Have you ever wondered how neck rings and guide plates are produced? And don’t get confused with the neck rings worn by African and Asian women where it is said they are worn to make the neck look longer, they are worn to make a woman look not so inviting to the men of other tribes or to indicate the wealth and status of the wearer and the husbands’ wealth – there are many various myths and reasons. We are talking about the neck rings that are commonly used in the forming of the ‘finish area’ of a glass container.
We went to visit Neck Ring International, one of a few manufacturers of neck rings used in the glass industry in South Africa. We met up with Willem Swanepoel, Technical Manager at Neck Ring International, and he explained what a neck ring is.
Business partners Operations Director Dave Stewart and Jan Swanepoel, who is the MD of Neck Ring International
“The neck ring of a glass container is arguably the most important part of the container, whether it be a glass bottle or a glass jar. The neck ring gives the container strength, facilitates filling and emptying, and allows the container to be sealed to preserve the contents. As a result, it needs to be absolutely perfect, both in terms of shape and the thickness of the glass. Additionally, the surface finish is very crucial.”
“Neck rings on glass bottles and jars too can all be looked at as specific parts. The uppermost part is called the ring or finish. It includes the bore, sealing surface, and bead or collar, depending on how the bottle is to be sealed. The neck sits below this and stretches from the parting line or collar to the curve of the shoulders.”
“The finish of the bottle is formed in the neck ring mould before the container is blown or pressed to shape. The mould needs to be the perfect size and must be free of dirt and debris. If there is a problem with any of these the finished product will be flawed.”
Neck Ring International is not limited to machining neck rings only
“The quality of the neck ring finish depends on several factors, including the material used to make the mould itself. On top of this the temperature and rate of cooling are important. Both of these also have an impact on how long the glass must remain in the mould.”
“All glass container manufacturers who make products that need to be sealable understand how important it is to use the right moulds and keep them in the perfect condition. Doing so retains the quality of the finished products. In order to accomplish both things the right tools are needed. Neck ring profile gauges are important as they allow the mould to be accurately measured to ensure the dimensions of the container are correct.”
Neck rings ready for delivery. The company can manufacture up to 1 000 different neck rings in a month
“In a neck mould for forming the finish portion of a glass container, a pair of semicylindrical outer metallic body members are formed of bronze alloys or hardened tool steel, for example, with each of said members having an internal, recessed shoulder thereon, a pair of semicylindrical metallic neck ring inserts, said inserts being formed of metal selected from the group consisting of bronze, cast iron and beryllium nickel alloy, said inserts adapted to seat on the shoulders formed in the body members, the internal configuration of said inserts being that of the external finish of a glass article to be formed.”
The machine shop at Neck Ring International
Willem Swanepoel (34) has been with Neck Ring International for 10 years. He previously obtained an electrical diploma while working in that industry before joining his father’s company. Jan Swanepoel is the MD and his partner in the business is Operations Director Dave Stewart.
The two directors acquired the company in 1999. At the time Neck Ring International was a business unit within Eloptro, a company that was part of the SOE Denel Group at the time. Jan Swanepoel was General Manager of Eloptro and Dave Stewart ran the Neck Ring International business unit. Neck Ring International was established in 1987 in response to international economic sanctions. The government’s interministerial cabinet committee agreed on the sale of certain state assets in 1999 with Neck Ring International being one of them.
Other business units in Eloptro to be sold were Voltco, the consumer electrical products division, Syncat, the specialist catalyst producer. Eloptro has subsequently been closed and the remaining assets acquired by Micromax.
The company now offers CNC turning, CNC milling, fabrication and assembly as its services
“The glass container industry is still huge in South Africa. Our neck rings are used by glass container manufacturers that ultimately are in the non-alcoholic, alcoholic beverage and food industries. Glass packaging is having a bit of a renaissance since the world has become very conscious of recycling and sustainability and as a result plastic packaging has taken a beating by environmental groups because of its long-life and the impact it has on the environment,” explained Jan Swanepoel.
“The stakes are high, from landfills overflowing with waste to the depletion of finite resources. Glass, being 100% recyclable, presents an incredible opportunity to address these challenges. However, despite its recyclability, a significant portion of glass still ends up in landfills. People need to be educated. They say each ton of recycled glass added to a furnace saves 1.2 tons of raw materials, about 580kg CO2 is saved throughout the supply chain, air pollution is reduced by 20% and water pollution cut by 50%.”
A component that was final machined
“We don’t have local figures but the current UK glass container market is approximately 5 billion containers with a turnover in the region of £500 million shared amongst five manufacturers. The European market is 30 to 40 billion containers worth approximately £4 billion. Locally a plant has been completed in Nigel, which makes it the largest glass container production facility in Africa and one of the largest and most efficient facilities globally.”
Neck Ring International has an EDM spark eroder
“When we acquired the business, its focus was 100% on manufacturing neck rings. This still plays an important role in our mix of services but we have taken away the ‘all eggs in one basket’ syndrome and moved it into a situation where it now offers CNC turning, CNC milling, fabrication and assembly as its services. This has certainly spread the risk but it has also given us the opportunity to grow the business over the years.”
“We now have a number of clients that are either directly or indirectly active in the mining, agriculture, hydraulic and general engineering industries. The amount of different components that we have machined goes into the hundreds. Some recent examples are a lever assembly that we machined and fabricated for the mining industry, brake discs for mine ventilation fans, heat-treated sprockets for a double chain, air filters turned and milled according to a customer drawing and bearing end caps with a grease nipple that was machined from brass.”
“Some other components that we have machined include adaptors, anchor blocks, cylinders, swivel links, idler shafts, oil plugs, screws, shells, levers, magnet frames, end plates, bearing sleeves, gear wheel shafts, couplings, covers, camshafts, shafts, custom bolts and washers, sleeves, spacers, motor support beams, pins, pistons, traction handles, valve housing, glands and cylinder shafts.”
A neck ring before it has been machined
“We also machine many wear part type components and here we either make from scratch or supplied drawing.”
“We certainly are a fully-fledged CNC machining operation and currently we have seven mills/machining centers and 13 lathes on the floor. We could be looking at investing in new machines in the future.”
“We also have an EDM spark eroder, a CMM and shadow graph for inspection and offer other services such as welding, metal spraying, finishing and fabrication.”
“We are only involved in the glass industry. Making moulds for the plastic injection industry is not what we know and we stay away from it.”
Neck Ring International has seven mills/machining centers and 13 lathes on the floor
“Back to the glass industry. We are not restricted to just manufacturing neck rings. We have manufactured plungers from raw material to pre machining to metal spray welding and then the final machined component. Other components for this industry include blanks, baffles and guide plates.”
“It’s essential to have a clear understanding of bottle neck finishes, thread sizes, and dimensions when considering packaging for your product. When it comes to the process of selecting a closure for your bottle or another container, there are several measurements needed to ensure a secure and sealed fit. In this guide, we will cover the key points you need to know to understand bottle neck finishes.”
“As said previously the neck ring is manufactured in two halves and besides bronze alloy or hardened tool steel they can also be manufactured in an aluminium nickel. We import our material from Hungary and New Zealand. The size range we work in is 92 diameter up to 120 diameter.”
“We can manufacture up to 1 000 different neck rings in a month and usually manufacture them in batches between 100 and 400.”
A neck ring is manufactured in two halves and besides bronze alloy or hardened tool steel they can also be manufactured in an aluminium nickel
“Some of our clients in the glass container manufacturing industry include Allied Glass, a UK company that makes the bottles for Diageo’s Tanqueray No.10, which is reportedly the world’s best-selling gin, Cape Town based company Amcor, Swiss engineering group Bucher Emhart Glass that manufactures equipment for glass container manufacture, our very own Consol Glass which is now part of the Ardagh Glass Packaging group, Sisecam from Turkey, a company that has 44 glass container manufacturing plants, Japanese glass container manufacturing company Toyo Glass and German company Glass Technology International.”
The company’s DN Solutions Daewoo ACE V-35 vertical machining center has been a workhorse for the company
“There are also other companies in Portugal, South America, Cameroon, the US and Germany that are connected to the food, beverage and brewing sectors, as well as manufacturing pharmaceutical glass bottles and jars.”
“We now have a team of over 50 staff who are led by the seven managers that we have appointed. With the trust that we have placed in these guys we have a source of business intelligence that helps Dave and myself make more accurate decisions. There is also a sense of empowerment.”
Other services offered include welding, metal spraying, finishing and fabrication
“Not all of the staff operate from our facility in Roodekop, which is an industrial area south of Johannesburg. We have a second workshop not far from our main facility. It is located on the premises of one of our bigger clients. We have 24 staff based there and they run on a three-shift system.”
“They are there exclusively for the client to maintain and repair, where necessary, the client’s neck rings, moulds and other associated components and products. There are no CNCs there, only welding equipment and other hand-held equipment and tools so that there is immediate reaction to any breakdowns. It is an arrangement that we have had with the client for some time.”
Brothers Willem and Henro Swanepoel
“New developments such as brand identity, e-commerce, sustainability and lifestyle are impacting bottle design. Rapidly evolving consumer demands, along with strict retail and regulatory requirements, are driving packaging companies to push the boundaries of what a bottle can be. While evolving design tools allow designers to be more creative and help customers achieve their unique brand identity through shape, embossing and etching, there’s more to it than that.”
“Next time you take a sip of your favourite beer or pour a glass of wine, obviously from glass containers, or you take a scoop of mayonnaise or peanut butter, think of what design and machining has gone into that glass bottle. It is surprising how many critical engineering and design methodologies that are deployed long before the final product reaches the customer.”
For further details contact Neck Ring International on TEL: 011 724 3900 or visit www.nri.co.za
