Milk Roll Cages, They Look All The Same, But Are They??


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Milk Roll Cages, They Look All The Same, But Are They??

18 August 2020

Milk Roll Cages, They Look All The Same, But Are They??

Current Higher Cert student, Rory Comerford, Director of Sales at Capcon LTD discusses supply chain in the first of a two part article written this month. 


For those of you that are responsible for the acquisition of Milk Roll Cages or Mik Trolleys as they are sometimes called you could be forgiven for thinking that all Milk Roll Cages are the same!

They look the same, they move the same, they essentially operate the same or so you thought!

Milk Roll Cages like anything in life are a deeply intricate and complicated product & to be honest a feat of engineering if done correctly!

This article is part one of a two-part series of articles that sets out to explain what to look for in a Milk Roll Cage. Essentially what "they" are not telling you. In this series of articles, I will delve into the pits of the cages looking at the production, the quality of steel used, the plating, the wheels & all things associated with well a Milk Roll Cage.

Firstly the most important thing you need to consider is who is making them? "Why" you might ask!? Well, the answer lies in the "Supply Chain".

The supply chain has been defined by Professor Edward Sweeney a renowned supply chain expert as "A product or service is delivered to the ultimate customer through a complex interaction of several companies on the way, i.e. through a supply chain". (2002)

So what do I mean by this, and how does this affect the factory making them or even you as a buyer?

This means that you need to observe closely a range of factors either by asking or seeing for yourself the entire set up of the factory who are manufacturing these cages. Everything from where is the factory located? Do they speak English as a native language? Does the main point of contact speak English? What is the communication structure like? Are the staff full time or temporary? Do they bring in outside agency staff with no experience for production only when they get an order, or are the staff full time & well versed in making trolleys? Where do they source raw materials from? is there a backup? Are they using welding robots or is it manual welding? What is the general layout of the workshop? is it organized? Is the equipment modern? The lists are endless.

Time after time I hear of horror stories in the industry 20,000 cages not fit for purpose, weld spatter on shelving ripping cartons, wheels falling off you name it, the issues are real & present. This is why all of the above is relevant and needs to be considered. If the person you are speaking with doesn't speak English or write English well then important criteria can be misinterpreted, misunderstanding can arise. If the staff are temporary & only brought in for that "job" this can impact production as you have staff who are not adequately trained to operate on assembly lines.

Manual welding can reveal inconsistencies and human error can be a real threat, not to mention a man is more expensive than a machine per item vs automated welding robots that are faster, consistent, and therefore cheaper! Welding robots can cost up to $100, 000, so you can easily gauge the factories capabilities & resources by how many robots they have on-site.

Next, let us talk about the material. As stated above all Milk Roll Cages look the same, but two different styles of cages together and you wouldn't notice any difference to the naked eye, but put 200 litres of milk on them and roll them around a warehouse and on/off a truck and you soon notice the difference.

This is because Milk Roll Cages are made from black mild steel, which like all-steel comes with different grades, diameters & gauges, or wall thickness. However when the cage is rolled off the container how would you know what steel is used?

The answer is you wouldn't know not only that but the alarming fact is that most organizations who purchase items such as these probably couldn't tell you what steel is used on their trolleys either.

It's like buying a PC or laptop but not knowing the capability of the machine. You just wouldn't do it!

Steel grades in China have various "Q" grades (Q” is the first letter of Chinese spelling of “qu fu dian”, the translation is “Yield Point” or “Yield Strength”) that are the equivalent of EN standard for steel or put simply the strength.

In Trolley making these Q grades range from Q195, Q235, Q345 all of which have a huge difference In the cost & quality of the cages. In areas where the weight is significant like the wheel plate or wheel box then the higher end of tensile strength is required to ensure the cage doesn't collapse with 200 liters/200kg (1kg = 1L) of milk on an employee or a customer in the shop! in areas where the weight is less, you can use other strengths comfortably. Generally speaking, cages should be made from Q235 steel with Q345 steel used for more specific areas that require higher strength.

One way to ensure that the "correct" steel is being used is to look for certificates from the factory who in turn receives them from the steel mill.

So the next time you have a tender or order cages and you specify a quality of steel make sure the organization you are dealing with supplies you with the appropriate certificates.

If I am quoting for a tender against the desired specification and another company wins the business at a much lower rate then I know the specification is not being met, as the true cost price to make the cage is only so much. This is great news for the procurement department who is getting a "good deal", but ultimately its bad news for Operations & the organization as a whole when lack of cages for production becomes an issue cause they are in the yard broken or when maintenance costs go through the roof.

Trolley buying needs to become more of an Operational (Op's) focus instead of a Procurement focus. Op's directors need to understand the complexities of the cages and put forward a strong case to procurement based on their "recommendations" or experience on the ground as it were. Not the other way around!

I have encountered numerous Op's people throughout the years who again see the company that supplied sub-standard cages the previous year, which caused heartache & dismay back on the list for this year's tender! Production of certificates should be a tender requirement.

The next items on the agenda for discussion and one of the most important are the wheels on the cages. Again look at any two wheels side by side and they both look the same, but like most things, they vary greatly.

Milk Roll Cage wheels are recommended to be made from a Nylon Compound which is a harder plastic substance than it's sister Polypropylene. This ensures decent shore hardness and longevity. Alternative wheels can be used depending on companies' expectations, but none the less the conversation needs to be had.

Asides from the wheel material another crucial aspect is the bearings inside the wheels. Generally speaking for harsh conditions and heavy usage the wheels should have ball bearings or a cluster of little bearings pressed inside the wheel, again this is more expensive but this ensures longevity, and as the housing containing the bearings is sealed so dirt and grime are less likely to get in.

Recently I viewed some cages that were fifteen years old & never used. They were lying in the same spot since the day they arrived on-site fifteen years ago and when moved for the first time in 15 years, they moved like they were just off production for the first time. This is because the bearings did not gather grime or dirt during the 15 years! I often see cages in excess of 10 years in operation with the same wheels as originally supplied.

Quality wheels make all the difference, be sure to know what wheel spec you are getting on your cages! The difference could only be a few shekels but it beats replacing them every few years!

The same goes for plating, they all look nice and shiny when they are new, but six months down the road how do they look?

Plating is the secret ingredient to the Milk Roll Cages, rust on the packaging means a rejection & dumping of product. Plating makes the cages resilient to the harsh wet environments of the UK & Ireland.

High-quality electro-zinc plating applied to a thickness of 8 to 12 µm with blue passivate finish giving a silver colour to the surface is the correct requirement for trolleys. After electro-zinc plating, the components are dip-lacquered with an acrylic lacquer approved for contact with food and drugs. When zinc plating and lacquer finish is completed it should resist a salt spray test (no red rust) according to ISO 9227 for at least 96 hours.

You might say "well how would I know this is being done"? The answer is simply to ask for the certificates or better yet go and visit the plating factory and ask them to do a salt test.

While production can be fast-tracked using additional robotics and longer shifts, its the plating factory where you are likely to encounter the "bottleneck". In China, for example, there has been a government crackdown on plating factories due to emissions, so there are fewer than there once were. In addition, automated plating vs hand-dipped plating is not only safer but also faster.

All factories in a province can link to the one plating factory creating weeks of delay. That's why it is important to visit the plating factory and look for automation if sourcing from China. Also, you can see what the relationship is like between your production factory and the plating factory, and if needs be can your goods be fast-tracked or given priority.

Any organization selling Milk Trolleys worth their salt "should" happily bring you to see not only the plating factory but production itself even if that is in the far east!

The Chinese people are exceptionally warm & welcoming and factory owners appreciate foreign agents or agents & customers visiting their beloved factory. They don't forget & this endeavour builds a strong and lasting relationship with them.


All too often in life & milk trolleys, there is a race to the bottom mindset, adversarial relationships created to ensure the "cheapest" price possible. Supplier 'A' is 1-2 USD/EUR/GBP less than supplier 'B', therefore supplier 'A' wins. But what does this 1-2 USD/EUR/GBP more mean? Does it mean that for an extra Dollar/Euro/Pound there is extra thickness on the wheel box, ball bearings in your wheels &/or a harder wearing wheel, or does it mean quality plating or a full-time workforce?

In an article published in (2010), Professor Sweeney suggests that supply chains should not be a "zero-sum game" based on "adversarial relationships" but instead they should be a "win-win" game based on co-operation.

Taking the time to understand what to look for in the milk trolley, the strengths & weaknesses of the trolley, along with a comprehensive engagement with possible vendors, and checking to see has this detail been met post-delivery is paramount to the acquisition of Milk Trolleys. An Operational focus with a "crossflow communication" model is essential for any organization to ensure they are acquiring quality cages that are correctly placed at a price point in the market.

The proof is in "the pudding" not in "the price"

About Capcon Premier Service Solutions:

Capcon has been in the trolley game since 2003 when the company was first founded specifically to source quality cages for the IE / UK market place.

Since that time Capcon has developed and refined its Roll Cage offerings by working closely with a number of high-quality manufacturers directly both in the EU & Far East alike.

Capcon is current suppliers to "big name" dairies in Ireland & the UK and thrives on comprehensive engagement and customer satisfaction.


Sweeney, E.: "The Four Fundamentals of Supply Chain Management".Logistics Solutions, the Journal of the National Institute for Transport and Logistics, Vol. 5, No. 1, February 2002.

Sweeney, E.: "Supply Chain Change Management: an Internal and B2B Relationship Perspective". Supply Chain Perspectives, the Journal of the National Institute for Transport and Logistics, Vol. 11, Issue 1, 2010, p. 18-21.

With Thanks;

Thanks to our friends in & for their contribution to this article.