Factory layout (where) - A216

 

Factory layout (where)
Document Type	Article
Document Identifier	216
Tags	Factory cell Process step

Overview

Factory cells are the areas of the factory where process steps are grouped together and carried out. This is illustrated in the following figure where an arbitrary number of process steps are grouped together into a single factory cell.

The process steps may be carried out simultaneously (e.g. in a preparation cell the resin may be prepared at the same time as the reinforcement material/consumables) or they may be carried out consecutively (e.g. in a deposition cell the gel-coat must be applied before the reinforcement and bulk matrix material).

Factory cells can be grouped into a number of categories, generally named by the primary function that takes place within them; but this naming often becomes confusing when two primary functions take place within the same cell. For example, in liquid composite moulding (LCM) processes the resin deposition and thermal transformation steps often occur in the same physical space and therefore the cell is a deposition/thermal transformation hybrid cell. The distinction of which is not important, other than for considering the movement of the part, material, and assets (equipment & tooling) through the factory; which is always a non-value add activity. In general, the movement of the part, material, and assets through the factory should be minimized; but this is limited by the required footprint of equipment, the desired rate of production, how many activities can take place simultaneously in the same physical location, and whether or not the same employees/equipment can carry out multiple steps or if the part needs to be handed off multiple times. For example, large, difficult to move parts may be kept in the same physical space during most of their production and employees/equipment may be moved relative to them, whereas small easier to move parts may physically move between cells as they progress through the factory. In this sense, the definition of a factory cell is flexible, but they are generally grouped into categories based on the process steps taking place within, which, generally speaking are:

• Receiving steps
• Testing steps
• Storage steps
• Preparation steps
• Deposition steps
• Forming steps
• Thermal transformation steps
• Demoulding steps
• Trimming and machining steps
• Inspection steps
• Assembly steps
• Coating steps
• Reporting steps
• Packaging and shipping steps

About	Help

An individual station within a factory where a given set of tasks are accomplished (also known as a "work cell"). Some cells may directly add value to the product (e.g. deposition), while others may serve support roles that are critical to maintaining part quality (e.g. receiving, storage, inspection & shipping).

For polymer matrix composites (PMCs), resin refers to the matrix; the continuous material phase that binds the reinforcement together, maintains shape, and transfers load. Resins are divided into two main groups: thermosets and thermoplastics.

The continuous material phase that binds the reinforcement together, maintains shape, transfers load, protects the reinforcement from environment and damage, and provides the composite support in compression.

Desirable characteristics:

• Moisture/chemical resistance
• Low density
• Processability

Engineered materials (designed to have specific properties) made from two or more constituent materials with different physical or chemical properties. The constituents remain separate and distinct on a macroscopic level within the finished structure.

Liquid Composite Moulding (LCM), a family of infusion processes refers to processes that saturate a dry reinforcement that is on/in the mould by means of a pressure differential (injection pressure, vacuum, combination of both).