Elastic strip-over

Within narrow iimits regarding the geometry and the material it is possible to demold undercuts through an elastic strip-over Moderate elastic deformation and high elongating capability of the plastic e.g. for the production of lids made from LDPE, may save a complex demolding mechanism. 

An elastic strip sewn to the face mask and going over the cop of the head is joined at the back by one sewn to the sides. 

Cross-linking the fibers with radiation lead to durable-stretch fabrics. The fabrics can be made by any process, such as weaving and knitting, and from any combination of cross-linked, heat-resistant olefin elastic and inelastic (hard) fibers, e.g., cotton and wool. These fabrics exhibit excellent chemical resistance (e.g., chlorine or caustic resistance) and durability, that is, they retain their shape and feel (hand) over repeated exposure to processing conditions, such as stone-washing, dye-stripping, and PET-dyeing. 

The anterior hairline is a special area. A first strip of Leukoflex is placed directly on the patient s skin, at the edge of the hairline. Any hair sticking out over this edge should be cut off so that it does not get pulled out when the mask is removed 24 hours later. A hairnet is placed on the patient s hair. An impermeable or plastic shower cap should not be used, as it holds the sweat on the scalp and makes the occlusion very uncomfortable for the patient. The (loose) elastic edge of the hairnet is positioned on the first strip of Leukoflex . A second layer of Leukoflex holds the elastic of the hairnet in place the net thus forms an integral part of the occlusive mask and can be used to pull the whole dressing off smoothly and painlessly when the time comes to remove the mask. 

A double beam specimen, shown in Fig. 9.4d, consists of two flat strips bent against each other over a centrally located spacer [10,16]. This specimen provides an uniform longitudinal stress in the convex space between the hnes of contact with the spacer. The stress decreases linearly to zero at the ends of the specimen. The elastic stress in the convex between the lines of contact is estimated hy Eq. (9.8). 

Tape n. (1) A narrow, woven fabric not over 8 in. in width. (2) In slide fasteners, a strip of material, along one edge of which the bead and scoops are attached, the bead sometimes being integral with the strip. Also see slit tape and non-elastic woven tape. 

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