Molding and casting
Material Safety Data Sheet Assessment
In the process of mold making and casting, correctly understanding and following the guidance of material safety data sheets (SDS) is very important, not only for the operator's health and safety but also affecting the quality of the final product. Below is a safety information assessment of the main materials used in this project
Silicone Rubber Safety Assessment
The silicone rubber hardener usage ratio is 100:2, with an operation time of about 5 minutes. According to safety data sheet analysis:
Hazard Identification
- Low toxicity, but avoid prolonged skin contact
- Releases small amounts of volatile substances during curing, operate in ventilated environments
- Not flammable, but avoid contact with open flames
Protection Measures:
Wear nitrile or latex gloves for operation
Work in a well-ventilated environment
If accidental skin contact occurs, immediately wash with soap and water
Avoid eye contact during operation, recommend wearing goggles
Storage Requirements:
Shelf life is 6 months
Store in a cool, dry place, avoid direct sunlight
Seal container to prevent air and moisture entry causing curing
Polyurethane Resin (AB Liquid) Safety Assessment
AB liquid weight mixing ratio is 1:1, curing within 1.5-2 minutes after mixing. The safety data sheet shows:
Hazard Identification:
Component B contains isocyanates, may cause respiratory and skin sensitization
Curing reaction releases heat, may cause temperature rise leading to burns
Reaction with water produces carbon dioxide gas, may cause pressure increase in sealed containers
Protection Measures:
Must wear protective gloves and goggles
Operate in a well-ventilated environment
Moisture adversely affects the quality of both A/B liquids, absolutely avoid introducing water
Component B will react with moisture to produce white turbidity or cure
First Aid Measures:
Skin contact: Immediately wash with plenty of water and soap
Eye contact: Rinse with flowing water for at least 15 minutes, seek medical treatment
Inhalation: Move to fresh air, seek medical attention if symptoms persist
Storage Precautions:
Recommended to use the product within 3 months of receipt
Component A will shrink, component B will expand, do not store for long periods to avoid bottle cracking and leakage
After use, please clean the bottle mouth, seal it, and store in a dry, dark place away from direct sunlight
White Vaseline Release Agent Safety Assessment
Hazard Identification:
Low toxicity, high chemical stability
Not flammable, not corrosive
Protection Measures:
Avoid prolonged skin contact
Use dedicated tools (clean soft brush) to apply evenly
Wash hands after operation
Storage Requirements:
Store sealed at room temperature
Avoid contamination
Indium-Tin-Bismuth Low-Temperature Alloy Safety Assessment
This alloy has a melting point of only 47°C. Safety data sheet information is as follows:
Hazard Identification:
Molten state may cause minor burns
Vapor may contain metal oxides, excessive inhalation is harmful
Long-term contact may cause skin sensitization
Protection Measures:
Despite being a low-temperature alloy, using heat-resistant gloves during operation is still recommended
Avoid contact between molten alloy and water, splashing may occur
Operation environment should be well-ventilated
Avoid inhaling possible fumes
First Aid Measures:
Skin burn: Immediately rinse with cold water, do not use ice
Fume inhalation: Move to fresh air
Accidental ingestion: Drink plenty of water, seek medical treatment
Environmental and Disposal:
Metal can be 100% recycled and reused
Waste should be collected and remelted for use
Avoid release into the environment
Industrial Wax Safety Data Sheet Assessment
Industrial wax is a commonly used material in milled mold making, with easy processing and low cost characteristics. According to safety data sheet analysis:
Hazard Identification:
Low toxicity, stable at normal temperature
May release hydrocarbon vapors when heated to high temperatures, avoid inhalation
Molten state may cause minor burns
Not flammable in solid state, but combustible in molten state
Protection Measures:
Wear dust mask when milling to avoid inhaling wax dust
Ensure good ventilation when heating to melt
If manual adjustment is needed, gloves are recommended to avoid skin contact
Avoid prolonged skin contact, may cause mild allergies
Wear protective goggles during milling to prevent debris from entering eyes
First Aid Measures:
Skin contact: If in contact with molten wax, immediately rinse with cold water, do not tear off wax adhering to skin
Eye contact: Rinse with plenty of clean water, seek medical attention if discomfort occurs
Inhalation: If large amounts of dust are inhaled, move to fresh air
Cleaning and Disposal:
Wax chips can be recycled and reused, melted then reshaped
Waste should be disposed of according to local regulations
When cleaning tools and work area, avoid using solvents that may react with wax
Storage Requirements:
Store in a cool, dry place, avoid direct sunlight
Keep away from heat sources and open flames
Storage temperature should be below its melting point (usually 60-80°C)
In our milled mold making practice, we particularly noted the following safety characteristics of industrial wax:
Processing Characteristics:
Wax material is soft, chips produced during processing easily adhere to the mold surface
Need careful cleaning to avoid damaging mold details
Cutting speed should not be too fast to prevent wax softening due to friction heat
Usage Precautions:
Before contact with silicone or other materials, ensure the wax mold surface is clean, free of residual chips
When wax molds contact silicone directly, silicone may have a slight dissolving effect on wax, appropriate release agent is recommended
Through reasonable protective measures and operation procedures, industrial wax can be safely and effectively used for mold making. Its low toxicity and reusable characteristics make it an environmentally friendly mold material choice.
Safety Operation Summary
During the implementation of this project, we strictly followed the above safety guidelines and took multiple measures to ensure safety:
Personal Protective Equipment Use:
Wore gloves, masks, and protective goggles throughout the process
Work Environment Management:
Maintained good ventilation in the work area
Covered the workbench with paper to prevent chemical contamination
Operated in separate areas according to material type to avoid cross-contamination
Waste Disposal:
Treated cured silicone and polyurethane resin waste as general solid waste
Collected and reused indium-tin-bismuth alloy residue
Separately collected waste liquid produced during tool cleaning
Industrial wax cutting fragments can be collected and melted for reuse
By carefully reading and implementing the guidance in material safety data sheets, we not only ensured the operator's health and safety but also improved product quality and work efficiency. In future projects, we will continue to improve safety measures and explore safer, more environmentally friendly materials and processes.
Detailed Comparison of 3D Printing and Milling Molds
Geometric Complexity and Precision
Feature | 3D Printing | CNC Milling |
Complex Geometric Shapes | ✅ Can create almost any complex shape, including internal structures, overhangs, curves, and organic shapes | ⚠️ Limited by tool accessibility, difficult to process deep grooves, sharp angles, internal cavities, etc. |
Fine Details | ⚠️ Depends on printing technology, FDM precision is lower, SLA/DLP/SLS can achieve higher precision | ✅ Can achieve extremely high precision (0.01mm level), good surface smoothness, but tool path marks may be obvious if not well controlled |
Dimensional Accuracy | ⚠️ May be affected by material shrinkage, warping, etc., requires calibration | ✅ High precision, good stability |
Surface Quality | ⚠️ Layer lines obvious (FDM) or requires post-processing | ✅ High surface smoothness, can be used directly as molds |
Internal Structure | ✅ Can create complex internal structures and channels | ❌ Difficult to create invisible internal structures |
Materials and Durability
Feature | 3D Printing | CNC Milling |
Material Selection | ⚠️ Limited, mainly various plastics, some metals and ceramics | ✅ Extensive, almost all solid materials: metals, plastics, wood, wax, stone, etc. |
Material Strength | ⚠️ Weak interlayer bonding strength, anisotropic | ✅ Maintains original material strength, isotropic |
Heat Resistance | ❌ Most printed materials have limited heat resistance | ✅ Can process high-temperature materials such as metals, ceramics, etc. |
Durability | ⚠️ Medium, depends on material and process | ✅ High, especially metal molds |
Water Resistance | ⚠️ Requires post-processing | ✅ Good, determined by material properties |
Production Efficiency and Cost
Feature | 3D Printing | CNC Milling |
Preparation Time | ✅ Short, only requires 3D model and slicing | ⚠️ Longer, requires CAM programming and tool planning |
Production Speed | ⚠️ Slow, especially high-precision printing | ✅ Fast, especially for simple shapes |
Prototype Iteration | ✅ Rapid, easy to modify designs | ⚠️ Each iteration requires reprocessing |
Small Batch Production | ✅ Economically efficient | ⚠️ Higher cost |
Large Batch Production | ❌ Uneconomical, slow speed | ✅ Fast speed, reduced cost |
Equipment Cost | ✅ Low to medium (home printers are inexpensive) | ❌ High (professional CNC equipment is expensive) |
Material Cost | ⚠️ Specialized materials relatively expensive | ✅ Standard materials, controllable cost |
Labor Cost | ✅ Low, simple operation | ❌ High, requires professional skills |
Waste Generation | ✅ Little, mainly support structures | ❌ High, cutting process generates substantial waste |
Operation and Maintenance
Feature | 3D Printing | CNC Milling |
Operation Complexity | ✅ Simple, low entry barrier | ❌ Complex, requires professional knowledge |
Equipment Size | ✅ Small, desktop devices usable | ❌ Large, requires dedicated space |
Noise and Pollution | ✅ Low noise, slight odor | ❌ High noise, dust or cutting fluid pollution |
Equipment Maintenance | ✅ Relatively simple | ❌ Complex, requires regular servicing |
Safety Risk | ✅ Low | ❌ Medium to high (high-speed rotating tools) |
Supervision Requirements | ⚠️ Medium, may need to monitor printing process | ✅ Once set up, lower supervision needed |
Suitable Mold Types
Mold Type | 3D Printing | CNC Milling |
Prototype Verification Molds | ✅ Excellent | ⚠️ Feasible but costly |
Low-Pressure Injection Molds | ✅ Suitable for small batches | ✅ Suitable for medium to large batches |
Silicone/Soft Mold Masters | ✅ Very suitable | ✅ Very suitable |
Metal Casting Molds | ⚠️ Only suitable for low-temperature alloys | ✅ Suitable for various metal castings |
Food-Grade Molds | ⚠️ Requires specialized food-grade materials | ✅ Can process food-grade stainless steel, etc. |
Large Molds | ❌ Limited by printing space | ✅ Can process large molds |
Precision Molds | ⚠️ Depends on printing technology | ✅ High precision |
Transparent Molds | ⚠️ Limited choices | ✅ Can process transparent materials like acrylic |
<<< Back to Lab Page