ISTA 3 Series procedures were created just around the turn of the century when more and more labs had access to various types of drop testers and servo hydraulic vibration tables. Another major factor that contributed to their unique test approach was the large and growing body of recordings of Vibration and Shock data, which was rapidly summarized into repeatable laboratory events. The 3 Series Procedures are commonly referred to as "General Simulation" tests. While they mimic in many ways the ISTA 1 and the ISTA 2 Series they depart dramatically from both of these in the following ways:
- They eliminate the stand-alone Compression Test and replace it with the so-called Compression Vibration which is Random Vibration under a Top Load in one or more (whenever possible) orientations of the package. The Top Load to be used is calculated and distributed over the test package based on its dimensions, and not based on its weight. The only exception here is ISTA 3E test which really seeks to simulate "Warehouse Compression", more common for the Full Truckload environment, rather than the combination of "Vibration and Compression" typical of the LTL environment.
- They reduce significantly the Drop Heights in all package weight categories to produce a more realistic and a more evenly distributed impact on edges, corners and faces.
- They employ two new, much more modern Vibration Profiles to reproduce A. the real Steel Spring Truck vibration, and, B. the much more bumpy Short Wheel Base truck, which is typical of the parcel delivery environment.
- The 3 Series visibly differentiates between different types of packages - Standard, Small, Flat, Elongated, Pail or Short Cylinder packages (in 3A), Individual Loads under and over 200 lbs, or Palletized Loads (in 3B) and Unitized (in 3E) loads. Each of these package types has a different test sequence which reflects their characteristic behavior in transportation. There is also a bonus: a very unique test method in ISTA 3A to address packages containing liquids when shipped by air, which requires vibration in a chamber under low pressure.
- In the ISTA 3B procedure for palletized loads a great deal of attention has been given to the Pallet Handling Simulation, reflecting push and pull of pallet, rotation of corners, the so-called "Forklift Abuse Course" cycles, which challenges the integrity of the pallet itself and the binding (connection) between the load and the pallet.
- ISTA 3B also uses a very critical stability Tip/Top Over 3B test which accurately predicts the loss of stability so critical for unitized loads and High Gravity Center palletized loads. This is very simple but revolutionary instrument to predict the aggregate effect of deceleration and centrifugal forces that very often take control over packages inside a truck. In simple language, it simulates what happens when the driver hits the brakes, goes into sharp turn and/or goes over some serious bumps on the road.
All of these changes have made for a very robust and reliable system of testing and evaluating small to large loads across their entire variety and reliably predicting their performance through the distribution channels. The 3 Series has been met with great approval by carriers and shippers alike and is currently the most popular approach of assessing small to large loads, whether individual or palletized.
ISTA 3A Procedure is intended for individual packages under 150 lbs. The ISTA 3A is the best test method to use for predicting the Parcel Shipping Environment. Climate Conditioning for 72 hours is optional, (there are 6 choices of temperature and humidity combinations). This Procedure differentiates between Standard, Small, Flat, Elongated and Cylinder packages. Each of these have a somewhat different test sequence.
The 3 mandatory parts for a Standard Package are:
A. Shock (Free Fall Drops) Sequence 1 - total of 9 drops of which the last 2 are on the bottom, with previous to last drop from twice the height of the other drops. Drop Height is smaller for heavier loads.
B. Random Vibration under calculated Top Load: Steel Spring Truck Profile - 60 minutes on Bottom face, 30 minutes on Large side, 30 minutes on Small side, plus another 30 minutes with no load on bottom per the "Short Wheel Base" profile.
C. Shock (Free Fall Drops) Sequence 2 - total of 7 drops, as above.
ISTA 3A also mandates that whenever a corrugated outer package is tested, a sample of that is tested for Basis Weight and the outcome recorded in the test report.
Packages containing liquids to be shipped by air and/or high altitude have two different vibration parts performed under low atmospheric pressure (partial vacuum) per a different Vibration Profile applicable for Air Transport.
ISTA 3B Procedure is intended for 4 package types: a. Standard packages under 200 lbs, b. Standard Packages over 200 lbs, c. for Cylindrical (regardless of weight) and d. Palletized or Skidded Package Types. The ISTA 3B is the best test method to use for predicting the LTL (Less Than Truckload) Shipping Environment.
Climate Conditioning for 72 hours is optional, (there are 6 choices of temperature and humidity combinations). The test sequence differs for each of these package types, so we will focus here on the Palletized Load Test Sequence, with 7 steps, which also happens to be the longest one.
A. Tip/Top Over test to 22 degrees, in both sides of pallet. If any of those cause pallet to tip over (we can hold the load from actually roll over, whenever possible) it must be marked on the report. Attention shippers of all things unitized, palletized and stretch wrapped - this will tell you in advance if your shipment will arrive in a fallen domino-effect to your customer.
B. Rotational Edge Drops and Corner Drops - first portion
C. Inclined Impact to 48 IPS on 2 opposite sides or optional Free Fall Drop from 3" first portion
D. Random Vibration with Top Load (Steel Spring Truck profile, time in hours = (transport miles)/5, in 30 minute increments)
E. Forklift Handling Sequence, including "Forklift Abuse Course" 4 cycles
F. Rotational Edge Drops and Corner Drops - second portion
G. Inclined Impact to 48 IPS or optional Rotational Edge Drops from 3" second portion
ISTA 3E Procedure: is intended for 3 package types, which are always secured together as a Single Load:
a. Unitized packages on pallet/skid held together with stretch wrap or strapping, regardless of weight,
b. Single machines banded to pallet or held to it by other mechanical means, regardless of weight,
c. Pallet with multiple items held together in sleeve with top tray, or HSC (regardless of weight).
The ISTA 3E is the best test method to use for predicting the FTL (Full Truckload) Shipping Environment.
Climate Conditioning for 72 hours is optional, (there are 6 choices of temperature and humidity combinations).
The test sequence is the same for each of these package types. There are 5 mandatory parts:
A. Shock (Inclined Impacts) to 42 IPS on all 4 sides
B. Shock: Rotational Edge Drops from 8" on 2 edges - first portion
C. Compression: (choice of Apply and Hold (AH),Apply and Release (AR) or Dead Weights (DW) on loadspreader)
D. Random Vibration (Steel Spring Truck profile, No Top Load, time in hours = (transport miles)/5, in 30 minute increments)
E. Shock:Rotational Edge Drops: from 8" on 2 edges - second portion