Cutting Archives - Greener Corporation

Adjusting Knives: Causes and Solutions for Excessive Shimming on Flow Wrappers & Rotary Vertical Baggers

Michael Wojtech — Tue, 28 Apr 2026 12:16:33 +0000

A Tech Bite from Greener Technical Service Manger Jeff Fouche

At times a client inquires why they need so much shim to get a new knife to cut on their flow wrapper or rotary vertical bagger, and our Technical Specialists have encountered this same issue during service visits. Excessive shimming of knives causes cutting problems that delay production, reduce knife and anvil life, and create sealing troubles.

This Greener Tech Bite identifies the optimal limits for shim thickness when adjusting knives and explains the reasons why excess shims may be required to get a knife to cut.

How Much Shim Should Be Required?

Greener Corporation sets and holds tight manufacturing tolerances on sealing jaws, knives, and anvils, so that the knife and anvil extend between the root and the mid-point of the serrations. The anvil does not require adjustment, and shims totaling no more than five to ten thousandths of an inch, or .12 to .25 millimeters, should be needed when setting up a new knife.

Problems Caused by Excessive Shims

Instability

With greater amounts of shim, the base under the knife becomes less solid and unstable.

Overadjustment

To overcome this instability the knife must be overadjusted to achieve the force necessary to cut against the anvil.

Premature Failure of Knives and Other Components

The heavy impact of an overadjusted knife—often conspicuous by the banging sound it makes as it strikes the anvil—causes knives, sealing jaws, springs, bearings, and other critical components to fail prematurely, increasing both downtime and spare part costs.

Poor Seal Quality

Overadjusted knives also create sealing problems, where the impact of the knife causes the sealing jaws to bounce apart, reducing the sealing pressure and seal quality on the leading end of the next package.

8 Conditions That Create the Need for Excessive Shims

1. The Knife and Anvil Are Worn and Need to be Replaced

When running sealing jaws, knives, and anvils from Greener, if a total shim thickness of more than fifteen or sixteen thousandths of an inch, or .38 to .4 millimeters, is needed under the knife, then a new knife and anvil should be installed.

2. A New Knife Was Installed With the Old, Used Anvil

With this practice, much greater force is required to achieve a cut and knife life can be reduced up to 50%.

3. Springs or Compression Washers Are Worn or Too Weak

Worn or weak springs or compression washers on the cutting and sealing head are failing to provide adequate cutting force.

4. Shims Have Burrs or Are Too Soft

Shims with burrs on their edges, or shims made from brass or another soft material, are flattening and compressing over time and failing to properly support the knife.

Greener can provide precut, high quality stainless steel shims that produce accurate, consistent knife adjustments.

5. Many, Thin Shims Instead of Fewer, Thicker Shims

The use of many, thinner shims instead of fewer, thicker shims has failed to provide a solid seat for the knife and reduced the available cutting force.

6. Clearance Set Too Wide

Clearance between the sealing jaws is set too wide, effectively deepening the slots in the jaws and requiring extra shims for the knife to cut.

If the clearance adjustment is incorrect, sealing problems will also be present.

7. Resharpened Knives and/or Anvils

Knives and/or anvils have been resharpened and need excess shim to compensate for their reduced height. Greener does not recommend resharpening knives and anvils unless it’s an emergency, where a new knife and anvil are not available to keep the machine running.

The price difference between a new and a resharpened knife is minuscule compared to the thousands of dollars in extra downtime costs required to setup and troubleshoot a resharpened knife.

8. Sealing Jaws With Deeper Slots – Shorter Knives and Anvils

Sealing jaws with deeper slots and/or knives and anvils with shorter heights are provided by some machine manufacturers and part suppliers. With these components, more than fifteen thousandths of an inch, or .38 millimeters, of shims may be needed to get a knife to cut—sometimes significantly more.

We don’t typically recommend shimming a new anvil. But if the anvil sits below the root of the sealing jaw serrations, it should be shimmed up to the mid-point of the serrations to reduce the shim thickness under the knife.

If the anvil sits too deeply, the knife will need to protrude above the tops of the serrations. The package is not supported as it spans between the edges of the anvil slot and can be fractured when the knife pushes it downward to meet the anvil.

Precise knife adjustment on your flow wrappers and rotary vertical baggers plays a vital role in optimizing package quality and productivity.

If you’d like input with establishing knife setup procedures, training, or troubleshooting chronic cutting problems, contact Greener Corporation. We provide integrated parts and technical services worldwide.

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Maintain Efficiency on Flow Wrappers with Systematic Preventative Maintenance

Michael Wojtech — Tue, 11 Nov 2025 16:46:06 +0000

A Tech Bite from Greener Technical Service Manger Jeff Fouche

Due to production demands and a shortage of experienced mechanics, maintenance on flow wrappers is often reduced to immediate problem solving. In the rush to restore production, this reactive maintenance relies on short-term fixes that don’t fully resolve the underlying cause of the problem and fail to restore peak efficiency. Repeat problems require additional quick fixes and further erode efficiency.

This Greener Tech Bite details systematic preventative maintenance practices for flow wrappers that sustain peak efficiency and production levels.

If you and your team don’t have the required time or experience to implement preventative maintenance, Greener’s Technical Specialists can provide regularly scheduled onsite visits to perform line evaluations, make necessary updates, and provide training on these procedures.

Systematic Preventative Maintenance

The following flow wrapper components and adjustments—from the product feed through to the package discharge—should be evaluated and updated at least every three months.

Product Infeed

On the product infeed, stretched or worn components cause product misalignment and create timing problems. Replace worn or stretched infeed flight chains. Inspect the belts—even those with automatic tensioners—and replace them if they are stretched, worn, or frayed and can’t hold the proper tension.

The product infeed should be level and aligned with the flow wrapper.

Rails – Deck Plates – Forming Box

Check the rails, deck plates, and the forming box for misalignment or damage and readjust, repair, or replace them as needed.

When not level, smooth, or properly positioned, these components inhibit movement of the product and packaging material, causing malformed packages that delay production.

Packaging Material Unwind

Replace the bearings of shafts and rollers on the packaging material unwind that don’t spin freely; they create excess tension that causes tracking problems.

Adjust rollers to create the proper tension on the packaging material as it moves throught he forming process.

Fin Wheels

Fin wheel issues can cause slippage, poor tracking, and seal problems. Make sure that the tension between the fin wheels is correct and adjust their tilt to prevent slippage and create tighter packages.

Replace fin wheels that are worn, damaged, or have sharp edges. Check the condition of the fin wheel bearings and replace them if needed.

Cutting and Sealing Head

The cutting and sealing head requires frequent inspection and updating.

Backlash

Check for and remove backlash between the upper and lower sealing jaws.

Gears

Inspect the gears and replace them if necessary.

Springs or Compression Washers

Assess the condition of the springs or compression washers and adjust or replace them as needed.

Bearings

Worn bearings cause chronic problems that can be difficult to diagnose. To determine if new bearings are needed, follow this bearing evaluation process.

Carbon Impression

Next, remove the knives and anvils and, with the sealing jaws at operating temperature, run carbon impressions to evaluate their condition and setup.

Sealing Jaws and Adjustments

Replace worn or damaged sealing jaws. Check and, if needed, readjust the clearance, phasing, serration alignment, and pressure.

Clean the slots to ensure that knives and anvils can be firmly and accurately seated. To prevent cutting problems, always replace the anvil when installing a new knife.

After adjusting the knife with shims or adjustment screws, re-check your sealing setup with another carbon impression.

Cleaning

At any point in the packaging process, insufficient cleaning can degrade efficiency.

Clean components such as belts, formers, deck plates, fin wheels, and both the upper and lower sealing jaws during scheduled production breaks and whenever time allows—before problems occur.

Regularly Scheduled Preventative Maintenance with Greener Corporation

Relying on reactive maintenance erodes package quality and output levels.

If you don’t have a systematic preventative maintenance program for your flow wrappers, consider partnering with Greener Corporation for regularly scheduled Technical Service visits. Our Technical Specialists will perform line evaluations, make necessary updates, and provide training to keep your flow wrappers running at peak efficiency.

To learn more contact Greener Corporation. We provide integrated parts and technical service solutions worldwide.

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How to Adjust Knives with Adjustment Screws on Flow Wrappers

Michael Wojtech — Sun, 20 Jul 2025 15:11:35 +0000

A Tech Bite from Greener Technical Service Manager Mark Green

Learning how to set up knives with adjustment screws can require time consuming trial and error. This Greener Tech Bite presents a fast, dependable, 8-step method for adjusting knives with adjustment screws on flow wrappers.

1. Bring the Jaws to Operating Temperature

To start, remove the old knives and anvils and bring the sealing jaws to operating temperature.

2. Check Sealing Adjustments

Then make sure your sealing adjustments are correct. Run some trial packages—with product if possible. Cut the packages apart with scissors, test the seals with your standard method, and make any necessary readjustments.

Clearance, the narrow gap between the upper and lower sealing jaw serrations, should be adjusted when the jaws are set up and generally left unchanged. Never use clearance to adjust the knife.

3. Clean the Knife and Anvil Slots

Once your seals are set, clean the slots to ensure a stable base for the knife and anvil.

4. Install the Anvil

Install a new anvil with the radiused, working surface facing up. The bottom edges of the anvil will be chamfered, unless your anvils have a radius on both sides.

The height of the anvil should range between the root and the mid-point of the serrations.

Jaws from some manufacturers have deeper slots that require shims to raise the anvil up to this level.

Always replace the anvil along with the knife. A new knife paired with a worn, scored anvil requires excess pressure to cut and will fail prematurely and cause sealing problems.

5. Install the Knife

Before you install the knife, back the adjustment screws out at least halfway. Then insert the knife with the bottom angle facing the screws.

Snug the knife retaining screws lightly. Do not overtighten.

6. Adjust the Knife

A. Using only the two outside screws, over-adjust the knife so that it protrudes slightly from the sealing jaw face.

B. Then back the two outside adjustment screws out from under the knife. The light tension from the set screws should hold the knife in place.

C. Roll the upper and lower jaws together. The anvil will push the knife back into the knife slot so that it is flush and level with the anvil.

D. Now turn the outer adjustment screws inward, using two fingers, until you feel them contact the bottom of the knife. Then turn each outside screw in an additional one-eight of a turn.

E. Insert a single sheet of copy paper between the jaws and roll the jaws together. You should have two short cuts on the outside edges. With small, incremental adjustments to the outside screws, increase the knife height until the small cuts are about one inch, or 25mm, long.

F. Now turn the center adjustment screw in, using two fingers, until you feel it contact the bottom of the knife. Then turn this screw slightly more—less than one-sixteenth of a turn—and run another sheet of copy paper through the jaws.

At this point the knife should either either cut all the way across, or you will lose the cut completely.

If you lose the cut, turn in the outside screws in extremely small increments until the one-inch cuts on the outer edges return.

Then repeat the previous adjustment process with the center screw until you get a clean, smooth cut.

7. Reset Over Adjusted Knives

If the knife is hitting hard, such that you can hear it banging and feel the heavy impact with your hands, it has been over adjusted.

In this case, back out all adjustment screws counterclockwise for one-half a turn and roll the jaws together, using the anvil to once again level the knife.

Then return to step 6D and repeat the knife adjustment process.

If at any time during this process you adjust one side of the knife to get it to cut and it causes the opposite side to stop cutting, do not adjust the opposite side. This indicates that you have over adjusted the knife.

In this case, back out the adjustment screw you last adjusted one-half a turn counterclockwise. Then roll the jaws together, using the anvil to push that side of the knife back in.

On the same side, adjust the knife out in small increments until you get a smooth, clean cut without banging.

8. Lock the Set Screws

And as a final step, once a good cut is achieved, go back and lock the set screws.

Troubleshooting

If your knife fails to cut after following these procedures, you may need to address other conditions on your flow wrapper such as spring pressure adjustments, worn springs, damaged bearings, and damaged sealing jaws or shafts.

To learn more about the full range of adjustments on your flow wrappers and vertical baggers, or to discuss training programs for your packaging team, contact Greener Corporation.

We provide integrated parts and technical service solutions worldwide.

The post How to Adjust Knives with Adjustment Screws on Flow Wrappers appeared first on Greener Corporation.

Align Flow Wrapper Packaging Processes on the Centerline

Michael Wojtech — Wed, 18 Jun 2025 09:34:35 +0000

A Tech Bite from Greener Technical Service Specialist Jeff Fouche

As product moves along the infeed and through your flow wrapper, each packaging process should accurately align on the centerline. This Greener Tech Bite explains how to detect and fix even small, seemingly insignificant misalignment of flow wrapper packaging processes that degrade package quality and delay production.

Symptoms of Misalignment

Symptoms of centerline misalignment include loosely wrapped packages, uneven fin seals that easily pull free from the fin wheels, and package wrinkles and pleats that cause sealing problems.

Assess Your Alignment

1. Align the Product Feed

First, make sure the product infeed is inline with your wrapper. Infeeds often get moved out of position and deliver the product at an angle, causing a number of chronic problems.

2. Center the Forming Box

Forming box adjustments can often be improved, especially if they have been moved off-center to compensate for product entering the wrapper at an angle. Ensure that the forming box is level, centered, and aligned with the product feed.

The packaging material tube should form evenly around the product, without wrinkles or gaps, and should help maintain the inline spacing between products to prevent them from interfering with the cutting and sealing process.

3. Center the Fin Wheels

Also make sure each pair of fin wheels is on the centerline.

Misaligned fin wheels create loosely wrapped, wrinkled packages that are more difficult to cut and seal.

4. Center the Sealing Jaws

On some flow wrappers the shafts have multiple mounting hole options. Make sure both the upper and lower sealing jaws are installed on center in relation to the package.

5. Center the Packaging Material Roll

Now check the packaging material roll and align it on center. The material may have been mounted off center to compensate for misalignments in other areas of the packaging process.

Once the first four processes and the packaging material roll are centered, the edges of the fin seal should meet evenly and create a clean, parallel edge.

6. Center the Product Rails

With the material on the center line, you can center the product rails so that they guide the product correctly into the forming box.

Remember to align flow wrapper packaging processes on the centerline as part of your preventative maintenance program and to resolve packaging problems.

If you have questions about preventative maintenance or packaging problems on your flow wrappers or vertical baggers, contact Greener Corporation. We provide integrated parts and technical service solutions worldwide.

The post Align Flow Wrapper Packaging Processes on the Centerline appeared first on Greener Corporation.

Install New Anvils When Replacing Knives on Flow Wrappers & Rotary Vertical Baggers

Michael Wojtech — Thu, 13 Mar 2025 11:39:27 +0000

A Tech Bite from Greener Technical Service Specialist Chris Stawasz

When you install a new knife on your flow wrappers and rotary vertical baggers, do you always install a new anvil? This Greener Tech Bite explains why reusing the old anvil when you install a new knife will cause cutting and sealing problems, delay production, and increase spare parts costs.

Why Anvils Don’t Get Replaced

The old, used anvil is often retained with good intent; when a knife fails, there is great pressure to minimize downtime. A new knife may be installed without a new anvil with the hope to save time and resume production as quickly as possible or to reduce spare parts costs.

Why You Should Replace the Anvil When Installing a New Knife

The expenses of a new anvil and the time it takes to install it are minimal compared to the costs of increased scrap rates and downtime caused by failing to replace the anvil.

Problems Caused by Not Replacing the Anvil

A new knife must be over adjusted to cut across the impression in the old anvil made by the previous knife.

When knives are over adjusted you can hear the heavy impact as they strike the anvil and feel the vibration when you put your hand on the machine. This condition causes multiple problems:

Premature Knife Failure

Over adjusted knives wear prematurely and must be replaced more often, increasing both downtime and spare parts costs.

Premature Failure of Critical Components

The heavy impact of the knife against the anvil also causes the premature failure of sealing jaws, springs, bearings, shafts, and other critical components.

Poor Seal Quality

When an over adjusted knife strikes the anvil with excess force, the trailing sealing faces of the jaws ”bounce” apart, reducing the transfer of pressure and heat to the leading seal of the next package and causing poor seal quality.

The missing serration imprints on this carbon impression clearly illustrate the bounce from an over adjusted knife.

Problems Caused By Compensatory Adjustments

Machine adjustments made to compensate for poor seal quality caused by an over adjusted knife often create additional problems.

Sealing Jaw Temperature

If temperature settings are raised in an attempt to restore seal quality, the additional heat expands the sealing jaws, knife, and anvil, making the knife over adjustment more severe and creating excessive pressure between the leading sealing faces of the jaws that can crush or split the trailing package seal.

Spring Pressure

Increasing spring pressure to compensate for an over adjusted knife can cause the knife to wear out even faster. And just as with higher temperatures, excess sealing pressure can split and damage the seals.

Clearance

Never adjust the clearance between the upper and lower sealing jaws to address cutting issues. Clearance should be set when the sealing jaws are installed and generally left unchanged.

Install New Anvils When Replacing Knives

Once you consider the problems caused by reusing anvils, you will better understand why installing a new anvil every time you replace a knife is the lowest cost, most productive practice for optimizing performance on flow wrappers and rotary vertical baggers.

To discover additional Technical Resources for flow wrappers and vertical baggers, consult our library of posts and videos and contact Greener Corporation.

We provide integrated parts and technical service solutions worldwide.

The post Install New Anvils When Replacing Knives on Flow Wrappers & Rotary Vertical Baggers appeared first on Greener Corporation.

Intermittent Cutting & Sealing Problems on Flow Wrappers: Diagnosing Worn Bearings

Michael Wojtech — Mon, 24 Feb 2025 05:07:25 +0000

A Tech Bite from Greener Technical Service Specialist Jeff Fouche

It can be difficult to determine the cause of intermittent cutting and sealing problems on flow wrappers. Issues may occur on two or three packages and then resolve, only to continually repeat at random intervals—perhaps in five minutes, then after twenty packages, and again an hour later.

This Greener Tech Bite explains how to diagnose and fix intermittent cutting and sealing problems on flow wrappers caused by worn bearings and other factors.

Severely Worn Bearings

Severe bearing wear causes cutting and sealing problems that are consistent, not intermittent. This severe wear allows movement in the shafts that you can feel when you tightly grip and push them up and down or side to side.

Uneven, Less Severe Bearing Wear

When bearings wear unevenly and develop random flat spots, you won’t be able to feel the shafts wiggle. Determining if this less severe bearing wear is creating your intermittent cutting and sealing problems requires the process of elimination—you will first need to rule out three other possible causes:

Worn Gears
Backlash
Misaligned Sealing Jaws
Worn Bearings

1. Worn Gears

To start, visually inspect the gears and replace them if they are worn. Worn gears mesh inconsistently and can cause poor seal quality and incomplete cuts at random intervals, especially when the wear is uneven.

Learn more from our post and video on the effects of worn gears.

2. Backlash

Also inspect for and remove backlash, or independent rotational movement between the upper and lower sealing jaws. Backlash causes intermittent cutting and sealing problems by allowing the knife to swipe across or leave multiple impressions on the anvil and by misaligning the serrations.

Visit our post and video about diagnosing and adjusting backlash on flow wrappers for more details.

3. Misaligned Sealing Jaws

Once backlash has been removed, the sealing jaws may still be misaligned. Run a carbon impression and check the alignment of the serrations. Misaligned jaws wear unevenly and cause intermittent problems when they don’t mesh properly.

Consult our Tech Bite on diagnosing sealing jaw misalignment with carbon impressions for more information.

4. Worn Bearings

If intermittent problems persist after you check and correct the first three issues, then your bearing are worn and should be replaced.

There is no reliable way to determine which bearings are bad, so when you invest the time to access the bearings you should replace all four of them.

The new bearings should eliminate your intermittent cutting and sealing problems.

If you would like to improve the forming, cutting, and sealing performance on your flow wrappers and vertical baggers, connect with Greener Corporation’s technical experts.

We provide integrated parts and technical service solutions worldwide.

The post Intermittent Cutting & Sealing Problems on Flow Wrappers: Diagnosing Worn Bearings appeared first on Greener Corporation.

Preventative Maintenance Quick Tips for Flow Wrappers and Vertical FFS Baggers

Michael Wojtech — Sun, 27 Oct 2024 12:20:59 +0000

Many simple, easily implemented setup and preventative maintenance steps on flow wrappers and vertical baggers can have an outsized effect on package quality and productivity.

This Greener Tech Bite presents a series of Quick Tips that prevent cutting, sealing, and forming problems and help you troubleshoot issues when they do occur.

Cutting

Clean Knife and Anvil Slots

The value of cleaning on a regular schedule, instead of waiting until product contamination causes problems, can’t be overstated.

To clean knife and anvil slots on rotary sealing jaws, cut a piece of scouring pad and push it down into the slot with a hex wrench. And don’t neglect to clean the anvil slot, even though it can be more challenging to access.

Product buildup in the slot creates an unstable base that can cause intermittent cutting problems and knife failure.

Sealing

Clean Sealing Jaws Regularly

Clean sealing jaws regularly, but don’t use stiff, coarse bristled brushes—they damage the serrations and cause sealing problems.

Brushes with finer, softer bristles are more forgiving. They can be trimmed in length to clean more effectively and to keep them from splaying out.

After cleaning the jaws, run a carbon impression to check the current set up so that you can make any necessary corrective adjustments before resuming production.

Install Sealing Jaws with New Bolts and Washers

Install sealing jaws with new mounting bolts and washers. Worn, damaged bolts and washers, which can easily go unnoticed, cause inaccurate mounting and make jaws difficult to remove in the future.

To ensure accurate setup and to prevent the jaws from shifting out of alignment, use hardened, flat washers to mount jaws on flat surfaces.

Spherical washers or, if they are not available, split washers are best for mounting jaws on round shafts.

Replace All Rotary Sealing Jaws at the Same Time

Replace all rotary sealing jaws on a machine at the same time, and make sure all the jaws come from the same supplier.

You may be tempted to replace only one jaw, or just one of multiple pairs, to save time or reduce costs. But inaccurate setup caused by sealing jaws with different wear levels and designs creates sealing problems.

Check Sealing Jaw Temperatures with a Pyrometer

Sealing jaws are often hotter in the middle than at the ends, where heat dissipates more quickly. The controller, however, does not reveal this variability, since it usually only indicates the temperature at one point within the jaw.

Use a pyrometer to regularly check multiple points across the functional length of the sealing face, to make sure temperatures remain within the seal range for your flexible packaging material and conditions.

Ongoing issues with inconsistent sealing temperatures can be solved with updated heater and sealing jaw designs.

Forming

Vertical Baggers: Maintain Proper Roller Adjustment

On vertical baggers, adjust the rollers to create even, consistent contact between the material and the forming collar wing—between positions 1 and 2 in the diagram.

Too much, too little, or uneven tension, demonstrated by positions 3 and 4, can cause wrinkles and creases that degrade package appearance and cause sealing problems.

Flow Wrappers: Adjust & Tighten Guide Rails & Deck Plates

On flow wrappers, make sure the product guide rails and deck plates are adjusted and tightened properly, and exercise care when removing and reinstalling deck plates—they can be easily bent or otherwise damaged.

Misadjusted rails or deck plates that are not level and smooth can inhibit the movement of the product and packaging material and cause malformed packages that delay production.

Also make sure the forming box is square and level.

Preventative Maintenance Quick Tips

By investing a relatively small amount of consistent time and effort, preventative maintenance can help you decrease problems that delay production and reduce package quality.

To learn more about solutions for improving package quality and productivity on flow wrappers and vertical baggers, visit our Technical Resource Blog and contact Greener Corporation.

We provide integrated parts and technical services worldwide.

The post Preventative Maintenance Quick Tips for Flow Wrappers and Vertical FFS Baggers appeared first on Greener Corporation.

Flexible Packaging Materials Consulting

Michael Wojtech — Mon, 23 Sep 2024 17:10:52 +0000

Greener Corporation provides a broad range of Flexible Packaging Materials Consulting resources for flow wrappers and vertical baggers.

Whether you need to assess your current material or evaluate new structures, our materials and machinery experts can help you Establish Objectives, Identify Options, Run Trials, and to Select and Implement the material that best meets your objectives.

Integrated Solutions

Greener’s integrated approach considers how the design and condition of your flow wrappers or vertical baggers will affect results and determines what machine adjustments or component updates may be needed.

Early Involvement & Collaboration

The earlier in your selection project that we work with you, and the more we collaborate with packagers, machinery OEMs, and materials suppliers, the more effectively we can integrate four essential elements of your process to produce optimal, timely results.

1. Establish Packaging Objectives

Greener can help you establish clear packaging objectives, based on the requirements of your product, distribution channel, and other criteria, that provide important standards for evaluating a material’s performance.

Barrier Properties

Barrier Properties protect against the transfer of odors, gases, or moisture.

Seal Integrity

Seal Integrity should correlate with your barrier requirements.

Sustainability

Sustainable recyclable and compostable materials must meet specific compositional and structural guidelines.

Machinability

Machinability testing indicates how a material’s thickness, stiffness, coefficient of friction, thermal conductivity, and other properties affect the packaging process.

Cost

Per-package material cost and the anticipated costs of machine downtime and scrap rates must also be considered.

2. Identify New Material Options

If you are unable to meet your objectives with your current material, we can help determine a list of new material options—perhaps even suggesting materials you may not have considered.

3. Trials and Evaluations

To help narrow your initial list down to the most promising options, Greener can assist with preliminary machine trials at your facility or run these trials in our Packaging Lab.

We can then help you run more extensive trials with this refined list of materials.

Adjustments and Part Designs

Before you run trials, Greener can assess the characteristics of these materials and recommend machine adjustments or updates to former, sealing jaw, and other part designs that are needed to optimize results and get a truer picture of each material’s potential.

A new material that meets your objectives for sustainability, for instance, might require higher seal initiation temperatures and be more easily damaged by excess pressure.

Package Testing

To evaluate machine trial results, we’ll help you establish criteria and determine the best package testing methods. For example, if your product does not require a material with a strong oxygen barrier, then seal integrity does not need to be hermetic.

Packages can be tested at your facility or in our Packaging Lab.

4. Select and Implement New Material

Well executed machine trials and testing can be used to determine which flexible packaging material best meets your objectives in a production setting.

We will help you implement changes to adjustment procedures and component designs, along with any necessary training, on the wrappers or baggers that will run the new material and ensure consistent results across different makes or models of machinery and at multiple facilities.

Greener’s Flexible Packaging Materials Consulting provides an additional resource to help you integrate and improve all aspects of your packaging process.

To learn more about solutions for improving package quality and productivity on flow wrappers and vertical baggers, contact Greener Corporation. We provide integrated parts and technical services worldwide.

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Sustainable Packaging Materials 2: Running Mono Polyethylene & Mono Polypropylene on Flow Wrappers & Vertical FFS Baggers

Michael Wojtech — Thu, 08 Feb 2024 14:51:49 +0000

Most traditional flexible packaging is made from multiple layers of different materials that can’t be easily separated. Mono polyethylene (PE) and mono polypropylene (PP) are produced from the same or similar materials, and are the most common polymer-based sustainable packaging materials we’ve encountered so far.

Segment 2 in our Sustainability Series explores the properties that can make mono PE and mono PP more challenging to form, cut, and seal, and presents solutions for maintaining package quality and machine speeds when running these materials on flow wrappers and vertical FFS baggers.

FORMING Mono PE & Mono PP Packaging Materials

During the forming process, the thicker, stiffer nature of mono PE and mono PP structures creates greater tension in the web. On both flow wrappers and vertical baggers, a power film drive will help keep these structures tracking properly.

Specially designed formers are often required to maintain consistently sized packages that are free from creasing and scoring.

CUTTING Mono PE & Mono PP Packaging Materials

The mechanical properties of these thicker and stiffer structures can also make cutting more challenging.

Knives designed for your specific packaging material will improve cutting performance.

Special features such as an extreme angle zig zag knife can improve openability for the consumer.

SEALING Mono PE & Mono PP Packaging Materials

As explained in our previous Tech Bite, the effective seal range of a packaging material is defined as the difference between the seal initiation temperature and the distortion temperature.

With all flexible packaging materials, machine speeds are limited by the need to fit normal sealing jaw temperature cycles within the seal range.

Many current mono PE and mono PP structures have a lower distortion temperature, which decreases their seal range.

And since these mono structures tend to be thicker and stiffer, higher sealing jaw temperatures are needed for heat to reach and activate the sealant layer. This further reduces the seal range.

With sealing jaw temperature increases limited by the lower distortion point, reductions to machine speed may be necessary to provide adequate dwell time for seal initiation.

Sealing Solutions

Advanced sealing jaw designs can help mitigate sealing issues encountered with mono PE and mono PP materials. Sealing jaws made from Greener Corp’s proprietary Dura-Therm alloy provide more responsive and consistent thermal conductivity across the sealing face to reduce temperature cycle fluctuations and help maintain seal quality and machine speeds.

Temperatures don’t spike as high when the machine idles, or drop as far when the line restarts.

Customized sealing jaw serration patterns and options such as Easy Seal™ FLEX jaws can also reduce temperature cycles by optimizing thermal transfer and sealing pressure.

In addition to sealing jaw design, optimized adjustment procedures and training are critically important for maintaining seal quality and machine speeds on flow wrappers and vertical baggers.

To learn more about sustainable flexible packaging materials, advanced part designs, machine adjustments, and training, contact Greener Corporation.

We provide integrated parts, industrial packaging solutions and technical services worldwide.

The post Sustainable Packaging Materials 2: Running Mono Polyethylene & Mono Polypropylene on Flow Wrappers & Vertical FFS Baggers appeared first on Greener Corporation.

Setting Up Shim Style Knives and Anvils on Flow Wrappers

Michael Wojtech — Thu, 24 Aug 2023 13:49:59 +0000

Establishing accurate knife and anvil adjustment methods on flow wrappers is critical not just for cutting, but also for producing quality seals and avoiding preventable production delays.

This Greener Corporation Tech Bite details setup procedures for shim style knives and anvils that consistently optimize package quality and productivity.

1. Check the Seal

Before installing knives and anvils, make sure your sealing adjustments are correct.

Temperature Settings

For heat seal applications, confirm that temperature settings are within the prescribed range.

Clearance

Clearance, the narrow gap between the upper and lower sealing jaw serrations, should be set just wide enough to create an interference fit for a double layer of film—generally about the thickness of a sheet of paper.

Trial Packages

Run trial packages, with product if possible. Cut the packages apart with scissors and test the seals with your standard method.

2. Clean the Slots

Once you are producing quality seals, remove old shims and clean product buildup in the anvil and knife slots.

Left uncleaned, this residue creates an unstable base that prevents knives from cutting cleanly and consistently.

3. Install the Anvil

Install a new anvil in the clean slot, typically in the lower sealing jaw.

Always replace the anvil along with the knife. A new knife paired with a worn, scored anvil requires excess pressure to cut and will fail prematurely.

Make sure you install the anvil with the working surface, which is ground with a radius, facing up. (Some anvils have a radius on both sides.)

The height of the anvil should range between the root and the mid-point of the serrations. Sealing jaws from some manufacturers have deeper slots that require shims to raise the anvil up to the proper position.

If your anvils and knives are held in from the end, don’t overtighten the set screw—this can arc them upward in the center and prevent a clean cut.

4. Adjust the Knife

Shims

Install the new knife with a .005” or .15 mm thick shim. If your sealing jaws have deeper slots, you’ll need a thicker shim to start.

Shims should be high quality stainless steel, free from burrs or kinks, and slightly longer than the knife.

Check Setup

If your sealing jaws are heated, allow the knives and anvils to reach operating temperature.

Check your set-up by running a standard piece of notebook paper through the jaws.

Additional Shims

If the knife doesn’t cut, add a .003″ or .05 mm shim and check again.

If it still doesn’t cut, raise the knife by replacing the two shims with a single, .010″ or .25 mm shim.

Continue to add shims, if needed, until the knife cuts cleanly.

Always use as few shims as possible. Multiple shims create an unstable platform that prevents the knife from producing consistent cuts.

Troubleshooting

If a new knife needs to be overadjusted to cut, such that you can hear it banging and feel the heavy impact with your hands, you may need to address other conditions on your flow wrapper such as spring pressure adjustments, worn springs, damaged bearings, and damaged sealing jaws or shafts.

Never use clearance to adjust the knife. This will cause sealing problems and force you back to the first step, to readjust your sealing setup and then reset the knife.

Once you are successfully cutting and running production, be aware that temperature variations, due to changes in line speed or for different products or packaging materials, may require slight readjustments of the knife.

If you’d like to improve your knife and anvil setup and train your staff on optimal quality packaging procedures, contact Greener Corporation’s Technical Support Team.

Greener Corp provides integrated parts and technical services worldwide.

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