Frequently Asked Questions

Do you have questions regarding Insulated Shipping Systems? Find answers to frequently asked questions here.

  • What is Polyisocyanurate Foam?
  • What is an R-Value?
  • How do you Measure a Box?
  • What size Insulated Box do I need?
  • How do you determine what type of refrigerant and what thickness of insulation you need?
  • What is a refrigerant?
What is Polyisocyanurate Foam?

Polyisocyanurate foam is a rigid board insulation material composed of a uniform closed cell, Polyisocyanurate foam core bonded on each side to impermeable trilaminate foil facers.  Polyisocyanurate is now produced with a non-CFC and non-HCFC blowing agent, meeting the latest environmental regulations for using chemicals that do not harm the protective ozone layer in the earth’s atmosphere.  The new formula enhances the positive environmental profile for this energy saving product.

Laboratory and field testing data suggest that the stabilized R-value of rigid foam with this metal foil facing remains unchanged after 10 years.  Panels with foil facings also have higher stabilized R-values.

What is an R-Value?

Insulation is rated in terms of thermal resistance, called R-value, which indicates the resistance to heat flow.  The higher the R-value, the greater the insulating effectiveness.  The R-value of thermal insulation depends on the type of material, its thickness, and its density.

How do you Measure a Box?

Measuring a box is as easy as 1-2-3.

Simply measure the length, width, and height of what you would like to pack and express the measurements.  Make sure to give the measurements in this order:

1.  Length
2.  Width
3.  Height

Allow a minimum of 1/8” extra to each dimension for the fitting.  Be sure that the length and width do correspond to the opening of the box.

What size Insulated Box do I need?

Measure your product length, width and height.  Allow some additional space for refrigerant packs (coolants) or wet ice or dry ice. Keep in mind the ideal location of refrigerant in packing is on top or around your product.  Once you have determined this space you have your inside cavity space.  To that space, you will add two times the thickness of insulation to each dimension.


You have determined your inside cavity required is – 9” x 9” x 9”.
Your temperature specifications require 1-1/2” insulation.
Add ( 2 x 1-1/2”) or 3” to each dimension……..
(Add 3” to the length, add 3” to the width, add 3” to the height)
Insulated Box Size Required:  12” x 12’’ x 12”

How do you determine what type of refrigerant and what thickness of insulation you need?

These are determined by:

1. What temperature you need your product to maintain.
2. How long your product needs to maintain that temperature
3. What type of transportation will be used for shipping.

What is a refrigerant?

Refrigerants are products designed to control the internal temperature of a package.  There are typically only three temperature ranges refrigerants can maintain:  frozen, refrigerated, and room-temperature. The temperature requirements of your perishable product will determine the type of refrigerant you need to use.  Some common types of refrigerants are refrigerant packs (gel, foam), wet ice or dry ice.

Need Support?

The majority of True Pack’s orders are our standard patented insulated shipping containers with only the size of the box and the size and thickness of the insulation changing. If there is a request for an item that is not our standard product we proceed with design and development to meet the customer’s specific requirements.

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