Introduction to liquid pouch fill and seal machines
Otherwise known as pouch filling or pouchpacking machines, this packaging equipment type fills premade pouches withproduct and then seals them shut.
Pouchfill and seal machines come in two main varieties: Rotary and inline. For thepurpose of todays article, we are diving deeper into the more popular Excel Filtration.
This machine design conserves valuable plantfloor space and is designed with packaging simplicity top-of-mind.
Rotary pouch packing machines are firstloaded with premade bags. There can be one, two, or four bag in feed lanes,with the single lane (SIMPLEX) MODEL being the most popular.
Upgrading to a model with additional lanes isnecessary when throughput needs cannot be met with a single bag in feed.
As the pouches are fed into the packagingmachine, they are gripped and held as a rotary table moves counter-clockwise throughdifferent static machine stations that are laid out in a circular fashion onthe perimeter of the equipment.
There are usually between 6 10 stations ona rotary pouch packing machine, the most popular configuration being 8stations. Different steps of the pouch filling and sealing process occur a teach station.
So let's dive right in! Here's how liquidpouch filling and sealing machines work:
Preformed pouches are first loaded intothe bag magazine of the liquid filling and sealing machine.
This is a manual process to be completed atregular intervals by an attentive human operator.
The pouches are then conveyed to the interiorof the machine by a bag feeding roller.
In 2018, Viking developed proprietary roboticinfeed technology for pouch fill and seal machines.
Basically, a robotic arm uses vacuum suctionpads to grasp each pouch and transfers it to the bag grippers.
This solution effectively eliminates much ofthe labor involved in manual bag loading and shingling. CONTACT US to see this innovative technology in action.
When a pouch is detected in the magazine by aproximity sensor, it is grasped with vacuum suction pads and lifted to a set ofbag grippers, which will consistently hold the bag through its entire journeyto each station of the pouch packing machine.
These grippers can support up to 10 kg (evenwith high use over time) on the best AUTOMATIC POUCH FILL ANDSEAL MACHINES.
A note regarding stand-up pouches with pourspouts: Constraints of some liquid pouchpacking machines mean your spouted pouch must fall within certain designparameters to be properly gripped by the machine.
If date or lot codes are required on the finishedpackage, this station can be fitted with printing or embossing equipment.Inkjet printers are recommended, but thermal transfer options are available.
The embossing option places raised charactersinto the bag seal area.
At this step, vacuum suction pads grasp theoutside of the liquid pouch and gently open the bag. If the pouch is fittedwith a zipper, vacuum suction will open the bag and opening jaws catch the topside of the bag to open it.
In either case, a blast of clean air is usedto ensure the pouch is fully open and ready to be filled.
Sensors are present in the bag area to detectwhether a pouch is present. If a pouch is askew or missing, these sensors willcommunicate that to the filling and sealing stations, which will not engage forthat particular pouch.
This ensures spilling and PRODUCT LOSS ARE VIRTUALLYELIMINATED and alsoallows the empty pouch to be reused in a future cycle.
Liquid product filling
A pre-specified dose of the liquid product isnow pumped into the pouch by a liquid piston filler that can draw product froma holding tank or hopper.
The specifications of the filler aredependent upon the LIQUID PRODUCT PROPERTIESAND VISCOSITY.
In general, liquid pumps can handle anythingfrom water-like products to thick sauces with particulates.
In the case of a solid + liquid productmixture like soup or MREs, this station will dispense the solid product only.
A settler will 'shake' the bag to encouragesolid components to the bottom of the pouch.
Optional second filling station
If the product has both liquid and solidcomponents or the bag requires a high volume liquid fill, a second fillingstation will dispense liquid product.
First sealing station & deflation
Prior to liquid pouch sealing, two wiredeflator components ensure any extra air is squeezed out of the bag.
To ensure proper pouch closure, two sealingstations are usually required for liquid applications, this being the first.
A pair of heat seal bars closes over thesealing area on the top part of the pouch, adhering sealant film layers to oneanother to create a closed seam.
Alternatively, ultrasonic sealing can beutilized, which uses vibrations to induce molecular friction that generatesheat only in the area between film layers.
Ultrasonic sealing is more costly than heatsealing but can create a more effective seal for some liquid packagingapplications.
Your POUCH PACKING MACHINE MANUFACTURER can guide you to the best sealing option for yourparticular needs.
Second sealing station
Identical to the previous step, the secondheat sealing station reinforces the seal, ensuring a completely closed packageseam. A second station is not required for ultrasonic sealing.
Seal cooling & discharge
To strengthen and flatten the seam, a coolingbar now passes over the sealed portion of the pouch.
This cooling bar can also add serrations tothe seam if desired.
The finished liquid pouch is now dischargedonto a conveyor and can be held in a receptacle or transported downline toancillary equipment like case or carton packers.