Looking towards the tannery of tomorrow1 January 2002
Curtin have a number of new products aimed at the early stages of leather making. Many have been developed in order to reduce the environmental load from the tanner and advance cleaner processing. The innovations are as follows: Adunil ZP is a new soaking enzyme, which is a mixture of proteolytic enzymes with an alkaline support. Being alkaline, the product allows the optimum pH of enzyme activity to be obtained. However, the pH value may have to be adjusted between 9.0-10.5 in order to obtain the maximum activity of digestion and solubility of the leather's proteins. The off-white powder has a medium enzymatic strength to enable a deep soaking effect in a short time. Curtin recommend using quantities between 0.5-1.2% based on salted weight and Adunil ZP can be used with Curtin's special surfactant Adunil FB during soaking which allows the tanner to produce waterproofed leathers. Adunil ZP is biodegradable and has enzyme activity of 1400 LV units. Adunil HR is a powerful soaking agent with a mild enzymatic activity. It is recommended to be used during 24 hour soaking of cow hides. The brown biodegradable powder is a combination of several ingredients and contains a small percentage of proteolytic enzymes as well as a high HLB surfactant. It also includes another constituent, which acts as a dirt dispersing agent. Like Adunil ZP this product is alkaline to enable optimum enzyme activity and support a partial saponification of the natural fat found in the hides. Curtin recommend a dosage between 0.6-1.5% based on 25-30kg European salted bovine hides with a drum speed of 1.5-3.0 rpm. Adupel S is a liming auxiliary, which accelerates the unhairing process. It is made up from a blend of reducing agents and enables the tanner to achieve a better unhairing and a cleaner grain. The epidermis is removed when using this low viscous liquid. In a typical hair burn process 0.3-0.5% Adupel S is required to improve skin quality and where lower quantities of reducing agents are required for hair save liming Curtin recommend an offer of 0.7-1.2%. Using Adupel S, the tanner is able to avoid excessive hide swelling and is able to reduce the quantities of sodium sulfide or sodium hydrosulfide. Adupel S also improves the hide/skin structure for subsequent processing and can improve area yield. Adukal DA is a fast acting deliming agent, which is a composition of polyfunctional organic acids and salts with a buffering effect. The white powder has a 100% active material and is totally soluble in water. Adukal DA is a deliming agent with a strong buffering action making it a non-astringent product when deflating hides and skins to leave a fine grain. It is especially recommended for use on bovine hides but can also be used on sheep and goatskins. Adukal DA can be offered undiluted between 1.0-3.0% depending on the thickness of the hide or skin and the level of deliming needed. Aduzyme T is a conventional bating enzyme comprising of a blend of pancreatic enzymes, kaolin and nitrogenated salts. The white powder has an enzymatic assay value of 750 LV units per gram. Aduzyme T should be added as a powder to the bating bath between 33-36°C for 1-2 hours depending on the leather type and the desired effect. The optimal pH range is 8.2-8.5. The dosage ranges from 0.3-2.0% depending on leather type, lime liquor used and desired effect. Aduzyme T enables the processor to eliminate epidermal deposits, hair residue and other unwanted material found on the pelt. Kaolin is preferred to saw- dust as a carrier as it has better adhesion to the leather and also has a sliding effect, which reduces the incidence of knotting during processing. Leathers bated with this product exhibit a cleaner grain, improved elasticity and a better overall handle. Adunil ED is an environmentally sensitive liquid degreasing agent, which is suitable for all leather types. This compound is a polyglycolether of a linear fatty chain. Up to 2% of Adunil ED is recommended when degreasing cattle hides and up to 5% should be used on sheep and pigskins based on skin weight. The use of solvents such as kerosene is not required as Adunil ED has the capacity to dissolve, emulsify and remove natural animal fats and also acts as a suitable surfactant for general use. This product has a solid content of approximately 85% and the pH of a one percent solution is between 5.0-7.0. Please refer to safety data sheets for transport, storage and handling conditions of each of the leather chemicals mentioned above.