How the USDA and Meat Industry Use Impulse Sealers

The FSIS/ USDA Guide for Meat & Poultry Hazards and Controls states that packaging/ packaging materials for these products must:

  • Provide adequate protection against physical, chemical and bacterial contamination
  • Be sealed properly, with seals being subjected to appropriate testing
  • Maintain package integrity
  • Maintain adequate protection against environmental contaminants (dust, moisture, and so on) during storage/ shipping

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The USDA and Impulse Sealers

According to the USDA’s ‘Food Safety Regulatory Essentials for Processing Methods for Commercially Sterile Foods’ (Flexible and Semi-rigid Containers Section, Page 72ff), an impulse sealer is used to seal flexible containers (pouches) consisting of multiple layers of specific plastics/ foils.

Sealing is achieved by applying a current to the impulse sealer’s heat ribbon when the sealing bars are pressed together. This subsequently provides the necessary temperature and pressure to melt the pouch’s layers and form a secure fusion seal. For adequate formation of seals, the following conditions must be met:

  • Sealing duration, pressure and temperature must be set and maintained in accordance with specifications provided by pouch/ film manufacturers
  • Seal areas must be wrinkle-free
  • Seal areas must be contamination-free

This process may or may not be accompanied by air evacuation/ flushing with gas.


The Meat Industry and Impulse Sealers

ONPUL impulse heat and vacuum/ gas flush sealers allow the meat industry to seal packages of varying sizes in compliance with these recommendations/ regulations by providing the necessary control/ monitoring features to obtain consistently strong, durable seals.

Sealing Temperature – Only applied when the impulse sealer is actually in use (preventing over-heating and subsequent deterioration of seals, a frequent issue with permanent heat sealers), the precise temperature specified for any given material can be set using the unit’s control panel.

This temperature is continually monitored via a combination of low profile, high-precision heat-sensors and micro-computer technology, preventing fluctuations due to environmental temperature changes and/ or increases in impulse sealer temperature due to prolonged use.

Heating/ Cooling Duration – The impulse sealer’s control panel also allows users to set precise heating/ cooling durations according to film/ pouch manufacturer’s specifications. As seals are allowed to cool under pressure, seals are consistently clean and strong.

Vacuum/ Gas Flush – On some impulse sealer models with vacuum/ gas flush option, operators are able to choose from a variety of settings, including:

Three Work-Method Options

  • Sealing only
  • Air removal and sealing or
  • Multiple gas-flush cycles and sealing

Three Vacuum Control Options

  • Vacuum gauge (fully adjustable from 0 to -100Kpa)
  • Vacuum timer (fully adjustable from 0 to 99.9 seconds)
  • Manual Operation

Three Gas-flush Options

  • Single gas flush
  • Multiple (up to 99 times) flush cycles
  • Circulating gas-flush (this option requires modification of piping)

These options can be combined to provide a total choice of 13 different sealing methods, allowing the operator using an impulse sealer to match methods to the exact sealing requirements of the product to be packaged.

In a similar manner, the gas/ gases used are also matched to the requirements of the specific product. This may be a single selection or a combination of two or more of the following gases (or other varieties):

  • Argon
  • Carbon dioxide gas
  • Nitrogen gas

It should be noted here that not all packaging materials can be used in combination with gas. Permeable materials like polypropylene and polyethylene, for instance, are not suitable for this purpose. Film suppliers will provide advice with regards to the correct materials to use, which essentially consist of materials laminated into high gas-barriers, like, for instance, EVOH films.

Benefits for the Meat Industry

The benefits of investing in an impulse heat sealer for the meat industry are, however, not restricted to consistently strong, tidy seals in compliance with applicable USDA rules and regulations. Here are some of the additional advantages of using an impulse heat sealer.

Safety – Accidents caused by continually hot surfaces typical with constant heat sealers are prevented as surfaces only heat up during the sealing process. Additional safety measures/ cutouts prevent trapping, over-heating and other issues likely to cause accidents.

Cost – The fact that these units are instantly ready for and easy to use, as well as not using use power/ heating up when not in use results in multiple cost-savings by:

  • Reduction of required training periods (saving both time and material related expenses)
  • Reduction of labor cost (no waiting times for unit to pre-heat)
  • Reduction of costs incurred through accidents
  • Reduction in energy consumption/ cost

The latter, by the way, is achieved in a two-fold manner:

  1. Energy is only consumed during actual operation
  2. Absence of permanently hot surfaces means environmental temperatures are not affected, allowing A/C units to be kept on lower settings than if permanent heat sealers were in use

In short, an impulse sealer provides strong, durable and USDA compliant seals in the most cost-effective, efficient and safe manner possible.