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Turning on the No Jam feature on your Pack 101 can be done in just three easy steps. The No Jam feature senses when product is in the way of the crimper. It allows the crimper to remain open while a designated number of products pass through before running production again.


Step 1: In the HMI, select “Recipe”, then “Crimper”
Step 2: Turn the No Jam feature to “ON”
Step 3: Select the number of “No Jam” cycles

Watch for more tech tips and instructional videos for your Bosch equipment. For questions or technical support, contact us.

This is the second in a series of blog articles intended to educate users new to flow wrapping and serve as a quick reference for experienced users .  It explains the sealing fundamentals of horizontal flow wrapping. This is useful in selecting the general type of packaging material and determining the machine settings that can be adjusted to influence the seal quality. (Read the first article in the series “Principle of Operation of a Horizontal Flow Wrapper“)

Generally speaking, two types of film can be distinguished: (1) heat seal film and (2) cold seal film. The choice of using heat or cold seal film depends on a variety variables, such as:

  • Product characteristics
  • Material costs
  • Required capacity/speed
  • Necessary barriers (Ultraviolet, Oxygen, etc.)
  • Hermetic seal strength or integrity

 Cold seal films consists of a base material (carrier) and a thin layer of glue. The sealing of this type of film is achieved by pressing the two layers of glue together. One of the advantages of this film is that it can be used at higher film speeds than heat seal films.   It also requires no heat to seal, so the lack of hot machine surfaces may be beneficial when dealing with temperature sensitive products, such as chocolate. However, there are some disadvantages.  Primarily that they can never offer the same protection and hermetic seal qualities as heat seal film.  They also need to be stored in a climate controlled room and lastly, the cost is generally higher than that of heat seal film. Therefore this type of film is less common than heat seal film.

Heat seal jaws cutting and sealing packages on a Pack 101 flow wrapper.

Heat seal jaws cut and seal packages on a Pack 101 flow wrapper.

Heat seal films are often multi-layered and consist of an outer coating that prevents the film from melting,  the core of the film such as polypropylene, and a sealant layer on the interior which has a lower melting temperature and bonds to seal the package together.  When high integrity seals are required, heat seal film offers the best alternative.  Generally, it is also less expensive than cold seal films.   Heat seal films are also offered in a wide range of laminations so that barrier properties can be optimized to meet product protection requirements.

The three important factors that should be kept in mind and controlled when producing a seal are:
(1) Heat: Temperature of the sealing surfaces (heat is not necessary with cold seal film)
(2) Dwell: Amount of time the machine jaws are in contact with the sealing material
(3) Pressure: Amount of pressure applied to the sealing material

Whenever a change is made in any one of these factors, one or both of the other two factors must be adjusted to compensate for this change. For example, when machine speed increases significantly, the dwell time will drop, so the temperature (and sometimes pressure) may need to be increased to compensate for this.

More details on optimizing sealing parameters and an overview of  different packaging films and their uses can be found in Bosch’s Guide to Flow Wrapping. It’s available for free download under the “Links and Downloads” section on the Pack 101 flow wrapper webpage on the Bosch Packaging website. This guide contains other sections to assist users in initially setting up their wrapper, changing over to new products, or solving problems common in flow wrapper operation.

Following Errors are one of the most commonly reported errors. Several weeks ago, we published a blog post pertaining specifically to Troubleshooting Following Errors on Stratus Wrappers. While this topic was very well received and helpful for those of you with Stratus wrappers, what about those of you with Linium wrappers? This week, we will provide a few simple steps to Linium (PC-104) Open Loop Diagnostics.

As discussed previously, a Following Error is generated by the machine motion controller triggering incorrect feedback from the motor to the computer.

The Open Loop diagnostic allows maintenance personnel to select a motor, enter a voltage (velocity) and run the motor (enable). Once the desired motor is selected, the velocity is set, and the enable is set to yes, pull out the emergency stop button. Press and hold in the start button. The selected motor will run in an open loop mode as long as the start button is held in.

Access the “Diagnostic Open Loop” screen to display information helpful to diagnose motors and encoders.

Note: The Emergency Stop button must be pressed in before entering this diagnostic for the function to work.

Linium Open Loop Diagnostic Image

The diagnostic screen displays the following information:

Motor: Turn the Press-To-Accept knob to select the desired servo motor drive (infeed, finwheels, or cutting head; power feed roll and discharge motors are not servo motors and cannot be tested with this diagnostic).

Velocity: Indicates the desired analog voltage being sent to the motor drive. Turn the Press-To-Accept knob to change the analog voltage.

Enable: To start the diagnostic, rotate the Press-To-Accept knob to display “Yes”. This will enable the drive.

Encoder: Indicates the encoder position of the selected motor. When the motor is rotating in the correct direction, this value should be incrementing.

Direction: Indicates the status and direction the motor is rotating. When the motor is rotating, it should display “Forward”.

And just like that, you’re back in business! Continue to watch for future posts pertaining Following Error troubleshooting as well as other tech tops for Bosch Wrappers. If you are interested in tech tips not specific to Following Errors, inquire and we will publish a blog that can be helpful for everyone!

As always, contact our technical experts for further assistance with your Bosch Packaging Equipment.

A Following Error is generated by the machine motion controller triggering incorrect feedback from the motor to the computer.  In Layman’s terms, the motor was commanded to move to a specified point in a specified amount of time, if it does not get there in the correct amount of time, a fault occurs, and this is called a Following Error.   A simple product jam or mechanical failure may cause a Following Error resulting in unnecessary downtime.  Should this fault occur, do you know how to quickly and effectively diagnose the problem?

Open and closed loop speed commands are used to troubleshoot motors, cabling, amplifiers, resolver feedback, and wiring associated with the close loop feedback.

Stratus Key Pad

By using the diagnostics drive setup, a small voltage can be sent to an individual axis without the machine homed or synched. By monitoring the direction on the drive set-up screen you can also verify the correct encoder feedback. Note: All the amplifiers cabling and motors are the same. Cable swapping can be done to easily identify a bad component.

Note: Machine must have power off and locked out while swapping cables.

The below picture is an example of moving the cutting head motor cable and feedback to the finwheel drive. Once the cables are swapped output a speed command from the finwheel axis to verify if the motor or the amplifier is the problem.

Stratus-cutting head motor cable

Perform the following steps to access the diagnostics screen and the drive set-up screens:

Step 1: Press the diagnostics key on the control panel. (Figure 1 screen will appear.)

Step 2: Rotate the press to accept button until the drive set-up is highlighted.

Step 3: Push the press to accept button. (Figure 2 screen will appear.)


Step 4: By rotating the press to accept dial, select the axis you wish to run and set the enable motion on.

Step 5: Set output voltage to approximately 1 volt and press start.

Note: All emergency switches have to be pulled out and guard switches closed.

Watch for future posts and tech tips pertaining Following Error troubleshooting for other Bosch Wrappers (Stratus, Linium, Pack Wrapper PC-104/WinPack Key Pad and Pack Wrapper Touch Screen).

Contact our technical experts for further assistance with your Bosch Packaging Equipment.

A common question raised by first-time manufacturers or manufacturers launching a new product is “What type of flexible packaging film is best for my product?”  While there is a large variety of films available today, we’ve listed the top 10 that we see used in horizontal form fill seal (flow wrapper) applications.  The most popular film for flow wrapping by far is Polypropylene.  It is used in some form in almost 90% of applications.

Top 10 FilmsPolypropylene  (PP – OPP) Film

Polypropylene is the most commonly used film for horizontal form fill and seal.  It is used to over wrap snack foods, candy, baked goods, etc.  The common make-up of this film consists of an outer layer, a polypropylene core and a sealant layer on the interior.  The outer layer is commonly acrylic coated to prevent the film from melting on the crimping jaws and also to reduce friction on contacted surfaces.

Polypropylene film over wrap provides a containment seal and protection from dirt and dust.  It also provides some degree of protection from moisture and oxygen, but over time this film does allow exchange of atmosphere.

Polypropylene film can come in literally hundreds of laminations depending on your specific needs.  Unprinted polypropylene is a clear film that provides complete visibility of the product inside.

Polypropylene film can be supplied with several types of heat seal layers or with a cold seal adhesive layer.  Sealant layers such as metallocene, surlyn or EVA melt at lower temperatures than most sealant layers and tend to increase line speeds.

Polypropylene films can be laminated with other materials such as low density polyethylene and used for Modified Atmosphere Packaging or gas flush applications.  These gas flush applications require a barrier film and “hermetic” seals. Barrier films will not allow for exchange of atmosphere from the inside of the package to the outside or vice versa.  In modified atmosphere packaging the oxygen inside the package is replace with nitrogen, carbon dioxide or a blend of both gases. This inhibits the growth of mold and extends the shelf life of the product inside the package.

Polypropylene film is also available as an opaque film.  This film provides a nice white appearance and also provides for very attractive graphics when printed.  This film is commonly used for chocolate bars and ice cream treat over wraps. This film can also be either heat sealable or cold seal.  The white layer helps to slow product deterioration due to light sources.

A third type of polypropylene film is metalized.  This film has a vacuum deposited aluminum layer applied when the film is produced.  The metallization of film enhances the film’s ability to protect the product from outside oxygen and moisture.  It also provides some degree of protection from light deterioration of the product.

Metalized opp is used for candy bars, breakfast bars and in some applications pharmaceutical applications where it replaces foil laminates.

Most polypropylene films run in a temperature range of 225F – 425F, depending on thickness of film, sealants, coatings and speed.

Polyester (PET) Film

Polyester films are commonly used as an outer layer in laminations with other materials.  Polyester has good heat resistance which performs well in high speed applications.  This film will not shrink due to high temperatures like polypropylene will.  The polyester layer in a laminate also adds some structure strength to the film.

Light gauged polyester has become the standard over wrap material for toaster pastries.  Because of its heat resistance, polyester wrapped products can be heated in microwaves.  There is also a variety of polyester that can be used in ovens.  This material is used to wrap products such as French bread.  It is also used for lidding material on most frozen trayed products.  These products can go directly from freezer to oven!

48 gauge polyester along with a sealant layer of LDPE is widely used for moist towelettes and baby wipes.

Polyester films will typically accept temperature settings as high as 500F +.

Polyethylene (PE) Film

 Polyethylene film comes in two common versions:

  1. Low Density Polyethylene (LDPE) commonly used in shrink applications such as pizzas, soap bars for South America and a variety of other shrink bundle applications.  LDPE can also run on a fin seal type horizontal wrapper if the film is produced with a sealant layer on the inside.  Typically EVA is used for a sealant layer.  This film is primarily used for wrapping plastic cutlery, syringes for the pharmaceutical industry and literature over wrap. Sealing temperatures for LDPE with an inside sealant layer are usually in the 225F – 250F range.  Linear Low Density Polyethylene (LLDPE) is used in laminations of materials to add tear resistant properties to the finished film structure.  It can also be used as a sealant layer in laminated films.
  2. High Density Polyethylene (HDPE) requires a sealant layer in order to seal on a fin seal type horizontal wrapper.  It is used as an outer layer along with LDPE and an EVA sealant layer for wrapping Waffles, crackers and plastic cutlery, to name a few applications.  Sealing temperatures for HDPE blends are typically in the 250F -300F range.

Foil Laminations

 Foil laminations are made up of an aluminum alloy sheet sandwiched between another film layer and an inside sealant layer.  These laminations can be several layers thick depending on the desired film properties.  Thickness of the foil layer can also vary widely.

Foil laminations are used for pharmaceutical products and light sensitive products. The outer layer of a foil lamination may be paper, polyester, nylon and polypropylene or others.

Foil laminates have the highest barrier properties of any material used for over wrap.

Seal temperature for foil laminations can range from 300F-500F depending on thickness, outers layer and sealant layer.

Foil laminations often require extended dwell wrappers to seal properly.

Paper/polyethylene laminations

Paper/poly laminations are commonly used to wrap gauze bandages.  Several frozen food products such as pot pies and burritos are wrapped in paper/poly films.  Some manufacturers have added a thin metalized layer to the film; this is called “suseptor” film.  The suseptor layer works in the microwave to help brown or promote crispness of the product.

Paper/poly films typically do not run at high rates of speed due to the insulating factor that the paper creates.

Typical heat ranges are 350F – 500F and may require preheat in order to attain line speeds required.

Glassine Film

Glassine is a grease resistant paper with an inner sealant layer.  It is typically use for fried products such as fruit pies found in vending machines.  This type of film is being phased out in favor of other materials that run faster and are not a prone to tearing.

Valeron Film

This is a name that has been given to a film that was developed for its superior tear strength properties.  It is used for wrapping most chlorine tablets for toilet tank and swimming pool use.  This film provides an excellent moisture barrier, but its highest asset is its very high resistance to punctures and tears. These qualities make it child resistant which is a requirement for commercial chlorine products.

This film typically will not seal at speeds above 450 inches per minute.  The film also has a very narrow sealing window.  This means the temperature window between good seals and melting the film is very narrow!

Shrink Film

There are several films that fall into the shrink film category and include films made from polyethylene. Low density polyethylene and linear low density polyethylene films are common along with some polypropylenes. Shrink films can also be made from an ethylene-propylene copolymer and multi-layer polyolefin.

These films are always run on a wrapper using a lap bottoms and a hot knife end seal.

Product wrapped using shrink films are: compact disks, candles, greeting cards, box over wrap and trays of frozen product.

Polyvinyl Chloride (PVC)

Also included in the shrink film category is Polyvinyl Chloride (PVC).  PVC is used because of its high clarity and stiffness.  It is used in place of polyolefin film where very high clarity is desired.

PVC films are run using a lap seal that is usually a static seal.  The end seal is created by a special PVC knife that seals and separates the packages. These films are also used to wrap candles, greeting cards and compact disks.

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