The development of Sandretto's MEGA T and MEGA H range provides customers with Injection Moulding Machines capable of large-sized mouldings. These machines can provide greater productivity, minor production costs and high returns on investment.

Click on any of the stories below to read more about how our clients make use of Sandretto Injection Moulding Machines:

• Tenma UK Limited
• Brightwell Dispensers
• TSR Plastics Limited
• Wheelie Bin Production

Tenma UK Limited
TENMA SETS NEW STANDARDS IN QUALITY AND SIZE WITH 1600 tonne SANDRETTO MOULDING MACHINE

The largest injection moulding machine in Scotland is the Sandretto ‘Mega’ 1600 tonne installed recently at the Cumbernauld factory of custom moulder Tenma (UK) Limited. With two 1300 tonne and three 850 tonne machines amongst its 27-machine moulding plant, Tenma was already well equipped in the custom moulding service it was providing for Scottish industry.

Complete with gas-assisted injection facilities and de-mould robot, the Sandretto 1600 tonne machine is part of a recently completed £2.5M investment in what can best be described as a purpose-built manufacturing facility at Tenma. Comprising, also, a double-oven spray painting line, this investment has substantially increased the company’s finishing and spray-painting capability.

STEADY EXPANSION OVER 12 YEARS

Since opening in 1989, primarily to produce finished mouldings and assemblies for UK-based tv equipment manufacturers, this factory remains the only Tenma manufacturing unit in Europe. The 50-year old company has five moulding plants in Japan and two in China.

In twelve years, the Scottish operation has almost trebled its production floor area to 22,000 sq metres on an 88,000 sq metre site which is fronted by a lake and Japanese garden. Whilst remaining a major supplier of some of the highest quality mouldings of their type in Europe, Tenma (UK) has succeeded in diversifying by developing and supplying moulded parts for, typically, business equipment and industrial air conditioning systems.

Because of having specialised in the supply of tv casings and surrounds, much of the Tenma factory is taken over by fully automatic lines for spray-painting mouldings and assemblies, together with the pre- and post-spray finishing and packing lines. The older unit, installed less than two years ago, is designed for applying a single coating. The recently commissioned and much larger unit first applies an undercoat to de-ionized parts suspended on a conveyor; these feed through the first oven before lacquer spraying and into a second and hotter drying oven.

EXCEPTIONAL QUALITY STANDARDS

The standard of quality, demanded for what is the most expensive range of wide-screen tv sets on the market, is extremely high and rigidly maintained by individual inspection at every stage. The semi-translucent front surround, moulded in a low-butyl grade of ABS, has the effect of magnifying any blemishes in the base moulding. The surface finish of these mouldings is described by Moulding Manager William Shaw as automotive standard.

This moulding and finishing capability has led to the company now having reached advanced stages of completion on five quite different projects. These will take the company into new industry outlets and several will employ the substantial production capability of the new Sandretto.

Whilst the mould tools for the current range of 32 inch tv housings are easily accommodated on the platens, and a shot weight of 3.5 kg well within its capability, one of the new projects is for an extremely deep draw component. This will require most of the machine’s opening stroke.

LOOKING TO THE FUTURE

It was William Shaw’s responsibility to specify the most suitable moulding machine when the latest – 32 inch – tv housings were being developed. Furthermore, for such a major purchase, it was agreed that the specification should anticipate the future requirements of both this and the new markets into which Tenma is moving.

Competition for the order was against Far Eastern sources as well as other European manufacturers, on the basis of performance, reliability record, price and delivery. The Sandretto 1600 tonne is the first, large non-Japanese moulding machine in the shop. Consequently, Sandretto supplied platens which would accommodate existing mould tools as well as meeting current Euromap standards. The capacity of the travelling crane has been increased to accommodate the new tv front and back cover mould tools.

Brightwell Dispensers
BRIGHTWELL DISPENSES SUCCESS FROM MAJOR SPECULATIVE INVESTMENT

Sandretto 1000 tonnes produces larger paper towel dispenser moulding from 3-impression tool.

Brightwell Dispensers of Newhaven, East Sussex, is now reaping the benefits of a speculative decision made 18 months ago to invest in a Sandretto MEGA T 1000, a much larger injection machine than those currently in use.

In the words of Managing Director Neal Pybus: "That was the way we saw the market going. We were not prepared to restrict the future expansion of the company by delaying investment until the hygiene market picked up; if necessary we were prepared to produce smaller parts in the machine for a period. In the event we will have had little more than three months of running it under capacity, albeit 18 hours per day."

AUTOMATIC TIE-BAR REMOVAL

A major manufacturer of its own soap and paper towel dispenser enjoying increasing export sales, Brightwell used the 1993 Interplas exhibition to make a first judgment on injection machines of around 1000 tons lock. The final decision to purchase a MEGA T 1000 from Sandretto was settled by the availability of a removable tie bar to accommodate height restrictions in the moulding shop.

"It works really well" explains Neal Pybus, "At the push of a button, the tie bars slide back, providing full access for the gantry to unload and load moulding tools.

380 TONNE TO SATISFY GROWING MARKET

With six months to go before the Sandretto 1000 tonne was scheduled for installation, the market continued to grow and Brightwell found themselves sub-contracting production on eight mould tools. To meet this additional demand, the company installed a 380 tonnes Series Eight Sandretto in the new, purpose built moulding department, bringing its number of Sandretto machines to seven.

Improvements to its in-house moulding facility were already giving the company the tight control it desired over component costs. Consequently, an ability to maintain control over costs with the new, larger moulding tools had been a contributory factor in the decision to install a 1000 tonnes machine.

The first project uses a three impression, hot runner mould to produce the cover, back plate and bottom tray for the company's new BP4S large hand towel dispenser. Assembled, it measures 400 mm by 290 mm and stands 145 mm out from the wall.

EXPORTS AT 47%

With exports now running at 47% of turnover, the new, large Sandretto injection machine places Brightwell Dispensers in a position to broaden its activities in the wider aspects of waste disposal products and systems.

SERVICE 'SECOND TO NONE'

"When we first began using Sandretto machines" states Neal Pybus, "the UK company promised us back and support services which would be second to none. I can honestly state that, in all of our dealings with them over the past few years, this has always been the case".

TSR Plastics Limited
TSR PLASTICS RAISES THE ROOF TO INCREASE PRODUCTION

"Investment in more efficient manufacture is vital to withstand international competition and gain larger market share"

Carlo Tai, Managing Director TSR Plastics

When planning the current expansion of its Northamptonshire moulding factory, the third expansion in the 9 years it has occupied the site, TSR Plastics took the opportunity of literally raising the roof. "We can see an imminent need to install even larger injection machines in the near future" explains Managing Director Carlo Tai, "so we've raised the roof line by several metres, giving us the headroom for a 10 tonne gantry crane to lift the larger moulds we will soon be using, as well as upgrading the services, in particular the cooling water supply system.

"By constructing the new building around and over the existing structure, the impact on production was minimised. Furthermore, the new walls are over a metre outside the old walls, so the moulding shop is wider as well."

Specialists in the field of designing, manufacturing and marketing plastic ware for the garden and home - and most recently for the playroom with the Kiddyland range - TSR Plastics has spent almost £10 million in the last few years on new buildings, new plant, additional warehousing, a further 8 acres of land and the company's infrastructure.

REGULAR MACHINE REPLACEMENT THEORY

TSR's plant replacement programme is impressive; with the exception of one or two "classics" from the company's early yeas in Watford, none of the 30 machines is more than 5 years old. Two 200 tonne, two 270 tonne and one 550 tonne, all Sandrettos, are a part of a major investment programme over the last six months.

For the last 20 years, the company has built up what it describes as an excellent relationship with Sandretto and, with the obvious benefits in production control and maintenance, TSR Plastics has operated a policy of buying only Sandrettos. "We seek a high degree of reliability and a rapid response to any request for service back-up" explains Carlo Tai.

TSR Plastics Limited is a leading and independent UK manufacturer of plastic ware for the home and garden. Its b-line range is sold widely in the UK - in stores, DIY outlets and garden centres - and overseas. In order to fight international competition and gain a larger market share, constant reduction in unit costs is essential; investing in the latest technology is a necessary step towards achieving the goal. In recent years TSR has enjoyed substantial growth in export business, but the high value of the £-sterling is eroding margins, making investment in more efficient manufacture vital to maintaining profitability.

SELF-SUFFICIENT IN DESIGN - AND IT SHOWS

The 26-year old company, which moved to its present site at Finedon 9 years ago, is now totally self-sufficient in design and tool development, with tool repair and new tool manufacture lying within TSR's capability on site. The last few months has seen £1/4 million spent in setting up a new, fully functioning toolroom with CNC machines and EDM equipment under the reasonability of a new tooling manager.

With its own design team, TSR constantly updates its products and colourways; in both areas it can lay claim to have influenced the market. If the design requires larger machines, the company has always been prepared to invest, such as the Sandretto "Mega 750" machine to produce a large swing-top bin and the 55 litre linen hamper.

Examples of TSR innovation include the unique "Studio Drainer", several new colourways for its housewares, use of in-foil moulding with a traditional 'narrow-boat' design and the lion's foot pot supports for the garden market.

NEW WAREHOUSING MEETS NEW MARKET REQUIREMENTS

Introduction of the Kiddyland playroom range, which TSR moulds, assembles and packages on site, is dependent on the company maintaining stocks in all standard colours. Completion of Phase III of the warehouse expansion, with its high-reach/narrow-aisle stacker trucks, has provided the necessary space to hold stocks to meet customer demand. An 8 acre site close to the existing facility is to be developed under Phase IV. It will comprise a high bay warehouse for bulk raw material storage, enabling TSR to benefit from out-of-season raw material pricing, and for transport fleet servicing.

FLEXIBLE WORKING ENVIRONMENT

Complementary to the massive capital expansion programme is the manner in which the company has produced a working environment which recognises the social needs of its employees.

"In an industry with a history of long hours and inflexible structures" says Carlo Tai, "we have introduced flexibility at all levels. Shop-floor production staff are now contracted for 4 days in a week, absenteeism and high workforce turnover associated with long hours have dropped significantly and we are now able to recruit from a wider group of people whose social and family ties can be more easily satisfied with our new system.

"In the long run, we see the new shift system adding to the overall efficiency of the company. This, together with the new capital investment and further factory expansion, all contribute to placing TSR Plastics in a strong position to meet the demands of the millennium."

• Wheelie Bin Production

The machine we are proposing has been specifically developed to produce the classic 240 litres wheelie bin and it is just the result of past and recent experiences in this application.

It is important to underline that the cycle time shown after in this report will be strongly effected by the mould performance and consequently this would be a point of discussion with the customer.

The technical specs of the bin are:

240 litres wheelie bin body
Wall section: 4mm
Shot Weight: 8,913 Kg
Material: HDPE (usually MFI= 4-5 dg/min)

The usual technical specs required to the machine are:

1. A clamping force of 1750 ton, a clamping stroke of 2100 mm and platen dimensions able to accept a mould of dimensions 1500x1500x1650 mm.
2. A very generous injection unit due to low HDPE melted density and consequently high volume to be transformed, able to inject at high injection pressure (i.e. 1800 bar) due to the depth of the bin and the most reduced thickness of the wall.
3. The shortest cycle time compatible with the mould performance (70 to 65 seconds).
4. The lowest power consumption possible.

Sandretto Dedicated Press and Cycle Time

Just making treasure of our experience in this field and thanks also to our brand new range of high tonnage presses, we are glad to present a dedicated machine as per following short description...

Just summarizing the performances, we are proposing a press with high injection pressure, high injection speed, dedicated screw for high productivity, electric screw drive for maximum overlapping of plasticising to the mould movements and further reduction of power consumption and the following cycle time:

Reduced Power Consumption

Two main reasons of power dissipation are avoided with the new hydraulic system ESD compared to the variable displacement pump + proportional and servo valves circuits:

• The ESD system directly control speed and pressure of all the press actuators by modulating the speed of the electric motor, driven itself by the accuracy of the inverters. In that way Servo and proportional valves after the pumps, present in the traditional circuits and one of the main sources of energy dissipation, are no more necessary. Result: saving energy with high efficiency during the movements of the press.

• During the cycle phases where pups are not required to work (i.e. during cooling time, loading and un loading and partially during keeping pressure) the ESD system simply stops the motor rotation and consequently no oil flows. While in the traditional variable displacement pumps the pumps go in venting dissipating energy as heat during the flow to the tank.

Moreover it must be considered that with the electric screw on board additional energy efficiency is achieved due to the direct actuation of the screw by the motor without oil transmission in the middle.

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