Strictly-Extrusion

In-house colouring of thermoplastics and elastic polymer blends such as ABS has been used in the industry for many years to manufacture high quality engineering plastics components. The Plastics Industries BU of the Pigments and Additives Division, Market Segment Masterbatch & Compounding in Gersthofen, has worked on raw materials formulations for in-house colouring of ABS for some considerable time.

ABS belongs to the group of elastomer-modified thermoplastics. When manufactured by the emulsion or suspension processes, variations in inherent colour often occur. During processing, exposure to high temperatures may lead to undesirable yellowing which renders the task of in-house colouring more difficult. To achieve high quality nevertheless, the opaque raw material should exhibit inherent colour, which is as light and uniform as possible.

Extensive research by Clariant’s experts into optimised formulation has perfected the in-house colouring process as regards colour yield and freedom from streaking. Temperature control, type of mixer and the formulation of dispersing agents are particularly important for successful colouring.

Besides optimal pigment dispersion, specially matched dispersing agents and carrier substances based on wax prevent deterioration of the ABS to be coloured. Furthermore, the mechanical, thermal and rheological properties of the material are retained after colouring. The formulation is adjusted to be compatible with the plastic to be coloured.

Specially designed extruder screws and temperature controls are other useful methods for achieving an optimum result without streak formation. High quality constituents in the formulation, such as pigments with low filter values, are further key factors for manufacturers of masterbatches and compounds.

Colour changes necessary at the compounder can be undertaken at any time.

Window profile extruder Aluplast, downline equipment manufacturer Greiner Extrusionstechnik and plastics machinery system supplier Fux have developed an inline method of cladding PVC window profiles with decorative film that is claimed to cut production costs by more than 32%. The project was described at the K show last week by Fux managing director Harald Humpl. He said the cost saving had been calculated based on annual production of 160,000 running metres of window profile. PVC profiles are clad inline directly after calibration, but before co-extrusion of elastomer seals, eliminating the conventional transfer of cut profiles between containers and an offline cladding operation.

EVAL Europe N.V. has completed the manufacturing capacity expansion of its EVAL™ ethylene vinyl-alcohol (EVOH) copolymer resin plant in Antwerp. Total capacity of the site is now 24,000 tonnes per year, overtaking Kuraray’s American EVAL™ production site to become the largest EVOH plant in the world. Mechanical completion was completed in September, 2004. Expanded EVAL™ resin production began on 18th October. The additional manufacturing capacity represents an investment of approximately 80 million euro.
EVAL™ resins have the highest gas impermeability rate of any plastic (approximately 10,000
times that of ordinary polyethylene). The primary application for EVAL™ EVOH copolymer resins is food packaging, where EVAL™resins provide excellent gas barrier properties and resistance to odour and flavour permeation. Another high growth market for EVAL™ resins
is as a barrier layer in plastic automotive fuel systems. EVAL™ resins help to protect the environment by minimising harmful fuel vapour permeation from fuel tank, line and filler pipe, allowing fuel systems to conform to strict international emission standards. EVAL™ is also
used to make pipes for floor heating systems, and in other residential, cosmetic, medical and appliance-related applications.
Kuraray became first the world to develop and commercialise the high-performance EVOH resin EVAL™ in 1972. EVAL Europe N.V., established in 1997, is a fully owned subsidiary of
Kuraray Co., Ltd. The plant started production in September 1999 with an annual capacity of 10,000 tons, quickly expanded to 12,000 in 2001. In addition to EVOH resin production, the EVAL Europe N.V. site includes sales, technical service and administrative offices. Linked to the capacity expansion, EVAL Europe has constructed a new processing and development
hall for their European EVAL™ Technical Centre, which serves customers in Europe, Africa and the Middle East. This will both accelerate and increase the amount of EVAL™ EVOH research and product development done in Europe.
The new capacity ensures Kuraray’s position as the leading manufacturer of EVOH resins and demonstrates its continued confidence about the future growth of EVOH markets worldwide.
The average annual growth rate of demand for EVAL™ EVOH copolymer resins is expected to be 10% over the next decade. Growth is centered in Europe, North America and Japan., but new demand growth is predicted in Eastern Europe, the Middle East, South
Africa, Asia and Latin America where lifestyles and standards of living are changing.
Kuraray is the world’s leading manufacturer of EVOH resins. Kuraray supplies its customers world-wide with EVAL™ EVOH copolymer resins from plants in Pasadena, Texas, USA (23,000 tonnes per year, previously the largest EVOH facility in the world), Okayama, Japan
(10,000 tonnes per year) and Antwerp, Belgium. With the expanded EVAL Europe plant, Kuraray’s total world-wide capacity for EVAL™ resins now exceeds 57,000 tonnes per year.
The USA plant (EVAL Company of America) announced on August 2, 2004 its plan to
expanded its manufacturing capacity by 24,000 tonnes per year, scheduled for completion in March 2006. This new planned expansion will bring the total EVAL™ capacity to 81,000 tonnes per year. The capacity expansions in Europe and the USA position Kuraray to
continue to support its customers’ increasing EVOH requirements and demonstrate Kuraray’s global commitment to new application development.

A new surface winder from Davis-Standard, the PAC 60, enables film converters to wind 60-inch (1,500mm) diameter rolls on 6-inch (150mm) cores at speeds up to 600 feet per minute (180 meters per minute). This winder is ideal for large roll mill operations where film is either converted into a lamination or made into bags or sacks off-line. Davis-Standard recently supplied nine of these winders to a major can liner manufacturer.
The PAC 60 is unique in that it features lay-on pressure control to prevent blocking at the core, a problem which is typical on most large-roll surface winders where the lay-on force is not controlled. This is made possible via a hydraulic control circuit and roll mounted force transducers utilizing an actual pressure feedback circuit to consistently maintain lay-on pressure. Other advantages include a shaft accelerator to bring the new core to the higher line speeds and transfer via an auto-cut traversing knife to a new core. The shaft is positively clamped with a pneumatic latch during the transfer cycle for positive roll starts and dependable transfers.
The AC drives and controls for the PAC 60 are mounted on the winder frame for a single power drop. This winder is also pre-wired and fully tested, and is available in 40, 50, 60 and 70-inch width (1,000 to 1,800mm) models.
For more information, contact Rick Keller at rkeller@davis-standard.com.

Krauss-Maffei (KM) will build plastic metal composite pipe production systems in cooperation with THE Thomas Machines.

KM has signed a cooperation agreement with the Swiss firm to produce the machines and equipment for the pipes, which have an aluminium or a steel outer layer and typically a PE-X inner layer. Production systems for plastic metal composite pipe up to 110mm in diameter will be available immediately from KM.

KM said these composite pipes were “increasingly preferred for applications from drinking water pipe, radiator connections and underfloor heating to gas and fuel supply lines”.

The company said its “Latig” unit combined all components required for two longitudinal weld processes – laser welding and inert gas welding with a tungsten electrode (TIG welding) – switching between the two as required.

KM said the cooperation between the two companies had produced a wide portfolio of machine variants.

UK polycarbonate extruder Polyex has acquired a majority stake in Victoria Plastics, the Hull-based distributor that trades as Stereon. Stereon was formed by a management buy-out of the company from GE in 2003. It has a nationwide customer base that includes DIY giant Wickes. Adrian Titmus, managing director of Stereon, will continue to run the company. Polyex managing director Roger Hartshorn said: “We are proud to welcome Stereon to the Polyex group, and see this as a major step towards building a truly national distribution network.” Polyex opened its EURO 11.6m multiwall polycarbonate extrusion plant at Alfreton, Derbyshire, earlier this year. It recently acquired Roofpax, a cutting centre in Barnsley.

US machinery firm Milacron is returning to the global market for wood-plastic extruders for the first time since it sold its European arm to SMS in 1999. Milacron sold its Austrian business, now known as Cincinnati Extrusion, to SMS with the agreement not to compete in each other’s territories for five years. This restricted Milacron to North America and gave Cincinnati Extrusion access to Europe and the rest of the world.
However, it is now free to compete with Cincinnati Extrusion, which in 2002 sold wood profile extrusion lines based around its Fiberex extrusion systems worth around EURO 27m. In that year 96% of its total sales were outside North America.
Milacron said it will rely on its global infrastructure to quickly penetrate overseas markets, using manufacturing facilities in Germany, Italy, Czech Republic and India. Abbiati said the company was ramping up production in China.

TER HELL PLASTIC, a company specialised in distribution, compounding and trading in plastics, has successfully concluded its entry into the Chinese market, made within just a few months. The company, with its headquarters in Herne (Germany) has been selling its products since the beginning of the year through four sales offices of the TER GROUP in Shanghai, Qingdao, Guangzhou and Hong Kong. They take care of comprehensive coverage of plastics customers in the key industrial regions in China. Apart from that, TER HELL PLASTIC has signed a co-operation agreement at the beginning of July, 2004, with Chinese compounder Su Chen in Suzhou.

These newly established business relationships of TER HELL PLASTIC will become evident at two large international meetings of the plastics industry: At K 2004, the company expects guests even from China on the stand (Hall 8, Stand 8 H 10). Local presence will also be shown later by TER HELL, together with Su Chen, at the 6th China Plastics Exhibition in Yuyao from 5th to 8th November 2004 (Stand A 2070). TER HELL’s presence at this exhibit in China will pave the way towards developing important business contacts that will enable further penetration of the Chinese market.

By moving into China, TER HELL PLASTIC is expanding into another extremely dynamic region, after successfully building up its Eastern European business during the past three years. The reasons are clear: Many TER HELL customers are transferring production activities to China, or are expanding their existing capacities there. They want to make use of both the favourable business conditions that this country offers, as well as the high growth potential of its markets.

With TER HELL PLASTIC, these companies can rely on a partner in Asia whom they have known with a long tradition in the European market. When, for example, a processor has to fulfil material specifications with its products made in China, TER HELL PLASTIC is able to supply the materials with the corresponding approvals locally. Through its four sales offices, TER HELL PLASTIC offers a variety of products from its own TEREZ® brand as well as other commodity and engineering plastics to the Chinese market.

Yet another reason for moving into China is the increasing demand of plastics producers who have long since operated globally. They are increasingly asking for the internationally oriented distributor – especially in Asia. Through its international structure, TER HELL PLASTIC provides new sales channels to achieve additional growth abroad.

What appears to be a huge step is, however, relatively simple for TER HELL PLASTIC, as the company can use structures that already exist: “Our parent company TER HELL & Co. GmbH has been successfully active in China over the past 20 years and has a well established organisation there”, explains General Manager Klaus Kleeb. “We utilise this organisation with immediate effect for our plastics group. The synergies within the TER Group provide us with a competitive advantage and make room for our principals to focus on their core competences”.

While the co-operation with Su Chen strengthens the sales structure of both contractual parties, TER HELL PLASTIC gains immediate access to a large number of medium-sized processors in China. Su Chen additionally possesses front-edge technical know-how in SBS and SEBS plastics*. Use of this knowledge sets the stage for TER HELL to further expand its strong position in Europe.

“The actual selling in China is done exclusively by our Chinese experts”, says Kleeb of the business philosophy of his company for this specific market. “The principle of ’think globally – act locally’ comes fully into play with our engagement in China. But it is also important that, through the support of the local employees in the sales offices, we are in the position to adapt ourselves right from the beginning to Chinese cultural customs.”

With its network of sales offices in China, TER HELL PLASTIC will focus on serving medium-sized customers. With this strategy, the company remains true to its traditional orientation towards small and medium-sized enterprises. Supply of plastics raw materials to medium-sized companies has always been the basis for the company’s business as a distributor. While this took place at the beginning almost exclusively on a national basis, TER HELL’s international business has gained increasingly in strategic importance during the past years.

Davis-Standard supplies the industry’s most diverse line of processing equipment to the evolving wood-filled marketplace. Equipment options include single screw extruders, twin screw extruders and Davis-Standard’s unique Woodtruder®, each designed to accommodate various applications and budget requirements. Following is a summary of advantages and disadvantages of each technology.
Single Screw Extruder
Single screw extruders are best suited for profile applications using
pre-compounded pellets with dried fiber materials. Using 60 percent wood fiber and 40 percent polyethylene, the output for a 4 1/2-inch (115mm) extruder is around 800 to 900 pounds (360 to 400 kg) per hour while a 6-inch (150mm) extruder can achieve upward of 1,600 pounds (730 kg) per hour. Disadvantages of single screw extruders include a lower rate versus melt temperature, poor venting and the use of pre-compounded material which has one heat history.
Twin Screw Extruder
Four types of twin screw extruders can be used in wood-filled processes. These machines include co-rotating twin screw, counter rotating conical twin screw, counter rotating parallel twin screw and counter rotating twin screw using ancillary equipment.
A co-rotating twin screw extruder can process powder or pellet-fed polymers and wood fibers with up to 8 percent moisture content. This extruder provides excellent mixing and venting, but has poor pumping stability therefore requiring a screw or melt pump. A typical rate for processing 50 percent polypropylene and 50 percent wood fiber on a 47mm co-rotating twin is 300 pounds (135 kg) per hour at 300 RPM.
The counter rotating conical twin screw extruder is designed with a larger feed diameter for processing low bulk density materials such as dried wood and powdered polymers. This machine offers good mixing and pumping capabilities at lower melt temperatures. However, venting is limited and using pellets can be problematic. Typical output rates for a 61mm conical are around 300 to 400 pounds (140 to 180 kg) per hour.
Like the conical twin, the parallel counter rotating twin screw extruder has good mixing and pumping characteristics at reduced melt temperatures, but limited venting and difficulty processing pellets. A crammer feeder is recommended with this machine. Typical output rates are 500 to 600 pounds (225 to 270 kg) per hour for a 94mm extruder, 900 to 1,000 pounds (410 to 450 kg) per hour on a 114 mm machine and 1,600 to 1,800 pounds (730 to 820 kg) per hour using a 140mm extruder.
Ancillary equipment such as a pre-heater and crammer feeder can be used on conical and parallel twin machines for added flexibility. A pre-heater is required when processing wood fibers with moisture content above 1 percent or when using pellets. The pre-heater, located above the extruder, warms the material to around 200 degrees Fahrenheit and meters it directly into the extruder using intermeshing co-rotating screws. A crammer or force feeder is needed when feeding low bulk density wood flour/polymer blends. The feeder increases efficiency by utilizing an auger to force materials into the feed zone of the extruder screws.

Woodtruder
The Woodtruder™ is another Davis-Standard option for processing wood-filled products. This machine utilizes a single screw side injection extruder to melt the polymer and a parallel twin screw extruder for drying, mixing and pumping. There is no pre-drying or wood blending required and nearly all polymer forms can be used. A gravimetric feeder provides input consistency and moisture is removed via an atmospheric and vacuum venting system. This extruder is very efficient at pumping and mixing at low melt temperatures and processors have the option of using wet wood. Disadvantages include an output rate sensitive to wood type and moisture content as well as difficulty with evolved moisture. Typical processing rates are 500 to 600 pounds (225 to 270 kg) per hour for a 94mm Woodtruder, 900 to 1,000 pounds (410 to 450 kg) per hour on a 114mm machine and 1,500 pounds (680 kg) per hour on a 140mm model.
For more information about Davis-Standard’s wood-filled processing capabilities, contact Wendell Whipple at wwhipple@davis-standard.com.