Mold Design and Maintenance Principles

Mold Types

• Two Plate Molds and Three Plate Molds

Mold Maintenance

• Preventive Maintenance
• Breakdown Maintenance
• Predictive Maintenance

Mold Elements

• Locating Ring
• Top Plate
• Cavity Plate
• Stipper Plate
• Core Plate
• Spacers
• Ejector Plate
• Ejector Return Plate
• Bottom Plate

Measuring Instruments with Least Counts

• Vernier Caliper: 0.02
• Micrometer: 0.01
• Height Gauge: 0.02

Types of Machines

• Conventional Machines
• CNC Machines

Types of Runner and Gate Systems

• Runner Types:
  • Round
  • Half Round
  • Parabolic
  • Trapezoidal
  • Rectangle
• Gate Types:
  • Edge Gate
  • Tunnel Gate
  • Submarine (Sub) Gate
  • Direct Sprue Gate
  • Tab Gate
  • Banana Gate

Hot Runner vs Cold Runner

• Cold Runner: Runner is not heated up
• Hot Runner: Runner is heated up

Ejection Systems

• Pin Ejection
• Sleeve Ejection
• Blade Ejection
• Stipper Ejection

Hot Runner System Advantages and Disadvantages

• Advantages
  • Resin cost savings by eliminating cold runner and sprue
  • Reduced cycle time due to lower fill and cooling time
  • Improved part quality through reduced pressure drop during part filling
  • Melt temperature control helps improve melt flow and part quality
  • Effective control of weld line position through sequential hot runner systems
• Disadvantages:
  • High maintenance cost
  • High part manufacturing cost

Cooling Channel Types

• Baffle Cooling
• Bubbler Cooling
• Thermal Pin Cooling

Metal Hardening Methods

• Heat Treatment
• Flame Hardening
• Surface Hardening
• Induction Hardening

Mold Material and Elements

• Locating Ring (C-45 or Equivalent)
• Top Plate (S-50C or Equivalent)
• Core Insert (1.2344 ESR)
• Cavity Insert (1.2344 ESR)
• Spacer (S-50C or Equivalent)
• Ejector Plate (S-50C or Equivalent)
• Guide Pillar (En-31)
• Guide Bush (En-31)

Heater Types

• Tubular Heater
• Band Heater
• Cartridge Heater
• Tube Heater
• Coil Heater
• Ceramic Band Heaters
• Mica Heaters

Kaizen (Continuous Improvement)

• Kaizen is a Japanese philosophy that emphasizes continuous improvement. It suggests constantly seeking small improvements to processes, products, and services.

5S Methodology

• Sort: Eliminate unnecessary items
• Straighten: Organize remaining items
• Shine: Clean and inspect the work area
• Standardize: Establish standards for 5S processes
• Sustain: Consistently maintain 5S standards

Poka Yoke (Mistake Proofing)

• Poka Yoke aims to prevent errors by designing systems that make errors difficult or impossible.
• Example: Sim card slot on a mobile phone

Types of Fits and Tolerance

• Clearance Fit: The hole has a larger diameter than the shaft.
• Interference Fit: The shaft has a larger diameter than the hole.
• Transition Fit: The fit lies between clearance and interference fits.

Beryllium Copper Inserts

• Advantages:
  • Reduced overall cycle time
  • Increased productivity
  • High toughness
  • Less stress in mold parts
  • Reduced dimensional variation
  • Easy machinability to a good finish
  • Improved control of warpage
  • Superior corrosion resistance
  • Excellent tensile strength range

Electrode Materials

• Copper
• Tungsten
• Graphite

HRC Hardness

• HRC stands for Hardness Rockwell C Scale. This is a common hardness measurement scale for metals.

Plastics - Thermoplastics and Thermosets

• Thermoplastics: Can be repeatedly melted and solidified without significant chemical change.
• Thermosets: After initial curing, they undergo an irreversible chemical change and cannot be remelted.

Thermoplastics Materials

• Polypropylene (PP)
• Polyethylene (PE)
• Polyvinyl Chloride (PVC)
• Polycarbonate (PC)
• Polyamide (PA)
• Acrylonitrile Butadiene Styrene (ABS)

Thermoset Plastics Materials

• Epoxy
• Silicone
• Polyurethane
• Phenolic
• Polyester
• Vinyl Ester
• Polyimides

Steel Types

• Stainless Steel
• Tool Steel
• Carbon Steel
• Aluminum
• Chrome Steel
• Alloy Steel
• Cast Iron

Test your knowledge on various mold types, maintenance strategies, and essential elements used in mold making. This quiz covers topics such as runner systems, ejection methods, and measuring instruments. Perfect for engineering students and professionals in the manufacturing field.