Plastics embossing

Correct identification of patients and specimens is a major concern for laboratories. The highest frequency of errors occurs with the use of handwritten labels and request forms. One method for checking identification is to compare identifiers such as the patient s name and his or her unique hospital number. The identification on the specimen label should also correspond with the identification on the requisition form. The use of plastic embossed patient identification cards to imprint the patient s name on test request forms and on blood collection labels can eliminate transcription and identification errors but does not guarantee that tiie patient name on the labels correctly identifies the donor of the specimen. The integration of bar code technology into the analytical systems that are used by clinical laboratories has significantly reduced identification problems (see Chapter 11). 

Nowadays, however, zinc-coated steel sheets, either continuously galvanised or electroplated, are often used as a basis material for overcoating with plastic materials or paints. The coatings are usually applied continuously and have a range of uses both externally and internally. Many surface finishes are obtainable, e.g. plain or embossed, and in an extensive range of colours, to suit almost any requirement . 

Basically the calendering process is used in the production of plastic films and sheets. It converts plastic into a melt and then passes the pastelike mass through roll nips of a series of heated and rotating speed-controlled rolls into webs of specific thickness and width. The web may be polished or embossed, either rigid or flexible (9). One of its sheets major worldwide markets is in credit cards. At the low cost side these lines can start a million. A line, probably the largest in the world... 

Both the indenter and the specimen surfaces should be smooth and homogeneous in order to minimize friction. If the indenter is not smooth, under pressure that is sufficient to cause plastic flow. The specimen will become embossed by the indenter, tending to lock the surfaces. This will induce a large effective friction coefficient. 

Inserts can be incorporated into the mould before injection or placed after demoulding into a moulded hole. For neat resins, the first solution is generally avoided because of the big difference between the coefficients of thermal expansion of metals and plastics. In both cases, inserts and embossing must obey some general rules. Among these, some, but not all, are recalled below ... 

Integration, thanks to the plastic elements, of the maximum number of functionalities mountings, fastening points, fixings, cable holders, housings, embossings, eyelets, clips, etc. 

My book The Zen of Magic Squares, Circles and Stars was my only one in which the publisher used a physical object, namely a plastic sliding puzzle embossed with the name of the book, to help promote the book. Simon Schuster used a similar gimmick when promoting their children s book Doctor Dan and the Bandage Man. The publisher decided to give away several Band-Aids with each copy. The publisher wired a friend at Johnson Johnson Please ship half-million Band-Aids immediately. The friend replied, Band-Aids on the way. What the hell happened to you 2 ... 

Zhu et al. [76] designed and fabricated microfluidic devices on polymethylmethacrylate (PMMA) substrates for electrochemical analysis applications using an improved UY-LIGA process. The microchannel structures were transferred from a nickel mold onto the plastic plates by the hot embossing... 

Moreover, a Zeonor plastic plate, normally used to manufacture CDs and DVDs, was hot-embossed (130°C, 250 psi) using a Si master. The embossed chip (with microchannels 60 im wide and 20 pm deep) was thermally bonded to another Zeonor plate (85°C, 200 psi, 10-15 min) [808], In another report, a 2-mm-thick cyclo-olefin (Zeonor 1020 R) substrate was embossed using a Si master to create 20-pm-wide and 10-pm-deep channels [788],... 

FIGURE 2.23 Scheme for fabrication of plastic microdevices from silicon master using an intermediate soft mold, (a) Silicon structures are fabricated using conventional photolithography and reactive ion etching, (b) PDMS is cured in situ over the silicon master, (c) Polystyrene is hot embossed onto the PDMS mold or polymerized in situ from partially polymerized styrene, (d) Polystyrene replica is separated from the mold [85]. Reprinted with permission from Springer Science and Business Media. 

In the early days a calender train for plastics was a very basic affair, consisting of a line of small rollers to transport the film to an embossing nip, and a set of three or four larger cooled rollers to bring it to a crude wind-up. Probably there would be only three motors to drive the whole train and very little adjustment of speed ratios would be possible—a far cry from modern equipment, in which there may be twenty motors for a train. 

Since plasticized PVC is thermoplastic both compact and expanded wallcoverings can be given a surface texture by hot embossing. This usually is the last stage of production before trimming and reeling. 

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