Film press, surface sizing

Combination sizing (optimised AKD at the wet-end and surface size at the size/ film press)... 

Chem. Descrip. Hydroxyethylated corn starch CAS 9005-25-8 EINECS/ELINCS 232-679-6 Uses Film-former, sizing agent for paper and textiles surface sizing agent applied at size press and calendar starch binder in coating applies. warp sizing agent for textiles... 

The numerical integration of (9.74) was carried out using the fourth-order Runge-Kutta procedure with adaptive step-size control as described in detail by Press et al. (1992). The parameters in the continuum description of the energy were chosen to be = 0.03 J/m, /3i = 15 J/m, tq = IJ/m, Cm = —0.01 and (Ss = 2.86 J/m. It is assumed that the elastic modulus and the Poisson s ratio are lO N/m and 0.3, respectively, for both the film and substrate materials. For the compressively strained film, the surface energy of the film (sketched schematically in Figure 8.26) attains a minimum when 6 = 0.12, which implies that the sidewalls of the stepped mounds would evolve naturally toward this angle. 

Starch or size can be appKed in a film press or a pond size press to enhance surface strength and bending stiffness. In this case an after-dryer section is required for baseboard drying. 

Uses Oil/grease/water resist, aid for paper and paperboards used in packaging for the Food Service and Quick Service Restaurant market Features Effectively applied either in wet end, surface (size or film press) and coating do not contain any chlorofluorocarbons not intended tor use in microwave or bakery applies. 

The gate-roU size press is used for the appHcation of high soHds, high viscosity compositions to the surface of the sheet (92). The material to be appHed is transferred over a series of roUs, and a thin film from the appHcator roU is appHed to the sheet. 

A further problem of the size press operation is that of films splitting. At the exit of the nip, the film sometimes splits into two layers with one part following the paper and the other remaining on the roll surface. The problem manifests itself as small scale nonuniformities on the paper surface caused by threads of the size solution being drawn out and deposited unevenly on the surface to give a kind of orange peel effect. 

WET PRESSING. Where wet presses have a plain roll in direct contact with the wet paper web, serious difficulties have been encountered, attributed to hydrolysed and poorly retained neutral size residues (22). These are deposited on the surface of the roll, building up a film to which the wet web adheres, causing wrap rounds and web breaks. If no solution can be found, this would be a big enough problem to preclude running neutral/alkaline particular attention needs to be paid to minimising pre-hydrolysis and maximising size retention. 

The templates for the oxygen and hydrogen flow fields/electrodes in this book (see page 248) are intended to be printed on plastic transfer film and then transferred to copper circuit board for etching. This method is commonly used to transfer printed circuit board designs to the copper surface of the boards. We used Press-n-Peel , which is a plastic film that has an emulsion on one side and comes in sheets of 8V2"x 11" size. The plastic sheet is loaded into the printer just as any other 8 /2"x 11" paper would be. 

Slow cure is normally seen in high moisture papers and boards and the effect will be greater for AKD than for ASA, because of the slower reactivity of AKD and the difference in melting points, i.e. a liquid versus a low melting point wax. It is possible to improve the curing of AKD (and ASA) by running to a lower moisture <4% prior to a size press/film sizer and subsequently drying less after the size press/film sizer, but this may impact on the surface properties. 

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