Inventor’s Corner

Laminated packaging material and methodology

Laminated packaging materials for liquid-food items that use paper or cardboard usually have one or more barrier layers, to prevent the contamination of the packed product due to oxidation, and to preserve the product’s taste and vitamins. This invention relates to a laminated packaging material that is suitable especially in heat-sealable packages for liquid food, such as milk, cream, and juice cartons, and encompasses the manufacturing of the material.

The material comprises a core of paper or cardboard, and oxygen- and aroma-proof barrier layers of ethylene-vinyl alcohol copolymer (EVOH) and polyamide. The intent is to provide a solution for combining the EVOH and polyamide, especially in a laminated packaging material for liquid food, without the typical drawbacks (mechanical weakness resulting in cracks, etc.) Also, it strives to keep the amount of polymer in the layers as low as possible, since, in general, laminated polymeric layers of cardboard potentially have a negative effect on the product’s smell and taste. Yet, the packaging material would be strong enough to endure the sterilization process of aseptic packaging.

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The laminated packaging material of the invention is characterized by the layer of EVOH and polyamide, which are joined together without a layer of adhesive in between, and that the material comprises a polymeric heat-sealing layer on both sides so that the core of paper or cardboard and the barrier layers are interposed between the heat-sealing layers. The absence of the adhesive layer reduces the number of layers compared to other conventional multi-layer structures, so the extrusion process is simpler and saves on materials.

Therefore, the laminated packaging material would consist of: (A) the packaging material and (B) the second surface layer, which form the outer surface of the package to be manufactured and act as a heat-sealing layer in the package. It is made of low-density polyethylene (LDPE). Next, there is the core (C), manufactured of cardboard, followed by the oxygen- (D) and aroma-proof barrier layers (E), joined together and to the cardboard core (C) without intermediate adhesive layers. The EVOH layer (E) is followed by an adhesive layer (F), which binds the EVOH layer to the second surface layer (G) of the material. As a heat-sealing layer, it joins the second surface layer (B) and forms an inner surface that is in contact with the liquid in the finished package.

The manufacture of the packaging material is carried out by extruding the polymeric layers to a moving cardboard web (C), forming the material core, while the extrusion process is controlled by rollers (H). Before coating, the cardboard web is subjected to corona treatment (I). The four superimposed polymeric layers (D-G) to be placed on the cardboard are each led from their own containers (J-M), where the polymers are guided to a nozzle (N) that algamates the molten polymers to one another in layers, and feeds the polymers to the cardboard in one combined web (O).

Patent number: 6,964,797
Date: November 15, 2005
Inventors: Matti Salste, Tapani Penttinen, Jalliina Järvinen, Risto Salminen, Terttu Heinonen, Tuomo Kuuppo (Helsinki, Finland)

Semiconductor wafer container washing apparatus

This invention, a semiconductor-handling equipment cleaning apparatus, is for use with wafer carriers within a cleanroom environment, for reducing contamination. To this end, the cleaning apparatus comprises a base portion with a first and second aperture. The base of the apparatus supports the wafer carrier in sealing contact near a first aperture. A first fluidic circuit introduces a first cleaning fluid to the inner surface of the carrier. A second fluidic circuit introduces a second cleaning fluid to the outer carrier surface. The carrier forms a barrier with the base so that the cleaning media is isolated, preventing the second fluid from mixing with the first fluid, thereby reducing cross-contamination between the fluids. Because the exterior and interior preparation fluids are contained within the separate fluidic circuit, the fluids for cleaning the interior surfaces may be recycled and used to clean the exterior surfaces.

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The cleaning fluids are used to periodically clean, rinse, dry, or otherwise prepare (for example, decontaminate) the interior and exterior surfaces of a wafer carrier. Preferably, the fluids are applied through dedicated mobile sprayers that are connected to the fluidic circuits. The fluidic circuits include the necessary drains, valves, filters, and pumps for the applied fluids (interior and exterior). The valves enable the fluids in the circuits to be recycled, combined, purged, or recharged as desired. In an alternative embodiment, multiples of wafer carriers may be cleaned concurrently.

The wafer carrier cleaner (A) comprises a chamber (B) that has a first and second sidewall, a rear wall, and a base. The first sidewall has an aperture (C) that is sized to receive a portion of a first or exterior sprayer (D), and the second sidewall has a support/aperture (E) sized to receive another portion of the exterior sprayer. The base includes a first and a second aperture (not shown). The exterior sprayer is configured so that it circumscribes the exterior of the wafer carrier (F). Finally, the separated fluids may be routed to receptacles (G) for processing or recycling.

Patent number: 6,926,017
Date: August 9, 2005
Inventor: David L. Halbmaier (Shorewood, MN)


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