Glue, animal

Early aircraft were constructed using spars of solid wood and laminated wooden structures. The latter being used where constructions containing simple or complex curvatures were required. Initially ash was used but this was later replaced, to a great extent, by spruce. The glues used at this time for bonding wood were based on proteins extracted from animal products such as bone, hide, fish skins, blood or milk. 

These adhesives were split into two broad classes  

The more solid structmes, such as propellers and curved frame members, were prepared by laminating solid pieces of timber, between 3.0 and 15.0 mm thick, with all grain directions parallel to each other. Such structures are defined as layers [2] or glued laminated structmes [3]. 

The applications using assembly glues could tolerate adhesives with short working lives, whereas those used for pljrwood manufactme needed much longer set-up windows in order to accommodate the time needed to lay up the packs of veneers before pressing took place. 

The first assembly glues would have used collagen-based systems [4], which are all traditionally called animal glues these would have later been replaced by casein-based glues. 

---

Animal glues Animal oil Animal products Animal testing Animal waxes Animation effects... 

The proteinaceous gelatins in the various animal glues were also widely used as paint media, as well as in illuminations. Glues, the traditional media in Oriental painting, remained the prevalent binders for ground layers in European painting long after oils had become virtually the only medium for the color layers. 

Animal glue or gelatin has also been used, 0.2 g/L. Peptone is predissovled and stored warm for a few days before use. 

Several types of adhesive are used for attaching the pages of books to the spine. Traditionally, where repulpability is critical, such as phone books, animal glue... 

Tannin-containing woods also darken with ammonia, a process which is usefully employed in darkening oak furniture by fuming . Ammonia stains can originate from animal glue, amino-type adhesives and concrete additive sources, particularly where damp conditions exist. 

A safety match head is, essentially, K chlorate in a matrix of animal glue. The striking strip is composed of red P in a similar binder. Use of additives and adjustments in the mfg process results in a safety match which ignites easily when rubbed on the striking surface. The friction and contact of K chlorate crystals with red P results in the ignition of the match head which, in turn, causes the ignition of paraffin impregnated in the match splint... 

Animal glue is a complex colloidal mixture of proteins. The related gelatins are also complex heterogeneous mixtures of proteins. They are strongly hydrophilic and rich in the amino acids glycine, proline, lysine, hydroxyproline and hydroxylysine. Casein is a phosphoprotein obtained from the milk of mammals. 

Proteins Egg, milk and casein, animal glue, silk, wool, vegetable proteins (e.g. garlic, beans), human and animal tissues (e.g. mummies) Paint binders, adhesives, textiles, commodities, parchment... 

Amino acid Egg white Egg yolk Casein Animal glue (collagen) Wool (keratin) Silk (fibroin) Garlic... 

At the same time, natural adhesives such as casein glues, animal glue and polysaccharide gums have gradually been replaced by synthetic adhesives vinyl thermoplastic adhesives [poly(vinyl acetate)], adhesives obtained by reticulation in situ of two components (as epoxy resins), represent very important materials in this field. 

Adhesive Improving cohesion Colophony, gelatine, animal glue, casein... 

The type of proteinaceous binder was correctly identified in all model samples. In only one case (S10), the animal glue was additionally identified, although the restorer who prepared these model samples declared that the sample contained only egg binder. It is possible that this sample was contaminated during its preparation or during laboratory treatment. The results indicate that this method does not allow reliable identification of the presence of individual egg yolk and egg white most probably it is caused by the presence of a trace of egg white that is always present in the egg yolk preparations (and vice versa) and can be detected by the highly sensitive PMM method. The identification of individual types of animal glues will never be reliable by MALDI-TOF mass spectrometry because of their similar composition the application of ESI (electrospray ionisation)-MS/MS (Section 6.5) could possibly overcome this problem. Only the fish glue, whose peptide... 

Figure 6.5 Mass spectrum of sample P3 from Portrait of Friedrich Nietzsche. The mass peaks of animal glue are labelled by the arrows and the mass peaks of whole egg by the dots...

S.M. Harrison, I. Kami, V. Prokoratova, M. Mazanek, E. Kenndler, Characterisation and identification of proteinaceous binding media (animal glues) from their amino acid profile by capillary zone electrophoresis, Anal. Bioanal. Chem., 382, 1520 1526 (2005). 

---