Sag - SI - Momentive Performance Materials Inc

Kunststoffe international, 2005-11-21, Blown Film Extrusion Today
...ing on application, the film may be guided by wooden boards or rollers (made of aluminium or CRP). Because of their light weight, these rollers do not require their own drive, even for large working widths, and guarantee minimum film sag on account of their low thermal conductivity. The design of the reversing rod systems on reversing take-off units used as standard today depends on the maximum layflat film width. Horizontal reversing rods, normally used to process stretchable products that must...

Kunststoffe international, 2005-11-21, Comprehensive Product Range: Advancing into New Dimensions
...-effectiveness. For processing different sheet thicknesses, no additional settings are necessary because up to 10mm, automatic compensation takes place. This also applies to the UA 300g machine with automatic sheet feed. If the sheet is too hot and sags, it is supported with compressed air. This intervention is controlled by the sheet sag monitor. For the main movement sequences, distance measuring systems are provided for position control. Gentle, uniform heating of the sheet is essential for ...

Kunststoffe international, 2005-11-21, Fibre Composites: Bonding Automotive Bodies
Fibre Composites: Bonding Automotive Bodies In small to medium-sized series vehicle, fibre composites are increasingly used materials for exterior body panels. Adhesive bonding is raising in importance as it often is the only suitable joining technology. Jochem Sauer Plastics currently make up 13 to 18% of a motor car. This is predicted to grow at an annual rate of 4.7% in the West European automotive industry. Plastics applications are distributed between the car interior – by far the gre...

Kunststoffe international, 2005-11-21, Plastic Goes Online
...e also has an effect on the mechanical properties of the parts. For example, an increase of 10°C (from 190 to 200°C) in the temperature of the oven raises the flexural modulus of Spectrim HH 400 from 1680 to 1780 MPa. At the same time, heat sag (measure of dimensional stability) is improved from 7 to 4 mm. During their passage through the oven - at least 30 min at 180°C - the mouldings require complete support. As soon as they have cooled to below 80°C, they can be removed from t...

Kunststoffe international, 2005-11-21, Plastics Gain Ground in Car Body Production
...stic used in the production of car outer body parts Fig.2. Flow chart of the painting process in automotive production (the oval fields show at what point in the process the plastic parts are fitted to the steel body) Fig.3. The heat sag test demonstrates that the heat resistance of the polyamide/ABS copolymer TriaxDP3155 in the temperature range 180 to 200°C is more than 100% higher than that of comparable (PPO+PA) blends Absenkung = Lowering; Temperatur = Temperature; spritzfrisch = fres...

Kunststoffe international, 2005-11-21, Which Way is the Wind Blowing for GRP?
...r Potlife and Curing Times Some rotor blade manufacturers still use unsaturated polyester resins (UP) as the matrix for the fire composites on which the blade constructions are based. Thixotropic grades prevent any ‘curtaining’ or sagging on inclined surfaces; for reduced styrene evaporation, skinning agents are sometimes added, too. Use is also increasingly being made of styrene-dissolved reactive resins such as vinyl ester resins (VE), which are tougher and have higher dynamic strength than ...

Kunststoffe international, 2008-10-17, It’s the Cycle Times that Dictate the Profits
...s are produced. In the case of a manual feed, the operator influences the cycle time. The loading device contains the transport facility for conveying the material into the thermoforming machine. This also permits sheets that display a great deal of sag after being heated up to be transported into the machine, and allows the removal from the machine of positively and negatively thermoformed parts, including those with the maximum thermoforming depth. The transport is conducted in a raised, upwar...

Kunststoffe international, 2010-07-22, Handrail with Modular Design
...e tracks by longitudinal forces when passing over concave balustrade segments. Similarly, as the handrail moves along its track, its profile must exhibit high dimensional stability in both positive and negative bends so that the profile does not sag, which would increase its frictional resistance. In summary, the following demands are placed on semi-flexible composites: Longitudinally: high tensile stiffness and tensile strength, good fatigue characteristics under dynamic bending strain, and low...

Kunststoffe international, 2010-09-24, Two Centuries of Polyolefins
...led the production not only of ever better pipes with longer service life [23], higher pressure resistance (PE100) and larger diameters (“low sag” or LS types), but also stronger and ever lighter packaging films [24]. And what about PE-LD that has been d “dead” for years? Thanks to its unrivalled purity, it is today the standard worldwide for the insulation of medium and high-voltage cables. It can be radically or hydrolytically cross-linked by a variety of methods. In the meantime it is produce...

Kunststoffe international, 2012-09-17, Simple, Precise and Automated
... for processors to handle. The problem is that the pellets need to be removed as completely as possible so that they can be processed. The effort required here is not to be underestimated. Big bags, especially, are not dimensionally stable and sag more and more as they are emptied, thereby posing a challenge for automation. Enter Moretto SpA Massanzago, Italy, with the answer in the guise of the new octabag. This system empties pellet bags and octabins fully automatically, without employee assis...

Kunststoffe international, 2012-11-26, Inliner for Automotive High-Pressure Natural Gas Tank
...n is first extruded and then inflated in the mold (blow molded). From this new polyamide, parisons weighing 3.5 to 4 kg have been extruded in lengths of 1,000 mm. Thanks to the high melt strength of the polyamide, the parisons hardly sag at all under their own weight so that even large CNG tanks can be produced. It should be perfectly possible to successfully process parisons that are even longer and heavier. The considerably better thermal stability of the new material as compared with HDPE, fo...

Kunststoffe international, 2014-10-10, Sophisticated Skin Design
... positive effect on the extent of grain stretching and grain distortion. The film’s surface area which has to be heated is reduced as a result and the energy demand is therefore also lower (Fig. 5).Decorative films, especially PVC, tend to sag after heating and so the chainrail has been optimized to stretch the film not only across its width but also along its length. Between the heating and forming station, the distance of the two pin chainrails that grip the edges of the film and transport it ...

Kunststoffe international, 2014-11-26, Compensation of Stresses in Intermediates
...of the frozen stresses, the forming temperature and the size (area) and thickness of the intermediate, the following behavior is to be observed:Case A. The intermediate expands continuously until it reaches the forming temperature, thereby sagging more and more:The size of the sag results from the thermal expansion, the shrinkage due to relaxation of the internal stresses, the load exerted by the material weight and the spread during mechanical holding – generally using transport chains – and th...

Kunststoffe international, 2015-05-21, Wrinkling – How to Prevent It?
...the plug would simply fold over the wrinkle. If the area of the heated materialis larger than the area of the thermoforming mold, thermoformed parts with surface wrinkles result. This is especially true when there is significant material sag after heating in combination with a flat mold. In such cases, the mold should be built higher in order to create a larger area (mold plus increase). This area must then be at least as large as the area of the material created by the sagging material.… and wi...

Kunststoffe international, 2015-10-12, In-Mold Foamed Cores for Lightweight Design
...ined with temperatures of between 80 and 180 °C) with little or no yielding, and must therefore have high thermal and mechanical stability, and if required, creep strength.Ideally, the fibers should have a flat support during curing to prevent them sagging. Foam cores offer such a support, while the voids in competing honeycomb systems are weak points here. If the fibers sag, their strength cannot be fully exploited, so additional fiber layers have to be used, which increases the weight. Althoug...

Kunststoffe international, 2015-10-12, Vacuum or Pressure Forming?
...e vacuum forming reaches its limits in terms of transparency, wall thickness distribution, and contour definitions of the molded parts. In this respect, most PP materials are problematic due to their low melt strength (considerable film sag during heating), OPS because of its low molding temperature range, as well as APET due to its worsening transparency and moldability at higher temperatures. Moreover, a lower distortion of the image is achievable with preprinted film, because forming with com...

Kunststoffe international, 2016-02-17, Backmolding Formed Glass
... delaminate (Fig. 4). Forming of the Glass SurfacesThese results gave us the confidence for the next step, namely forming the glass. For this purpose, lime-soda glasses were subject to a special forming test, which differs from conventional sag and press bending. Lime-soda glasses with a thickness of 1 mm were used. In the next step, the formed glasses had to be stabilized and/or functionalized on their reverse side (Fig. 5).The keying of the adhesion promoter on the reverse side presented a pro...

Kunststoffe international, 2016-10-17, Complex Hollow Parts Made in One Go
...ter heating is completed, both heating units move out of the thermoforming station very quickly – within less than 3 s – so that the films cool down as little as possible by the time molding begins. Foam films extend when heated, and they sag unless the semi-finished product can be extended and stretched over the period of heating. It is therefore important to prevent the two film webs from touching each other when heated. Adjusting the distance between the two clamping levels accordingly can ...

Kunststoffe international, 2018-03-09, Efficient Heat Dissipation
...for assemblies operating at temperatures which do not necessarily require silicones. Easy ApplicationMany silicone-based thermal interface materials are available in paste form. These TIMs are shear thinning compounds and so will not sag when at rest, but will flow when exposed to shear forces. They are dispensed onto the heat sink in the form of a bead (Title figure). The assembly to be cooled is then mounted on top and pressed into place. Pourable types are also available in the form of resins...

Kunststoffe international, 2018-05-15, Recycling of Long Carbon Fibers
...project can reproducibly perform this task (Fig. 4). As the incoming and outgoing interface, plastic spools are mounted on the system. To ensure the material is processed with as little stress as possible, the regulated drive of the spools has a sag controller, which employs light-barrier signals.The patented binder mesh packaging [3] represents the most important individual function, since this step crucially determines the quality of the semi-finished product that is produced. The sliver is co...