Over the last decade, Sandretto has acquired a specific know-how in the injection moulding of large-size containers.
The use of thermoplastic materials in packaging applications has found great acceptance in a variety of markets: from industry to food applications, from building to chemical, from agriculture to textiles.
|- Waste Containers
||- Coat Hangers
Click on any of the stories below to read more about how our clients make use of Sandretto products.
PLASTIC LEGNO REDOUBLES
Just a few days ago Plastic Legno - Italy - informed about their decision to reconfirm their trust in Sandretto. This decision was supported by the positive experience started only a few months ago with their new department for plastic packaging moulding for the food industry, completely equipped with 6 Sandretto Mach injection molding machines. This is why they have now decided to double their production capacity by placing an order with Sandretto for another seven models of Mach presses.
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DAL MASCHIO ROBOTS ON SANDRETTO INJECTION MACHINES IMPROVE QUALITY AND REDUCE MANUFACTURING COSTS FOR BARPLAS
Sandretto injection machines, from a ‘Micro’ 50 tonne up to a 380 tonne, are employed by Bradford specialist moulder Barplas in the manufacture of paint containers. Everything from the handles, fittings, rings and lids to the largest 10 litre containers are moulded, printed and assembled by the company.
Latest addition to the moulding shop are two ‘Series Nove’ 300 tonne Sandrettos, both fitted with Dal Maschio 3E 1200K 3-axis servo-drive de-mould robots.
Considerable precision is required to maintain close dimensional tolerances on the container rims and the lids. The finished containers are delivered direct to paint manufacturers’ filling lines and the lids must fit perfectly, first time, with no leakage.
As part of its efforts to reduce production costs and raise consistency levels still further, Barplas made investigations into the use of robots. “Initially, we produced our paint containers from metal” explains proprietor Brian Baghout, “and Sandretto specialists provided invaluable advice during the change-over to plastics moulding. Their presence – as we grew from a small, inexperienced company with a couple of machines to a far more capable, medium-size moulder – proved to be a significant factor in our success. For precisely the same reasons we sought their help this time.”
COSTS DOWN AND QUALITY UP
Until the introduction of mechanised handling, finished containers were ejected into tote boxes beneath the machine daylights, requiring operators to empty the boxes every few minutes. Robots have substantially improved the situation.
On one of the ‘Series Nove’ 300 machines, producing 10 litre paint containers, parts are de-moulded and stacked ten high on an indexing conveyor which accommodates almost an hour’s production. This is accomplished by using a 4 metre long conveyor which is wide enough to stack the containers in two rows, side by side.
Alongside this machine, the second Series Nove is producing paint trays. Because of the shape of the tray, stacking presented a problem; the robot – very user-friendly as there is no need to program inputs and outputs – rotates alternative trays through 180? to produce a stable stack.
Cycle times remain almost identical; the slightly longer mould-open time is overcome by being able to have a shorter mould cycle as the robot can handle a hotter moulding without causing distortion. Benefits are measured in much improved consistency, elimination of the occasional blemishes through manual handling, greater cleanliness and, vital in any competitive business, reduction in labour costs – one operator less per machine per shift.
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EIGHT INJECTION MACHINES IN MANUFACTURING CELL IMPROVE THROUGHPUT AND QUALITY AND REDUCE COSTS
At its Portsmouth plant, Rexam Containers produces a range of Sharpak containers used in hospital operating theatres. Purpose designed to receive and eventually dispose of items such as needles and scalpels, the assembled containers incorporate moulded-in membranes, through which the used, sharp items can be pushed for safety, and snap-lock devices to seal the closures when they are full. Filled containers are finally sent away by the hospital for incineration.
Late in 1998, Rexam Containers commenced the redesign of its Sharpak containers which it was then moulding and assembling in Hereford. Redesign was specifically intended to reduce the handling, increase throughput and improve quality standards and consistency. At the same time it was decided to move production to its Portsmouth factory where Rexam has well established injection moulding, blow moulding and extrusion plants producing components for medical and pharmaceutical applications.
Described by Engineering Manager Richard Underhill as “just the first stage” of a major project to automate moulding and assembly, the dedicated manufacturing cell comprises eight Sandretto injection moulding machines of 270 tonne and 550 tonne clamp, together with over £300,000 worth of automation equipment. A conveyor is positioned alongside every moulding machine which are serviced by seven ATM ES-series all-electric, three-axis de-mould robots; these are PC-controlled using the company’s new touch-screen system.
The complete, fully-guarded cell operates under strict, clean-room conditions, the few operators needed to remove finished assemblies being required to wear masks and headgear.
DESIGNED FOR ROBOT HANDLING
Three sizes of Sharpak container are produced, of 6.5, 12 and 22 litres capacity. Redesign had to take in the requirements of robot de-moulding and the subsequent down-stream handling which would take the parts through labelling, stacking and assembly. First step was to reduce the number of components from five to three; a container now comprises a closure and cover, assembled automatically in the cell, and a base. All are delivered to a sister company which completes the assembly for delivery to hospitals.
It was at the design stage when, as self-confessed newcomers to automated manufacture, Rexam Containers made presentations to what had become a short list of machine manufacturers and automation specialists. The presentation spelt out precisely what Rexam needed to achieve in terms of throughput, cost reduction and quality levels, and requested practical responses from their prospective suppliers.
“By far the most practical and comprehensive responses came from Sandretto and ATM” states Richard Underhill, “and it became their joint responsibility to provide the plant.”
Facing a very short lead time, engineers from both companies met to determine the sizes of machines, the tooling requirements and – a major exercise – the necessary on-machine and downstream handling systems for the entire cell to function without operators.
In the cell, commissioned in April 1999, is a row of four 270 tonne Sandretto moulding machines alongside a row of four 550 Mega T machines ordered specifically for the project. Six of the moulding machines are equipped with ATM de-mould robots; the seventh robot serves two machines and the linked assembly fixture.
COMPLEX MANUFACTURING CYCLES
Bases are moulded on three of the 550 tonne machines – in two-impression moulds for the 6.5 and 12 litre sizes, and a single impression for the 22 litre. The fourth 550 tonne moulds the 12 litre covers from a two-impression tool.
This is one of two particularly complex cycles performed by robots in the cell. During the dies-closed period, the robot collects closures from a hopper-based orientation device alongside the moulding machine. Labour is required in this instance to maintain the supply of closures which are moulded on one of the 270 tonners.
The closures are small, round caps incorporating the aperture through which the used surgery items are inserted. An elevating conveyor takes these closures past sensors which use the apertures to orientate the closures for the robot to place them correctly into an assembly fixture.
The mould then opens for the robot to remove the two covers and place them over the closures in the assembly fixture. The robot retracts, to allow the fixture to snap the covers over the closures, and then returns to pick up the assemblies and stack them on the take-off conveyor at the side of the moulding machine.
The 270 tonne injection machine moulding these 12 litre closures in a six-impression tool is also used mould the 6.5 litre covers from a 2-impression tool. The remaining moulding machines are dedicated to the production of single items.
VITAL ENGINEERING CO-OPERATION
The sub-cell comprising the two, linked 270 tonne machines operating on identical cycle times employs a single ES2000 robot, travelling on a gantry between them. First operation is to de-mould a 22-litre closure from the one and place it in a fixture. It moves to the second machine, as the dies open, to remove the cover and place it over the closure already in the fixture. The robot withdraws, for the fixture to snap the mating parts together, and returns to the first machine to de-mould the next closure. A small pick-and-place robot is used to pick up the assembly and stack it for collection.
Essential for the successful operation of this cell are identical cycle times for two quite different mouldings, one of them incorporating a membrane.
AUTOMATION COMMENCES WITH MATERIAL FEED …
Law requires that every base carries a detailed instruction label; these are applied automatically as part of the post-moulding operations. Automation also extends to the handling of materials to the masterbatch units on every machine; bases and covers are yellow, closures are blue.
The demands of the application require that production is subjected to close and constant monitoring particularly on needle penetration through the membrane. For this reason polypropylene with a melt index of 3.5 has to be used.
… AND WILL MOVE ON FURTHER
Richard Underhill explains that, following pre-production trials on the downstream handling equipment, the eight moulding machines, robots and handling systems had all functioned smoothly and very much to specification. “Next stage” he says, “is to automate more of the assembly – along the lines of the covers-to-closures already carried out on the pair of 270 tonners – and final packaging of our assemblies.”
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800,000 DRINKS CAPSULES MOULDED EVERY WEEK BY FOURFOLD MOULDINGS FOR H P BULMER’s NEW ‘CHASER’
Flavoured schnapps for the newly launched ‘Crack-a-Glass’ chaser from Cider producer H P Bulmer is contained in 30 ml capsules moulded in PET by Fourfold Mouldings of Keighley in Yorkshire.
Two Sandretto injection machines – both Serie Nove 220 tonne units – have been installed by Fourfold Mouldings specifically to produce the capsules which are designed to fit over either the rim of a drinking glass or the neck of a bottle. H P Bulmer anticipates a high demand for this totally new concept; consequently two, 16-cavity, hot-runner moulds have been constructed. Current output is 800,000 per week and this is anticipated to increase to 1.2 million per week by March of 2001.
NEW, PURPOSE-BUILT CLEAN ROOM
Fourfold had been approached by Wakefield-based Design For Plastics to carry out what would clearly be a demanding moulding contract. “We’d worked together on earlier projects” explains …(title)… Martin Wilson, “and were confident that, not only could we produce the parts, in PET, but mould them under strict clean-room conditions to meet food standards.”
Both injection machines, together with dessicant driers and automatic bulk packing equipment, are housed in a separate clean room, complete with suspended ceiling, constructed within what had been a storage area on the Keighley site. Mouldings are produced on a 20 second cycle and, after bulk packing, are delivered direct to H P Bulmer for filling and labelling.
40 YEARS OF MOULDING EXPERIENCE
Fourfold Mouldings was formed 40 years ago from toolmakers Fourfold Precision which had been set up in 1946. In addition to the two compression presses from its early days, the moulding shop now houses 20 injection moulding machines, of which the company has invested in 5 new Sandretto’s this year.
Choice of the Serie Nove injection machines for the H P Bulmer contract was influenced by the performance of the existing Sandrettos at Keighley where Fourfold had recently installed three Micro machines. These hydraulic clamp tonne, 40 tonne, 50 tonne and 65 tonne machines are equipped with Dal Maschio sprue pickers, also supplied by Sandretto UK. Work for these machines includes small, glass-reinforced nylon components for the automotive industry and, from a total of 30 mould tools, a variety of equally small and intricate parts for fishing tackle.
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Mainetti UK Limited
SIX SANDRETTO 300 TONNE NOVE Series S MACHINES ORDERED BY MAINETTI UK LIMITED
Sandretto UK is supplying six of its new NOVE S Series injection moulding machines to Mainetti UK’s manufacturing site based at Jedburgh, Scotland. Mainetti is the world leader for designing, developing and manufacturing garment hangers.
Mainetti placed the order for six 300 tonne machines following its own, in-depth market study, and the successful performance of a 130 tonne NOVE S machine installed earlier.
The Sandretto NOVE S machines, introduced at the K-2001 exhibition, employ technology developed by Sandretto to give high energy savings combined with high performance.
The six new 300 tonne injection machines are scheduled for delivery before June 2002.
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45 SANDRETTO INJECTION MOULDING MACHINES INSTALLED AT CEICA GROUP
A total of five Sandretto injection moulding machines have been installed this year in the Ceica Group in France - three series Eight 330 tonnes at the Ceica Gateau plant in Brion and two series Eight 200 tonnes at the Rose plant in Bresolles. With these latest acquisitions, Sandretto has installed 45 out of the Group's 113 total injection moulding machines.
The 16 Sandretto presses installed at Ceica Gateau as well as the 5 presses of Ceica Plasticos de Mexico S. S. are used for the manufacture of caps and closures in PP and PE for the cosmetics market. The 25 Sandretto presses installed at Rose are used for manufacture of caps and closures in PP and PE for the selective perfume industry.
Specialising in technical plastic parts fabrication for the perfume and cosmetics industry, the Ceica Group has experienced strong growth over the past few years, thanks to it's innovative spirit and numerous investments. Today, Ceica is comprised of seven companies, five of which are based in the Rhone-Alpes region, with a production plant in Mexico and a sales office in New York. Ceica is part of the PSB Industry Group, which is active in the packaging, materials and domestic aquatic markets. The PSB Industry Group's turnover reached 665 MF in 1997.
For the Ceica Group, 1997 was undeniably the year of investments with the buyout of Rose, a company specialising in the cosmetics and pharmacy markets. This buyout an illustration of the Group strategy to develop standard products, an activity representing 40% of Rose's business.
In addition to Rose's buyout, a new 2000m2 production plant has been established in Izernore for CCM, a company specialising in finishing, glass clear coating, plastic part UV clear coating, and vacuum metallization. This new process includes part degreasing with plasma. Integration of these new activities allows Ceica to better satisfy its major customers - such as Bourjois, Lancome, Beiersdorf, Yves Rocher, Sanofi - and to develop new products with all it's customers worldwide.
Additionally, Ceica has seen its subsidiary Ceica Plasticos - created in Toluca Mexico in 1996 - take off to answer the needs of the North American market. This company realized its turnover of $3 million USD in 1997 - 40% of which was exported on the American continent.
As for CMSI, the perfumery subsidiary, it has shown sustained growth, with new developments for Chanel, Lancome, Yves Saint-Laurent, Jean Patou, Clarins, Lancaster, Revlon, Azzaro etc. CMSI was recently awarded the Chanel Quality Trophy, and was certified ISO 9002 by Lloyds. CCM and Ceica Plasticos are expected to earn ISO certification, following in the steps of Ceica Gateau and Rose, who were awarded ISO 9001 in 1996, and SR2P, who was awarded ISO certification in 1998. SR2P, who specialises in technical parts for the automotive and pharmaceutical industries, has reported a growth in activity of 15%.
1998 has been regarded as the year of new installations. Indeed, Rose has moved into the new 6000m2 plant, located close to the Lyon Airport, Satolas, on which all the Rose activities have been regrouped. Consequently, the five companies located in Ain country - Ceica, SR2P, CCM, CMSI and Rose - are now situated within a 50 km radius. The Mexican subsidiary will also benefit from a plant extension expanding from 3500m2 to 6000m2. Turnover is expected to reach $6 million USD in 1998, of which 60% is for export. The Ceica Group has shown very significant growth in a very competitive market. In 1997, turnover reached 229 MF. In 1998, the Group is expected to double its growth.
The business relationship between Sandretto and Ceica, which started in 1982, is based on several criteria. Ceica employees list machine reliability, performance and conviviality, the quality of the after sales service and very short machine delivery time as the main factors which keep the relationship strong.
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Sandretto Mega HC ES: A Giant in the Packaging Market
4500 ton, 260 mm, 35 kg: these are respectively the locking force, screw diameter and quantity of material injected by the new Sandretto Mega HC ES injection moulding machine, installed last February at Arca Systems' factory.
Designed in combination with the development of an innovative mould, this huge production unit will be used for moulding new-design containers for agricultural use.
Arca Systems has grown steadily since its foundation, nearly twenty years ago, as a Division of Perstorp AB - a Swedish Group specialized in wood packaging - and has become a European leading Company. It also ranks third among the most important American manufacturers of material handling systems.
At the Finnish, French, Austrian, Spanish and American factories of the Company plastic containers and pallets are produced every year in a variety of sizes with an annual turnover of € 195 million (2001 Sales) with a work force of 900 people.
The significant investment plan in Research & Development allows Arca Systems Group to replace traditional materials, such as wood and steel, with more innovative, more economical and environment-friendly plastic resins (plastics can be recycled) thereby permitting highly qualified and advanced logistic solutions to be adopted.
Within the investment plan expected to be implemented by the Group over the next three years for producing more and more competitive products capable of meeting the demanding market requirements, the Management & Technical Dept. of Nuriex-based Company's factory recommended Sandretto as a reliable and qualified partner. This partnership will focus on developing innovative and efficient moulding systems, with the capability of technically meeting the production specifications required by Arca Systems.
Two Mega HC ES - 4500 and 2300 ton - have been purchased by the Arca Systems' Headquarters in Perstorp (Sweden). These machines are the latest generation of large tonnage machines developed by Sandretto.
Both machines make use of the hydro-block technology for mould clamping.
In spite of the difference in size of the machines, the injection unit adopted - ES Series - is the same for both models: 115-litre EUROMAP with double hydraulic injection cylinder. This Series makes use of a bimetal barrel with 260 mm Ø barrier-type screw profile, which is currently one of the biggest available on the market.
The over 600 gr/sec plasticizing capacity, meets fully the Customer's contractual requirements.
These new Series ES moulding systems are compact, high performance and energy efficient units equipped with inverter driven system coupled to a fluid transmission.
This "high level hybrid approach" grants the machine the following advantages:
* increased performance: a 25-30% increase in injection speed from previous series and multiple overlapping of movements are just some of the ways this machine gives increased performance and, as a consequence, increased output;
* reduced power consumption: it is lower than conventional variable pump systems and this is true for a much wider range of cycle times and material throughputs with savings up to 40%.
This technology gives a large improvement to local environmental conditions as it is a much quieter system and releases almost no heat to the atmosphere compared with traditional fixed or variable pump systems (additional improvements using optional water cool motors).
A complete inverter driven system controls the speed of rotation of the electric motors to give the speed and pressure required moment by moment. This has a distinct advantage over hydraulic variable pumps.
During the cooling stage (idle machine) or when waiting for piece removal through robot, the machine primary centralized system consumes 10% that of a conventional machine with fixed pumps and equivalent injection speed, or 25% that of an equivalent variable displacement system with equivalent performance.
The 4500 ton machine, installed last year, will be used for producing 1000 x 1200 mm PP containers for agricultural use. Expected weight is max 35 kg, whereas the production cycle is 28 pcs/hour which will be achieved via an optimised mould, designed and manufactured by Officina Meccanica Renier based in Rozzano (Milan).
The new-design container sums up a series of functional characteristics such as maximisation of inside volume, reduction in weight and optimum structural performance ranking it at top levels of the market.
The development stages, simulation and engineering of the product, conducted by Officina Meccanica Renier in conjunction and under the supervision of the Arca Systems' French Research & Development Dept., have capitalized on data base resulting from previous experiences, validation of Arca Systems' Labs as well as on accurate market analysis conducted by the Marketing & Sales Dept. of the Swedish Group which has dictated the technical and functional specification for the article.
The very same attention was paid to designing and making the mould. Here, the continual search for innovative solution and the comparison between the experience of mould maker and moulder have allowed optimising kinematics, minimising overall dimensions and weights (the traditional practice of mould oversizing, which is an operational limit for large-sized moulds, was abandoned), pushing ahead for cooling uniformity and implementing an effective and well balanced new injection system. All these advances also translate into a significant reduction of cycle times.
The integration of all these factors has resulted in increased output and optimum functional and quality levels, up to now impossible for this type of articles. This equipment approach witnesses the effectiveness of the interdisciplinary approach based on integration and competence of all Companies taking part in the design.
The second machine – a 2300 ton lock Sandretto Mega HC ES – delivered in March 2002, will be used for producing pallets and medium/small volume cases with tilting walls.
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Mach: a "Record" Performance
When choosing an injection moulding machine, especially high speed machines, cycle time, energy consumption and safety do represent profitability elements.
The results obtained with the new generation of injection moulding machines - the Mach machines from Sandretto-Metalmeccanica - carried away a Dutch moulder to a point that he defined the Mach line a "special series”.
When Plantpak - an important Dutch moulder of garden items - was seeking a new, high speed injection moulding machine for moulding flower-pots, one of the aspects of primary importance was the machine cycle time which was to be better, even though slightly, than current 5.8 seconds and with 3 sec. cooling time.
This performance was achieved through a Mach 200/860 which, tested at Sandretto's factory of Collegno, in the presence of the customer, was able to mould 4-litre, 21 cm diameter, 90 g polypropylene pots with 5.1 sec cycle time and equal cooling time. Better results were even reached with 4.1 sec cycle time and 2 sec. cooling time.
“Enrapturing results” says Bennie Jansen – Project Manager of Plantpak – also supported by significant energy consumption which, compared to the previous Mach Series, has been cut to a half: 0.62 kWh/kg.
“But even more surprising” states Jansen “is the optimum safety of the mould clamp, which was difficult to reach with high speed machines used for this application up to now”.
“ When I saw it in operation, I couldn't do anything but congratulate Sandretto-Metalmeccanica technologists for this machine”
They were able to demonstrate how traditional solutions adopted for the safety of mould clamp, which limit pressure to the piston, are totally unsuited because of kinematics and inertia of the clamping system.
The study made by Sandretto-Metalmeccanica technical team does not only limit clamp pressure, it also continually watches the actual force exerted by the piston through a pressure transducer installed on each side of the piston itself. If this force exceeds the safety limit, the control system will instantly shut down the mould clamping stroke.
Reduced cycle times, energy consumption reduced to a half, safety of the mould clamp: three optimum reasons which make a Mach a "very special machine".
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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 spec 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:
|Mould opening, core disengagement, ejection plus robot
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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