A method for producing an article by injection molding, the method comprising molding a first type component of the article in a first mold plate of a first double-sided mold; substantially parallel to molding the first type component, molding a second type component of the article in a first mold plate of a second double-sided mold; substantially parallel to molding the first and the second type components, molding a welding seam bonding together a first type component positioned in a second mold plate of the first double-sided mold, and a second type component positioned in a second mold plate of the second double-sided mold.