How to improve the efficiency of water-jet cutting machine in processing die cushion?

In order to improve the efficiency of water-jet cutting machine in processing die pads, it is necessary to solve the core pain points of "easy rebound, need to slow down and fear deformation" in the processing of elastic materials (rubber, polyurethane, etc.) from four dimensions: optimization of process parameters, upgrading of equipment configuration, simplification of production process and material pretreatment on the premise of ensuring accuracy (tolerance within ±0.05mm) and quality (no burr and deformation). The following are specific optimization strategies that can be implemented, which are explained in order of "priority" and "practicality":

First, the core: accurate matching of process parameters (zero cost increase, immediate effect)

The cutting efficiency of elastic materials directly depends on the matching degree of "pressure, speed and abrasive", so it is necessary to avoid efficiency waste caused by conservative parameters or quality problems caused by too high parameters.

1. Dynamic balance between pressure and cutting speed

Core logic: within the material tolerance range, moderately increase the pressure of the high-pressure pump and simultaneously increase the cutting speed (avoid the inefficient combination of "low pressure+slow speed").

Parameter reference of different materials (taking 3mm thick spring pad as an example):

Recommended pressure of material type (MPa) and recommended cutting speed (mm/min) are more efficient than conventional parameters.

Soft polyurethane (50-60 Shore A) 180-220 60-80 20%-30%

Rigid polyurethane (70-90 Shore A) 220-250 50-70 15%-25%

Nitrile rubber (60-75 Shore A) 200-230 55-75 18%-28%

Trial cutting verification: before adjustment, process 1-2 pieces of samples to check whether the cut is smooth (without burr and "hanging edge") and whether the size is up to standard-if it is rough, increase the abrasive flow (50-100 g/min); In case of deformation, the speed should be reduced appropriately (10-15mm/min).

2. Cutting path optimization (reducing idling and deceleration)

Path planning principles:

"Dense first, then sparse": priority is given to processing dense areas (such as multiple positioning holes and avoidance grooves), and then the outer contour is cut to avoid deformation caused by the weakening of material fixing force in the later period and reduce the repeated positioning time;

"Arc instead of sharp angle": the sharp angle of < 30 is changed into a small arc of R0.5-R1mm (which does not affect the use of the spring pad of the knife die), so as to avoid the deceleration due to sharp angle (the conventional linear speed is 60mm/min, and the sharp angle needs to be reduced to 20mm/min), and the efficiency of a single path is improved by more than 40%;

"Avoid cross-cutting": Do not cut repeatedly in the same area, for example, the outer contour does not cross the path of the internal slot, so as to reduce the idle cutting (the idle cutting speed is 200-300mm/min, but it has no machining value, so it needs to be compressed as much as possible).

Typesetting optimization: adopt "closely nested typesetting" (for example, reduce the contour spacing of multiple elastic pads to 0.5-1mm instead of unconventional 2-3mm), maximize the utilization of plate area, and reduce the idle time of cutting head's "cross-regional movement"-take a 1000mm×1000mm plate as an example, after optimization, the number of single processing can be increased by 15%-20%, and the total processing can be increased.

3. Adaptation of abrasive and nozzle

Abrasive particle size and flow rate: coarse-grained abrasive is not needed for processing elastic materials (which may easily lead to rough cuts), garnet sand with 80-120 meshes is preferred, and the abrasive flow rate is controlled at 150-200g/min (200-300 g/min for conventional metal processing)-which not only ensures smooth cuts, but also avoids downtime and feeding time caused by abrasive waste;

Selection of nozzle diameter: according to the thickness matching of the elastic pad, choose 0.15mm nozzle for thickness < ＜2mm (fast cutting speed) and 0.2mm nozzle for thickness of 2-5mm (to ensure penetration) to avoid "repeated cutting" of small-caliber thick-cut materials or "too wide incision" of large-caliber thin-cut materials.

Second, the key: equipment configuration upgrade (long-term investment, double efficiency)

If the knife die cushion is processed for a long time (the monthly order quantity is more than 500 pieces), upgrading the equipment configuration can greatly improve the efficiency and reduce the unit time cost.

1. Add multi-head cutting system (the most direct efficiency improvement)

Core value: single-head cutting → double-head/triple-head cutting, which directly doubles the efficiency (it is necessary to ensure the multi-head synchronization accuracy ≤0.02mm to avoid dimensional deviation);

Case: processing 3mm thick polyurethane elastic cushion (complex parts, single piece processing for 3 minutes), processing 20 pieces in one hour with single head and 38-40 pieces in one hour with double heads (deducting a small amount of synchronous calibration time), the daily output is increased by 90%-100%;

Precautions: it is necessary to match the high-power high-pressure pump (for example, more than 37kW pump is needed for double-head cutting to ensure the pressure stability) to avoid insufficient pressure caused by shunt.

2. Upgrade high-pressure pump and cooling system.

High-pressure pump upgrade: upgrade the 22kW low-pressure pump (max. 200MPa) to the 37kW high-pressure pump (max. 300MPa), and the cutting speed can be increased by 25%-30%-especially for thick elastic pads (> ＞3mm), avoiding layered cutting (increasing the single cutting depth from 1mm to 2mm, reducing the cutting times);

Optimization of cooling system: install an independent cooling water tank (temperature control accuracy is 2℃) to avoid the high-pressure pump from heating up due to long-term operation (> 60℃ will lead to pressure fluctuation) and reduce the downtime adjustment time caused by pressure instability (30-60 minutes per day).

3. Introduce automatic loading and unloading.

Applicable scenario: batch orders (> 100 pieces/batch) to avoid waiting time for manual material picking and loading;

Configuration scheme: mechanical arm+storage bin (which can store 50-100 pieces of elastic cushion materials) to realize the full-automatic cycle of "feeding → cutting → taking materials → testing"-manual refueling takes 5-10 minutes, automatic refueling only takes 10-20 seconds, saving 15-20 minutes per hour and improving daily efficiency by 15%-20%;

Low-cost replacement: If the budget is limited, you can install a "vacuum sucker manual feeding table" (the cost is only 1/10th of that of automation) to reduce the material positioning time (from 3-5 minutes/batch to 1-2 minutes/batch).

Third, auxiliary: production process and material pretreatment (reducing cost, improving efficiency and reducing waste)

1. Material pretreatment: reduce "unexpected downtime" during processing.

Multi-layer overlapping cutting (applicable to thin materials): For the elastic cushion with a thickness of < ＜2mm, use special adhesive film (such as PET high-temperature resistant adhesive film) to bond and fix 3-5 pieces of materials (to ensure no dislocation), so as to realize "multi-layer synchronous cutting"-for example, the elastic cushion with a thickness of 1mm, and a single cutting after five layers are overlapped is equivalent to processing 5 pieces, and the efficiency is improved by 3-4 times (it is necessary to ensure that the high pressure is enough to penetrate multiple layers, such as 250-)

Pre-cutting of materials: If the original material is a large-size plate (for example, 2000mm×1000mm), it will be cut into a small size (for example, 5-10mm larger than the finished product) with a common cutting machine in advance, so as to reduce the "invalid path" of water jet cutting (for example, large-area outer contour cutting) and shorten the single processing time by 20%-30%.

2. Simplification of post-processing flow: batch operation replaces single-piece processing.

Centralized cleaning: after processing, the abrasive on the surface is uniformly blown by high-pressure compressed air (0.6MPa) (instead of single cleaning), and the cleaning time of 100 elastic pads is reduced from 30 minutes to 10 minutes;

Batch inspection: adopt the mode of "full inspection of the first piece+batch sampling inspection" (the key dimensions of the first piece are detected with calipers and micrometers, and one piece is sampled every 20 pieces in batch) to avoid efficiency waste caused by full inspection of a single piece (the inspection time is reduced by 60%-70%);

Optimization of drying treatment: the elastic material is easy to absorb water after processing (for example, the water absorption of rubber is 0.5%-1%), so it needs to be naturally dried for 1-2 hours-a drying box (temperature 40-50℃, wind speed 1m/s) can be installed, and the drying time can be shortened to 15-20 minutes, so as to avoid the subsequent processing delay caused by waiting for drying.

IV. Details: Equipment maintenance and operation specifications (reduce downtime and stabilize efficiency)

1. Regular maintenance: avoid efficiency loss caused by equipment failure.

Nozzle and pipeline: for every 50㎡ elastic cushion processed, remove the nozzle to clean up the residual abrasive (to avoid pressure drop caused by blockage), and replace the aging high-pressure pipe (once every three months)-to reduce the shutdown adjustment caused by nozzle blockage (it takes 10-15 minutes to deal with a single blockage, and more than 90% of such problems can be avoided by regular maintenance);

Vacuum adsorption system: check the sealing performance of the sucker every day (replace the aging sealing strip), and clean the drainage hole of the workbench (to avoid the decrease of adsorption force caused by sewage blockage)-reduce the rework caused by material displacement (it takes an extra 3-5 minutes to rework a spring pad, which can reduce 3-5 rework times per day).

2. Operation specification: reduce human error.

Parameter preset: preset "parameter template" (such as "50 Shore A polyurethane-3mm thick" template, including pressure, speed and abrasive flow) for elastic pads with different materials and thicknesses to avoid re-debugging every time (debugging time is reduced from 15-20 minutes/batch to 2-3 minutes/batch);

Personnel training: familiarize operators with "abnormal judgment" (such as rough incision → abrasive adjustment, size deviation → adsorption check) to avoid invalid adjustment caused by misjudgment (ineffective operation can be reduced by 20-30 minutes per day).

Summary: Priority of efficiency optimization in different scenarios

Small batch (10-50 pieces): give priority to optimizing "process parameters+path typesetting" (zero cost, 20%-30% increase in efficiency), without equipment upgrade;

Medium batch (50-500 pieces): the efficiency is improved by 40%-60% by stacking "multi-layer cutting+automatic loading and unloading (low cost version)";

Mass production (> 500 pieces): upgrade "multi-head cutting+high-power high-pressure pump" and cooperate with "automatic process" to improve efficiency by 80%-120% and realize "mass production and cost reduction".

Through the above strategy, the efficiency of water jet cutting can be maximized on the premise of ensuring the quality of the die cushion, which is especially suitable for the processing scene of small and medium-sized batches and complex irregular cushion, and balances the "precision demand" and "efficiency goal".