摘要:
Apparatuses for producing and dispensing a reaction mixture include a mixing head for mixing the reaction components that are fed via two supply lines. The apparatuses also include a decompression system to relieve pressure from the supply lines to avoid the reaction components seeping into the mixing head. The decompression system includes two pressure vessels each with two sides, separated by a membrane. One of these sides forms an expansion chamber for the reaction component while the other side is connected to a pneumatic system. With this pneumatic system, the expansion chamber can be pressurized before the production of the reaction mixture is started. After the production of the reaction mixture, the pressure can be relieved.
摘要:
Through three separate passages opening in a common plane at right angles to one another into a mixing chamber, three components of a reactant polyurethane or polyurea elastomer composition to form in a mold cavity are introduced. One of the components is an aliphatic polyether amine having primary amino function and substantially free from free hydroxyl groups, catalysts with tertiary amino groups, carbon dioxide as a carbamate reactive with the polyether amine and optionally other inert gases and conventional polyurea additives. The second component is a polyisocyanate or prepolymer thereof and the third component C is water. The reacting mixture is formed through a throttle gap into the mold to form low-density foamed products under low fuming conditions and has no unreacted diisocyanates.
摘要:
A bag for producing a foam-in-bag dunnage material comprises a closed edge portion and, in a non-sealed state of the bag, an open edge portion, the closed and open edge portions delimiting an inner bag volume. The invention proposes that a bag structure of the bag comprises a mixing chamber which is adapted to receive foam precursor substances, which is arranged within the inner bag volume, which is at least partially and initially delimited against the remainder of the inner bag volume, and which in the non-sealed state of the bag is connected to the open edge portion.
摘要:
The present invention provides an apparatus for use in mixing and dispensing a curable fluid stream (stream) into an open mold to fill the mold to make polishing pads for chemical mechanical planarization of substrates. The apparatus comprises an actuator frame on which is mounted (i) a set of two plates releasably attached to the actuator frame and adapted to cut the stream when the mold is full and to release from the actuator frame after cutting the stream, and (ii) a dispenser unit for continuous pouring of the stream into an open mold, the apparatus adapted to enable removal of the released plates from the actuator during the continuous pouring after the mold is full, e.g. by raising the actuator frame and the (ii) dispenser unit, whereby one can place a container above the mold to catch the plates.
摘要:
An improved process for producing a molded microcellular elastomer with a reduced number of voids from at least two liquid reactants and a gas, which process comprises introducing into at least one reactant a gas to form an admixture; passing the admixture through a static mixer at superatmospheric pressure; then immediately mixing the admixture with the other reactant at superatmospheric pressure to form a reaction mixture; introducing the reaction mixture into a mold in which the pressure is substantially below the superatmospheric pressures used above; and curing the reaction mixture in the mold to produce a molded microcellular elastomer with a reduced number of large voids.
摘要:
The invention relates to a method of introducing reaction mixtures for single-component foams into pressure containers. The reaction mixture comprises at least two reaction components and a blowing agent and is formed in an injection mixing head. The reaction mixture is then introduced into an evacuated pressure bottle provided with a valve. Additional pure blowing agent is added via the injection mixhead subsequent to the introduction of the reaction mixture into the pressure container.
摘要:
Foam dispensing systems and methods are disclosed. Such systems and methods may include a foamed material dispenser, a dynamic mixer having a gas input, a process material input, and a foamed material output. The foamed material output may be in fluid communication with the foamed material dispenser. A pump having an output may be in fluid communication with the process material input of the dynamic mixer, and a gas injection valve may be in fluid communication with the gas input of the dynamic mixer. A gas pressure regulator may be coupled between the pressurized gas supply and the gas injection valve, and a gas injection cycle timer may be operatively connected to the gas injection valve, the gas injection cycle timer causing the gas injection valve to pulse open and closed to send pulses of pressurized gas into the dynamic mixer through the gas input.
摘要:
Through three separate passages opening in a common plane at right angles to one another into a mixing chamber, three components of a reactant polyurethane or polyurea elastomer composition to form in a mold cavity are introduced. One of the components is an aliphatic polyether amine having primary amino function and substantially free from free hydroxyl groups, catalysts with tertiary amino groups, carbon dioxide as a carbamate reactive with the polyether amine and optionally other inert gases and conventional polyurea additives. The second component is a polyisocyanate or prepolymer thereof and the third component C is water. The reacting mixture is formed through a throttle gap into the mold to form low-density foamed products under low fuming conditions and has no unreacted diisocyanates.
摘要:
Disclosed is a method for forming pre-froth plastics foam which comprises the steps of mixing the plastics components with a volatile liquid under pressure, causing the mixture to flow to a point of use, and maintaining a series of controlled pressure drops by means of present automatic valves or by passive means such as orifice plates. Typical foams are polyurethane and phenolic.