Insights of a customized production
In this article we introduce you to the heart of the procurement process: The production itself. Before going into production, it is important that all final details have been clarified. The manufacturer will make final preparations, set up the molds and discuss the exact production process with the workers involved. For complicated productions, the workers must be specially trained. In the case of new developments, even parts of the production process often have to be planned from scratch, including the corresponding supply chains outside and inside the factory.
A production process refers to a standardised manufacturing method by which a usable product is manufactured in an industrial plant by the mechanical and/or manual treatment and processing of raw materials or productparts. This process is based on various production steps, which are described in more detail below. Standardised means that each production step is subject to certain quality requirements, which are controlled and approved internally or by the customer. The aim is to optimally design the production process with regard to quality, feasibility and efficiency.
New shapes are created from particles and materials through various defined production steps. The underlying production or manufacturing processes can be divided into six main groups. The classification refers to the cohesion of particles of a solid body. This is either created (original forms), maintained (forming, rearrangement of material particles), reduced (separation, separation of material particles) or increased (joining, coating, introduction of material particles).
1. Forming
A workpiece is produced from shapeless material where the cohesion of material particles is created. Among the best known processes are casting and sintering and, more recently, rapid prototyping processes such as 3D printing.
2. Re-forming
This part includes all processes that serve to change the shape of the workpiece without changing its mass. The most important forming processes include rolling, forging, pressing, deep drawing and bending.
3. Cutting
Cutting removes and reduces the material cohesion at the respective processing point. The best known cutting processes are machining (sawing, planing, milling, drilling) and cutting (shearing, burning).
4. Joining
This process refers to the long-term connection of several workpieces or individual parts to form a cohesive workpiece. Joining is usually done by assembling, welding, gluing, soldering, screwing or riveting.
5. Coating
In most cases, the workpieces are coated to improve their longevity and/or their look and haptic. The best known include painting, electroplating, galvanizing and powder coating.
6. Change material properties
For some workpieces it is necessary to change the material properties accordingly for subsequent use or further processing. This includes both hardening and annealing.
Different production types can be distinguished with regard to the product quantity produced or the size of a batch:
- Single-part production:
Each product is unique and is manufactured individually. None of the goods is exactly the same as the other. These are mainly special and custom-made products or samples of products, which are often manufactured as individual pieces.
- Series production:
In series production, a limited number of similar consumer or investment goods are produced. With regard to the number of goods produced, a distinction is made between small, medium and large series production. If the same production facilities are used several times within a series, conversion may be necessary.
- Variety production:
In the case of variety production, different variants of a product are produced one after the other, e.g. various types of screws. The manufacturing process and the raw materials used are identical, only functionality and shape differ.
- Mass production:
The production of large quantities of homogeneous goods is referred to as mass production. Due to the very high number of pieces, the rationalisation possibilities are fully exploited and the production costs per piece are enormously reduced. In addition, a high degree of automation does not require any costly conversions of the production facilities.
Injection Moulding
One of the best known and most widely used manufacturing processes is injection moulding, which we would like to introduce to you in more detail below. The process is mainly used for large quantities, for products which are manufactured several thousand times. Through mass production injection moulding can easily be scaled. Thus the unit price in the injection moulding production becomes extremely low after covering the fixcosts. However, this also shows why factories often set a minimum order quantity of 1000 to sometimes even 3000 pieces.
Under this quantity the scaling effect cannot show its full potential, because the initial fixed costs are too high and are not profitable with a small number of pieces. Only when the fixed costs can be apportioned to many hundreds or thousands of copies do these no longer carry much weight. In addition to the initial fixed costs for the injection moulding tools and molds, there are also costs for training the workers as described above.
Another enormous advantage of the injection moulding process is the low reject rate. For example, CNC machining results in considerably more rejects, as large parts of the plastic block or sheet are always cut away. During injection moulding, plastic waste usually only occurs in the sprue channels and when overflowing from the component cavity. However, this is a much lower percentage compared to CNC production.
Thermosetting materials can be used here, such as epoxy resin, which hardens through air contact. Alternatively, thermoplastic materials can also be used, which can also be recycled as they do not ignite when melted down. The melted material can be returned directly to the production process. However, quality controls ensure that only a certain amount of recycled material is in the process, otherwise the properties of the plastic may change adversely.