Flexible Pouch Summary

Abrasion

Classification
  • A major defect if pronounced (A penetration deeper than the outer layer).
  • A minor defect if slight (A penetration only the outer layer).
Identification

An abrasion is a scratch through any of the layers of the package.

Causes
  1. The pouches were manually scraped on the retort racks, other equipment or other pouches.
  2. Pouches rotated or shifted over top of one another (for example, if unrestrained in retorts or in bulk packaging).
  3. Plastic was left on the sealing bar from previous sealing.

Cut (Fracture)

Classification
  • A critical defect.
Identification

This defect is a mechanical slash or slicing that goes into the package with a loss of hermatic integrity.

Causes
  1. The pouch has contacted sharp edges of other pouches.
  2. The pouch has contacted burrs or sharp corners on equipment.
  3. The pouches were abused during on-line or post-process handling.

Delamination

Classification
  • A major defect if in the seal area, or when delamination, anywhere in the inner or outer plies of the pouch, is in excess of 1 cm2 (or equivalent area).
  • A minor defect if outside the seal area, or when delamination, anywhere in the inner or outer plies of the pouch, is less than 1 cm2 (or equivalent area).
Identification

Delamination is a separation of the laminate materials. This can occur anywhere on the pouch.

Causes
  1. If at the seal, the bars were too hot during the seal formation.
  2. If located elsewhere on the pouch, the material bond strength is inadequate.
  3. The residual air in the retort pouch was not properly controlled to eliminate sharp corners on the edge, which would make the pouch expand during retorting.

Flexcracks

Classification
  • A minor defect.
Identification

Flex cracks are small breaks in one or more layers of the laminate materials.

Causes

The package flexed during vacuum-sealing, processing and/or handling.

Hotfold

Classification
  • A minor defect.
Identification

A hot fold is a permanent bend in a seal, formed after sealing and before the area has cooled. This may appear as a large wrinkle or a fold that has been sealed over.

Causes
  1. At the sealing machine, the plastic was folded while the pouch material was still soft.
  2. In the retort, the edges of the pouch were folded during the cook process.

Leaker

Classification
  • A critical defect.
Identification

A leaker is a retort pouch that is unsealed or in some way has lost container integrity. Contents generally seep from the pouch. The leak may occur anywhere on the pouch.

Causes
  1. The pouch was punctured or cut during processing, handling or distribution.
  2. The sealing bar settings were not correct (i.e., the temperature, pressure and/or dwell time).
  3. The seal area was contaminated with product, moisture, grease, or other contaminants.
  4. The corner folded during the sealing operation, resulting in non-fusion at the corner.

Leaker (Channel)

Classification
  • A critical defect.
Identification

This is an are non-bonding across the width of the seal that will generally leak.

Causes
  1. The sealing bar settings were not correct (i.e., the temperature, pressure and/or dwell time).
  2. Contaminants were present in the seal area during seal formation.

Leaker (Notch)

Classification
  • A critical defect.
Identification

A leak occurring at the manufactured notch (which is intended for easy opening of the retort pouch) has compromised the container integrity.

Causes
  1. The machine setting at the pouch manufacturer was incorrect, allowing the notch to be cut too far into the seal.
  2. The notch was correctly formed but was torn in transit or during handling.
  3. The sealing bar settings (i.e. the temperature, pressure and/or dwell time) were not correct during sealing cold seal next to the notch.
  4. The seal area was contaminated with product, moisture, grease, or other contaminants.

Puncture (Pinhole)

Classification
  • A critical defect.
Identification

Mecheanical piercing of the pouch.

Causes

Sharp objects such as staples, knives or other similar tools have punctured the pouch during processing and/or post-processing and handling. During manufacture of film.

Seal Defects (Blister)

Classification
  • A major defect if the width of the continuous intact seal is reduced to less than 3 mm (3/32-inch).
  • A minor defect if there is 3 mm (3/32-inch) or more of continuous intact seal.
Identification

A blister appears as a void within the bonded seal. A blister resembles a bubble or has a raised appearance in the sealed area of the retort pouch.

Causes

Food, grease or other contaminants were present in the seal area during seal formation.

Seal Defects (Compressed)

Classification
  • A major defect if:
    1. There is visual evidence of seal overheating, such as bubbles or exposed foil
    2. There is less than 3 mm (3/32-inch) of continuous good seal (non-delamination)
  • Is considered a minor defect if:
    1. There is some visual evidence of seal overheating, such as bubbles or exposed foil
    2. There is more than 3 mm (3/32-inch) of continuous good seal
Identification

A compressed seal is any separation of the laminated plies in the seal area. The material bond strength is questionable in the area of the defect.

Causes
  1. The sealing bar settings were not correct during sealing (i.e. excessive temperature, pressure and/or dwell time).
  2. Material bond strength is inadequate.

Seal Defects (Contaminated)

Classification
  • A major defect if the width of the continuous intact seal is reduced to less than 3 mm (3/32-inch).
  • A minor defect if there is 3 mm (3/32-inch) or more of continuous intact seal.
Identification

Foreign material is trapped in the seal area. A retort pouch with contamination will have a noticeable raised area in the seal where the sealing bar has sealed over the contamination.

Causes

The seal area was contaminated during the filling stage.

eal Defects (Convolution/Embossing)

Classification
  • A minor defect.
Identification

A slight visual impression in the seal indented on one side and raised on the other side.

Causes
  1. The seal area of laminate package containing metal layers was contaminated with product, moisture, grease, or other contaminants.
  2. There are minor irregularities in sealing bar or anvil surfaces.

Seal Defects (Creep)

Classification
  • A major defect when the seal width is reduced to less than 3 mm (3/32-inch).
  • A minor defect when the seal width has 3 mm (3/32-inch) of bonded seal present.
Identification

Seal creep appears as a partial opening of the inside border of the seal.

Causes
  1. The sealing bar settings (temperature, pressure and/or dwell time) were not correct during sealing.
  2. The seal area was contaminated with product, moisture, grease, or other contaminants.

Seal Defects (Crooked)

Classification
  • A major defect if the width of the continuous intact seal is reduced to less than 3 mm (3/32-inch).
  • A minor defect if there is 3 mm (3/32-inch) or more of continuous intact seal.
Identification

A crooked seal is a seal that is not parallel to the cut edge of the pouch.

Causes

The pouch was misaligned in the sealing jaws.

Seal Defects (Misaligned/Deformed)

Classification

A major defect when the seal width is reduced to less than 3 mm (3/32-inch).
A minor defect when the seal width has 3 mm (3/32-inch) of bonded seal present.

Identification

Misaligned seal is a seal that is not formed in a continuous, straight line.

Causes
  1. The seal was positioned improperly.
  2. The sealing bars were misaligned.
  3. The pouch was not placed properly within the sealing jaws.
  4. The vacuum packer drew the top of the retort pouch over the shape of a rigid product (i.e., salmon side) while the pouch bottom lay flat on the sealing bar.

Seal Defects (Nonbonding/Weak)

Classification

A critical defect.

Identification

The sealing films fail to weld (combine) during the sealing process. This defect appears as a very faint sealing bar impression on the retort pouch seal.

Causes
  1. The seal area was contaminated.
  2. The sealing bar settings were not correct (i.e the pressure/temperature/dwell time).

Seal Defects (Stringy)

Classification

A minor defect.

Identification

Stringy seal appears as the presence of excessive plastic threads showing at the edges of the seal area.

Causes

The heat and pressure at sealing were excessive.

Seal Defects (Uneven Juncture)

Classification

A minor defect.

Identification

The bonded polymer at the inner seal juncture appears wavy or rough (may also be called wavy seal). This will appear as small wrinkles, but not the fold over type.

Causes
  1. The pouch was misaligned.
  2. The pouch laminates were heated unevenly.

Seal Defects (Wrinkle)

Classification

A major defect if the fold in the seal area leaves less than 3 mm (3/32-inch) continuous acceptable seal.
A minor defect if the fold in the seal area leaves greater than 3 mm (3/32-inch) continuous acceptable seal.

Identification

A wrinkle is a material fold in the seal area.

Causes

The sealing surfaces were not flat and parallel or were not tensioned properly.

Swell (Swollen Package)

Classification
  • A critical defect.
Identification

The pouch bulges due to gas formation from bacterial contamination, or excess internal residual air.

Causes
  1. The pouch was overfilled or a proper vacuum was not drawn, which resulted in an improper thermal process.
  2. The pouch leaked after processing.
  3. The pouch was under-processed.
  4. There was insufficient chlorine in the cooling water.
  5. The post-process handling was too rough.

Waffling

Classification
  • A minor defect.
Identification

Waffling appears as heavy embossing of the retort tray rack pattern on the surface of the pouch body, from contact with the racks during thermal processing.

Causes

The pouch expanded against the racks during thermal processing and a heavy impression was left on the surface of the pouch material.