Compression Molding

World-Class Injection Molding Services

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Compression Molding is the original production method for molded rubber. It is a useful molding process for forming bulky parts, bellows, grommets, gaskets, seals and O-rings, etc. It is a widely used, efficient, economical production method for many products particularly low production volumes of medium to large parts, materials with a high cost and applications that demand extreme hardness. The process involves compressing preformed rubber in a mold with a press. During the compression process, rubber is forced into the mold cavity to form the final product.

Advantages of Compression Molding

Compression molding offers significant cost savings compared to rubber transfer molding and LSR injection molding. Its simplicity and efficiency make it a low-cost option suitable for both low and high-volume production.

With short setup times, compression molding enables rapid production transitions, allowing for quick changes in material hardness and colors. This flexibility ensures efficient operations and swift adaptation to varying production needs.

Compression molding stands out as the exclusive method for crafting silicone products with stunning marble colors. This distinctive capability adds aesthetic appeal and sets products apart in the market, enhancing their visual appeal and desirability.

Through the use of high-quality steel materials, precisely located pins, and advanced mold-making equipment, compression molding achieves exceptional precision and consistency in part tolerance, with control as fine as 0.02-0.1mm. This ensures that every product meets stringent quality standards, minimizing defects and maximizing customer satisfaction.

Compression molding offers a wide range of material options, making it suitable for various applications. From common silicone to specialized grades such as food-grade silicone and medical-grade silicone, as well as natural rubber, EPDM, Neoprene Rubber, and Nitrile Rubber, the versatility of compression molding enables the production of parts with diverse properties and functionalities. This breadth of material choices ensures compatibility with specific application requirements, expanding the scope of potential uses for compression-molded products.

Compression Molding Materials

In compression molding, thermosetting plastics, rubber, and composite materials are commonly used due to their ability to undergo a curing process and achieve a stable, rigid form. The selection of materials depends on the desired characteristics of the final molded products.

Rubber Materials

Silicone
EPDM (Ethylene Propylene Diene Monomer)
Nitrile (NBR)
Neoprene (CR)
SBR (Styrene Butadiene Rubber)
Natural Rubber (NR)
Butyl Rubber (IIR))

Plastic Materials

Compression Molding Surface Finishing

SPI Finish Standards	Surface Roughness RA (mm)	Finishing Method	Texture	Steels Recommended
SPI A1	0.012 to 0.025	6000 Grit Diamond	Super High Glossy finish	S136 (54HRC) or 8407(52HRC)
SPI A2	0.012 to 0.025	3000 Grit Diamond	High Glossy finish	S136 (54HRC) or 8407(52HRC)
SPI A3	0.05 to 0.10	1200 Grit Diamond	Normal Glossy finish	S136 (300HB) or 718H
SPI B1	0.05 to 0.10	600 Grit Paper	Fine Semi-glossy finish	718H
SPI B2	0.10 to 0.15	400 Grit Paper	Medium Semi-glossy finish	718H
SPI B3	0.28 to 0.32	320 Grit Paper	Normal Semi-glossy finish	718H
SPI C1	0.35 to 0.40	600 Grit Stone	Fine Matte finish	718H
SPI C2	0.45 to 0.55	400 Grit Stone	Medium Matte finish	718H
SPI C3	0.63 to 0.70	320 Grit Stone	Normal Matte finish	718H
SPI D1	0.80 to 1.00	Dry Blast Glass Bead	Satin Textured finish	718H
SPI D2	1.00 to 2.80	Dry Blast	Dull Textured finish	718H
SPI D3	3.20 to 18.0	Dry Blast	Rough Textured finish	718H

Plastic Parts Surface Treatment

Matte Finish

A matte finish lends an understated elegance, providing a smooth yet non-reflective surface that exudes sophistication. Its subtle texture invites tactile exploration, offering a refined aesthetic suitable for a variety of applications.

Textured Surface

Textured surfaces add depth and visual interest, incorporating intricate patterns or textures that enhance both aesthetics and functionality. From subtle embossing to bold relief, textured surfaces offer tactile appeal and a distinctive look.

Common Polishing

Common polishing delivers a glossy, reflective surface with a smooth finish, enhancing the appearance of molded parts with a high degree of clarity and shine. It showcases the material's inherent beauty while offering durability and resistance to wear.

Mirror Polish

Mirror polishing achieves an impeccable, mirror-like surface finish that reflects precision and attention to detail. With its flawless appearance and exceptional reflectivity, mirror-polished surfaces elevate the aesthetic appeal of molded products to a premium level.

Laser Engraving

Laser engraving enables precise customization and branding, adding intricate designs or text onto the surface of molded parts with exceptional accuracy. This advanced technique offers endless possibilities for personalization and product differentiation.

Powder Coating

Powder coating provides a durable and attractive finish, applying a dry powder electrostatically to the surface of molded parts before curing to form a resilient coating. It offers excellent corrosion resistance and color retention, ideal for enhancing both aesthetics and functionality.

Printing

Printing allows for the application of detailed graphics, logos, or designs onto the surface of molded parts, offering versatile branding and customization options. Whether through screen printing, pad printing, or digital printing, this process adds visual impact and branding consistency.

Segmented Colors

Segmented colors involve the incorporation of multiple color segments into molded parts, creating visually distinct patterns or sections. This technique allows for the precise control of color distribution, enabling the creation of eye-catching designs and functional elements.

Mixed Colors

Mixed colors blend different colored materials during the molding process, resulting in unique color combinations or gradients within molded parts. This versatile technique offers endless possibilities for customization, allowing for the creation of visually striking and dynamic products.

Quality Control（QC）

In the injection moulding production process, quality inspection is a key component to ensure that the product meets the design specifications and quality standards.Xinjuexin quality inspection process involves not only finished product inspection, but also raw material inspection, production process control and final product inspection and other stages.

Raw Material Inspection

Raw Material Quality Inspection: Before production begins, raw materials are inspected to ensure that they meet production requirements. This includes testing the physical and chemical properties of the plastic pellets, such as melting point, flow rate, colour stability, etc.
Supplier Evaluation: Suppliers are evaluated and audited on a regular basis to ensure that the raw materials they provide are of a consistently high quality over time.

Production process control

On-line monitoring and testing: Real-time monitoring of the production process, such as dimensional accuracy, colour consistency, physical properties, etc., is carried out by setting up testing points and using automatic testing equipment.
Process Audit: Regular audits of the production process, including operator practices, maintenance of machinery and equipment, and cleanliness of the production environment.

Final Product Inspection

Dimensional and Appearance Inspection: Conduct dimensional measurements and appearance inspections of completed products to ensure that there are no defects, such as fusion lines, air bubbles, discolouration or deformation.
Functionality Test: Test the functionality of the products to ensure that each product works properly and meets the design requirements..
Durability and Reliability Test: Test the durability and reliability of the products by simulating the conditions of long-term use, such as heat resistance, cold resistance, chemical resistance and mechanical strength.

Packaging and final pre-shipment inspection

Packaging Inspection: Ensure that the products are firmly packaged with appropriate protective measures to prevent damage during transport.
Pre-shipment sampling: Random sampling before final shipment to ensure that the quality of mass-produced products is consistent with the samples.

Compression Molding Process At Xinjuexin

See how RapidDirect processes your orders, from quotation, high-quality injection mold making, to production-grade plastic parts, ensuring timely delivery with our skilled team and machinery.

Customer Confirmation Sample

Successful test samples are sent to the customer for final confirmation to ensure that the product fully meets the customer's expectations.1.Receive product drawings: After the customer sends the product drawings, the product is initially evaluated and quoted. If necessary, we can sign NDA agreement to protect customer's intellectual property rights.

Feasibility assessment and DFM report

A team of engineers will conduct a detailed feasibility assessment of the customer's design and provide a DFM (Design For Manufacturing) report. This is to ensure that the design is realisable prior to production and also to help the customer understand any design adjustments that may be required.

Design the mould drawings and make the moulds

After the DFM report has been approved by the customer, work will begin on designing the mould drawings and making the moulds.

Trial production and testing

After the moulds are made, trial production is carried out and samples are tested to ensure that the dimensions and performance meet the requirements. If the test fails, necessary mould modifications or moulding parameter adjustments will be made, and then the test will be repeated until the sample meets the requirements.

Customer Confirmation Sample

Successful test samples are sent to the customer for final confirmation to ensure that the product fully meets the customer's expectations.

Quality inspection and production

Once the samples have been approved by the customer, raw material procurement and quality inspection begins, followed by the production process of mixing, moulding, trimming, etc., and several quality inspections are carried out during the process to ensure product quality.

Assembly and packaging

After completing the production, the necessary assembly and packaging work is carried out to prepare the product for final shipment.

Shipment Preparation

Once the entire order is ready, a packing list is sent to the customer to assist in arranging shipment.

Why Choose Us

No MOQ

No minimum order reguirement helps move plastic molded partsfrom design to production in a fast turnaround and supports youron-demand injection molding needs with reduced cost.

High Quality and Consistency

Owing lsO certified factories, conducting in-process inspectionsand dimensional verification after production, guarantee thecustom molded parts consistency regardless of the complexshape with high precision.

Fast Turnaround

With certified domestic factories and a strong supply chainsystem, we accelerate the product development cycle andbridge plastic parts production as fast as 2 weeks, or less.

Injection Molding Expertise

Collaborate with our experts, boasting 10+ years in injectionmolding, for mold design guidance, material and finish choices,ensuring a smooth transition from prototyping to production.

FAQS

Xinjuexin Injection Molding Service FAQ

These are the common injection molding questions at Xinjuexin.

How long does it take to make an injection mold tool?

This depends on the complexity of the tool design and the type of material the tool is made from. Generally speaking, a very basic square shape made from relatively soft steel such as P20 can be made in less than one week. Very hard steels take longer to cut and to heat treat, while complex shapes or advanced surface textures can require three or more weeks to prepare.

What should you expect from a plastic mold manufacturer?

A reputable manufacturer will positively identify all incoming raw materials, and will carefully control every stage of production to ensure process repeatability. Full ISO certification is a good demonstration of their commitment to excellence.

How can I reduce mold costs?

A product developer should be looking to save money on the cost of a mold tool. In most cases, a less expensive tool is going to be of poorer quality, less durable, with looser tolerances and a bad surface finish. These are not cost-savings. Instead, they’re expensive mistakes. Rather, savings can be made long-term through production efficiency, fast cycle times, and process stability. As volumes increase, the relative cost of the tool goes down until it’s almost free.

What makes Xinjuexin’s injection molding service special?

Our molding service is strengthened by our extensive expertise and a wide range of production capabilities. Our industry-leading facilities allow us to handle projects ranging from micromolding (10 tons) to large projects over 500 tons. This means we’re capable of producing parts ranging from millimeters to cubic meters in size. Our production of such a wide variety of parts enables us to best meet your needs. Further, we have unique access to tooling experts with decades of experience. They are available for video conferencing and customer support. We’re united in our efforts to help you have a satisfactory injection molding experience!

What types of tools and resins do you offer?

We make tools and dies from S136H, 2316H, H13 hardened, 2316H, P20, 8407, and NAK80 semi-hardened steels. We offer standard SPI finishes, EDM texturing, and several different types of etched textures. We also have thousands of thermoforming plastics available – contact us for details.

Can Xinjuexin provide design services, industrial design support, or product development support as an extension of their molding services?

All orders are carefully reviewed by our tooling engineers to provide design for manufacturing optimization. We also work closely with outside design consultancies who can offer expert advice on the process of moving a product from the concept stage to production-ready.

What are Xinjuexin’s quality standards for plastic injection molding services?

Our quality-control system includes several steps to ensure safe, high-performing products for our clients. As with all of our services, we conduct comprehensive material verification and testing before molding begins. This includes the metal used in our molds and the plastics used in production. During production, we carefully control all processing conditions — including temperature and humidity — to maintain repeatable results. Many molding companies neglect to do this, which can lead to flaws in the finished parts. We also 3D scan complex shapes to ensure accuracy.