Dip Molding Companies and Manufacturers

Dip Molding

Dip molding, also spelled dip moulding, is a manufacturing process used to create plastic parts, products, and components. As the name suggests, manufacturers achieve this by dipping a mold into liquid plastic, allowing it to set, and then carefully removing the finished product from the mold.

The History of Dip Molding

The modern dip molding process took shape in the United States and the United Kingdom during the 1930s. While similar techniques existed long before—such as in the making of hot wax candles—dip molding as an industrial process gained momentum around World War II. The war effort significantly accelerated the use of plastics and polymers, leading manufacturers to realize that dip molding offered a quick and efficient way to create plastic shapes for a variety of applications, including containers and tool handles. As the process evolved, they discovered that dipping the mold multiple times produced thicker walls, expanding the range of potential products.

For the first several decades, dip molding primarily relied on natural latex and PVC. However, in 1993, the FDA reported that latex allergies affected between 2% and 10% of the U.S. population, prompting significant changes in the industry, particularly in the medical glove sector. To address these concerns, manufacturers introduced a finishing process to remove residual process powders and sought ways to eliminate problematic proteins from latex. More importantly, the industry began exploring alternative polymer materials, such as nitrile rubber, neoprene, polyurethane, and styrene-butadiene rubber (SBR), broadening the scope of dip molding applications.

Today, the dip molding industry continues to thrive, with plastic dip molding standing out as a dominant sector. The process is poised for further growth as automation advances, equipment becomes more efficient, tooling costs decline, and an increasing variety of polymer blends become available.

Advantages to Dip Molding

Dip molding and dip coating offer numerous benefits. One of the key advantages is the speed and cost-effectiveness of prototyping. The process features short lead times and minimal setup costs due to its relatively simple equipment and methodology. With automation playing a significant role, labor costs remain low, and the streamlined nature of the process allows for high turnaround rates.

Dip molded parts also boast exceptional flexibility and malleability, making it easy to strip even the most complex shapes from their molds without damage. Additionally, dip molded products require little to no secondary processing, reducing material waste and further enhancing efficiency.

Beyond production advantages, dip molded and dip coated products offer durability and aesthetic appeal. These plastic coatings not only provide a smooth and visually attractive finish but also enhance corrosion resistance, scratch resistance, and wear protection. They deliver a comfortable, tactile grip that improves safety and handling across various applications. Moreover, dip molding’s versatility allows for a broad range of wall thicknesses, textures, and part sizes, making it a highly adaptable manufacturing solution.

Applications of Dip Molding

Dip molding plays a crucial role in plastic product manufacturing, serving both decorative and protective functions. By applying a plastic coating to various objects, the process enhances comfort, improves grip, and introduces an additional design element to the final product. This makes it particularly valuable in applications where both aesthetics and functionality matter, such as tool handles, appliance components, and sports equipment.

Dip molded parts and dipped products are widely used across numerous industries, including consumer goods, medical devices, electronics, and retail. Within these sectors, dip molding has proven especially vital in areas such as biking, medical device manufacturing, sanitation, appliance production, and sports and recreation. The adaptability of dip molding allows it to meet the specific demands of these industries, providing durable, ergonomic, and cost-effective solutions.

Dip Molding Products

The dip molding process yields a diverse range of plastic components, including plastic caps, plastic plugs and various types of plastic closures. It is commonly used to create handles and grips for appliances, such as pump grips and handlebars, as well as cap plugs and protective covers for sports and recreational equipment. Additionally, dip molding is instrumental in producing gloves, custom-molded coatings, and countless small plastic products used in everyday applications. The versatility of dip molding ensures that it continues to be a preferred method for creating durable, high-quality plastic components across a wide spectrum of industries.

Materials Used for Dip Molding

Dip molding primarily utilizes plastisol, but the process is also compatible with materials such as latex, neoprene, urethane, and epoxy. Each material offers distinct advantages that make it suitable for various applications, allowing manufacturers to tailor the final product to specific performance and aesthetic requirements.

Plastisol

A vinyl (PVC) compound, plastisol remains in liquid form at room temperature, making it an ideal choice for dip molding due to its low energy requirements during manufacturing. Once heated, plastisol hardens permanently, ensuring durability and stability. This characteristic makes plastisol dip molding—also known as PVC dip molding or vinyl dip molding—an essential method in plastic product manufacturing.

Latex

Until the late 1980s, latex dip molding was the most widely used method in the industry. Latex, which can be naturally extracted or synthetically produced, is known for being inexpensive and non-toxic. However, as awareness of latex allergies grew, demand for latex-based dip molding declined, leading manufacturers to explore alternative materials.

Neoprene

A highly versatile material, neoprene is valued in dip molding for its chemical resistance, ozone resistance, flexibility, and non-toxic nature. It closely resembles latex but is a safer alternative for individuals with latex allergies, making it a popular choice in applications requiring both durability and hypoallergenic properties.

Urethane

Also known as polyurethane, this polymer is recognized for its exceptional resilience, durability, and light stability. These properties make urethane an excellent material for applications that demand longevity and resistance to wear.

Epoxy

A high-performance material, epoxy is widely used in dip molding due to its mechanical strength, chemical resistance, heat and temperature resistance, and excellent insulating capabilities. Its durability makes it particularly suitable for products that require long-term structural integrity.

Dip Molding Process

The dip molding process begins with heating the polymer or vinyl until it reaches a liquid state. Two critical variables that influence both the quality and appearance of the final product are the temperature of the mold and the temperature of the material. Maintaining the polymer at the correct temperature and ensuring optimal viscosity are essential for a smooth and consistent molding process.

Once the material is properly heated, manufacturers must determine the optimal dipping and withdrawal speed. These factors play a crucial role in ensuring even coating distribution and maintaining product consistency.

In the next stage, manufacturers heat mandrels, or molds, so that the molten polymer adheres uniformly to their surfaces. The molds are then carefully lowered into the liquid plastic, ensuring even coverage and consistent wall thickness. Since the plastic is heated, this process is referred to as hot dip molding. The thickness of the final product is determined by the duration of immersion, known as the "dwell time"—the longer the mold remains submerged, the thicker the resulting walls.

After reaching the desired dwell time, manufacturers slowly and consistently remove the mold from the liquid, ensuring a smooth finish and preventing inconsistencies in wall thickness. Some polymers, such as plastisol, undergo an additional heat treatment in an oven to fully cure and stabilize the material.

Once the material has hardened, the polymer is carefully stripped from the mandrel. While most dip molded products are highly precise and require little to no additional processing, some may undergo secondary finishing if necessary.

When designing dip molded plastic products, manufacturers consider key factors such as texture, hardness, dimensions, and other specifications required for the final product. The process offers significant design flexibility, allowing for a wide range of colors, textures, and finishes. By employing various molding techniques, manufacturers can refine surface characteristics, control hardness levels, and enhance aesthetic appeal, ensuring that each product meets specific functional and visual requirements.

Dip Molding Types

Cast Molding

This process involves dispensing plastisol into a mold, placing it in an oven, and heating it until the plastisol fuses into the finished part. Cast molding is particularly advantageous for producing multi-colored parts, making it a popular choice for applications requiring both functionality and visual appeal.

Cold Dip Coating

Used primarily for applying thin plastisol coatings, this process involves dipping an object into plastisol without preheating it. The coated object is then placed in a heated chamber, allowing the material to cure and adhere to the surface. Cold dip coating is ideal for applications that require a uniform, lightweight coating without excessive material buildup.

Dip Coating

A widely used technique, dip coating consists of fully submerging an object into a tank filled with coating material. This process ensures complete surface coverage and can be adjusted to achieve different coating thicknesses, depending on the speed and duration of immersion.

Dip Molding

A thermal process in which metal molds are dipped into liquid plastic, allowing the material to form around the mold and take its shape. Once the coating has set, the finished product is removed, revealing a seamless, molded plastic component.

Hot Dip Coating

This method involves preheating an object before dipping it into plastisol. The coated object is then transferred to a heated chamber, where fusion occurs, ensuring strong adhesion and a smooth, uniform finish. Hot dip coating is frequently used to enhance the durability and wear resistance of metal components.

Plastic Caps

These protective plastic covers are formed through dip molding, providing an easy and cost-effective solution for covering exposed edges, sealing components, or adding a comfortable grip to handles and tools.

Plastic Dip Coating

A process designed to coat metal objects with a layer of plastic, offering both aesthetic and protective benefits. Plastic dip coating enhances corrosion resistance, improves grip, and provides a smooth, durable finish to a variety of products.

Plastic Plugs

Formed using the dip molding process, plastic plugs serve as protective caps or sealing components, offering a reliable solution for covering open ends and preventing contamination in industrial and consumer applications.

Polymer Coatings

These coatings act as a protective barrier, particularly in corrosive environments. By enhancing the abrasion resistance of a component’s surface, polymer coatings extend product lifespan and improve performance in harsh conditions.

Rotational Molding

A specialized technique in which a controlled amount of plastisol is placed inside a mold, which is then rotated while being heated. The continuous motion ensures even distribution of the plastisol, resulting in a hollow, seamless product. This method is widely used for producing large, durable plastic components such as tanks, containers, and automotive parts.

Saturation Coating

This method involves completely immersing an object in liquid plastisol, ensuring that it is fully saturated before allowing it to gel. The result is a uniform, protective coating that provides superior coverage and durability.

Vinyl Coating

A process in which wear-resistant vinyl compounds undergo dip coating to form rigid, smooth, or textured protective layers over substrate surfaces, typically metals. Vinyl coatings enhance both the aesthetic and functional properties of products, making them more resistant to wear, impact, and environmental exposure.

Molding Machinery Used

Dip molding processes rely on a variety of machines, systems, and tools to ensure precision, efficiency, and consistency in production. Each piece of equipment plays a critical role in shaping, coating, and curing dip-molded products.

Automatic Rack Transfer System (ARTS) Station

Primarily used with rotary dip molding machines in rotational molding, this system enhances operational efficiency in several ways. It increases the number of operator positions available for reloading and unloading without requiring racks to be taken offline. Additionally, it allows for extra positions dedicated to cooling and priming metal parts, which is essential for coating preparation or the automatic lubrication of mandrels.

Molding Blower

A high-temperature air mover, the molding blower is designed to increase turbulence and improve heat transfer to the mandrel or tool in the preheat oven. It also plays a vital role in the cure oven by accelerating the curing process and reducing heat stratification, ensuring an even and consistent cure.

Closeable Dam

This device is installed in the dip tank and functions to completely halt the flow of plastisol over the weir during the dip cycle. The closeable dam must work in perfect synchronization with the dip tank agitation system and recirculation pump cycle to maintain proper material distribution and consistency.

Molding Mandrel

Also known as a metal mold, the mandrel forms the internal shape of a dip-molded part. Typically crafted from steel, aluminum, or other durable alloys, the mandrel ensures precision in product formation. To further customize the dip molding process, manufacturers can mount multiple mandrels onto a bar that is then placed into a master rack, or they can affix them directly to the arm of a molding machine.

Master Rack

A structural frame used in dip molding, the master rack is usually composed of aluminum or steel. It features symmetrically positioned pins or indentations designed to retain adapter bars securely. Custom-built for specific dip molding machines, master racks are versatile and compatible with multiple tooling bars, making them integral to high-volume production.

Overhead Dip Station

Engineered for continuous, multi-dip operations, this dip station is designed to accommodate multiple colors, multiple grades, and repeat dipping cycles. Featuring a two-axis system, its vertical axis removes preheated racks of parts or tools from the machine, while the lateral axis moves them to any of up to four dip tanks, enabling seamless production transitions.

Molding Pawl

A key component of the overhead dip station, this J-shaped gripper is typically used in pairs, though it can be customized for specific applications. Its primary function is to securely grasp and transport the rack of tools slated for dip coating, ensuring precise handling throughout the process.

Profile Dripping

This system is used to regulate drip patterns and control coating thickness. Relying on pre-programmed positions, speeds, and dwell times, profile dripping adjusts the dip speeds of a tool or mandrel. Designed for versatility, it is compatible with both traditional moving tank designs and overhead dip systems, allowing for precise customization of final product dimensions.

Strip Heater

An essential component of cure ovens, the strip heater is an electric heating element responsible for transferring heat to the plastic coating during the curing process. Airflow over the heater moves the heat efficiently, ensuring even distribution. Most strip heaters are insulated with mica, though manufacturers can customize them with alternative insulation materials such as mineral insulation or nickel-chromium insulation for specialized applications.

Tubular Heater

A high-surface-temperature electric heater, the tubular heater is primarily installed in the preheat section of dip molding machines. Utilizing customizable airflow and infrared radiation, it efficiently transfers heat to the mandrel or tool, ensuring optimal coating adhesion and uniformity. Its high durability and adaptability make it a crucial component in achieving consistent dip-molded product quality.

Variations and Similar Processes of Dip Molding

To achieve the best results, manufacturers often explore variations of dip molding as well as similar processes that complement or enhance the dip molding technique. These methods offer unique advantages in terms of material properties, durability, and customization options.

Dip Coating

A closely related process, dip coating involves partially or fully submerging products in a protective liquid material to form a coating. Dip coaters use the same dipping method as dip molding, applying coatings such as polymer or vinyl. Among the most common are PVC coatings and plastisol coatings,  which provide exceptional protective and insulative benefits. Dip-coated products, such as electrical wires, jumper cables, and extension cords, gain enhanced electrical insulation, while other coated items benefit from reduced noise, vibration dampening, and improved thermal insulation. Additionally, the dip coating process eliminates the need for deburring by covering sharp edges on metal components. It also extends the lifespan of fences, wires, and other outdoor structures by increasing corrosion resistance. 

Powder Coating

Unlike dip molding, which uses liquid plastic, powder coating relies on a dry, free-flowing powder that is electrostatically applied to a product and then cured under heat. One of its key benefits is that it does not require solvents to keep the coating material in liquid suspension, making it an environmentally friendly option with minimal volatile organic compound (VOC) emissions. Powder coating also allows for the creation of thicker walls without the risk of sagging or running. Additionally, it enables manufacturers to produce specialty finishes not achievable with conventional coatings, all while ensuring faster curing times.

Injection Molding

Similar to dip molding, injection molding utilizes molds and liquid materials to create plastic parts. However, instead of dipping, injection molding uses a ram or screw-type plunger to force molten plastic into a mold cavity, where it takes shape, cools, and solidifies. Plastic injection molding, one of the most widely used forms of this process, is known for its efficiency, cost-effectiveness, and minimal material waste. It yields high volumes of durable, precisely molded products, making it ideal for mass production.

Blow Molding

A specialized molding technique primarily used for creating hollow plastic parts, blow molding involves melting plastic and shaping it into a parison or preform. This tube-like structure is then clamped into a mold and inflated with compressed air, forcing it to conform to the mold’s shape. Once cooled and hardened, the final product is ejected from the mold. The three main types of blow molding—extrusion blow molding, injection blow molding, and injection stretch blow molding—offer flexibility for producing a wide range of products. This method is valued for its fast production rates, ability to create complex shapes, and low tooling costs.

Silicone Dip Coating

A subcategory of dip coating, silicone dip coating involves immersing finished metal products into molten silicone or elastomer to form a durable exterior coating. Silicone, a synthetic rubber composed of silicon, oxygen, hydrogen, and carbon, provides superior flexibility, chemical resistance, and temperature stability. This process is widely used in industries requiring heat-resistant, non-stick, or medical-grade coatings.

UV Coating

A protective finishing process, UV coating involves the application of UV-curable coatings to enhance a product’s resistance to wear, scratches, fogging, chemicals, microbes, and ultraviolet rays. Commonly applied through spray, dip, roll, or flow methods, UV coatings are ideal for outdoor products that require long-term durability. Since UV coatings cure without heat, they are particularly useful for pre-formed plastic parts, ensuring a strong, resilient finish without warping or distortion.

Things to Consider When Choosing Dip Molding

If you are considering dip molding services, partnering with a knowledgeable and reputable manufacturer is essential. While many suppliers offer dip molding and related services, their capabilities, quality standards, and expertise vary widely. To find the right manufacturer, discuss your project’s specific application requirements, ensuring they understand your specifications, budget, and timeline. A trusted dip molding company will be committed to delivering a high-quality solution tailored to your needs. Begin your search by exploring the many excellent dip mold manufacturers available and evaluating their experience and service offerings.

Dip Molding Terms

Air Release

A testing method that evaluates how easily air bubbles can be removed from plastisol during processing, ensuring a smooth, defect-free finish.

Automatic Rack Transfer System (ARTS) Station

A system primarily used with rotary dip molding machines, designed to optimize workflow efficiency. It increases the number of operator positions for reloading and unloading without removing racks from the production line. Additionally, it provides extra positions for cooling and priming metal parts, enhancing coating preparation and enabling automatic lubrication of mandrels.

Blister

A surface irregularity that appears as a raised bubble or defect in fused plastisol, typically caused by contamination from water, air, or solvents.

Blower

A high-temperature air mover that enhances turbulence and heat transfer to the mandrel or tool in the preheat oven. It is also used in the curing oven to accelerate the curing process and reduce heat stratification, ensuring uniform heating.

Brookfield Viscosity

A standardized measure of plastisol viscosity, indicating its flow characteristics and consistency.

Closeable Dam

A device installed in the dip tank to completely stop the flow of plastisol over the weir during the dip cycle. It must be carefully synchronized with the dip tank’s agitation system and recirculation pump cycle to maintain process control.

Deaeration

The process of removing trapped air from plastisol, typically achieved using a vacuum during mixing or at later stages of production to prevent defects.

Dip Line

The uppermost boundary of the dipped plastic coating on a molded part, marking the transition between coated and uncoated areas.

Elastomer

A flexible, rubber-like material that, when stretched to twice its original length at room temperature, returns immediately to its initial shape.

Elongation

A measure of how far fused plastisol can be stretched before breaking, indicating its flexibility and durability.

Fillers

Additives incorporated into plastisol formulations to modify physical properties or reduce production costs while maintaining product performance.

Gelatin

A condition in which plastisol becomes immobile after its liquid plasticizer is fully absorbed by the resin, indicating the early stages of solidification.

Leaching

The migration of plastisol components out of fused or partially fused vinyl film, which can affect the stability and integrity of the finished product.

Mandrel

A metal mold, typically made of steel, aluminum, or other alloys, that forms the internal shape of a dip-molded part. Mandrels can be mounted in groups on a bar placed in a master rack or directly attached to the arm of a molding machine.

Master Rack

A structural frame, usually made of aluminum or steel, designed to hold multiple tooling bars in place. It features precisely positioned pins or indentations to ensure alignment and is typically customized for specific dip molding machines while maintaining compatibility with multiple tooling setups.

Organosol

A variation of plastisol that includes added solvents to modify its flow characteristics and application properties.

Overhead Dip Station

A specialized dipping system designed for continuous multi-dip operations, accommodating multiple colors, grades, or coatings. It features a two-axis design, with the vertical axis removing preheated racks of tools or parts from the machine and the lateral axis transferring them to any of up to four dip tanks.

Pawl

A J-shaped gripper used in overhead dip stations to securely hold racks of tools or parts during the dip coating process. Typically used in pairs, it ensures smooth and precise movement of components through the system.

Plasticizers

Compounds used to enhance the flexibility of PVC resins. These can be low-melting-point solids or high-boiling-point liquids, depending on the desired characteristics of the final product.

Plastisol

A thermoplastic liquid blend composed of polyvinyl chloride (PVC) resins and plasticizers. Upon heating, plastisol undergoes a transformation, solidifying into a durable plastic coating or molded part.

Profile Dripping

A controlled process that adjusts dipping speeds, dwell times, and programmed positions to regulate coating thickness and drip formation. It is used with both traditional moving tank designs and overhead dip systems to maintain product consistency.

PVC Dispersion Resin

Finely ground PVC particles that, when mixed with plasticizers, create plastisol, forming a smooth and uniform liquid suitable for molding and coating applications.

Severs Viscosity

An alternative method for measuring the viscosity of plastisol, used to assess flow properties and process stability.

Specks

Dark inclusions in fused plastisol caused by burnt resin, typically resulting from overheating or improper temperature control.

Strip Heater

An electric heating element commonly used in curing ovens. It is typically insulated with mica and relies on forced airflow to transfer heat efficiently to the plastic coating during the curing stage.

Surfactant

An additive used in plastisol formulations to reduce viscosity and improve air release, preventing defects such as trapped bubbles.

Tubular Heater

A high-surface-temperature electric heater, typically installed in the preheat section of dip molding equipment. It utilizes both airflow and infrared radiation to transfer heat effectively to the mandrel or coated tool.

Viscosity Aging

The gradual increase in plastisol viscosity over time when stored, affecting its flow characteristics and usability in molding and coating applications.