US 4,051,209 A · Continuous rigid foam panel production

Abstract

Composite panelling of upper and lower metal skins with side configurations for interlocking and a rigid foam core are continuously made by feeding separate upper and lower skin panels secured together by preassembled rigid foam end dams continuously past a foam station having a small height mixing head mounted on cross slides to lay down a zigzag pattern of foam between the skins, with the first and last transverse run of foam being parallel to the ends of the skins. A mixing head is such that valves are located within the head so that the two foamable chemicals do not contact each other until they are fed into the mixing chamber wherein a mechanical mixer mixes them immediately prior to being deposited, which mechanical mixer and valves are of minimum height and fully insertable within the molding space between the skins. A drive motor for the mixer is located in the main body supporting the mixing head, which main body does not enter into the mold cavity. The valves and cross slide are operated automatically, and if there is too long a delay between foam deposits, the chemical valve faces, mixing chamber, mechanical mixer and other parts exposed to the mixed chemicals will automatically be flushed with a solvent and air.

Claims9

Dependent claims

In a method of mixing two separately supplied chemicals to provide a foamable mixture and in response to a deposit signal, depositing the foamable mixture in a mold form to produce rigid synthetic foam, with contact between the two chemicals being only within a common mixture area before depositing, the improvement comprising:

depositing the foamable mixture in response to a deposit signal in a mold form as the chemicals are supplied to, mixed in and flow through the common mixture area;
thereafter discontinuing the depositing;
thereafter automatically timing the period wherein mixed chemicals are maintained in the common mixture area without substantial depositing and flow of the chemicals through the mixture area;
after said step of timing, depositing additional foamable mixture in response to a deposit signal only if the period of time after the last depositing step was discontinued is less than a fixed period of time that would result in substantial solidification of the chemicals, and preventing the depositing of additional foamable mixture despite the deposit signal only if the period of time after the last depositing step was discontinued is more than a fixed period of time that would result in substantial solidification of the chemicals;
and automatically washing the mixture area with a solvent in response to the period of time after the last depositing step and before additional depositing exceeding a fixed period of time that would result in substantial solidification of the chemicals.

2 more elements

A method of forming rigid foam panels by depositing foamable chemicals in a generally horizontally extending closed top mold moving past a foam depositing apparatus in a molding direction with a transverse mold wall forming one end of the mold and thereafter allowing the foamable chemicals to foam and cure within the mold as it continuously moves through a foaming and curing zone, the improvement comprising the steps of:

continuously moving the mold on an endless belt conveyor in the molding direction throughout the method;
automatically sensing the position of the continuously moving transverse wall;
automatically driving the foam depositing apparatus in the molding direction at the same speed as the continuously moving mold when the foam depositing apparatus is adjacent the interior edge of the transverse wall, and simultaneously moving the foam depositing apparatus transversely into the mold while depositing foamable chemicals along the interior edge of the transverse wall for substantially the full length of the transverse wall;
thereafter reducing the speed of the foam depositing apparatus in the molding direction so as to provide a relative speed in the molding direction between the foam depositing apparatus and the continuously moving mold, and simultaneously moving the foam depositing apparatus transversely back and forth within the mold while depositing the foamable chemicals to form a zigzag pattern of chemicals deposited within the mold;
withdrawing the foam depositing apparatus and thereafter curing the foam within the continuously moving mold in a pressure tunnel formed between the endless belt conveyor and an opposed endless belt conveyor.

2 more elements

A method of forming rigid foam panels by depositing foamable chemicals in a generally horizontally extending mold area having access only horizontally between top and bottom mold closure sheets that continuously moves past a foam depositing apparatus in a molding direction and thereafter allowing the foamable chemicals to foam and cure within the mold area as it continuously moves through a foaming and curing zone, the improvement comprising the steps of:

automatically driving a first foam depositing apparatus inserted within one side of the mold in a zigzag pattern relative to the mold area while depositing foamable chemicals in the mold area along a first line as determined by the relative movement between the mold area and the foam depositing apparatus;
simultaneously automatically driving a second foam depositing apparatus inserted within the side of the mold in a zigzag pattern relative to the mold area while depositing foamable chemicals in the mold area from the second foam depositing apparatus along a second line spaced from said first line, with the second line being determined by the relative movement between the mold area and the second foam depositing apparatus;
said first foam depositing apparatus determining a foam depositing pattern within the mold area on the one side of the mold separate from and spaced from the foam depositing pattern on the other side of the mold determined by said second foam depositing apparatus;
and automatically controlling the depositing of foamable chemicals by said one foam depositing apparatus and said second foam depositing apparatus in response to signals generated according to program to produce a large area free of cured and expanded foam in the final product between the patterns of foamable chemicals deposited by the one and second foam depositing apparatus.

1 more element

Dependencies are inferred from the claim text.

Continuous rigid foam panel production

Life of this patent

Continuous rigid foam panel production

Life of this patent

Abstract

Claims9