substrate reinforcement, wherein a modulus of elongation for the warp and fill directions is defined as between 950-1050 kPa, and wherein the incorporation of the substrate reinforcement defining the aforementioned isotropic elongation results in a rubber brake diaphragm with a manufacturing scrap rate of less than 20%.
4. A rubber molded brake diaphragm defining a bowl shaped portion, and comprising a substrate reinforcement configured to improve shape retention and overall structural stability of the brake diaphragm by defining a fabric, circular in shape and of sufficient size to match a size of the bowl, with isotropic elongation in both a warp and weft directions, and a resorcinol-formaldehyde adhesion promoter, wherein the isotropic elongation is the result of weaving without size, reducing a number of weft yarns relative to a number of warp yarns woven, and overfeeding to increase a ratio of the warp yarns relative to the weft yarns by 5-10% in a manufacturing process of the substrate reinforcement, wherein a modulus of elongation for the warp and fill directions is defined as between 950-1050 kPa, and wherein the incorporation of the substrate reinforcement defining the aforementioned isotropic elongation results in a rubber brake diaphragm with a manufacturing scrap rate of less than 20%.
5. The brake diaphragm of claim 4 , wherein the ratio of the warp yarns relative to the weft yarns overfed in a manufacturing process of the substrate reinforcement is 9%.