Design Tips

The Importance Of Material Selection

Selecting the right material is crucial in engineering projects, as it directly impacts the functionality, durability, and safety of the final product. Each material possesses unique properties like strength, flexibility, thermal conductivity, and resistance to environmental factors, dictating its suitability for specific applications.

Choosing an inappropriate material can lead to structural failures, reduced lifespan, or increased maintenance costs. Additionally, the right material choice can enhance efficiency and sustainability, reducing environmental impact. Engineers must consider these aspects, alongside cost and availability, to ensure the success and longevity of their projects, making material selection a fundamental aspect of engineering design.

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Physical Properties

Functional Requirements

Environmental Considerations

Price Restrictions

Assembly Requirements

Safety Requirements

Understanding Plastics

Plastics are composed of elements like carbon, oxygen, hydrogen, and nitrogen, often combined with other organic or inorganic substances. These elements form polymers, giving plastics their distinct characteristics. Typically solid at room temperature, plastics become malleable when heated, allowing them to be easily shaped. This transformation is central to the manufacturing process, where heat softens the plastic, and pressure shapes it into desired forms. Upon cooling, the plastic solidifies into its new shape.

This ability to melt, reshape, and then solidify is what makes plastics so versatile. By varying the composition, plastics with different properties can be created, ranging from rigid and strong to flexible and resilient. The term 'plastics' encompasses this diverse and adaptable group of materials, capable of fulfilling a wide range of applications, from household items to complex engineering components.

Material Properties

Abundant raw materials, low cost.

Easy-molding, easy to achieve complicated shapes, can achieve mass production.

Light weight, low density(the proportion of plastic is 0.9~2, aluminum 2.7, iron 7.8).

Continuous distortion occurs easily under the action of external forces.

Bright colours, easy to tint, you can change the colour by adding colouring agents.

Good resistance to corrosion, water, oil, acid, chemical and rust.

Poor heat resistance, the heat resistance temperature of most plastics is below 150 ℃

Wall thickness of plastic parts

Wall thickness too thin

  • Low strength;
  • increased flow resistance, which results in insufficient filling of molds

Wall thickness too thick

  • Parts have quality problems such as shrinkage, holes and warping
  • Parts require longer cooling time and lead time.
  • Parts require more material, which increases the cost of parts.

Suitable wall thickness ranges for common plastic materials(Unit: mm):

maximum 0.9 0.6 0.6 1 1 1.5 1.5 1.5 1.5 1.5
minimum 4 3.5 3 4 4 5 5 5 4.5 5

Factors determining the wall thickness:

  • Strength requirements on parts
  • Whether the part can resist demolding force in molding
  • The part can resist fastening force in assembling
  • When there’s metal insert, whether the strength around the insert is enough
plastic-ribs

Demolding Draft

Plastics with large shrinkage require a larger demolding draft

Make the demolding angle of the male die less than the female die to ease demolding

Smaller demolding drafts for parts that require high dimensional accuracy

Design larger draft angles when the part is larger or has thicker walls

demolding draft optimised design
support pillar design

Supporting Pillars

Plastics with large shrinkage require a larger demolding draft

Make the demolding angle of the male die less than the female die to ease demolding

Smaller demolding drafts for parts that require high dimensional accuracy

Design larger draft angles when the part is larger or has thicker walls

Why Choose Coler Supply for Plastic Injection Moulding

Place your confidence in our over 50 years of expertise in injection moulding technology, our adept manufacturing management team, and our methodical management system. Rely on our high-quality and efficient production capabilities. We excel in devising suitable manufacturing strategies that meet exacting product quality standards, optimising costs, and reducing lead times.