NOVELTY - Making (M1) a poly(vinyl butyral) (PVB) sheet involves providing a first poly(vinyl butyral) resin in a first amount; providing a first plasticizer in a second amount; melt blending the first amount of the first poly(vinyl butyral) resin with the second amount of the first plasticizer and a third amount of a hydrogen peroxide to create a poly(vinyl butyral) melt blend; and extruding the poly(vinyl butyral) melt blend into a poly(vinyl butyral) sheet.    USE - For making a poly(vinyl butyral) sheet (claimed) used for laminating multiple layer glass panels such as windows of motor vehicles and photovoltaic solar panels.    ADVANTAGE - The poly(vinyl butyral) sheet has a lower melt viscosity compared to a poly(vinyl butyral) sheet formed by melt blending the first amount of the first poly(vinyl butyral) resin with the second amount of the first plasticizer without any hydrogen peroxide. The reduced surface roughness in PVB sheet formed from PVB resins with hydrogen peroxide added during melt blending can often be used to reduce the level of mottle in some multilayer interlayers. The hydrogen peroxide, when used at the high temperatures normally associated with polymer extrusion, is expected to have no effect on the PVB sheet because it would quickly decompose completely in the very beginning of the extrusion at extrusion temperatures. This latter indication provides extruded PVB sheet including minimal, if any, amounts of leftover hydrogen peroxide. Thus, the inclusion of hydrogen peroxide in the PVB melt blend alters the resultant chemical composition of the PVB in any significant way. The hydrogen peroxide can be included in a melt blend of PVB to lower the average molecular weight of PVB resin and, thus, melt viscosity, resulting in a PVB sheet shows improved and beneficial properties, specifically, increased flowability, compared to the same PVB sheet manufactured without use of hydrogen peroxide in the melt blend.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) poly(vinyl butyral) melt blend comprising a poly(vinyl butyral) resin; a plasticizer; and hydrogen peroxide; and    (2) poly(vinyl butyral) sheet produced by method (M1).