Hot Gas Welding of Thermoplastics

FMEA is a systematic, bottom-up, inductive method for identifying potential failure modes in a system, product, or process. For each failure mode, it assesses the potential effects or consequences, their severity, likelihood of occurrence, and the ability to detect them. The goal is to prioritize and mitigate high-risk failure modes before they occur.

The PDCA cycle, also known as the Deming Cycle or Shewhart Cycle, is an iterative four-step management method used for the control and continuous improvement of processes and products. It provides a simple and effective approach for solving problems and managing change, ensuring that ideas are tested on a small scale before being implemented organization-wide.

Powder coating is a dry finishing process where a thermoplastic or thermoset polymer powder is applied to a surface, typically electrostatically, and then cured under heat. The powder particles are charged, causing them to adhere to the grounded substrate. Heating melts the powder, allowing it to flow and form a continuous, durable, and high-quality finish, often superior to conventional paint.

Numerical Control (NC) is the automated control of machining tools using a program composed of precisely coded alphanumeric data. This program dictates the tool's path, feed rate, speed, and other operational parameters. Early NC systems utilized punched paper tape as the input medium, marking a significant technological leap from manual control via handwheels or physical templates.

A structured methodology for creating new products, typically involving analysis, concept development, and synthesis. It is an iterative cycle where designers research user needs, brainstorm ideas, create prototypes, and test them to refine the final product. This process ensures that the end product is both functional and meets market demands effectively before full-scale production.

Heijunka is the principle of production leveling or smoothing within the Toyota Production System. It involves averaging out the production volume and mix over a fixed period to eliminate peaks and valleys in workload. This creates a predictable and stable manufacturing environment, which is a prerequisite for implementing Just-in-Time (JIT) and standardized work effectively.

The Hollomon equation is an empirical power-law relationship that describes the portion of the true stress-true strain curve between the onset of plastic deformation (yielding) and the onset of necking (UTS). The equation is \(\sigma_t = K \epsilon_t^n\), where \(\sigma_t\) is the true stress, \(\epsilon_t\) is the true plastic strain, K is the strength coefficient, and n is the strain-hardening exponent.

A foundational economic fact is that the total monetary volume of business-to-business (B2B) transactions significantly surpasses that of business-to-consumer (B2C) transactions. This is because a single finished consumer product often involves a long supply chain with multiple B2B transactions—from raw materials to manufacturing components to wholesale distribution—before the final B2C sale occurs.

Kanban, meaning "visual card" or "signboard" in Japanese, is a scheduling system integral to the Toyota Production System. It uses visual cues, typically cards, to trigger action and manage workflow. It is a "pull" system that signals the need to move materials within a manufacturing facility or from an outside supplier into the production facility.

A thermal lance, or thermic lance, is a tool that cuts materials using the intense heat from the oxidation of iron. It consists of a steel tube packed with steel rods. Pressurized oxygen is fed through the tube, and the tip is ignited. The iron in the lance acts as fuel, burning in the oxygen stream to create a high-velocity, high-temperature jet.

Neutron embrittlement is the loss of ductility and toughness in materials subjected to neutron irradiation. In nuclear reactors, high-energy neutrons displace atoms from their lattice sites, creating defects like vacancies and interstitials. These defects accumulate and form clusters that impede dislocation motion, thereby increasing the material's hardness and strength but severely reducing its ability to deform plastically before fracturing.

Spin coating is a procedure for depositing uniform thin films onto flat substrates. An excess of a coating solution is placed on the substrate, which is then rotated at high speed. Centrifugal force spreads the solution, and solvent evaporation or curing solidifies the film, with the final thickness determined by viscosity, concentration, and spin speed.

The Fill Factor (FF) is a key parameter that determines the quality of a solar cell. It is the ratio of the maximum power a cell can produce (\(P_{max}\)) to the theoretical power if it were an ideal voltage and current source (\(V_{oc} \times I_{sc}\)). A higher fill factor indicates lower parasitic resistance losses and a more 'square' I-V curve.

The Toyota Production System is founded on the complete elimination of waste, categorized into 7 types, 3 main being described here: Muda (non-value-adding work), Muri (overburden), and Mura (unevenness). While Muda is the most commonly discussed, TPS recognizes that Muri and Mura are often the root causes of Muda and must be addressed first to achieve a truly lean system.