Physico-chemical properties of hides and skins

The quality of hides and skins is defined by organoleptic, microbiological, histological and chemical characteristics (i.e. moisture, structure of the dermis, percentage of fat and collagen). Each type of hide/skin has specific physical and chemical properties that affect the type of tanning operations and the most suitable end use of the leather.

physico-chemical properties of skins
physico-chemical properties of skins and hides
physico-chemical characteristics of skins and hides
physico-chemical properties of hides
skins and hides physico-chemical properties
physico-chemical characteristics of hides and skins

knowledge

sector-specific

Physico-chemical properties of hides and skins is an essential knowledge of the following occupations:

Tanner: Tanners program and use tannery drums. They perform the work according to the work instructions, verify the physical and chemical characteristics of the hide, skin, or leather and of the liquid floats (e.g. pH, temperature, chemicals concentration) during the process. They use the drum for washing the hide or skin, removing the hair (not in the case of hides and skins tanned with the hair or wool on), bating, tanning, retanning, dyeing and milling.
Leather wet processing department manager: Leather wet processing department managers plan and organise the work, the staff and equipment of the department involving the washing of the raw hides or skins. They remove unwanted elements, they weigh and prepare it for tanning. They coordinate supply of chemicals and raw materials. They perform elaboration of manufacturing recipes and monitor quality.
Raw materials warehouse specialist: Raw materials warehouse specialists organise and monitor the reception and storage of raw materials in the warehouse according to the required conditions. They monitor the stock levels.
Leather production manager: Leather production managers plan all aspects of the leather production process. They ensure the required throughput of the factory in terms of quality and quantity of the leather. They organise the production staff. They monitor and ensure the operation of machinery and equipment. They cooperate with managers of each production department.
Leather laboratory technician: Leather laboratory technicians perform and report chemical analyses and physical tests of leather. They also perform and report chemical analyses of auxiliaries, environmental emissions and discharges. They ensure that the tests are carried out according to appropriate national, international or customer standards.
Leather raw materials purchasing manager: Leather raw materials purchasing managers plan and purchase supplies of hides, skins, wet-blue or crust in coordination with the production requirements. They negotiate processes and forecast the levels of demand for products to meet business needs and keep constant check on stock levels and quality to maximise business efficiency. They identify potential suppliers, visit existing suppliers, and develop business relationships with them.
Hide grader: Hide graders sort hides, skins, wet blue, and crust depending on the natural characteristics, category, weight and also magnitude, location, number and type of defects. They compare the batch to specifications, provide an attribution of grade and they are in charge of trimming.
Leather sorter: Leather sorters inspect and classify leather during and at the end of the production process according to the qualitative features, destinations of use and customer requirements. They work in the tannery and in the warehouses checking the quality, colour, size, thickness, softness and natural defects. 

Physico-chemical properties of hides and skins is optional for these occupations. This means knowing this knowledge may be an asset for career advancement if you are in one of these occupations.

Colour sampling operator: Colour sampling operators apply colours and finish mixes according to the defined recipes. They apply pigments, dyes or other finishing mixes.
Leather measuring operator: Leather measuring operators use machines to measure the surface area of leather and ensure that the machines are regularly calibrated. They note the size of leather and ensure its recording for further invoicing.
Leather production machine operator: Leather production machine operators use the tannery machinery and programs according to the specific requirements to achieve the department’s standards. They do routine maintenance of the machinery.
Leather goods artisanal worker: Leather goods artisanal workers manufacture leather goods or parts of leather goods by hand according to the specifications of the customer or their own design. They do repairs of leather goods such as shoes, bags and gloves.
Finished leather warehouse manager: Finished leather warehouse managers organise and monitor the finished leather warehouse, stock levels and organise product packing and dispatch. They maximise the warehouse space and manage time to control the orders.
Leather finishing operator: Leather finishing operators use machines for finishing leather according to the required specifications by the client for surface characteristics such as colour nuance, quality, pattern and special properties such as waterproofness, antiflame retardance, antifogging of the leather. They arrange the dosage of finishing mixes to apply to the leather and do the routine maintenance of the machinery.
Leather production planner: Leather production planners are responsible for planning and following production planning. They work with the production manager to follow progress of the schedule. They work with the warehouse to ensure optimum level and quality of materials are provided, and together with the marketing and sales department to meet customer order requirements.
Leather finishing operations manager: Leather finishing operations manager plan and organise the work of the finishing department. They are in charge of chemical supply and equipment management. They also coordinate the staff.

References

1. Physico-chemical properties of hides and skins – ESCO