Semi-rigid and Rigid Plastic Container 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

The packages were manually scraped on the retort racks, other equipment or other packages.

Crushed

Classification
  • A major defect if affecting the seal area.
  • A minor defect if not affecting the seal area.
Identification

This is the alteration of the package original dimensions by force.

Causes

The packages were abused during on-line or post-process handling.

Cut (Fracture)

Classification
  • A critical defect.
Identification

This defect is a mechanical slash or slicing that penetrates the package, causing a loss of hermatic integrity.

Causes
  1. The package has contacted sharp edges of other packages.
  2. The package has contacted burrs or sharp corners on equipment.
  3. The packages 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 package laminate materials.

Causes
  1. If at the seal, the sealing head was too hot during the seal formation.
  2. If located elsewhere, the bond strength of the lid stock or container material is inadequate.

Flexcracks

Classification
  • A minor defect.
Identification

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

Causes

The packages were flexed and stressed during vacuum-sealing, processing and/or handling.

Foreign Matter Inclusion

Classification
  • A minor defect.
Identification

Unintended matter was imbedded in the plastic body.

Causes
  1. Unintended impurites from plastic pallets entered into the injection/blow molding or thermoforming process for plastic containers.
  2. Over-processed and brurnt plastic residuals were carried over from previous processing operations.

Gels

Classification
  • A minor defect.
Identification

This is improperly processed plastic included in the plastic container material.

Causes

The settings for injection/blow molding or thermoforming of plastic containers were not correct.

Label Foldover

Classification
  • A minor defect.
Identification

This is the label material folded over on itself.

Causes

The settings for labeling machine for plastic containers were not correct.

Leaker (Channel)

Classification
  • A critical defect.
Identification

This is a path of non-bonding across the width of the seal that will generally leak.

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

Malformed

Classification
  • A minor defect.
Identification

This is the plastic container that does not conform to mold contours as designed, or material distribution that does not conform to specifications such as waves, thin spots or discontinuous layers.

Causes

The settings for injection/blow molding or thermoforming of plastic containers were not correct.

Puncture (Pinhole)

Classification
  • A critical defect.
Identification

This defect is a mechanical piercing that penetrates the package, causing a loss of hermatic integrity.

Causes
  1. The package has contacted burrs or sharp objects on equipment.
  2. The packages were abused during on-line or post-process handling.

Seal Defects (Burnt)

Classification
  • A minor defect.
Identification

An area of the seal was discolored due to over heating.

Causes
  1. The sealing head 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
Identification

Foreign material is trapped in the seal area, such as, but not limited to, water, grease, or food. A package with contamination will have a noticeable raised area in the seal where the sealing head has sealed over the contamination.

Causes

The seal area was contaminated during the filling stage and/or during the sealing if vacuumed.

Seal Defects (Incomplete)

Classification
  • A critical defect.
Identification

This is a portion of the seal that has a lack of adhesion between lid and body. This defect appears as a very faint sealing head impression on the seal.

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

Seal Defects (Uneven Impression)

Classification
  • A major defect
Identification

This is a defect that may lead to an out-of-specification seal.

Causes
  1. Pneumatic pressure was not evenly distributed to sealing areas of the sealing head.
  2. The plastic container was misaligned.
  3. There are irregularities in sealing head or anvil surfaces.

Seal Defects (Seal-width Variation)

Classification

A major defect if the width of the continuous bonded 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 bonded seal.

Identification

This is a seal that has less than specified seal width.

Causes
  1. The lid stock was not placed properly on the container under the sealing head.
  2. The sealing head was misaligned.

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

Causes
  1. The food was underprocessed or contaminated during aseptic processing.
  2. The package material was not properly sterilized or was contaminated during aseptic processing.
  3. The package was overfilled or a proper vacuum was not drawn, which resulted in an improper thermal process.
  4. The food package was under-processed during thermal processing.
  5. There was insufficient chlorine in the cooling water.
  6. The package leaked after processing.
  7. The post-process handling was too rough.