A heat recovery wheel for a heat exchanger includes a wheel rim defining an outer perimeter of the heat recovery wheel, and a plurality of wheel passages located between the wheel rim and the wheel axis. The plurality of wheel passages are arranged in a plurality of radial layers relative to a wheel central axis. Each layer is defined by a first shaped material having a first cross-sectional shape and a second shaped material assembled to the first shaped material, the second shaped material having a second cross-sectional shape. Radially adjacent layers of the plurality of layers are secured directly to one another, and the plurality of wheel passages are configured for flow of a first airflow and a second airflow therethrough for thermal energy exchange between the first airflow and the second airflow.

An electrical heating unit for heating a heat shrink cover includes an electrical heating element and a carrier unit on which the electrical heating element is assembled. The carrier unit is attachable to the heat shrink cover. The carrier unit has a corrugated shape formed by a plurality of ridges extending along a longitudinal axis of the carrier unit.

A method of forming a corrugated thermoplastic matrix composite sheet includes preheating a thermoplastic matrix composite sheet including a thermoplastic matrix and a reinforcement material to at least about a melting temperature of the thermoplastic matrix; preheating at least one of a pair of complementary corrugating tools to at least about a glass transition temperature of the thermoplastic matrix; compressing the preheated thermoplastic matrix composite sheet between the pair of complementary corrugating tools to form a corrugation in the thermoplastic matrix composite sheet; and holding the corrugation between the pair of complementary corrugating tools until a portion of the thermoplastic matrix composite sheet having the corrugation is below the melting temperature of the thermoplastic matrix to form the corrugated thermoplastic matrix composite sheet.

A method for manufacturing a three-dimensionally deformed plate made of a wood fiber material comprises providing a prefabricated, flat wood fiber material plate as the original plate, preheating the original plate in sections, wetting the preheated section of the original plate with an atomized liquid mixture of water and a separating agent, introducing a section of the original plate that is preheated and wetted with a liquid mixture of water and a separating agent between two rollers of a molding station, wherein the rollers respectively provide a corrugated profile in the peripheral direction of the external surface, such that the original plate is being deformed in sections into a plate with a wave shape, wherein rollers are being used, the respective profiling of which has half-waves which follow one another in the peripheral direction and which at least partially have a different extension in the peripheral direction.

A system for manufacturing a three-dimensionally deformed plate made of a wood fiber material comprises a preheating station, a wetting device, and a molding station including two rollers spaced apart for receipt of a preheated and wetted flat wood fiber material plate therebetween. The rollers respectively include an external surface including a wave-shaped profiling in the peripheral direction, wherein the respective profiling has half-waves which follow one another in the peripheral direction, and which have a different extension in the peripheral direction