Melting heater and method for manufacturing molded product

A method for manufacturing a molded product, the method comprising:

• injection molding a pair of semi-molded products by a pair of molds using a melting heater including two glass plates arranged in parallel to each other and a plurality of element heaters arranged in a unit having a flat plate shape as a whole between the two glass plates;
• leaving one semi-molded product in one mold and leaving the other semi-molded product in the other mold;
• aligning joining end surfaces of the pair of semi-molded products by bringing the joining end surfaces of the pair of semi-molded products close to each other and causing the joining end surfaces to face each other;
• melting the joining end surfaces of the pair of semi-molded products by inserting the melting heater between the joining end surfaces of the pair of semi-molded products in a non-contact manner to melt the joining end surfaces;
• and
• pressure-bonding the joining end surfaces of the pair of semi-molded products by retracting the melting heater, closing the molds, and pressure-bonding the joining end surfaces to each other,
• wherein the glass plate is subjected to surface processing corresponding to a shape of the joining end surfaces and is designed to control infrared rays emitted from the plurality of element heaters, the plurality of heaters selectively heating and melting the joining end surfaces while melting of other portions of the pair of semi-molded products is prevented.

A melting heater configured to melt joining end surfaces of a pair of semi-molded products in a case where the joining end surfaces are melted and joined to manufacture a molded product, the melting heater comprising:

• two glass plates arranged in parallel to each other;
• and
• a plurality of element heaters arranged in a unit having a flat plate shape as a whole between the two glass plates,
• wherein the glass plate is subjected to surface processing for controlling infrared rays emitted from the plurality of element heaters,
• wherein the melting heater has a two-layer structure comprising a planar first layer and a planar second layer,
• wherein the planar first layer is formed of substantially half of the plurality of element heaters,
• wherein the planar second layer is formed of the remaining number of element heaters, and
• wherein each of the plurality of element heaters of the melting heater is subjected to surface treatment for reflecting the infrared rays on a surface on a side where the first layer and the second layer face each other.