Transport Vibration - Should you be Concerned? Part 1

http://www.lansmont.com/transport-vibration-concerned-part-1

When transporting products from one location to another, we use packaging materials and technologies to protect them from the various hazards present within the distribution environment. Some of those hazards are climatic (temperature, humidity, atmospheric pressure) and some are dynamic (shock, vibration, compressive forces).   Shock and vibration dynamics possess energy that has the potential to cause both physical and cosmetic damage to packaged products. Over the next series of Lansmont communications, we’ll dig into the vibration hazard, explaining how it’s different than shock, and why you need to be concerned with it. Let's get started with a basic comparison of shock and vibration dynamics and their differentiating characteristics.   What is a Shock event? Shock and vibration are described by the same unit of measure – the change in acceleration (G) over time. The difference between the two is primarily defined by how that change in acceleration occurs over time. From a distribution packaging perspective: Shock events can be described as sudden, quick, and transient - lasting only fractions of a second. Once it occurs, it’s over. Shock events possess comparably more severe acceleration amplitude than vibration inputs. Risk of exposure to many Shock events during transport is comparably less than vibration input. No pun intended, but transport shock is hit-or-miss! The 275g shock event in Figure 1 occurs over just a few milliseconds and the entire recording window is only 30 milliseconds.

What about Vibration? Vibration is an oscillatory motion that occurs about an equilibrium, or symmetrical reference - think bouncing up and down. Vibration tends to occur continuously over some length of time. Think of a truck or railcar sitting at rest. When that vehicle starts to move, dynamic inputs are transmitted from the interface surface (road, rails) upwards through the vehicle suspension and into the cargo. When a vehicle is physically moving - there will be vibration – it is unavoidable. From a distribution packaging perspective: Vibration occurs throughout transport, and the total time of exposure is of concern. Vibration intensity (amplitude) is comparably less severe that shock inputs. Unlike shock however, vibration is unavoidable during transport. The vibration event in Figure 2 has a maximum amplitude of only 0.8g and the dynamic lasts continuously over the entire 1,000 millisecond recording window.

ASTM vs. ISTA for Package Testing

ASTM vs. ISTA for Package Testing – Which Is Better?

https://pkgcompliance.com/ista-or-astm-which-do-you-need/

So many standards, so little time. Faced with uncertainty over transit testing standards? You certainly have options:

• ISTA 1A
• ISTA 2A
• ISTA 3A
• ASTM D4169

If you’re feeling a little lost, you’re not alone. The top consideration to guide your transit tests is the answer to this question:

How will your product get from manufacturing floor to end user?

ISTA AND ASTM standards put sterile products through simulations that address distinctly different distribution scenarios. The real-world, worst-case scenarios your sterile product could face will vary greatly based on how it will be shipped.

Ordering tests that focus on unlikely scenarios for your product’s journey are a waste of time and money. The wrong tests can also leave you at risk for actual situations that could occur.

The Differences: ISTA vs. ASTM

Both ASTM and ISTA standards have dual approaches to transit testing.

ASTM tests include:

• ASTM D4169: Standard Practice for Performance Testing of Shipping Containers and Systems

• ASTM D7386: Standard Practice for Performance Testing of Packages for Single Parcel Delivery Systems (such as UPS and FedEx, where comparably lower volumes of product are delivered, altering the transit experience)

• Universal requirements for ASTM D4169 and D7386 testing are clearly stated and must be followed. There are other testing criteria, such as levels, sequences, and orientations are up to you.

ISTA test methods include:

• Series 2: Partial Simulation Performance Tests

• Series 3: General Simulation Performance Tests

So what happened to “1A”? Here’s the deal: Although ISTA 1A method is listed as a transit standard, a review of the guidelines reveals that Series 1 is not meant as a validation method. The ISTA 1 Series is a feasibility study while in the design phase, so while it is related to transit, it applies to a much earlier part of the sterile device launch process.

ISTA Series 2 and Series 3 can be tailored to more specific situations or package configurations. ISTA 2A, ISTA 3A along with every other protocol in ISTA is very detailed and has specific step-by-step instructions that must be meticulously performed.

Laboratory Package Drop Testing

Numerous field studies conducted by many parties, have shown that the probability of a “design drop height” event during distribution is very small, on the order of 5% or less during any particular shipment. Yet the majority of laboratory package drop test procedures typically call for 10 impacts from the design drop height on different faces, edges, or corners of the package system. Does this not
constitute a substantial over-test? This paper will examine the nature of package drop testing, why it evolved in its current format, and the significance on package performance and optimization.

When studying the distribution environment to determine typical package drop heights, it becomes apparent very quickly that the vast majority of the data is rather boring in that most impacts are at a relatively low level. For a very few number of impacts, however, the drop height can be significant, certainly significant enough to cause potential damage to a packaged product. But these less than 5% of the total recorded impacts most of the time, the vast majority of studies report only one impact from this “higher” drop height. In fact, most environmental data recorders, so called “ride recorders”, are often set up to reject data below a certain drop height because the amount of data collected would be very difficult to analyze based on the large number of very minor impacts. Thus, from a statistical standpoint, it’s very difficult to even determine the percentage of “total” drops simply because much of the data from lower drop heights is not even collected.

ConclusionIt has been shown that the nature of the package test specifications, especially in terms of the orientations and number of impacts, is conservative by its nature and will likely lead to more expensive and over-designed package systems from a shock mitigation standpoint. Where multiple impacts on a product-package system are desired for a package drop test sequence (and the authors certainly believe that that is the case), perhaps these additional impacts should be conducted using a fresh package system for each orientation. It may also be feasible to use one package for several drop orientations where a crushable package system, for example, will still offer adequate protection. In this manner, a fresh package impact orientation could be maintained with as little as 3 or 4 package prototypes during the test protocol in the laboratory.

Substantial improvement in package optimization and reduction in package cost – along with better sustainability overall – can be anticipated if and when this topic comes under more scrutiny by package test specification writers.

BibliographyForest Products Laboratory, "An Assessment of the Common Carrier Shipping Environment," General Technical Report FPL 22, U.S. Department of Agriculture, Madison WI, 1979
Kipp, Bill and Russell, Paul, “European Express Shipping Drop/Impact Study” ISTA Dimensions.06
 

Reliability Vibration Testing - By Westpak

Vibration testing is the ability to replicate vibration that occurs in the real world to your product and/or packages in order to witness the effects and identify weaknesses. Vibration occurs in all forms of transportation and at varying levels of intensity in the use environment. In the real world, vibration is much more complex and can excite the natural frequencies of a product causing rapid fatigue and failure. The cushioning of a package system also has a natural frequency. If the natural frequency of the product and the package are the same, damage can result quickly. Similarly, if a product is going to be mounted to the chassis of a vehicle, the same principle applies.
Vibration testing should be conducted on both the product and the package. Determining the product’s sensitivity to vibration is necessary in order to formulate intelligent decisions about the product sensitivity or the package design.
Measuring the resonance of the package system will help determine the ability of the package to dampen the vibration amplitude at the critical frequencies of the product. A more simplified concept is to think of the package system as the shock absorbers on a car. The shock absorbers dampen the amplitude levels of vibration from the road to the passengers.

Typical Vibration Testing Procedures/Protocols

ASTM D3580
ASTM D4728
ASTM D5112
IEC 60068-2-6
IEC 60068-2-64
ISO 2247
ISO 8318
MIL STD 167
MIL STD 810G
MIL STD 883

http://www.westpak.com/page/reliability/reliability-vibration-testing

FUNDAMENTOS DOS TESTES CLIMÁTICOS

Tipos de Testes Ambientais

Tipo de Processo / Teste	Objetivo	Executado em	Tentativa de simular ambiente de serviço
Desenvolvimento de produto	Verificar antecipadamente se componentes, materiais e conceitos atenderão as especificações	Amostras e protótipos	Sim
Verificação de Projeto	Verificar se os sistemas atenderão as especificações de projeto	Mais próximo possível da configuração de produção	Sim
Desenvolvimento de Confiabilidade	Encontrar e eliminar itens de  projeto e processo que reduzem a confiabilidade	Mais próximo possível da configuração de produção	Não (mas às vezes tenta equivocadamente)
Rastreamento de estresse ambiental	Transformar falhas latentes em falhas evidentes antes de enviar ao consumidor final	Máquina produzida	Não

Climatologia

É a ciência da medição, análise, controle e testes com clima, tempo, ou às condições meteorológicas. Embora seja geralmente considerada como sendo condições naturais, que muitas vezes são criados ou modificados pelo homem.

Lida com as variáveis ​​de temperatura, pressão, umidade, ambientes corrosivos, areia e poeira, gelo, a radiação solar, e combinações.

O que faz um Engenheiro de Teste Ambiental?

• Traduz requisitos de sistemas operacionais em projeto ambiental e requisitos de teste para os sistemas, subsistemas e componentes, para garantir a durabilidade do ciclo de vida.
• As funções incluem a participação no projeto, teste e procedimentos de fabricação descritos (mas não limitado a) nas seguintes tarefas:
• Determinar os requisitos do ciclo de vida de sistemas, subsistemas e componentes. Solicitar uma análise detalhada de outros (FEA, análise térmica), quando necessário.
• Fornecer projetos ambientais e requisitos de teste com margens adequadas para os tipos de hardware e desenvolvimento de fase. Adaptar requisitos padrão para aplicação (IEC, ISTA, UL, 810F).
• Realizar análise de projeto de compensação para controle ambiental, mitigação, ou proteção e inserção dos resultados no projeto, confiabilidade e outros.
• Preparar requisitos de ensaios ambientais para testes de laboratório internamente; inserir especificação de requisitos para os testes de fornecedores.
• Monitorar ou participar de testes ambientais (fornecedor, internamente, cliente) e revisar, reportar e usar os resultados para uma possível ação corretiva de projeto.
• Coletar e manter um banco de dados ambientais.

Lista de Unidades

• 1   Operacional – Alta Temperatura
• 2     Operacional – Baixa Temperatura
• 3   Armazenagem e Transporte – Alta e Baixa Temperatura
• 4.       Choque de Temperatura
• 5.       Umidade – Condensando e Não-Condensando
• 6.       Altitude – Operacional / Transporte para armazenagem; Temperatura / Altitude
• 7.       Descompressão Rápida / Descompressão Explosiva
• 8.       Ambientes Combinados
• 9.       Radiação Solar – Efeitos químicos e térmicos
• 10.   Névoa Salina
• 11.   Areia e Pó
• 12.   Chuva
• 13.   Imersão
• 14.   Atmosfera Explosiva
• 15.   Congelamento
• 16.   Fungo
• 17.   Aceleração
• 18.   Simulação de Espaço
• 19.   Documentação de Teste

 Esboço da Unidade (exceto para as últimas três)

·         Definição do ambiente climático

·         Discussão  da fonte da requisição

·         Revelação que o teste pode proporcionar

·         Câmara / Equipamento – Simulação do Ambiente

o   Estrutura

o   Controlador

o   Instrumentação

§  Sensores

§  Gravadores

o   Fixações

·         Execução do Teste

·         Aceleração do Teste

·         Suposição de erros

  Onde o Laboratório se encaixa?

·         Análises

·         Simulação

·         Testes de Laboratório

·         Testes de Campo ou desenvolvimento