How can mold manufacturing shorten the manufacturing time of LSR injection molding projects?
Table of Contents
- How can mold manufacturing shorten the manufacturing time of LSR injection molding projects?
- High-quality mold manufacturing can shorten the production time of LSR injection molding projects.
- Optimizing the design of LSR components can shorten project manufacturing time.
- Seven ways to shorten the production cycle time of LSR injection molding projects
- Why should you choose Elimold’s precision LSR injection molds and molding services?
- in conclusion
Both conventional injection molding and LSR injection molding involve mold manufacturing. Only high-quality molds can guarantee the quality of the final product and shorten the project production cycle.
Therefore, we must overcome several challenges when designing components for silicone molds. These include ensuring, from the project’s inception, that the manufacturer can produce suitable LSR molds. This is crucial for achieving the required precision and quality of the finished product, ensuring the final product meets production standards, and guaranteeing that production volume can be completed within a short timeframe.
Because mold issues can impact project production cycles, liquid silicone rubber (LSR) injection molded parts require strict tolerance control. Furthermore, the tolerance requirements are even higher than those for traditional thermoplastic molding processes. Additionally, the first step in the design and manufacturing process should be the research and development phase, followed by prototype production. This helps avoid unexpected problems during production.
This silicone injection molding process guide will explore the factors that affect the time of LSR injection molding projects and how we can shorten manufacturing time.
High-quality mold manufacturing can shorten the production time of LSR injection molding projects.
Regardless of the type, LSR injection molding projects begin with sophisticated mold engineering and continue through every stage of manufacturing to ensure high quality and reliability of the final product. Therefore, understanding the key steps, methods, and potential challenges is crucial for shortening project manufacturing cycles and achieving consistent results.
Tooling design, process steps and production methods
Mold engineering is crucial for the success of liquid silicone injection molding. Mold manufacturing requires proper design, precision machining, and the correct selection of mold materials to ensure it can withstand wear during mass production. Key features include a flash-free structure, minimal runners, thin walls, appropriate venting, and correct geometry and part design to facilitate smooth demolding from the production mold.
Three common tool choices
- Aluminum molds : providing an economical, efficient, and fast-delivery solution for small-batch production. Due to their short processing time, low cost, and high production speed, they are ideal for prototyping, small-to-medium batch production, and iterative design adjustments.
- Steel molds : They offer excellent durability and are suitable for mass production, but have longer lead times. They are best suited for continuous production requiring consistent dimensional accuracy, high wear resistance, and minimal maintenance over a long service life.
- Rapid Molding : This type of mold offers high production speeds, but with relatively lower precision compared to other materials. The mold cavity is manufactured using high-precision CNC machining or industrial-grade 3D printing technology to achieve the required dimensional accuracy and surface quality. Aluminum alloy soft molds can withstand 200-500 molding cycles, offering greater durability for small-batch production. In contrast, resin molds are ideal for prototyping up to 50 pieces. The mold surface undergoes precision polishing or special coating treatments to achieve smooth demolding and high detail fidelity, ensuring consistency across multiple production runs.
Optimizing the design of LSR components can shorten project manufacturing time.
Product functionality is usually the starting point for part design. Another factor to consider when designing parts and their subsequent components is manufacturability. Part design should also prioritize ease of manufacture, as this helps reduce costs and enables robust, reliable production processes and rapid production. Therefore, multiple design factors need to be considered, such as the part’s geometry, location, dimensions, and the shape of critical surfaces. Below are several design techniques we’ve summarized that can shorten LSR part production time.
Wall Thickness Guide
The optimal wall thickness range for LSR parts is 0.5 mm to 10 mm. Uniform wall thickness prevents stress concentration and ensures uniform curing of the entire part.
Draft angle
For ease of demolding, a minimum draft angle of 0.5° is recommended. The inherent demolding properties of liquid silicone rubber (LSR) generally reduce the draft angle requirement compared to other materials.
Gate design and layout
Gate design has a significant impact on part quality. Common gate types include pin gates, side gates, and hot runner systems. Proper gate placement ensures even filling and minimizes defects.
Mold temperature control
Mold temperature stability is crucial for uniform curing. Temperature fluctuations can lead to uneven cross-linking, resulting in performance differences and potential defects.
Parting line design
Because LSR has a low viscosity, the parting line must be precise to avoid excess resin. Even so, the parting line is often visible on the molded part. Demolding is affected by the geometry of the part and the position of the parting surface. Designing the part with a slight chamfer helps ensure consistent adhesion to the other half of the mold cavity.
Shrinkage calculation and control
The calculation and control of shrinkage rate for LSR products first considers the mold. Shrinkage rate can be affected by factors including mold temperature, the temperature of the rubber compound during demolding, the pressure within the mold cavity, and the subsequent compression of the rubber compound. Additionally, since the shrinkage rate in the direction of rubber compound flow is generally greater than that perpendicular to the flow direction, the location of the injection point also needs to be taken into account. Finally, if the product requires secondary vulcanization, an additional 0.5%-0.7% shrinkage may occur.
Seven ways to shorten the production cycle time of LSR injection molding projects
This is true from both a time and cost perspective. Of course, time is money in any manufacturing process, meaning that shortening the production cycle time of LSR injection molding projects can significantly increase your profits. To help you address inefficiencies and identify potential areas for improvement, the following steps contain practical information on how to shorten the production cycle time of LSR injection molding projects.
Design products with minimum wall thickness
Try to keep the wall thickness within the minimum range required for the effective operation of the part or product. This minimalist part design approach means less material needs to be injected into the mold cavity, thus progressively reducing injection time. However, always consider the strength required by the product wall thickness and follow the best design specifications for minimum wall thickness.
The machine was finely tuned.
Ensure your machine is finely calibrated to handle the appropriate injection pressure and speed. Avoid inconsistent or unstable injection pressure and speed during production. This means your production cycle will not be optimal. Errors in pressure or filling time will also lead to more scrap, increasing overall production time and extending the effective production cycle.
Develop or build an experienced production team
Invest in people, not just machines. Successful and efficient LSR project manufacturing is not simply a matter of setting up the machines and getting them running. There are many subtle adjustments and improvements involved that cannot all be found in books or charts. Most of the time, it takes experienced and talented injection molding engineers to intuitively and skillfully identify those subtle adjustments among variables such as injection speed, buffer, and holding time that have a significant impact on part quality and production cycle.
Correct material selection
Choosing the right materials can also speed up production. Some materials have higher filling pressures or higher flow rates, allowing them to enter the mold faster and fill all cavities more quickly. Material selection is often overlooked or underestimated, but it’s essential to study whether the properties of different resins are suitable for your part’s application. This research can help shorten production cycles.
Cooling time control
Re-examine the product’s wall thickness design. Reducing wall thickness not only speeds up injection molding but also directly affects cooling time. In fact, cooling time is generally proportional to the square of the wall thickness; typically, thinner walls result in shorter cooling times. Our recommendation is to keep the wall thickness to the minimum feasible range while still meeting the part’s strength specifications.
High-quality LSR mold design
Besides the materials, the mold itself is the most significant factor affecting cooling time. A well-designed mold efficiently distributes water and air, and cooling channels should be well-maintained and cleaned regularly to ensure that parts cool as quickly and evenly as possible. Uneven cooling is a major cause of part defects, leading to part scrap and increasing machine uptime, thus extending effective cycle time.
Pay attention to the heat insulation design of the mold.
If you are producing LSR products using a hot runner mold, it is essential to ensure proper insulation between the mold and the hot runner. Without insulation, the heat generated by the material flowing through the hot runner is likely to be transferred to and trapped in the mold. This makes cooling more difficult and time-consuming. Accidental heat within the mold can also affect the material temperature, which in turn affects flow rate and other factors that impact injection and holding pressure success. Proper insulation ensures that temperature and other physical properties remain predictable and effective.
Why should you choose Elimold’s precision LSR injection molds and molding services?
We use the latest and most advanced technology in the industry to manufacture precision LSR molds and produce high-quality products through advanced equipment, which can significantly shorten your production time and minimize errors.
Elimold, one of China’s leading injection molding companies, specializes in liquid silicone rubber (LSR) materials. We have a long history of providing our customers with superior quality control and unparalleled manufacturing capabilities. Contact our experienced injection molding team for a free consultation. With exceptional customer service and sophisticated manufacturing technology, we can produce high-quality custom liquid silicone rubber (LSR) and multi-color LSR injection molded components to meet all your needs and specifications.
in conclusion
This article summarizes the factors that affect the production cycle of LSR injection molding projects and various methods to accelerate product production. With this guide, you can easily manufacture a variety of LSR products.
LSR (Liquid Silicone Rubber) manufacturing is a meticulous and detail-oriented process. From formulation and molding to validation, each step directly impacts product reliability and compliance. Furthermore, only by controlling the manufacturing details at each stage can project and mass production cycles be significantly shortened. Elimold combines its proprietary molds, robust systems, and extensive experience in regulated sectors to produce stable, high-quality components that meet stringent industry standards.
Partnering with Elimold ensures smooth processes and robust management, resulting in durable, compliant products for demanding applications. Contact us today to discuss project collaborations and learn how our expertise can help you successfully manufacture high-quality, proven components.