Latex Article
A Guide to Pumping Latex:
Latex is an emulsion which is composed of polymer particles that are suspended in water. It can be sourced naturally from the sap from rubber trees or synthetically made from petroleum-based polymers.
It is a highly versatile and durable material and is widely used in products such as mattresses, gloves, balloons, carpets and paints. Due to its unique properties, latex is sheer sensitive and poses a challenge when it comes to the manufacturing process.
Latex requires careful pump selection to maintain its consistency, avoid coagulation and ensure a smooth transfer process.
Challenges in Latex Pumping
Handling latex presents several difficulties, requiring specialised pump solutions to prevent contamination, consistency changes or blockages which can halt production or create an inferior product. The key challenges include:
1. Shear Sensitivity
Latex is highly shear-sensitive, meaning excessive agitation can break down the emulsion which can lead to clumping, thickening, or coagulation. Pumps must operate at low speeds and with minimal turbulence to maintain product integrity.
2. Air Sensitivity
When exposed to air, latex can harden or alter its properties which can cause blockages in pipes and pumps and damage components. Air-tight pumping systems are essential to prevent air ingress at seals, valves, or connections.
3. Material Compatibility
Latex can react with certain metals and rubber components which could lead to contamination or degradation, increasing maintenance time and cost. Latex pumps should use non-reactive materials such as stainless steel or chemically resistant polymers.
4. Viscosity Variation
The viscosity of latex can range from 40 to 200 cst with a specific gravity of 0.91 This means that latex pumps are required to handle varying consistencies without excessive force or mechanical stress.
Types of Pumps for Latex Applications
Selecting the right pump for latex depends on your specific process requirements and need to consider, viscosity levels and shear sensitivity of the pumped fluid. There are a number of pumps that can efficiently handle latex. Here we highlight the most popular type of pumps for latex processes.
1. Peristaltic (Hose) Pumps
Peristaltic pumps use a rotating roller mechanism to squeeze fluid through a flexible hose. This type of pump prevents the latex having direct contact with components and reduces the number of points requiring maintenance.
Benefits:
Shear-sensitive operation protects latex consistency.
Seal-less design eliminates air getting into the process, and also ensures seal faces do not stick.
Self-priming.
Handles viscous latex effectively.
Easy to clean should it solidify in the hose.
Drawbacks:
The hose requires periodic replacement.
Low flow rates compared to other pump options.
Pulsating flow if not used with a pulsation dampener
2. Diaphragm Pumps (Air-Operated Double Diaphragm - AODD)
Diaphragm pumps use compressed air to flex internal diaphragms, creating a pumping action that moves fluid through the system without the need for mechanical seals.
Benefits:
Gentle pumping motion minimises shear damage.
They are self-priming and able to dry-run.
Able to handle varying viscosities and flow rates.
Drawbacks:
The pulsating flow may require dampeners for smooth operation.
Lower efficiency than other pump types.
The design of the pump contains valves which can become clogged should the glue set
3. Vane Pumps
Vane pumps are another suitable option for pumping latex as they can handle viscous and sheer sensitive fluids with a smooth and pulseless flow. They use a rotor with extendable vanes that slide in and out as the rotor turns, trapping and moving fluid through the pump chamber.
Benefits:
Suitable for moderate-viscosity latex.
Self-priming capabilities.
Consistent flow for accurate dosing.
Drawbacks:
Not suitable for high shear-sensitive latex formulations. Internal wear over time can affect performance.
Seals may fail which can impact the latex quality.
4. Progressive Cavity Pumps
Progressive cavity pumps transfer using a helical rotor rotating within a stator. This delivers a smooth, consistent flow with minimal shear which is ideal for transferring latex.
Benefits:
Very gentle pumping action prevents coagulation.
Able to transfer high-viscosity latex with ease.
Handles accurate dosing and metering.
Drawbacks:
Regular maintenance required to prevent stator wear.
Run dry will damage the pump.
The pump contains a seal which should the latex set, the seal will fail causing leakage.
5. Gear Pumps
Gear pumps operate by using intermeshing gears that rotate to transfer fluid through the pump chamber. This provides a consistent and steady flow.
Benefits:
Compact design means it is suitable for confined spaces.
Consistent flow for applications that require a controlled flow.
Drawbacks:
High shear forces can damage latex emulsion.
The pump contains a seal which should the latex set, the seal will fail causing leakage.
Find the best Latex Pump for your Application
By carefully evaluating pump type, material compatibility and process conditions, businesses can optimise latex handling for long-term efficiency and reliability.
To discuss your latex pumping requirements contact us and talk to our process specialists.
