Toys Mould Exporter in India

Reasons for Injection Moulding Defects


Injection moulding is a widely used manufacturing process that offers numerous advantages, such as high production efficiency, cost-effectiveness, and design flexibility. However, much like any manufacturing process, injection moulding can experience flaws that affect the end product's quality and functioning. As a leading Toys Mould Exporter in India. In this blog, we will share some of the common reasons behind injection moulding defects, aiming to shed light on the factors that contribute to these issues.

  1. Material Selection:
    The choice of material plays a vital role in the injection moulding process.Incompatible or poor-quality materials can lead to defects.Issues may arise due to improper material flow, inadequate melt viscosity, or poor thermal properties. Additionally, variations in material properties, such as moisture content or degradation, can result in defects like warping, sink marks, or poor surface finish.
  2. Inadequate Mould Design:
    The design of the mould used in injection moulding significantly influences the final product's quality.Inadequate cooling, incorrect gate placement, or insufficient draught angles are a few examples of causes of defects. These shortcomings can cause issues such as part distortion, flash, short shots, or incomplete filling.
  3. Process Parameters:
    To enable successful injection moulding, process parameters must be controlled and optimized.Defects can arise when parameters such as temperature, pressure, injection speed, or holding time are improperly set. Inadequate or excessive cooling times may cause internal stress or incomplete solidification, whereas insufficient or excessive injection pressure may result in flow-related flaws.
  4. Poor Part Design:
    Part design plays a pivotal role in the injection moulding process.  Inadequate ribs, sharp corners, or insufficient wall thickness can all cause defects.Thick sections may cause sink marks or uneven cooling, while thin sections can result in warping or part distortion. Sharp corners can lead to stress concentration points and potential cracking.
  5. Contamination and Mould Maintenance:
    Contamination of the mould or material can introduce defects into the injection moulding process.  Foreign particles, such as dust, moisture, or degraded material, can cause surface imperfections, voids, or short shots. Part sticking, surface flaws, or dimensional errors can result from improper mould maintenance, which includes poor cleaning or worn-out parts.
  6. Human Error:
    Despite advancements in automation, human error can still contribute to injection moulding defects. Inaccurate assembly of the mould, improper setting of process parameters, or inadequate inspection can introduce defects into the final product. To reduce these errors, operator training, meticulousness, and strong quality control procedures are essential.


Injection moulding defects can be attributed to various factors, ranging from material selection and mould design to process parameters and human error. Manufacturers can apply corrective actions and improve the consistency and quality of their injection-molded goods by being aware of these potential problems. Effective material testing, robust mould design, optimization of process parameters, and regular maintenance are key to mitigating defects and achieving successful injection moulding outcomes.

R D Mould & Industries is a renowned  Plastic Toy mould manufacturer in Ahmedabad, Gujarat, India, providing various types of  Plastic Toy Mould Including  Plastic Toy Injection Mould, Plastic Toy Blow Mould & Etc.