The present invention relates to systems and methods for forming openings in water soluble packets involving the use of a laser.
Water soluble packets, also commonly referred to as pouches or sachets, provide a single dose of a product in one convenient unit. The water soluble packets include a water soluble film sealed around a pre-measured amount of the product. During exposure or contact with water, the film dissolves and the product mixes with the water. The water soluble packets provide many benefits to the consumer. The water soluble packets are pre-measured, and thus avoid any measuring by the consumer. The product is contained by the film, and it not prone to spilling.
The water soluble packets are commonly used with dishwasher and laundry detergents. During a wash cycle, the water soluble film dissolves when exposed to the wash liquid allowing the detergent to mix with the wash liquid. The water soluble packets may also be used in any of a variety of different applications and contain any of a variety of different products. For example, herbicides, fertilizers, lawn chemicals, rinse-aids, cleaners, etc. may all be sealed within the water soluble packets.
Conventional water soluble packets are formed by using a drum having rows of cavities on its exterior surface. A base or bottom layer of film, such as a polyvinyl alcohol (PVA) film, is applied over the cavities. A vacuum from inside of the drum draws the base layer of film into the cavities to form a receptacle to receive the product. A specified amount of the product is next metered onto the base layer of film. A lid or an upper layer of film, such as additional PVA film, is then sealed over the base layer of the film. The product is now sealed inside of a combination of the base layer and the lid layer of films. Rows and rows of water soluble packets are formed as part of a continuous process. As the drum rotates, individual water soluble packets are cut from the rows of water soluble packets. Such processes and equipment are described in U.S. Pat. No. 3,218,776, which is hereby incorporated by reference.
During the filling and sealing process, air becomes trapped inside of the packet with the product. The air forms an air bubble or an air pocket inside of the sealed water soluble packet. The air bubble or air pocket may cause inadvertent rupture of the water soluble packet and is not desirable from an aesthetic or packaging perspective.
In order to get the air out of packet, a water mist is typically sprayed onto the sealed water soluble packet by a mister. The water mist creates passages in the film of the water soluble packet to allow air trapped in the laundry packet to escape. Unfortunately, the water may also cause much of the film to discolor, which may not be cosmetically desirable from a consumer's or a retailer's perspective. Further, the water soluble packets may also become sticky and adhere to one another after being sprayed with the water mist. This causes problems in automated filling processes, which direct the water soluble packets into containers for retail sale. In these automated filling processes, the containers may be filled by weight, and multiple water soluble packets sticking together may interfere with such automated filling processes.
Systems and methods for forming openings in water soluble packets involving the use of a laser are herein described. The laser forms the openings to vent the water soluble packets. The openings provide for the escape or release of air trapped in the water soluble packets. The laser also forms the openings to assist in the filling of the water soluble packet with detergent or other product. The laser burns openings into the water soluble film that forms the water soluble packet.
The openings provide a number of improvements in the manufacturing process for water soluble packets and the resulting water soluble packets. First, the laser openings do not discolor the entire film of the water soluble packet. Second, the laser openings do not make the water soluble packets sticky, which is a problem associated with the use of a conventional water mister. Further, the laser openings, when applied in a pre-fill stage, assist in forming the water soluble packet with several beneficial aesthetic features that may be more desirable to consumer. The product in such water soluble packets is more tightly packed with fewer wrinkles in the film as compared to conventional packets. Further, the water soluble packets formed using the laser processes described herein are not generally pliable and do not exhibit a loose feel common to conventional water soluble packets.
The openings may include holes, perforations, voids, vents, etc. in the film. The laser burns the openings in the films. The openings permit air to escape from the packets. During the manufacturing process, air may be trapped inside of the packet with the product. The openings provide for the trapped air to escape or vent. The air trapped in the water soluble packet is generally under pressure, and the openings allow the interior of the water soluble packet to equilibrate in pressure with the atmosphere. By allowing air to escape, the water soluble packet has improved packaging characteristics. The water soluble packets are packed more tightly with product. Further, the film does not have bubbles or loose folds of the film. Also, the packets are not sticky or mostly discolored. Further, the packets tend to have a uniform and consistent appearance. These characteristics may be desirable to a consumer or retailer.
The laser may be configured to form the openings at any of a variety of stages during the industrial manufacture of the water soluble packets. During the manufacturing process, the product is filled into cavities which are lined with a base layer of the film. The cavities are in the exterior surface of a rotating drum. After the filling, a lid layer of film is sealed to the base layer over the product.
The laser may form the openings at a pre-fill stage or at a post-fill stage in the manufacturing process of the water soluble packets. In a first pre-fill process, the laser forms the openings after the base film is positioned over or drawn into the cavities of the drum and before adding the product to the cavities. In a second pre-fill process, the laser forms the openings before the base film is positioned over the cavities. For example, the laser forms the openings in the base film as the base film is unrolled. In a third pre-fill process, the laser forms the openings in the lid film before the lid film is sealed to the base film. For example, the laser forms the openings in the lid film as the lid film is unrolled.
The laser may also form openings in the sealed packets of product, i.e., at a post-fill stage. For example, the laser may be positioned over an output or take away conveyor and direct pulses to the sealed packets.
The laser forms the openings as part of a continuous manufacturing process, i.e., the laser forms the openings while the film or water soluble packets are moving. Typically, the films or water soluble packets are not intermittently slowed or stopped in order to form the openings with the laser. As such, the use of the laser does not slow down production rates of the water soluble packets.
The laser may also be used with or integrated into both horizontal and vertical form fill seal machines.
In one aspect, a system to form openings in water soluble packets is described. The system includes a packet forming assembly to form water soluble packets. The packet forming assembly includes one or more cavities, a base film supply roll that supplies a base film to cover the one or more cavities, a feed hopper meters an amount of a product into the one or more cavities over the base film, and a lid film supply roll supplies a lid film that is sealed to the base film. A laser forms one or more openings in the water soluble packets.
In another aspect, a method of forming openings in water soluble packets is described. The method includes providing a packet forming assembly to form water soluble packets. The packet forming assembly comprises one or more cavities. The method includes covering the one or more cavities with a base film. The method includes feeding an amount of a product into the one or more cavities over the base film. The method includes sealing a lid film to the base film to form the water soluble packets. The method includes forming openings in the water soluble packets with a laser.
The water soluble packets 50 include a product 60 sealed between a base layer 70 and a lid layer 80. The base layer 70 is formed from a base film 200, while the lid layer 80 is formed from a lid film 300. The openings 90 include holes, perforations, voids, vents, etc. in either or both of the base layer 70 and the lid layer 80. As described below, the laser 410 may direct its pulses at any of the base film 200, the lid film 300, and/or the sealed water soluble packets 50. Depending upon the set-up, the laser 410 burns the openings 90 in any or all of the base layer 70, lid layer 80, base film 200, or lid film 300.
The base film 200 is directed to the drum 110 from the base film supply roll 220. A base film roller 230 presses the base film 200 against a surface 115 of the drum 110. The base film 200 generally covers a plurality of the cavities 130. Guide rollers 240 and 242 assist in directing and transferring the base film 200 to the drum 110.
The lid film 300 is directed to the drum 110 from the lid film supply roll 320. A lid film roller 330 presses the lid film 300 against the base film 200. A guide roller 340 assists in directing and transferring the lid film 300 to the drum 110.
The drum 110 includes multiple rows 142 of the cavities 130. Generally, the surface 115 of the drum 110 is covered with the cavities 130. The laser 410 may simultaneously pulse groups 144 of the cavities 130. The groups 144 may cover multiple rows 142 of the cavities 130.
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The laser 410 may be integrated with the packet forming assembly 100 in any of a variety of configurations or positions. As described below in greater detail, the laser 410 may form the openings 90, shown in
With reference to
In this aspect, the vacuum is also drawing air through the openings 90 in the film, which sucks the product 60 into the base film 200. The product 60 may be deposited on the base film 200 in the cavities 130 while the vacuum force is drawing the base film 200 into the cavity 130 and air is passing through the openings 90 and into the vacuum opening 133. This assists in increasing the density of the product 60 within the packet 50. The product 60 in such water soluble packets 50 is more tightly packed with fewer wrinkles in the film as compared to conventional packets. Without the openings 90 and the drawing of air through the openings 90 by the vacuum, the water soluble packet 50 will have a softer feel and the product 60 will be more loosely contained in the water soluble packet 50.
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The laser 410 will now be described. The laser 410 forms one or more openings 90 in the water soluble packet 50 or the portion of the films 200 and 300 forming the water soluble packet 50. In some aspects, the laser 410 forms four openings 90 in each water soluble packet 50. The openings 90 may have various sizes and shapes. For example, the openings 90 may have a size up to approximately 1000 um.
The system 10, laser assembly 400, and/or the processes described herein may be incorporated into water soluble packet forming systems and equipment from Cloud Packaging Solutions of Des Plaines, Ill. Such equipment is commercially available under the tradename HYDRO-FORMA.
The laser 410 may be configured to provide enough power to generally only burn the openings 90 into the film, and, in post-fill applications, not to burn a significant amount of the product 60 therein. The pulses will not damage the cavities 130, belts, rollers, or other components of the water soluble packet forming system 10. Although the laser 410 will not hurt a worker with incidental, momentary exposure to the laser 410, the system 10 and its equipment may be provided with a protective shield and/or barriers to prevent accidental exposure of workers to the laser 410.
With reference to
Any of a variety of lasers may be used with the system 10 and the processes described herein. One suitable laser for the laser 410 is a commercially available laser as Model 3320 from Videojet Technologies, Inc. of Wood Dale, Ill. This laser is a 30 watt CO2 laser.
The laser 410 and/or the controller 420 may be programmed to modulate any of a number of parameters and attributes of the laser pulses, for example, the timing of the laser pulses, the frequency of the laser pulses, the shape of the laser pulse, the pattern of the laser pulses, the area of coverage of the laser pulses, etc. The laser 410 and/or the controller 420 may include user-input controls, such as a touch screen, keyboard, etc.
The laser 410 may simultaneously emit an array of pulses that simultaneously forms multiple openings 90. For example, the laser 410 may be configured to simultaneously form openings 90 in the base film 200 covering multiple rows 142 and groups 144 of the cavities 130 of the drum 110. The laser 410 may be configured to simultaneously form openings 90 in multiple packets 50, multiple rows of packets 50, and/or or multiple groups 144 of packets 50. Likewise, the laser 410 may be configured to simultaneously form openings 90 across a web of the films 200 and 300 in multiple columns and rows. For example, in a post-fill process, the laser 410 may be configured to simultaneously form openings 90 in approximately 12 water soluble packets 50. For example, in a pre-fill process, the laser 410 may be configured to simultaneously form openings 90 across a portion of the films 200 and/or 300 of approximately 24 inches wide by approximately 0.25 to 1 inches deep. For example, in a pre-fill process, the laser 410 may be configured to simultaneously form openings 90 in a base film 200 covering approximately 12 cavities of the drum 110. Further, multiple lasers 410 may be used together to fully cover a width of the drum 110, films 200 and/or 300, or the take away conveyor 190.
The lid film 300 and base film 200 may be a water soluble film, such as a polyvinyl alcohol (PVA) film. The films dissolve with contact of water or other fluids. The films may have a thickness of approximately 1 millimeter to approximately 5 millimeter. Such films are commercially available from Monosol of Merrillville, Ind. Other water soluble films for forming the water soluble packets 50 may include any water-soluble, film-forming polymer, copolymer, or mixtures of such polymers. The polymers may include vinyl polymers, including homopolymers and copolymers, having functionality rendering the polymers water-soluble, such as hydroxyl and carboxyl groups. Typical water-soluble polymers include at least one of polyvinyl alcohol, partially hydrolyzed polyvinyl acetate, polyvinyl pyrrolidone, alkyl celluloses such as methylcellulose, ethylcellulose, propylcellulose and derivatives thereof, such as the ethers and esters of alkyl celluloses, and acrylic polymers such as water-soluble polyacrylates, polyacrylamides, and acrylic maleic anhydride copolymers. Suitable water-soluble polymers further include copolymers of hydrolyzed vinyl alcohol and a nonhydrolyzable anionic comonomer.
Although the methods, systems, and assemblies described above are described with respect to laundry and dishwashing water soluble packets, the methods, the system 10, and/or the laser assembly 400 may be used to form water soluble packets 50 containing any of a variety of products 60 such as, for example, powders, granules, or other solid compositions for any application, such as, for example, herbicides, fertilizers, lawn chemicals, rinse-aids, cleaners, etc. Generally, the water soluble packets 50 will contain a dry product 60.
In addition to the packet forming assembly 100, one or more lasers may also be used with or integrated into horizontal form fill seal machines and/or vertical form fill seal machines in order form openings to vent the water soluble packets. Horizontal form fill seal machines and vertical form fill seal machines are also used to make water soluble packets. As with other aspects, the openings provide for the escape or release of air trapped in the water soluble packets. The laser also forms the openings to assist in the filling of the water soluble packet with detergent or other product. These aspects are shown in
The lasers 505a, 505b, 505c, 505d, and 505e may be integrated with the packet forming assembly 500 in any of a variety of configurations or positions. Although
The lasers 605a and 605b may be integrated with the packet forming assembly 600 in any of a variety of configurations or positions. Although FIG. 10 shows the use of multiple lasers, only one of the lasers 605a and 605b needs to be employed. The lasers 605a and 605b may form openings 91 in the packets 55 at a pre-fill stage or a post-fill stage in the packet forming process. For example, the laser 605a may form the openings 91 in the film 650 before the film 650 reaches the horn 620. For example, the laser 605b may form the openings 91 in the packets 55 on the take-away conveyor 690. The laser 605b may be positioned directly over the take-away conveyor 690.
The systems 500 and 600 may also include the controller 420 to program and/or modulate any of a number of parameters and attributes of the laser pulses. The systems 500 and 600 may also include the encoder 430 to register and time the pulses from the lasers to strike the films or packets at the appropriate interval and time.
This application claims the benefit of U.S. Provisional Patent Application 61/764,196 filed Feb. 13, 2013, which is hereby incorporated by reference.
Number | Date | Country | |
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61764196 | Feb 2013 | US |